USMLE surgery 601 to 750

A 71-year-old West Texas farmer of Irish ancestry has a nonhealing, indolent, punched out, clean-looking 2-cm ulcer over the left temple. The ulcer has been slowly growing over the past 3 years. There are no enlarged lymph nodes in the head and neck. Which of the following would best dictate proper management?

Ten days after undergoing liver transplantation, a patient's levels of gamma-glutamyl transferase (GGT), alkaline phosphatase, and bilirubin begin to rise. Which of the following is the most appropriate next step in diagnosis?

A previously healthy, intoxicated, 19-year-old man is driving a car without using a seat belt. He crashes the car into the back of a parked truck. In the process he slams his abdomen into the steering wheel and ruptures his spleen. Which of the following is the most important problem associated with this type of injury?

After suitable calculations have been made using the modified Parkland formula, a 70-kg man with extensive third-degree burns is receiving Ringer's lactate at the calculated rate, which happens to be 750 mL/hr. The infusion was started within 30 minutes of the time when the burn occurred. Over the next 3 hours, his urinary output is recorded as 15 mL, 22 mL, and 18 mL. It is verified that the Foley catheter is open and draining freely. The urine is dark yellow, without blood, and has a specific gravity of 1040 and a sodium concentration of 10 mEq/L. The patient's blood pressure is 100/70 mm Hg, his pulse is 98/min, and his central venous pressure is 2 cm H2O. On the basis of these findings, which of the following is the most appropriate next step in management?

A 27-year-old immigrant from El Salvador has a 14 × 12 × 9 cm mass in her left breast. It has been present for 7 years and has slowly grown to its present size. The mass is firm, nontender, rubbery, and completely movable, and it is not attached to the overlying skin or the chest wall. There are no palpable axillary nodes or skin ulceration. Which of the following is the most likely diagnosis?

A 32-year-old woman in the 2nd month of pregnancy is found to have a 5-cm mass in the upper outer quadrant of her left breast. Mammogram shows no other lesions, and core biopsy reveals infiltrating ductal carcinoma. Which of the following would be the best course of action at this time?

In the course of a robbery, a young woman is stabbed repeatedly. On arrival at the emergency department, she is shivering and asks for a blanket and a drink of water; she is noted to be pale and perspiring. Her blood pressure is 72/50 mm Hg and her pulse is 130/min. Her neck and forehead veins are large and distended. A quick initial survey reveals entry wounds in her left chest and upper abdomen. She has bilateral breath sounds and a scaphoid, nontender abdomen. As IV infusions of Ringer's lactate are started, her systolic blood pressure drops further to 40 mm Hg, no distal pulses can be felt, and she loses consciousness. Her central venous pressure at that time is 28 cm H2O. Which of the following is the most appropriate next step in management?

A 62-year-old man reports an episode of gross, painless hematuria. There is no history of trauma, and further questioning determines that he had total hematuria, rather than initial or terminal hematuria. The man does not smoke and has had no other symptoms referable to the urinary tract. He has no known allergies. Physical examination, including rectal examination, is unremarkable. His serum creatinine is 0.8 mg/dL, and, except for the presence of many red cells, his urinalysis is normal and shows no red cell casts. His hematocrit is 46%. Which of the following is the most appropriate initial step in the workup?

A 63-year-old man, who weighs 65 kg, is in his 2nd postoperative day after an abdominoperineal resection for cancer of the rectum. An indwelling Foley catheter was left in place after surgery. The nurses are concerned because, even though his vital signs have been stable, his urinary output in the past 2 hours has been zero. In the preceding 3 hours, they had collected 56 mL, 73 mL, and 61 mL. Which of the following is the most likely diagnosis?

A 37-year-old woman undergoes a lumpectomy and axillary dissection for a 3-cm infiltrating ductal carcinoma, diagnosed by core biopsies, located on the upper outer quadrant of her left breast. The pathology report of the surgical specimen is received 3 days after the operation. It indicates that all margins around the tumor are clear, and that 4 of 17 axillary lymph nodes have metastatic tumor. The tumor is reported to be estrogen and progesterone receptor negative. Which of the following should further therapy most likely include?

Radiation to both breasts and tamoxifen 611. A 45-year-old man with alcoholic cirrhosis is bleeding from a duodenal ulcer. He has required 6 units of blood over the past 8 hours, and all conservative measures to stop the bleeding, including irrigation with cold saline, IV vasopressin, and endoscopic use of the laser have failed. He is being considered for surgical intervention. Laboratory studies done at the time of admission, when he had received only one unit of blood, showed a bilirubin of 4.5 mg/dL, a prothrombin time of 22 seconds, and a serum albumin of 1.8 g/dL. He was mentally clear when he came in, but has since then developed encephalopathy and is now in a coma. Which of the following best describes his operative risk?

A 55-year-old woman falls in the shower and hurts her right shoulder. She shows up in the emergency department with her arm held close to her body, but the forearm rotated outward as if she were going to shake hands. She is in pain and will not move the arm from that position. Her shoulder looks "square" in comparison with the rounded unhurt opposite side, and there is numbness in a small area of her shoulder over the deltoid muscle. Which of the following is the most likely diagnosis?

A 22-year-old convenience store clerk is shot once with a .38 caliber revolver. The entry wound is in the left midclavicular line, 2 inches below the nipple. There is no exit wound. He is hemodynamically stable. A chest x-ray film shows a small pneumothorax on the left, and demonstrates the bullet to be lodged in the left paraspinal muscles. In addition to the appropriate treatment for the pneumothorax, which of the following will this patient most likely need?

68-year-old man is brought to the emergency department with excruciating back pain that began suddenly 45 minutes ago. The pain is constant and is not exacerbated by sneezing or coughing. He is diaphoretic and has a systolic blood pressure of 90 mm Hg. There is an 8-cm pulsatile mass deep in his epigastrium, above the umbilicus. A chest x-ray film is unremarkable. Two years ago, he was diagnosed with prostatic cancer and was treated with orchiectomy and radiation. At that time, his blood pressure was normal, and he had a 6-cm, asymptomatic abdominal aortic aneurysm for which he declined treatment. Which of the following is the most likely diagnosis?

A middle-aged homeless man is brought to the emergency department because of very severe pain in his forearm. He had passed out after drinking a bottle of cheap wine, and then slept on a park bench for an indeterminate time, probably more than 12 hours. Shortly after he woke up and began to walk, the pain began. There are no signs of trauma, but the muscles in his forearm are very firm and tender to palpation, and passive motion of his fingers and wrist elicits excruciating pain. Pulses at the wrist are normal. Which of the following is the most appropriate next step in management?

54-year-old obese man gives a history of burning retrosternal pain and heartburn that is brought about by bending over, wearing a tight belt, or lying flat in bed at night. He gets symptomatic relief from over-the-counter antiacids or H2 blockers, but has never been formally studied or treated. The problem has been present for many years and seems to be progressing. Which of the following is the most appropriate next step in management?

A pedestrian is hit by a car and knocked unconscious. Within a few minutes, he starts to move around and moan. When the ambulance arrives, he is moving all four extremities and mumbling that his neck hurts. Shortly thereafter, he lapses again into a deep coma. In the emergency department, it is noted that his left pupil is fixed and dilated, and he has clear fluid dripping from the left ear. The trauma team intubates him nasally over a fiberoptic bronchoscope and does a quick initial survey that reveals no other obvious injuries. He is hemodynamically stable. Which of the following is the most appropriate next step in management?

While working at a bookbinding shop, a young man suffers a traumatic amputation of his index finger. The finger was cleanly severed at its base. The patient and the finger are brought to a first-aid station, from which both are to be transported to a highly specialized medical center for replantation to be done. Which of the following is the correct way to prepare and transport the severed finger?

An out-of-shape, recently divorced, 42-year-old man is trying to impress a young woman by challenging her to a game of tennis. In the middle of the game, a loud "pop" (like a gunshot) is heard, and the man falls to the ground clutching his ankle. He limps off the court with pain and swelling in the back of the lower leg. Although he can still weakly plantar-flex his foot, he seeks medical help the next day because of persistent pain, swelling, and limping. He can put weight on that foot with no exacerbation of the pain, but the motion of taking a step is painful. Which of the following would be the most likely finding on physical examination?

A 66-year-old man with diabetes and generalized arteriosclerotic occlusive disease notices a gradual loss of erectile function over several years. Initially, he can get erections, but they do not last long enough. Later, he notices a decrease in the quality of his erections, and more recently he becomes, by his own criteria, completely impotent. He has occasional, brief nocturnal erections, but "he can never get an erection when he needs one." Which of the following is the most appropriate initial step in management?

54-year-old woman has a severe ureteral colic. An intravenous pyelogram shows a 7-mm ureteral stone at the ureteropelvic junction. She has a normal coagulation profile. Which of the following would most likely be the best therapy in this case? A. Plenty of fluids and analgesics and await spontaneous passage

A 68-year-old woman presents with an obviously incarcerated umbilical hernia. She has gross abdominal distention, is clinically dehydrated, and reports persistent fecaloid vomiting for the past 3 days. Although tired, weak, and thirsty, she is awake and alert and her sensorium is not particularly affected. Laboratory analysis reveals a serum sodium concentration of 118 mEq/L. Which of the following is the most likely physiologic explanation for the serum sodium?

A 31-year-old woman smashes her car against a bridge abutment. She sustains multiple injuries, including upper and lower extremity fractures. She is fully awake and alert, and she reports that she was not wearing a seat belt and distinctly remembers hitting her abdomen against the steering wheel. Her blood pressure is 135/75 mm Hg, and her pulse is 88/min. Physical examination shows that she has a rigid, tender abdomen, with guarding and rebound in all four quadrants. She has no bowel sounds. Which of the following would be the most appropriate step in evaluating potential intraabdominal injuries?

