Bypass grafting techniques and materials — MCQs

The surgical equipment used during a craniectomy is sterilized using pressurized steam at 121°C for 15 minutes. Reuse of these instruments can cause transmission of which of the following pathogens?

Three days after undergoing coronary artery bypass surgery, a 72-year-old man has severe right upper quadrant pain, fever, nausea, and vomiting. He has type 2 diabetes mellitus, benign prostatic hyperplasia, peripheral vascular disease, and chronic mesenteric ischemia. He had smoked one pack of cigarettes daily for 30 years but quit 10 years ago. He drinks 8 cans of beer a week. His preoperative medications include metformin, aspirin, simvastatin, and finasteride. His temperature is 38.9°C (102°F), pulse is 102/min, respirations are 18/min, and blood pressure is 110/60 mmHg. Auscultation of the lungs shows bilateral inspiratory crackles. Cardiac examination shows no murmurs, rubs or gallops. Abdominal examination shows soft abdomen with tenderness and sudden inspiratory arrest upon palpation in the right upper quadrant. There is no rebound tenderness or guarding. Laboratory studies show the following: Hemoglobin 13.1 g/dL Hematocrit 42% Leukocyte count 15,700/mm3 Segmented neutrophils 65% Bands 10% Lymphocytes 20% Monocytes 3% Eosinophils 1% Basophils 0.5% AST 40 U/L ALT 100 U/L Alkaline phosphatase 85 U/L Total bilirubin 1.5 mg/dL Direct 0.9 mg/dL Amylase 90 U/L Abdominal ultrasonography shows a distended gallbladder, thickened gallbladder wall with pericholecystic fluid, and no stones. Which of the following is the most appropriate next step in management?

In the coronary steal phenomenon, vessel dilation is paradoxically harmful because blood is diverted from ischemic areas of the myocardium. Which of the following is responsible for the coronary steal phenomenon?

A 53-year-old Asian woman comes to the physician because of a 2-month history of severe pain in her right leg while walking. She used to be able to walk a half-mile (800-m) to the grocery store but has been unable to walk 200 meters without stopping because of the pain over the past month. She can continue to walk after a break of around 5 minutes. She has hypertension, atrial fibrillation, and type 2 diabetes mellitus. She has smoked one pack of cigarettes daily for the past 32 years. Current medications include metformin, enalapril, aspirin, and warfarin. Vital signs are within normal limits. Examination shows an irregularly irregular pulse. The right lower extremity is cooler than the left lower extremity. The skin over the right leg appears shiny and dry. Femoral pulses are palpated bilaterally; pedal pulses are diminished on the right side. Which of the following is the most appropriate next step in management?

A 38-year-old man is brought to the emergency department 35 minutes after he sustained a gunshot wound to the right thigh. He has type 1 diabetes mellitus. On arrival, his pulse is 112/min, respirations are 20/min, and blood pressure is 115/69 mm Hg. Pulse oximetry on room air shows an oxygen saturation of 98%. There is an entrance wound on the anteromedial surface of the right thigh 2 cm below the inguinal ligament. There is no bruit or thrill. There is no exit wound. The pedal pulse is diminished on the right side compared to the left. The abdomen is soft and nontender. The remainder of the examination shows no abnormalities. Laboratory studies show: Hematocrit 46% Serum Urea nitrogen 24 mg/dL Glucose 160 mg/dL Creatinine 3.1 mg/dL Which of the following is the most appropriate next step in management?

A 65-year-old man comes to his primary care physician with a 6-month history of bilateral calf pain. The pain usually occurs after walking his dog a few blocks and is more severe on the right side. He has coronary artery disease, essential hypertension, and type 2 diabetes mellitus. He has smoked two packs of cigarettes daily for 43 years and drinks two alcoholic beverages a day. Current medications include metformin, lisinopril, and aspirin. He is 183 cm (5 ft 11 in) tall and weighs 113 kg (250 lb); BMI is 34.9 kg/m2. His temperature is 37°C (98.6°F), pulse is 84/min, and blood pressure is 129/72 mm Hg. Cardiac examination shows a gallop without murmurs. The legs have shiny skin with reduced hair below the knee. Femoral and popliteal pulses are palpable bilaterally. Dorsal pedal pulses are 1+ on the left and absent on the right. Ankle-brachial index (ABI) is performed in the office. ABI is 0.5 in the right leg, and 0.6 in the left leg. Which of the following is the most appropriate initial step in management?

A 72-year-old woman presents with left lower limb swelling. She first noticed her left leg was swollen about 2 weeks ago. She denies any pain and initially thought the swelling would subside on its own. Past medical history is significant for hypertension and hyperlipidemia. She is a smoker with a 35 pack-year history and an occasional drinker. She takes chlorthalidone, lisinopril, atorvastatin and a multivitamin. On physical examination, her left leg appears larger than her right with 2+ pitting edema up to her knee. She also has a few distended superficial veins along the posterior aspect of her left leg. Lower extremities have 2+ pulses bilaterally. The ultrasound of her left lower thigh and leg shows an obstructing thrombosis of the distal portion of the femoral vein. Which of the following veins serve as collateral pathways to help mitigate the consequences of this patient's condition?

A 31-year-old man presents to the Emergency Department with severe left leg pain and paresthesias 4 hours after his leg got trapped by the closing door of a bus. Initially, he had a mild pain which gradually increased to unbearable levels. Past medical history is noncontributory. In the Emergency Department, his blood pressure is 130/80 mm Hg, heart rate is 87/min, respiratory rate is 14/min, and temperature is 36.8℃ (98.2℉). On physical exam, his left calf is firm and severely tender on palpation. The patient cannot actively dorsiflex his left foot, and passive dorsiflexion is limited. Posterior tibial and dorsalis pedis pulses are 2+ in the right leg and 1+ in the left leg. Axial load does not increase the pain. Which of the following is the best next step in the management of this patient?

A 34-year-old woman is brought into the emergency department by emergency medical services after an electrical fire in her apartment. She is coughing with an O2 saturation of 98%, on 2L of nasal cannula. The patient's physical exam is significant for a burn on her right forearm that appears to be dry, white, and leathery in texture. Her pulses and sensations are intact in all extremities. The patient's vitals are HR 110, BP 110/80, T 99.2, RR 20. She has no evidence of soot in her mouth and admits to leaving the room as soon as the fire started. Which of the following is the best treatment for this patient?

A 55-year-old woman who works as a chef is brought to the hospital for evaluation of burns sustained in a kitchen accident. Physical examination reveals 3rd-degree burns over the anterior surface of the right thigh and the lower limbs, which involve approx. 11% of the total body surface area (TBSA). The skin in the burned areas is thick and painless to touch, and the dorsalis pedis pulses are palpable but weak. Initial fluid resuscitation has been started and the patient is hemodynamically stable. Which of the following is the most appropriate next step in management?