ملتقى طلاب الطب

An 81-year-old woman presents to your office accompanied by her husband. She has been doing well except for occasional word finding difficulty. Her husband is concerned that her memory is worsening over the past year. Recently, she got lost twice on her way home from her daughter’s house, was unable to remember her neighbor’s name, and could not pay the bills like she usually did. She has a history of hypertension and arthritis. She has no significant family history. Her medications include a daily multivitamin, hydrochlorothiazide, and ibuprofen as needed. Physical exam is unremarkable. Which of the following is associated with an increased risk of this patient’s disease?

A 32-year-old woman comes to the physician because of a 2-month history of fatigue, muscle weakness, paresthesias, headache, and palpitations. Her pulse is 75/min and blood pressure is 152/94 mm Hg. Physical examination shows no abnormalities. Serum studies show: Sodium 144 mEq/L Potassium 2.9 mEq/L Bicarbonate 31 mEq/L Creatinine 0.7 mg/dL Further evaluation shows low serum renin activity. Which of the following is the most likely diagnosis?"

An investigator develops a new drug that decreases the number of voltage-gated potassium channels in cardiac muscle cell membranes. Which of the following is the most likely effect of this drug on the myocardial action potential?

Four days after undergoing a Whipple procedure for newly-diagnosed pancreatic cancer, a 65-year-old man has shortness of breath. His surgery was complicated by bleeding for which he required intraoperative transfusion with 4 units of packed red blood cells and 1 unit of platelets. His temperature is 38.8°C (101.8°F), pulse is 110/min, respirations are 26/min, and blood pressure is 95/55 mm Hg. Pulse oximetry on room air shows an oxygen saturation of 85%. Cardiac examination shows normal heart sounds and no jugular venous distention. Auscultation of the lungs shows diffuse crackles bilaterally. The extremities are warm and there is no edema. Laboratory studies show a leukocyte count of 17,000/mm3 and hemoglobin concentration of 9.8 g/dL. Arterial blood gas on room air shows: pH 7.35 PaO2 41 mm Hg PaCO2 38 mm Hg HCO3- 25 mEq/L The patient is intubated and mechanical ventilation is initiated. An x-ray of the chest is shown. Transthoracic echocardiography shows a normally contracting left ventricle. Which of the following is the most likely cause of this patient's current condition?"

A 4-year-old boy is brought to the emergency department with intense crying and pain in both hands after playing with ice cubes. His mother denies any preceding trauma. The temperature is 37.0°C (98.6°F), the blood pressure is 90/55 mm Hg, and the pulse is 100/min. The physical examination shows swollen dorsa of the hands and scleral icterus. The laboratory tests show hemoglobin of 10.1 g/dL and unconjugated hyperbilirubinemia. The cellulose acetate electrophoresis shows 60% HbS and absence of HbA. Which of the following can reduce the recurrence of the patient’s current condition?

Three hours after delivery, a 1800-g (3-lb 15-oz) male newborn develops respiratory distress. He was born at 31 weeks' gestation to a 27-year-old primigravid woman. His temperature is 36.9°C (98.4F), pulse is 140/min, respirations are 69/min, and blood pressure is 60/30 mm Hg. Pulse oximetry on room air shows an oxygen saturation of 92%. Examination shows nasal flaring and expiratory grunting. An x-ray of the chest is shown. Which of the following is the most likely cause of these findings?