A 27-year-old man sustained penetrating injuries of the chest and abdomen when he was repeatedly stabbed with a long ice-pick. At the time of admission, he had a right pneumothorax, for which a chest tube was placed prior to undergoing a general anesthetic for exploratory laparotomy. The operation revealed no intraabdominal injuries and was terminated sooner than had been anticipated. The patient remained intubated, waiting for the anesthetic to wear off. Because he was not moving enough air, he was placed on a respirator. Then, he suddenly went into cardiac arrest and died. All through this time he had been hemodynamically stable, and never had any signs of hypotension or arrhythmias. Which of the following was the most likely cause of the cardiac arrest?

A 13-year-old, obese boy complains of persistent knee pain for several weeks. The family brings him in because he has been limping. He sits in the examining table with the sole of the foot on the affected side pointing to the other leg. Physical examination is normal for the knee, but shows limited hip motion. As the hip is flexed, the leg goes into external rotation and cannot be rotated internally. Which of the following is the most likely diagnosis?

A 72-year-old man has a 3-mm ureteral stone impacted at the ureterovesical junction. He has been having mild ureteral colicky pain for about 12 hours, and he has been given fluids and analgesics in the expectation that he will spontaneously pass the stone. He then has shaking chills, and spikes a temperature of 40 C (104 F). When seen shortly thereafter, he has flank pain and looks quite ill. Which of the following is the most appropriate next step in management?

A 14-year-old boy dives into the shallow end of a swimming pool and hits his head against the bottom. When he is rescued, he shows a complete lack of neurologic function below the neck. He is still breathing on his own, but he cannot move or feel his arms and legs. The paramedics carefully immobilize his neck for transportation to the hospital, and they alert the emergency department to his impending arrival. Once there, which of the following would most likely have an immediate benefit for this patient?

A 72-year-old man is scheduled to have elective sigmoid resection for diverticular disease. He has a history of heart disease, and had a documented myocardial infarction 2 years ago. He currently does not have angina, but he lives a sedentary life because "he gets out of breath" if he exerts himself. During the physical examination, it is noted that he has jugular venous distention. He has a hemoglobin of 12 g/dL. If surgery is indeed needed, which of the following should most likely be done prior to the operation?

A group of illegal immigrants is smuggled across the border in a closed metal truck in the middle of summer. When apprised by radio that the border patrol is on their trail, the smugglers abandon their charges in the middle of the desert, in the locked truck, with little water to drink. The victims are found and rescued 5 days later. One of them is brought to the emergency department, awake and alert, with obvious clinical signs of severe dehydration and a serum sodium concentration of 155 mEq/L. Which of the following would be the best choice and rate of IV fluid administration?

Of normal saline over 2-3 days 630. A 72-year-old man comes in complaining of persistent and nagging low back pain that he has had for several weeks. The pain seems to be increasing in intensity, is worse at night, is unrelieved by rest or positional changes, and is not exacerbated by coughing, sneezing, or straining to have a bowel movement. He is a chronic smoker, and for the past 3 months has had persistent cough with occasional bloody streaked sputum, as well as a 20-pound weight loss. On physical examination, he is distinctly tender to palpation at a particular spot over his lower thoracic spine. Which of the following is the most likely diagnosis?

The unrestrained front-seat passenger in a car that crashes at high speed is brought to the emergency department by paramedics. At the site of injury, the patient was unconscious and had gurgly respiratory sounds, and the EMTs successfully accomplished blind nasotracheal intubation. The initial survey in the emergency department shows normal vital signs, multiple facial lacerations, and an unresponsive, comatose patient with fixed dilated pupils. Preparations are made to do a CT scan of the head. It is imperative that which of the following should be obtained as well?

A 55-year-old woman has been known for years to have mitral valve prolapse. She has now developed exertional dyspnea, orthopnea, and atrial fibrillation. She has an apical, high-pitched, holosystolic heart murmur that radiates to the axilla and back. Because of her deterioration, surgery has been recommended. Which of the following is the most appropriate procedure?

23-year-old woman seeks help for exquisite pain with defecation and blood streaks on the outside of her stools, which she has been having for several weeks. Because of the pain, she has avoided having bowel movements, and when she finally did the stools were hard and even more painful. When seen, she has no fever or leukocytosis. Physical examination has to be done under spinal anesthesia, because the patient was so afraid of the pain that she initially refused even inspection of the area. The examination confirms the suspected diagnosis, and she is placed on stool softeners and appropriate topical agents, but without success. She is willing to undergo more aggressive treatment. Which of the following is the most appropriate next step?

An exploratory laparotomy for multiple intra-abdominal injuries has lasted 3 and a half hours. Multiple blood transfusions have been given, and several liters of Ringer's lactate have been infused. When the surgeons are ready to close the abdomen, they find that the abdominal wall edges cannot be pulled together without undue tension. Both the belly wall and the abdominal contents seem to be swollen. Which of the following is the most appropriate management in this situation?

61-year-old man comes in because of colicky abdominal pain and vomiting of 3 days' duration. On physical examination, he is moderately distended and has high pitched hyperactive bowel sounds and a 5-cm tender groin mass. On direct questioning, he explains that he has had that bulge for many years, but has always been able to "push it back in" when he lies down. For the past 3 days, however, he has been unable to do so. He has a temperature of 38.9 C (102 F) and a white blood cell count of 12,500/mm3. Which of the following is the most appropriate management at this time?

Urgent surgical intervention @ 636. In a rollover car accident, a 42-year-old woman is thrown from the car. The car subsequently lands on her and crushes her. On physical examination in the emergency department, it is determined that she has a pelvic fracture, which is confirmed by portable x-rays done as she is being resuscitated. Her initial blood pressure is 50/30 mm Hg, and her pulse is 160/min and barely perceptible. Thirty minutes later, after 2 L Ringer's lactate and 2 U packed cells have been infused, her pressure is only 70/50 mm Hg, and her pulse is 130/min. A sonogram done in the emergency department shows no intra-abdominal bleeding, and a diagnostic peritoneal lavage confirms that there is no blood in the abdomen (the recovered fluid is pink, but not grossly bloody). Rectal and vaginal exams show no injuries to those organs. There is no blood in her urine. Which of the following is the most appropriate next step in management?

A 52-year-old nurse seeks medical retirement because of a "heart condition." She complains of disabling attacks of tachycardia and palpitations. The physical examination and ECG studies confirm that indeed her pulse is between 100 and 105/min at all times, and she is in and out of atrial fibrillation. It is also noted that she is fidgety and constantly moving, and various examiners remark that she arrives for tests lightly dressed when it is rather cold outside. Thyroid function studies show elevated free thyroxine (T4) and undetectable levels of thyroid stimulating hormone (TSH). Her thyroid gland is not clinically enlarged or tender. Which of the following is the most appropriate next step in diagnosis?

Serum levels of triiodothyronine (T3) 638. A 59-year-old man is referred for evaluation because he has been fainting at his job, where he operates heavy machinery. He is pale and gaunt, but otherwise his physical examination is remarkable only for 4+ occult blood in the stool. Laboratory studies show a hemoglobin of 5 gm/dL with microcytosis, as well as decreased levels of serum iron and increased iron binding capacity. Which of the following will most likely establish the diagnosis?

A 24-year-old woman is admitted to the hospital for a broken femur. The patient was in a motor vehicle accident 20 hours ago and was brought to the hospital by EMS. On the scene, she was found belted in her car in the drivers seat, and her only documented injury was the leg fracture. She had no loss of consciousness or altered mental status. On arrival to the hospital, radiographs confirmed a fracture of her femur. She was stabilized overnight and scheduled for surgery the next day. Which of the following is the major surgical risk for this patient?

A 42-year-old woman hit her breast with a broom handle while doing housework. She noticed a lump in that area at the time, and 1 week later the lump was still present. She then sought medical advice. On physical examination, she has a 3-cm, hard mass deep inside the affected breast, and some superficial ecchymosis over the area. Which of the following is the most appropriate next step, or steps, in management?

Stectomy 641. The unrestrained front-seat passenger in a car that crashed at high speed arrives at the emergency department with signs of moderate respiratory distress. Physical examination shows no breath sounds at all on the left hemithorax. Percussion is unremarkable, and his vital signs are normal. A chest x-ray film shows a collapsed left lung and multiple air-fluid levels filling the left pleural cavity. A nasogastric tube that had been placed prior to taking the film shows the tube reaching the upper abdomen and then curling up into the left chest. Which of the following is the most likely diagnosis?

On the 7th postoperative day after the pinning of a broken hip, a 76-year-old man suddenly develops severe pleuritic chest pain and shortness of breath. When examined, he is found to be anxious, diaphoretic, and tachycardic, with a blood pressure of 140/85 mm Hg. He has prominent distended veins in his neck and forehead. Blood gases show hypoxemia and hypocapnia. His chest x-ray film is unremarkable. The nurses have placed him on supplemental oxygen by face mask. Which of the following is the most appropriate next step in management?

A young man sustains a gunshot wound to the base of his neck. He was shot point blank with a .38 caliber revolver. The entrance wound is above the left clavicle, below the level of the cricoid cartilage, and just lateral to the sternomastoid muscle. The exit wound is just above the spinous process of the right scapula. He has normal breath sounds on both sides, is awake and alert, is talking with a normal tone of voice, is neurologically intact, and is hemodynamically stable. Portable x-ray films of the neck and chest taken in the emergency department show some air in the tissues of the lower neck, but are otherwise non-diagnostic. Which of the following is the most appropriate next step in management?

A 67-year-old man shows up in the emergency department because he has not been able to void for the past 12 hours. He feels the need to, but he cannot do it. He gives a history that, for several years now, he has been getting up four or five times a night to urinate. It would take him a considerable time to get the urinary stream going, and the stream lacked force and often ended in a dribble. Because of a cold, 2 days ago he began taking an antihistamine, taking a decongestant, and drinking plenty of fluids. Physical examination shows a palpable, smooth, round mass arising from the pubis and reaching about half way toward the umbilicus. The mass is dull to percussion, and pushing on it accentuates the feeling of needing to void. Rectal examination reveals a large, boggy, non-tender prostate gland without nodules. This a classic presentation for which of the following acute conditions?

Several months after sustaining a crushing injury to his arm, a patient complains bitterly about constant, burning, agonizing pain in that arm, that does not respond to the usual analgesic medications. The pain in his arm is aggravated by the slightest stimulation of the area, such as rubbing from the shirt sleeves. The arm is cold, cyanotic, and moist, but it is not swollen. Pulses at the wrist are normal, and neurologic function of the three major nerves is intact. Which of the following is most appropriate to provide diagnostic confirmation of the nature of the problem and eventual therapy?

A 57-year-old alcoholic man is being treated for acute hemorrhagic pancreatitis. He was in the intensive care unit for 1 week, where he required chest tubes for pleural effusions and was on a respirator for several days. Eventually, he improved sufficiently to be transferred to the floor. Three days after leaving the unit, and about 2 weeks after the onset of the disease, he spikes a fever and develops leukocytosis. Which of the following developments do these recent findings most likely suggest?

A 31-year-old male immigrant from India is found on a routine physical examination to have a single, 2-cm nodule in the right lobe of his thyroid gland. The mass is firm, moves up and down with swallowing, and is not tender. The skin of his face and neck is pitted with multiple scars, which suggest smallpox; however, he explains that the scars are due to very severe acne that he had as a youngster, for which he eventually received external beam radiation therapy at the age of 14. His thyroid function tests are normal, and a fine needle aspiration (FNA) cytology of the mass is read by the pathologist as "indeterminate." Which of the following is the most appropriate next step in management?

33-year-old woman is involved in a high-speed automobile collision. She arrives at the emergency department gasping for breath. Her lips are cyanotic and she has flaring nostrils. There are bruises over both sides of the chest, and tenderness suggestive of multiple rib fractures. Her blood pressure is 60/45 mm Hg, pulse is 160/min and feeble, and central venous pressure is 25 cm H2O. Her neck and forehead veins are distended. She is diaphoretic and has a hint of subcutaneous emphysema in the lower neck and upper chest. Her left hemithorax has no breath sounds and is hyperresonant to percussion. The trachea is deviated to the right, as are the heart sounds. Which of the following is the most likely diagnosis?

A 44-year-old woman complains bitterly of severe headache that has been present for several weeks and has not responded to the usual over-the-counter headache remedies. She locates the headache to the center of her head. It is pretty much constant but is worse in the mornings. She has no other neurologic signs or symptoms. She has had "tension headaches" in the past, but she says that those were located in the back of her head and felt different from the present pain. She is currently under considerable stress because she has been unemployed since undergoing modified radical mastectomy for T3, N1, M0 breast cancer 2 years ago. She had several courses of post-operative chemotherapy, which she eventually discontinued because of the side effects. Which of the following is the most appropriate next step in diagnosis?

A 59-year-old black man has a rock-hard, discrete, 1.5-cm nodule that is felt in his prostate during a routine physical examination. He is completely asymptomatic, and his prostatic specific antigen (PSA) done 3 months ago was normal for his age. His last rectal examination was performed a year earlier and was unremarkable. Which of the following will best establish the diagnosis?

A 9-month-old infant is brought in by her parents because she has an umbilical hernia. Physical examination shows an umbilical defect about 1 cm in diameter, with a small bulge when the girl cries. The hernial contents can be easily reduced. The hernia is not painful, and the girl is otherwise asymptomatic. Which of the following is the most appropriate next step in management?

53-year-old male is brought to the emergency department after being involved in a motor vehicle accident (MVA) as an unrestrained driver. He was found unresponsive at the scene and was intubated by paramedics. He has received 1L of normal saline over the last 20 minutes. His blood pressure in the emergency department is 70/30 mmHg, and his heart rate is 100/min. On physical examination, he responds to strong vocal and tactile stimuli by opening his eyes. His pupils are equal and reactive to light. On exam, there are multiple bruises over the anterior chest and upper abdomen. The trachea is midline. A Swan-Ganz catheter reveals a pulmonary capillary wedge pressure of 12 mmHg. Rapid infusion of 1L of normal saline increases the pulmonary capillary wedge pressure to 17 mmHg, with a blood pressure of 75/30 mmHg and heart rate of 103/min. Which of the following is the best treatment for this patient?

Year-old male comes to the clinic for medical clearance prior to an elective abdominal aortic aneurysm repair. He denies any cough, shortness of breath or chest pain. He has coronary artery disease, diabetes and hypertension. He does not use tobacco, alcohol or drugs. His blood pressure is 120/76 mm Hg, pulse is 60/min, and respirations are 14/min. Examination shows no abnormalities, except prominent epigastric pulsations. Which of the following interventions would be most helpful in preventing postoperative pneumonia in this patient?

A 32-year-old male is rushed to the emergency room after a motor vehicle accident. He was driving 55 mph when he suddenly lost control of his vehicle and hit a tree. He was wearing a seat belt. On physical examination, the patient appears scared and complains of moderate chest and abdominal discomfort. His voice is soft. His blood pressure is 190/ 100 mmHg and his heart rate is 100/min. The pupils are symmetric and reactive to light and the trachea is midline. You note bruising over the chest and upper abdomen. No penetrating injuries are evident. Which of the following injuries is most likely in this patient?

A 23-year-old male is brought to the emergency department following a motor vehicle accident (MVA) where he was the unrestrained driver. The patient was found unresponsive at the scene and was intubated by paramedics. He receives 2.5L of normal saline over the 20 minutes before he reaches the ED. His blood pressure there is 70/30 mmHg and his heart rate is 120/min. On physical examination, he responds to strong vocal and tactile stimuli by opening his eyes. His pupils are equal and reactive to light. There are multiple bruises over the anterior chest and upper abdomen. His neck veins are flat, trachea is midline and extremities are cold. Cardiac monitoring shows sinus tachycardia. Which of the following is the most likely cause of this patient's current condition?

A 33-year-old male falls while riding his bicycle in the park, and presents to the emergency department. Physical examination reveals upper abdominal bruises. His abdomen is non-distended, soft, and mildly tender in the epigastrium. Abdominal CT scan does not reveal any abnormalities. The patient is sent home with analgesic medications. He returns one week later with fever, shaking chills, poor appetite and deep abdominal pain Which of the following is most likely related to this patient's symptoms?

A 34-year-old immigrant from Mexico presents following an episode of massive hemoptysis. He describes bringing up large amounts of bright red, foamy sputum. He denies any recent trauma. On physical examination, the patient is agitated and has difficulty speaking. His blood pressure is 100/60 mmHg and his heart rate is 110/min. On physical examination, breath sounds are audible bilaterally. You immediately initiate intravenous infusion of crystalloid. Portable chest x-ray shows an opacity in the right upper lobe. Which of the following is the best next step in the management of this patient?

34-year-old man is brought to the emergency department after being rescued from a burning building. His temperature is 36.90C (98.60 F), blood pressure is 90/60 mm Hg, pulse is 100/min and respirations are 28/min. Examination shows second and third degree burns over 15% of his body. His oropharynx shows erythema and scattered blisters. His lungs are clear to auscultation and his abdomen is soft and nondistended. His blood carboxyhemoglobin concentration is 20%. Which of the following is the best management for this patient?

36-year-old woman presents to the emergency department with severe epigastric pain and right shoulder pain of about two hours duration. She also reports having one episode of emesis. When asked about her diet, she explains that she unintentionally fasted yesterday and had a large meal two hours ago. Her past medical history is significant for frequent heartburn for which she takes ranitidine. Several hours after presenting, the patient's pain resolves completely. Which of the following best explains this episode?

A 74-year-old male is undergoing elective abdominal aortic aneurysm repair. He is given two units of packed red blood cells during the surgery. He develops fever and chills one hour after finishing the surgery and transfusion. He received one dose of prophylactic antibiotics before surgery. He had coronary bypass grafting two months ago. His temperature is 38.50 C (101.30 F), blood pressure is 130/76 mm Hg, pulse is 90/min and respirations are 16/min. Physical examination shows a mildly tender wound; there is no redness. The lungs are clearto auscultation. He has a Foley catheter and right subclavian central venous access, each placed at the time of surgery. Which of the following is the most likely cause of his fever?

A 63-year-old male presents to the urgent care center with a four hour history of abdominal pain which he describes as severe, diffuse and constant. He has had one episode of non-bloody vomiting since the pain started. His past medical history is significant for coronary artery disease, diabetes, hypertension, chronic atrial fibrillation and chronic kidney disease. His current medications are lisinopril, digoxin, warfarin, metoprolol, simvastatin and insulin glargine. On physical examination, his blood pressure is 130/70 mmHg and his heart rate is 100/min and irregular. Physical examination reveals an overweight male in moderate distress. His abdomen is diffusely tender to palpation with positive rebound tenderness. His laboratory findings are as follows: Hemoglobin 9.5 mg/dl W BC count 7,500/mm3 Platelets 90,000/mm3 Sodium 137 mEq/L Potassium 4.5 mEq/L Chloride 101 mEq/L Bicarbonate 22 mEq/L Glucose 210 mg/dl Creatinine 1.8 mg/dl INR 2.1 Blood digoxin level therapeutic An upright abdominal x-ray shows free air under the diaphragm. Which of the following is the best initial treatment for this patient?

Fresh frozen plasma@ 662. A 55-year-old male comes to the physician's office because of chronic pain in his buttock, hip and thigh muscles. The aching pain is present in both legs and usually is associated with walking. He has multiple medical problems and takes several medications. He has a 30 pack year smoking history. His temperature is 36.70 C (980 F), blood pressure is 150/88 mm Hg, pulse is 80/min and respirations are 16/min. Examination shows decreased femoral, popliteal and dorsalis pedis pulses in both legs. Which of the following additional complaints is most likely in this patient?

A 62-year-old female is hospitalized with epigastric pain and vomiting. Her past medical history includes mild COPD, congestive heart failure, diabetes mellitus and a stroke that occurred 2 years ago. Her current medications are insulin glargine and aspirin. Her blood pressure is 110/70 and her heart rate is 76/min. Comprehensive work-up is suggestive of acute calculous cholecystitis, and a cholecystectomy is planned. Which of the following would reduce postoperative mortality in this patient?

A 50-year-old postman presents with a six-month history of left calf pain that is brought on by walking and is relieved by rest. The patient reports no other symptoms. He has smoked cigarettes for the past 25 years, but does not drink alcohol or use illicit drugs. On physical examination, he has a blood pressure of 158/92 mm Hg and a pulse of 88 beats per minute. The heart and lung examinations are normal. A bruit is heard over the left femoral artery. Popliteal, dorsalis pedis and posterior tibial pulses are palpable bilaterally. The electrocardiogram shows normal sinus rhythm and Q-waves in II, Ill, and aVF. Which of the following is the best next step in management?

An 85-year-old male is placed on mechanical ventilation after a complicated elective hernia repair. After five days of endotracheal intubation with mechanical ventilation, the ratio of the rate of carbon dioxide produced to the rate of oxygen uptake is 1.05. What is the best explanation for these findings?

23-year-old male is brought to the emergency department after a motor vehicle accident. He was an unrestrained driver. He was found unresponsive at the scene of the accident, and was intubated by the paramedics. He has received 2L of normal saline over the last 20 minutes. His blood pressure is 80/40 mmHg, and heart rate is 120/min. He responds to strong vocal and tactile stimuli by opening his eyes. His pupils are equal and reactive to light. His neck veins are distended. There are multiple bruises involving the anterior chest and upper abdomen. His chest x-ray shows a small, left-sided pleural effusion and normal cardiac contours. Which of the following is the most likely diagnosis?

Bronchial rupture 667. A 65-year-old male comes to the ER because of sudden onset severe pain in his right leg. He says he has never previously had pain in his leg and denies any recent trauma, fever or chills. He recently suffered an acute anterior wall myocardial infarction that resulted in cardiogenic shock and is currently undergoing cardiac rehabilitation. His other medical problems include hypertension, diabetes and hyperlipidemia. His temperature is 36.70 C (980 F), blood pressure is 11 0/70 mm Hg, pulse is 90/min (regular) and respirations are 16/min. His lungs are clear to auscultation. His heart rate is regular with no murmurs. Below the knee the right leg is cool to touch and appears pale. The dorsalis pedis pulse is not palpable while the popliteal pulses are full. Pulses are normal in the contralateral extremity. Neurologic examination shows numbness over the dorsum of the leg and foot. Which of the following is the most likely cause of his symptoms?

A 27-year-old basketball player jumps to block a shot with his right hand. As his hand contacts the ball, he feels severe pain in his right shoulder. He presents to the emergency department with continuing shoulder pain. You note that he holds his right arm in slight external rotation, supporting its weight with his left hand. On physical examination, he resists internal rotation of his right arm. Which of the following nerves is most likely to be injured in this patient?

An 88-year-old male complains of severe right calf pain several hours after undergoing a right femoral artery embolectomy. He also complains of a burning sensation in his posterior right leg. He has a long history of atrial fibrillation and hypertension. His past medical history also includes stroke, bleeding duodenal ulcer, diabetes mellitus and diabetic nephropathy. On physical examination, his blood pressure is 160/70 mm Hg and his heart rate is 100 per minute and irregular. His right calf is swollen, tense and exquisitely tender; the pain is worsened by passive extension of the right knee. Dorsalis pedis and posterior tibial pulses are palpable in the bilateral lower extremities. Which of the following is the most likely cause of this patient's symptoms?

28-year-old man is brought to the emergency department 4 hours after being involved in a motor vehicle collision. His blood pressure is 90/50 mm Hg, pulse is 120/min and respirations are 30/min. Examination shows a stuporous man with bruises over his extremities and upper abdomen. His trachea is midline and his neck veins are flat. His abdomen is moderately distended but non-tender. Immediately after being intubated and placed on mechanical ventilation he goes into cardiac arrest. Which of the following could have prevented cardiac arrest in this patient?

A 42-year-old man develops right calf pain one week after having a left hemi-colectomy. On physical examination, there is moderate right ankle edema and right calf pain with dorsiflexion of the right foot. Duplex ultrasonography shows a clot in the right superficial femoral vein. Which of the following is the most appropriate initial treatment?

62-year-old man is brought to the emergency department after being involved in a motor vehicle collision where he suffered serious burns. On physical examination there are second degree burns covering both upper extremities and third degree burns over the anterior aspects of both lower extremities. On day three of his hospitalization, the patient develops tachycardia and decreased urine output. His blood pressure is 90/60 mmHg, pulse is 120/min, temperature is 95°F (35°C), and respirations are 26/min. Laboratory analysis reveals: Blood glucose 230 mg/dL WBC 16,000/mm3 Platelets 80,000/mm3 Which of the following is the best explanation for this patient's current condition?

28-year-old male is brought to the emergency department after being an unrestrained passenger in a motor vehicle collision. In the ambulance on his way to the hospital, he receives 2 liters of normal saline intravenously and 5 Umin of oxygen by nasal cannula. On physical examination, his blood pressure is 100/70 mmHg, heart rate is 120/min, and respiratory rate is 40/min. He is agitated and moves all four extremities spontaneously. His pupils are symmetric and reactive to light. His neck veins are distended, and his trachea is deviated to the right. Which of the following is the best initial management for this patient?

Needle insertion into the second intercostal space in the left midclavicular line@ 674. A 53-year-old male presents to the emergency room complaining of chest pain localized to the left chest wall and following a linear pattern along the fifth intercostal space. His past medical history is significant for polycystic kidney disease and hypertension. His current medications are metoprolol and amlodipine. He has a ten pack-year smoking history but quit 14 years ago. He consumes alcohol occasionally. His blood pressure is 160/90 mmHg and his heart rate is 90/min. Physical examination is noncontributory. His laboratory findings are as follows: Sodium 142 mEq/L Potassium 4.2 mEq/L Hemoglobin 9.5 mg/dl W BC 10,000/mm3 Creatinine 1 .9 mg/dl BUN 28 mg/dl Chest x-ray reveals a solitary round lesion in the left upper lung field that measures 2 cm in diameter. It does not about the pleura. Which of the following is the best next step in managing this patient?

36-year-old male presents with firm, non-tender swelling of his right cheek. He tells you that he had similar swelling at that site two years ago and was diagnosed with a tumor, which was subsequently removed without complication. Examination reveals fullness of the parapharyngeal space on the right side. Repeat surgery in this patient is most likely to result in which of the following complications?

A 34-year-old man complains of severe abdominal pain. He describes the pain as "sharp" and "unbearable." It is located in the lower left abdomen and radiates to the perineum. He has vomited twice since the pain began. He denies dysuria. On exam, he is afebrile. He cannot lie still on the examination table due to his discomfort. Mucus membranes appear slightly dry. Lungs are clear to auscultation. Heart sounds are normal and there are no murmurs or gallops. His abdomen is soft and non-tender to palpation. Inspection and palpation of his genitalia is unrevealing. Extremities have no cyanosis, clubbing, or edema. Which of the following is the best test to diagnose this patient's condition?

Radioisotope (HIDA) scanning

A 43-year-old male complains of right shoulder pain and weakness after falling on his outstretched hands two days ago. He denies any swelling or shoulder deformity. You passively abduct both his arms above his head and then ask him to bring his arms down slowly in an adducting motion. The right arm drops rapidly at the midpoint of its descent. What is the most likely diagnosis?

A 23-year-old male is brought to the emergency department from the scene of a motor vehicle accident. He appears distressed and complains of severe abdominal pain and distention. Urgent laparotomy reveals splenic laceration, and splenectomy is performed. There are no post-operative complications. The patient has no significant past medical history. He drinks alcohol occasionally but denies smoking cigarettes or using illicit drugs. He works as a computer programmer in a small office. Which of the following vaccines is recommended in this patient?

Salmonella 680. A 32-year-old female presents with intermittent blood staining of her bra from her left breast. She has not felt any lumps on either breast. Physical examination shows no breast mass or axillary lymphadenopathy. Ultrasonogram of the breast is within normal limits. Which of the following is the most likely diagnosis?

A 31-year-old male presents to your office with pain and swelling over his coccyx. He has never had symptoms like this before. His past medical history is significant for an appendectomy two years ago and acute pyelonephritis one year ago. Which of the following is the most likely diagnosis?

An 18-year-old male comes to the physician's office because of dull aching and fullness of the scrotum. Examination shows soft testicular swelling; transillumination testing is negative. The scrotal swelling increases when the patient performs the Valsalva maneuver. The physical examination is otherwise unremarkable. Which of the following is the most likely cause of his condition?

Cystic dilations of the efferent ductules 683. A 12-year-old boy is brought to the emergency department after being involved in a motor vehicle collision. He is in no distress and is admitted for observation. Two hours after admission, he develops tachypnea and tachycardia. His temperature is 36.70 C (980 F), blood pressure is 110/66 mm Hg, pulse is 110/min, and respirations are 22/min. Examination shows bruises on the right side of the chest, but palpation of the ribs does not elicit pain or suspicion for rib fractures. Breath sounds are decreased on the right side. ABG on 6 liters of oxygen shows PO2 of 60 mm Hg, PCO2 of 32 mm Hg, and pH of 7.42. An x-ray film of the chest shows a patchy irregular alveolar infiltrate in the right middle and lower lobes. Which of the following is the most likely diagnosis?

A 31-year-old male is brought to the emergency department after being involved in a motor vehicle collision as an unrestrained passenger. He was given 3L of normal saline in the ambulance on his way to the hospital and has been receiving 5 L/min of oxygen by nasal cannula. He is agitated and moves all four extremities spontaneously. His blood pressure is 85/55 mmHg and his heart rate is 120/min. His respiratory rate is 30/min. His pupils are symmetric and reactive to light. His neck veins are flat and his trachea is shifted slightly to the right. Over the left hemithorax, breath sounds are absent and there is dullness to percussion. Which of the following diagnoses is most likely?

A 45-year-old policeman presents to your office complaining of tiredness and sleepiness. He says that his job seems tiring to him recently. It is difficult for him to get up in the morning and go to work. He goes to bed early because he feels tired and sleepy. Two months ago, he was investigating a case of massive murder. He slipped on the blood on the floor, fell and hit his head. He also describes recent abdominal pain that is constant and gnawing, interfering with his sleep. His appetite is poor, and he lost 15 pounds over the last month. Physical examination is significant only for tenderness and fullness in the epigastrium. Which of the following is the most likely diagnosis?

Chronic subdural hematoma 686. A 68-year-old male undergoes colon resection surgery for diverticulosis. In the 24 hours following the surgery, he passes a total of 300 ml of urine. His past medical history is significant for coronary artery disease, right knee osteoarthritis and moderate chronic obstructive pulmonary disease. On physical examination, his blood pressure is 110/70 mm Hg and his heart rate is 90/min. His lungs are clearto auscultation and his abdomen is soft and non-distended. His current labs are given below: Hemoglobin 9.5 mg/dl W BC count 13,000/mm3 Platelet count 160,000/mm3 Sodium 138 mg/dl Potassium 5.1 mg/dl Glucose 108 mg/dl Creatinine 2.3 mg/dl BUN 82 mg/dl His indwelling bladder catheter is changed but no residual urine is drained. Which of the following is the best next step in managing this patient?

A 65-year-old diabetic male comes to the physician because of pain in his calf muscles. His pain increases with walking. He also has end stage renal disease, hyperlipidemia and hypertension. His temperature is 36.70 C (980 F), blood pressure is 150/96 mm Hg, pulse is 80/min and respirations are 16/min. Examination shows skin atrophy, shiny skin and loss of hair on both legs below the knee. Which of the following would be most appropriate next step in management?

A 63-year-old obese female undergoes an elective cholecystectomy after two episodes of acute calculous cholecystitis. Three days after surgery, her blood pressure is 150/100 mmHg, her heart rate is 90/min, and her arterial oxygen saturation is 91% on room air. She is afebrile. Which of the following would most likely increase her functional residual lung capacity?

A 42-year-old moderately obese female complains of abdominal discomfort two days after undergoing an elective cholecystectomy. Her past medical history is significant for hypertension, diabetes mellitus and hyperlipidemia. Her blood pressure is 132/90 mmHg and her heart rate is 76/min. Physical examination reveals a distended abdomen with decreased bowel sounds. Which of the following is most likely contributing to her current condition?

Absence of bile storage reservoir 690. A 54-year-old female with a 30 pack-year smoking history undergoes cholecystectomy after an episode of biliary pancreatitis. On the third postoperative day, she complains of discomfort in the upper abdomen. Though she is breathing comfortably, her oxygen saturation is 90%, compared with 98% yesterday. Her blood pressure is 130/80 mmHg, heart rate is 90/min, respiratory rate is 20/min, and temperature is 980 F (360 C). Arterial blood gas analysis reveals the following pH = 7.44 p02 =64 mmHg pC02 =34 mmHg Which of the following most likely explains the observed findings?

Ventilator-associated pneumonia 691. A 23-year-old male is found at the scene of a motor vehicle accident with bilateral lower extremity fractures. You also note extensive abdominal bruising and scalp lacerations. At the scene, the patient's blood pressure is 80/60 mmHg and his heart rate is 120/min. He is given 2 liters of IV fluids wide open. On the way to the hospital he becomes progressively drowsy, and he develops progressive weakness on the right side of his body. This patient is also likely to show deficits in the functioning of which of the following nerves?

35-year-old male presents with complaints of muscle weakness and sensory loss in his upper extremities. His medical history is significant for involvement in a motor vehicle accident seven years ago in which he sustained a whiplash cervical spine injury. Physical examination today reveals moderate wasting of the small hand muscles and impaired pain and temperature sensation in the bilateral upper extremities. Light touch, vibration, and position senses are all intact. Which of the following is the most likely diagnosis?

A 45-year-old male presents to his physician with persistent nausea and vomiting of partially digested food for the past month. He has also lost 5 lbs of weight during this period of time. His appetite is good but he feels full after a few bites. His past medical history is significant for a one-year history of type 2 diabetes and a suicide attempt 6 months ago in which he ingested acid. He drinks alcohol and smokes one pack of cigarettes daily. His temperature is 36.80 C (98.20 F), blood pressure is 110/65 mm Hg, pulse is 11 0/min, and respirations are 16/min. Mucous membranes are dry. Examination shows succussion splash on the epigastrium. Which of the following is the most likely diagnosis?

A 28-year-old woman with sickle cell anemia presents to the urgent care clinic complaining of 12 hours of right upper quadrant pain. She has had similar pain previously, usually after eating fatty foods. However, past episodes have always resolved within one to two hours. On examination, her temperature is 38.30 c and she has right upper quadrant pain with a positive Murphy's sign. Abdominal ultrasound reveals gallstones, a thickened gallbladder wall, and a normal common bile duct. Her alkaline phosphatase level is normal. What is the most appropriate next step in the management of this patient?

A 35-year-old man is brought to the emergency department after suffering a deep laceration from a rusted piece of barbed wire that was hidden in the grass. Examination shows a 6 cm laceration on the lateral leg that is contaminated with dirt and soil. The laceration is bleeding. The patient reports having received a complete set of childhood vaccinations. His last tetanus immunization was at age 23. Which of the following is the most appropriate next step in the management of this patient?

A 34-year-old unrestrained male driver is brought to the ER after a motor vehicle accident. His cervical spine is immobilized. At the scene of the accident, his blood pressure is 80/40 mm Hg and heart rate is 130/min. He is able to communicate and follows simple commands. Lungs are clear to auscultation. Abdominal wall ecchymosis is present. Abdomen is mildly distended. Bowel sounds are decreased. Neck veins are collapsed. After two liters of intravenous fluids, his blood pressure is 90/60 mmHg. Which of the following is the most appropriate next step in management of this patient?

A 42-year-old man comes to the physician because of a 3-month history of substernal chest pain after every meal. He has chronic alcoholism and a long history of heartburn. Upper endoscopy shows mucosal irregularity and ulceration of the squamocolumnar junction above the lower esophageal sphincter (LES). Multiple biopsies were taken. 4 hours later he is complaining of worsening substernal pain radiating to the back, left chest pain, and shortness of breath. His temperature is 37.10C (98.90F), blood pressure is 110/70 mm Hg, pulse is 140/min, and respirations are 34/min. An x-ray film of the chest shows minimal left pleural effusion. Which of the following is the most appropriate next step in management?

A 59-year-old man comes to the physician because of postprandial abdominal cramps, weakness, light-headedness, and diaphoresis. The symptoms begin 25-30 minutes after eating. He had a partial gastrectomy for intractable peptic ulcer disease two weeks ago. He takes no medications. His temperature is 36.70 C (980 F), blood pressure is 130/65 mmHg, pulse is 80/min, and respirations are 18/min. Which of the following is the most appropriate next step in management?

A 34-year-old male undergoes successful laparotomy for a gun-shot wound. He received 5 units of packed red blood cells during the surgery. He has been receiving incentive spirometry and ampicillin/sulbactam. However, he developed a fever of 38.70 C (101.70 F) on the sixth postoperative day. His blood pressure is 120/76 mm Hg, pulse is 97/min and respirations are 14/min. Examination shows an alert, pleasant male in no acute distress. The oropharynx is clear. The lungs and heart are clear to auscultation. The abdomen is soft and non-tender, and the wound has no discharge. He has a right femoral triple lumen catheter and Foley catheter in place. Extremities have no swelling or redness. Two days later, four bottles of blood cultures grew coagulase negative Staphylococcus. Which of the following is the most likely cause of his fever?

An overweight 12-year-old boy presents with left knee pain that has been going on intermittently for the past three months. Physical activity, especially stair climbing, exacerbates the pain. The boy's mother also points out that he has been limping recently. On physical examination, his anterior left hip is moderately tender to palpation, and when he is asked to stand on his left leg, the right half of his pelvis tilts downward. Which of the following best explains this finding?

A 23-year-old woman comes to the physician because of a 4-week history of a whistling noise during respiration. She underwent a difficult rhinoplasty a few months ago. The noise is getting louder and is annoying. Which of the following is the most likely diagnosis?

A 46-year-old man is brought to the emergency department after being involved in a motor vehicle collision. He is unresponsive. His injuries include a basilar skull fracture, brain contusion, fractures of ribs 7-10, hemopneumothorax on the right and a pelvic fracture. After placement of a chest tube and pelvis fixation, his condition stabilized. On the fifth day of his hospital stay, he is still unresponsive with a Glasgow Coma Scale of 8. He is breathing spontaneously. Examination shows an abnormal facial reaction to abdominal palpation. Pain appears to be elicited by palpation in right upper quadrant. Bowel sounds are diminished. Rectal examination shows no abnormalities. Nasogastric tube aspiration shows retention of gastric contents. An abdominal CT scan shows gaseous distention of the small and large bowels without airfluid levels. The gall bladder is distended and pericholecystic fluid is present. Stones are not seen. Which of the following is the most likely diagnosis?

A 62-year-old man presents to the emergency department (ED) with one hour of severe epigastric pain. He has been having some epigastric pain exacerbated by eating for the last several days. He feels nauseous, and has vomited once since the pain began. His past medical history is significant for hypertension, diabetes, hyperlipidemia, and coronary artery disease. He underwent coronary bypass surgery one year back. His current medications are simvastatin, aspirin, clopidogrel, metoprolol, enalapril and metformin. His blood pressure is 140/ 100 mmHg, and heart rate is 65/min. His ECG is normal. Chest x-ray findings are shown on the slide below: Which of the following is the best step in the management of this patient?

A 65-year-old man comes to the physician four years after suffering a burn injury to his entire right leg. One area of the leg never healed and has now started increasing in size. He has constant pain and drainage from the site of the lesion. Several topical creams and antibiotics have not helped. Biopsy of the lesion is attempted. Which of the following is most likely be identified on biopsy?

A 77-year-old woman is brought to the emergency department because of sudden-onset intense diffuse abdominal pain followed by vomiting. Her past medical history is significant for chronic uncontrolled hypertension, cerebrovascular accident, diabetes and hyperlipidemia. She takes multiple medications. She does not use tobacco, alcohol or drugs. Her temperature is 38.30 C (1010 F), blood pressure is 180/100 mm Hg, pulse is 11 0/min and irregular and her respirations are 22/min. She is in severe distress. Lungs are clear to auscultation. Abdominal examination shows severe pain to palpation and nearly absent bowel sounds. There is rigidity and rebound. Rectal examination shows heme-positive stools. EKG shows absent P waves, irregular rhythm and inverted T waves. There are no previous EKGs for comparison. An x-ray film of the chest shows cardiomegaly. Laboratory studies show: Hematocrit 49% Leukocyte count 17,500/mm3 Troponin I normal What is the most likely diagnosis?

A 37-year-old male is brought to the emergency department immediately after being smashed in a hydraulic press at a local factory. He is alert and oriented. Despite 10mg of IV morphine given by the paramedics, he is crying with pain. His blood pressure is 110/70 mm Hg, pulse is 11 0/min, and respirations are 18/min. Apparently, his left humeral shaft is fractured and the left arm is severely deformed being bent medially 90 degrees. Left radial artery pulse sensation and muscle strength in the left forearm are decreased compared to the right side. His right leg is shortened and externally rotated. Deformity of the right thigh is noted. Pedal pulses are symmetric. He has pain in the left anterior chest on antero-posterior sternal compression, but breath sounds are normal. Physical examination otherwise shows no abnormalities. The paramedics have placed 2 peripheral intravenous lines and immobilized the fractured limbs. Which of the following is the most appropriate next step in management?

A 47-year old woman comes to the clinic because of worsening left breast swelling and pain. She had mastitis when she nursed her first child 20 years ago. She has not seen a doctor since that time. She is afebrile. Breast examination shows the left breast is enlarged with a 7 x 6 cm area of edema and erythema. A poorly localized mass without fluctuation is palpated in that area. Scant non-bloody discharge is noted on the nipple, and several large axillary nodes are palpated. Which of the following is the most appropriate next step in management?

50-year-old man comes to the physician because of a 2-day history of constipation and not passing flatus. For the last 3 days he has been having intermittent, but worsening, right lower quadrant (RLQ) pain. He has vomited several times today and feels nauseated. Examination shows a distended abdomen with tenderness in the RLQ; there is no rebound; there are no masses or hernias; bowel sounds are absent. Rectal examination shows an enlarged prostate. An upright x-ray film of the abdomen shows gas distributed throughout the small and large bowel, and some fluid levels. After nasogastric tube placement and hydration, his temperature is 36.50C (97.60F), blood pressure is 140/80 mm Hg, pulse is 57/min, and respirations are 12/min. Laboratory studies show: RBC count 4.5 million W BC 7,400 Na 140 K 3.5 Cl 100 BUN 15 mg/dl Creatinine 1.0 mg/dl Urine pH 5.5 Urine sediment: 2 W BC and 15 RBC/high power field, and needle-shaped crystals are present. Which of the following is the most appropriate next step in management?

A 25-year-old male is brought to the trauma center by the paramedics after being involved in a road traffic accident that occurred 90 minutes ago. He was a front seat passenger in a 3-car accident. His initial blood pressure at the scene of the accident was 90/60 mm Hg and pulse was 126/min. The paramedics administered 2 liters of normal saline in the ambulance. In the ED, his blood pressure is 110/70 mm Hg and pulse is 90/min. His abdomen is tender in the left upper quadrant. Ultrasound shows fluid in the spleno-renal angle The most appropriate next step is to-

Laparoscopy 710. A 65-year-old male presented to the ER with increasing shortness of breath, fever and productive cough of 2 days duration. He has smoked for several years and has been on home oxygen. Chest x-ray showed right lower lobe consolidation. His vital signs on admission were temperature 38.70 C (101.70 F), blood pressure 120/76 mm Hg, pulse 11 0/min and respirations 26/min. His condition worsened over the next several hours and required oro-tracheal intubation and mechanical ventilation. He was transferred to the intensive care unit. Placement of a central venous catheter in the right subclavian vein for IV access was attempted. After the line is successfully placed, the patient begins to deteriorate. Repeat vital signs are blood pressure 80/50 mm Hg and pulse 130/min. Examination shows absent breath sounds on the right side and distended neck veins. Which of the following is the most appropriate next step in management?

Intravenous fluids and dopamine 711. A 36-year-old man is brought to the emergency department after being involved in a motor vehicle collision. He is in obvious distress. His blood pressure is 80/30 mm Hg, pulse is 140/min and respirations are 23/min. Examination reveals collapsed neck veins. Breath sounds are present bilaterally, heart sounds are normal and the trachea is midline. He is semiconscious and his pupils are bilaterally reactive. There is no obvious head injury. Abdominal examination shows distention with tenderness in all four quadrants with guarding and rigidity. After initial resuscitation including control of his airway, breathing and circulation, which of the following is the most appropriate next step in management?

A 35-year-old man is brought to the emergency department after being involved in a motor vehicle collision. He is unconscious. His blood pressure is 100/50 mm Hg, pulse is 100/min, and respirations are 19/min. Examination shows bilaterally reactive and non-dilated pupils. He does not follow commands and makes inappropriate sounds. A CT scan of the head shows numerous minute punctuate hemorrhages with blurring of the gray-white matter interface. Which of the following is the most likely diagnosis?

A 42-year-old man is found unconscious at the scene of a motor vehicle collision. He is rushed to the emergency department, where his blood pressure is found to be 70/40 mm Hg and his respirations are 28/min. On physical examination, his trachea is deviated to the left and his breath sounds are decreased on the right side. His neck veins are distended bilaterally. You also note significant swelling over the right femur. Which of the following is the most appropriate next step in the management of this patient?

A 65-year-old man with cervical spondylosis secondary to degenerative changes in the cervical spine was admitted after being involved in a motor vehicle accident. He regained consciousness after 5 minutes. After regaining consciousness, he had complete weakness in both upper extremities but was able to move his lower extremities. Vital signs are stable. Plain x-ray films of the cervical spine show no abnormalities except those consistent with mild degenerative changes. Which of the following is the most likely diagnosis?

A 54-year-old alcoholic man comes to the emergency department because of dysphagia, drooling and a fever. He has been sick for two days and has not been able to eat. His mouth is swollen and feels hot. Examination shows a pale, febrile man who is drooling. There is redness around the entire mouth extending into the floor of the mouth. A tender, symmetric and indurated swelling with palpable crepitus is present in the submandibular area. Laboratory study shows an elevated W BC count. Which of the following is the most likely source of the oral cavity infection?

A 46-year-old man comes to the physician because of a two day history of worsening abdominal discomfort and persistent vomiting. He has not had a bowel movement or passed flatus for 3 days. He had an appendectomy for appendicitis 20 years ago. Examination shows a distended abdomen that is tympanic on percussion. High-pitched bowel sounds and splashing are heard on auscultation. The abdomen is diffusely tender on palpation without rebound or guarding. An x-ray film of the abdomen shows distended small bowel loops with air-fluid levels; no gas is seen in the colon. IV rehydration is started. Which of the following is the most appropriate next step in management?

Total parenteral nutrition 717. A 25-year-old man comes to the physician because of a mass in his mouth. He has just noticed this mass and has had no trauma to his oral cavity. He does not use tobacco, alcohol or drugs. He has had no weight loss. Physical examination shows a large mass located on the hard palate of the mouth. On palpation, the mass is immobile, fleshy with bony surroundings and measures 3x 3 cm. Which of the following is the most appropriate next step in management?

69-year-old man is evaluated after undergoing an elective repair of a rapidly expanding abdominal aortic aneurysm. The surgical procedure was complicated by a significant amount of blood loss and required multiple transfusions. In the postoperative recovery room, he had weakness in both lower extremities and developed urinary retention. Neurologic examination shows spastic paraplegia and loss of pain sensation over the lower extremities; vibratory sensation is intact. Upper extremity examination shows no abnormalities. Which of the following is the most likely pathophysiologic mechanism of the neurologic dysfunction?

A year24-old woman comes to the physician because of a one-week history of increasing pain in the right leg. She is an active dancer and practices 4-5 hours a day. One week ago, she felt a dull aching pain in the right middle leg; the pain has been increasing since and is particularly bad when she dances. The pain is interfering with her dancing sessions. She is afebrile and her other vital signs are within normal limits. Examination shows point tenderness over the midpoint of the right leg; there are no abnormalities of the skin overlying the tender point. Knee and ankle examinations show no abnormalities. An x-ray of the lower leg shows no abnormalities. ESR is within normal limits. Which of the following is the most likely cause of her pain?

Neoplasm 720. A 32-year-old male comes to the emergency department because of a 3 day history of increasing lower abdominal pain, mild diarrhea and rectal pain on defecation. Ten days ago he had right lower quadrant (RLQ) pain for about 24 hours that resolved spontaneously. Since then, he has had malaise and low-grade fever. His temperature is 38.70C (101.60F), blood pressure is 150/90 mm Hg, pulse is 110/min and respirations are 15/min. Examination shows lower abdominal tenderness without rebound. No masses are palpable, and bowel sounds are decreased. Rectal examination shows a very tender, boggy and fluctuant bulging on palpation with the tip of the finger anteriorly. Laboratory studies show: Complete blood count Hemoglobin 14.0 g/L Platelets 270,000/mmJ Leukocyte count 15,500/mm3 His current condition is most likely a complication of?

A 70-year-old male rushed to the emergency department because of bright red bleeding per rectum. He says his commode is full of blood and has never experienced any bleeding before. He has a history of constipation. He takes daily aspirin for prevention of stroke and hydrochlorothiazide for high blood pressure. His temperature is 36.50 C (97.80 F), blood pressure is 100/60 mm Hg, pulse is 120/min and respirations are 20/min. He is not hypoxic. Abdomen is soft, non-distended and non-tender; no masses or organomegaly are palpated; bowel sounds are normal. Rectal examination shows bright red blood and an enlarged prostate. Nasogastric tube aspirate shows non-bilious stomach contents without blood. An x-ray of the abdomen shows no abnormalities. Which of the following is the most likely cause of his bleeding?

A 22-year-old man is brought to the emergency department after falling from a motorbike. He has right wrist pain. His temperature is 37.10C (98.60F), blood pressure is 110/70 mm Hg, pulse is 80/min, and respirations are 17/min. He is well oriented and cooperative. His pupils are bilaterally reactive. Physical examination shows no signs of trauma except for marked tenderness in the right anatomical snuff box. An x-ray film of the wrist joint shows a radiolucent line across the waist of the right scaphoid bone. Which of the following is the most next

A 62-year-old man complains of right knee pain. He says that the pain started two days ago and has been limiting his daily activities. He required 2 grams of acetaminophen in order to sleep through the previous night. He has a long history of rheumatoid arthritis treated with daily low-dose prednisone. Physical examination reveals swelling, limited flexion, and tenderness to palpation of the right knee. Synovial fluid aspiration is performed. Which of the following synovial fluid characteristics would warrant immediate surgical intervention?

A 38-year-old woman comes to the emergency department because of the sudden onset of severe abdominal pain. The pain started one hour ago in the epigastrium but now it is mostly localized to the lower abdomen. She has some nausea but denies any vomiting. Her last menstrual period (LMP) was 25 days ago. Her temperature is 36.8C (98.1F), blood pressure is 160/90 mm Hg, pulse is 11 0/min, and respirations are 25/min. The abdomen is tender on palpation with prominent guarding and positive rebound. There is no shifting dullness, and bowel sounds are absent. Laboratory studies show: Hb 13.1 g/dl Hct 43% W BC 10,900/mm3 Which of the following is the most appropriate next step in management?

An 11-year-old boy is brought to the emergency department for evaluation of an injury from jumping off a 10 ft wall, 2 days ago. He had some pain in his feet immediately following the jump, but was able to walk. The past 2 days, he has had increasing pain in his right foot with walking. He has no pain at rest. He has some "crunching" in the right foot. Physical examination shows the foot appears normal with the exception of suffusion on the plantar surface. Passive motion of the second toe and passive dorsiflexion of the foot produces pain in the middle of the foot. Which of the following is the most likely diagnosis?

23-year-old man is brought to the emergency department after being hit in the neck with a dull instrument. He has neck pain and stiffness. Vital signs are stable. Neurological examination shows no abnormalities. An astute medicine resident decides to order an angiogram of the neck vessels to rule out carotid artery injury. Diagnostic angiography shows an intimal flap in the left internal carotid artery just above the carotid bifurcation. Which of the following is the most appropriate next step in management?

A 36-year-old forest worker is brought to the emergency department after being hit by a falling tree, 3 hours ago. He has pain in the left subscapular region. His temperature is 360C (96.90F), blood pressure is 120/76 mm Hg, pulse is 90/min, and respirations are 18/min. Physical examination shows aggravation of the pain in the left subscapular region with taking a deep breath and with anteroposterior and lateral chest compression. He has ecchymoses on the anterior and posterior chest and on the upper abdominal wall. His abdomen is vaguely tender to palpation in the left upper quadrant (LUQ) and he has left costovertebral angle (CVA) tenderness. Examination otherwise shows no abnormalities. An x-ray film of the chest shows posterior factures of the 8th, 9th and 1Oth ribs on the left. An x-ray film of the abdomen shows blunting of the left psoas shadow. Abdominal ultrasound shows no abnormalities. Laboratory studies show: Hb 15.3 g/dL Hematocrit 43% W BC 6,200/cmm Urinary sediment Many erythrocytes; W BC 4-5/hpf; oxalate crystals. Which of the following is the most appropriate next step in management?

Renal angiography 728. A 35-year-old woman is being evaluated after having a screening mammography. A 3 x 3 cm speculated mass with coarse calcifications is seen in the upper outer quadrant of her right breast. She has no complaints. She has a history of bilateral reduction mammoplasty for mammary hyperplasia 12 years ago. She has no family history of medical problems. Breast examination shows her right nipple is slightly retracted. A fixed mass is palpated in the upper outer quadrant of the right breast. Ultrasonography of the breast shows a hypo-echoic mass. Multiple core biopsy samples show foamy macrophages and fat globules. Which of the following is the most appropriate course of action?

An 18-year-old woman at 9 weeks' gestation is brought to the emergency department because of an open fracture of the tibia and fibula. She is hemodynamically stabilized and referred to the orthopedic department. She is scheduled for internal fixation of the tibia for the following day. However, before the surgery she develops severe dyspnea and confusion. Her temperature is 37.70 C (99.90 F), blood pressure is 110/70 mm Hg, pulse is 110/min, and respirations are 22/min. Examination shows numerous non-palpable petechiae in the upper part of the body. Which of the following is the most likely diagnosis?

A 76-year-old woman comes to the emergency department because of left lower quadrant (LLQ) abdominal pain and fever. She takes acetaminophen for arthritis and docusate for constipation. A CT scan of the abdomen showed perisigmoid stranding suggestive of inflammation and sigmoid diverticulosis. She was started on intravenous ciprofloxacin and metronidazole; however, she had only mild improvement and is persistently febrile. Examination shows persistent LLQ tenderness to deep palpation. A repeat CT scan now shows a 5 x 6 cm mass in the left iliac fossa. Laboratory studies show: Hemoglobin 13.0 g/L Platelets 360,000/mm3 Leukocyte count 16,500/mm3 Which of the following is the most appropriate next step in management?

A 35-year-old woman presents to the physician's office after she palpated a lump in her right breast. She has no other complaints. She has not seen a doctor for 1 0 years. She regularly performs breast self-exams after menses. She has no significant past medical history. Her mother died of breast cancer at the age of 40. Breast examination shows a 1 x 1 cm, rubbery, firm, freely mobile round mass in the upper, outer quadrant of the right breast; no axillary lymph nodes are palpable. Which of the following is the most appropriate next step in management?

Mammography@ 732. A 55-year-old man comes to the physician because of a 4-month history of an ulcer on the sole of his right foot. He has had no trauma and does not remember how he got the ulcer. He states the ulcer has been difficult to heal and readily gets infected. He does not use tobacco, alcohol or drugs. Examination shows the ulcer is located on the sole of his foot just below the head of the first metatarsal bone. His foot is warm and dry and appears slightly deformed. Dorsalis pedis pulses are present. Which of the following is the most likely cause of his condition?

Posterior spinal cord lesion 733. A 7-year-old child is brought to the emergency department after being involved in a highway motor vehicle collision. He had blunt trauma to his abdomen. Vital signs are stable, except for a respiratory rate of 30 per minute. Physical examination shows bruising of the upper abdomen, abdominal distention, and tenderness. He is in moderate respiratory distress; breath sounds are decreased on the left side. Chest tube placement shows no blood or air in the pleural cavity. An x-ray film of the chest shows an elevated left hemidiaphragm. Laboratory studies show hemoglobin and hematocrit within normal limits. Which of the following is the most likely diagnosis?

A 44-year-old obese male is brought to the ER after a motor vehicle accident. His cervical spine is immobilized. He is alert and able to speak in complete sentences. He complains of abdominal pain. At the scene of the accident, his blood pressure is 90/60 mm Hg and pulse is 120/min. Lungs are clearto auscultation. Ecchymosis is present over the abdominal wall in distribution of the seat belt. Bowel sounds are decreased. Neck veins are collapsed. After receiving one liter of intravenous fluids, his blood pressure remains at 90/60 mmHg. A focused assessment with sonography for trauma is inconclusive due to the poor image quality. Which of the following is the most appropriate next step in management of this patient?

Ray of the chest 735. A 62-year-old man comes to the emergency department because of severe abdominal pain. He states that he suddenly felt weak, diaphoretic, and had no energy. He is a smoker and has hypertension. His blood pressure on initial examination was 11 0/70 mm Hg. Physical examination shows a diffusely tender abdomen. During CT scan he becomes pale and drowsy. CT scan is shown below: Repeat examination shows a man with anxiety and a blood pressure of 80/50 mm Hg and pulse of 110/min Which of the following is the most appropriate next step in management?

A 60-year-old man undergoes a laparotomy for intestinal obstruction secondary to postoperative adhesions. He has a history of diabetes mellitus, type 2, and hypertension. He underwent a cholecystectomy two years ago. His takes insulin, hydrochlorothiazide, enalapril, and pravastatin. On postoperative day number five, he has intense pain around the wound. His temperature is 38.30 C (1010 F), blood pressure is 120/76 mm Hg, pulse is 100/min, and respirations are 16/min. Examination of the wound shows a cloudy-gray discharge and crepitus; sensation at the edges of the wound is decreased. Which of the following is the most appropriate next step in management?

A 25-year-old motorcyclist is brought to the emergency department after being involved in a collision with an automobile. On arrival he is in obvious pain. He expresses an urge to void, but is unable to do so. Genital examination shows blood at the urethral meatus and a scrotal hematoma. Rectal examination reveals a high riding prostate. Abdominal examination is suggestive of a distended bladder. Which of the following is the most likely diagnosis?

A 43-year-old mildly overweight female complains of periodic right knee swelling and pain with physical activity for the past three months. She says that this problem started while on a hiking trip three months ago, at which point she experienced a 'popping' sensation in her right knee. She recalls that her knee was swollen the next day, and responded to over-the-counter pain killers. Recently, she has been having to limit her physical activities due to knee pain. On physical examination, there is tenderness of the anterior and medial right knee joint. Which of the following is the most likely diagnosis?

A 35-year-old black man is brought to the emergency department after a motorcycle accident. He hit the street with the side of his head. He was found unconscious when the emergency medical team arrived. However, on the way to the emergency department he regains consciousness. Upon arrival he is confused and complains of a headache. His temperature is 36.9C (98.5F), blood pressure is 100/60 mm Hg, pulse is 11 0/min, and respirations are 22/min. Examination shows a dilated pupil on the right side, with some weakness of the left arm and leg. CT scan of the head shows a biconvex hematoma on the right side of the head. Which of the following is the most likely diagnosis?

A 16-year-old boy was brought to the emergency department because of left shoulder and left hand pain after falling on his outstretched hand while playing soccer. He heard a crunching sound and had intense pain in his left shoulder area following the injury. Examination shows bruising around the clavicle area. He is holding his left arm with his right hand. There is a palpable gap in the middle of the clavicle. Auscultation shows a loud bruit just beneath the clavicle. An x-ray film of the left shoulder and chest shows the middle of the clavicle is fractured and displaced. Which of the following is the most appropriate next step in management?

A 16-year-old male is brought to the emergency department after falling off a bicycle and hitting the ground with his head. He briefly lost consciousness, but had no seizures. He has a mild headache but has no nausea or vomiting. Vital signs are stable. Examination shows no neurological deficit or any signs of fracture. Which of the following is the most appropriate next step in management?

54-year-old man is brought to the emergency department 1 0 minutes after being involved in a motor vehicle collision. On arrival, he is breathing spontaneously, is non-cyanotic and has no signs of external injury. His temperature is 37C (98.6F), blood pressure is 104/50 mm Hg, pulse is 122/min and respirations are 16/min. Examination shows bilateral round and reactive pupils of 4 mm. He is making some incomprehensible sounds. He responds to his name by opening his eyes and on applying supraorbital pressure he extends his left extremity and grasps your hand with his right hand. What is the Glasgow coma scale (GCS) in this patient?

A 46-year-old male is brought to the ER because of coffee ground emesis. He has a history of chronic hepatitis C and alcohol abuse. His temperature is 36.6C (97.9F), blood pressure is 120/70 mm Hg, pulse is 90/min and respirations are 14/min. He is oriented to time, place and person but somewhat sleepy. A flapping tremor is noted. His abdomen is soft, non-tender, and mildly-distended; liver and spleen are palpated below the costal margins; shifting dullness is present. Nasogastric tube aspiration shows bright red blood that was easily cleared with saline lavage. Endoscopy shows a fresh ulcer with a small adherent clot located high on the lesser curvature near the gastroesophageal junction. Non bleeding esophageal and gastric varices are also seen. Laboratory studies show: Hemoglobin 10.2 g/L MCV 105 fl Platelets 105,000/mm3 Leukocyte count 4,500/mm3 Prothrombin time 17 sec Aspartate aminotransferase (SGOT) 78 U/L Alanine aminotransferase (SGPT) 50 U/L Which of the following is the most appropriate next step in management?

A four-year-old boy is brought to the physician because of discomfort in the left hip and left knee that is causing him to limp. Examination shows normal knee joints bilaterally, but there is marked limitation of internal rotation and abduction of the left hip. His temperature is 37.1 C (98.6F), blood pressure is 90/60 mm Hg, pulse is 80/min and respirations are 16/min. Laboratory studies including complete blood count and basic metabolic profile show no abnormalities. Which of the following is the most likely diagnosis

65-year-old male is being evaluated for hip pain. The pain has been present for several months and is constant. He denies any weight loss or loss of appetite. His past medical history is significant only for high blood pressure. His temperature is 37.2 C (98.9 F), blood pressure is 150/88 mm Hg, pulse is 80/min and respirations are 12/min. Physical examination is unremarkable. Laboratory studies show: Alkaline phosphatase Elevated Gamma glutamyl transferase Normal Serum calcium Normal 25 (OH)2 vitamin D Normal Bone scan shows increased uptake in several spots. This patient is at high risk of developing?

A 45-year-old male comes to the hospital because of severe retrosternal chest pain that started suddenly a few hours ago. He says that he has been having mild chest pain for the past few days, but that this pain is completely different. His past medical history is significant for nonischemic cardiomyopathy for which he takes furosemide, carvedilol, spironolactone, lisinopril and potassium chloride. He also has HIV infection but is not taking any medications related to this diagnosis by his own choice. On physical examination, his temperature is 38.90C (1020 F), blood pressure is 110/65 mm Hg, pulse is 110/min, and respirations are 22/min. He is in obvious distress secondary to pain. His lungs are clearto auscultation and the remainder of his physical examination is unremarkable. His EKG is within normal limits. Chest X-ray shows a widened mediastinum and mediastinal air. W hich of the following is the most appropriate next step in the management of this patient?

A 78-year-old man with Alzheimer's disease was brought to the ER because of bright red bleeding per rectum. He has chronic constipation and is being treated with bisacodyl. On admission, his temperature was 36.60 C (97.90 F), blood pressure was 130/80 mm Hg with no orthostatic change, pulse was 90/min and respirations were 14/min. Nasogastric tube drainage showed normal stomach contents without blood. His bleeding stopped a few hours after admission, and he remained hemodynamically stable during that time. Colonoscopy showed extensive diverticulosis but no active bleeding source. Later that night he started bleeding again, and he is now hypotensive with a BP of 100/70 mm Hg. Packed red cells and intravenous fluid are started. Which of the following is the most appropriate next step in management?

A 44-year-old unrestrained male driver is brought to the ER after a motor vehicle accident. Cervical spine is immobilized. His breathing is normal. At the scene of the accident, his blood pressure is 70/30 mm Hg. After receiving two liters of intravenous fluid, his blood pressure is 80/40 mmHg. Neck veins are collapsed. Lungs are clear to auscultation. Abdomen is mildly distended. There is no obvious source of external bleeding. No intraperitoneal blood or solid organ damage is seen on ultrasonogram or diagnostic peritoneal lavage. Imaging studies reveal a pelvic fracture and fracture of the right fourth rib. Which of the following is the most appropriate next step in management?

A 3-year-old girl is brought to the emergency department because she is not moving her right arm. Her mother states that the child was perfectly normal in the morning. She remembers that she lifted the child with the child's right forearm and since then she has not been moving her right arm. Examination shows the right arm is held in pronation against the chest. The child avoids any movement of her right arm. Which of the following is the most appropriate next step in management?

A 23-year-old man is brought to the emergency department after being involved in a motor vehicle collision. He has multiple organ injuries and is listed in critical condition. Physical examination shows an open wound in the right lower extremity and significant blood loss. He is in hypovolemic shock. Which of the following is the first parameter to change in hypovolemic shock?