1. A 65 year old man with a 70 pack-year smoking history undergoes an elective 5-vessel and does well post-operatively for 48 hours. He then develops atrial fibrillation with chest pain, hypotension, and depressed consciousness. He is cardioverted out of atrial fibrillation and his mental status improves. Two hours later is he found slumped over in his bed and is difficult to arouse. He is tachypnic and diaphoretic. His pulse is 110 (and regular), blood pressure 160/90mm/Hg, temperature 101.2° (earlobe). Pulse oximetry reveals an oxygen saturation of 89% on 4 Liter/minute nasal canula O2. He cannot move his left hand and the left side of his mouth. Chest exam reveals right lower lobe "wet" crackles. An arterial blood gas on 4 Liter/minute nasal canula returns with a pO2 of 58mm, pCO2 24mm, pH 7.49. A chest radiograph shows a new right lower lobe consolidation which was not present on the previous hospital day. An ECG shows sinus tachycardia, mild PR depression throughout, diffuse non-specific ST/T wave abnormalities, and an old incomplete right bundle branch block. Renal function is stable and urine output is good. The most likely series of events was [1]:

   
   A. Post-CABG cerebral embolism (stroke) followed by aspiration
   B. Cerebral embolism (stroke) due to immobility followed by aspiration
   C. Aspiration pneumonia precipitating atrial fibrillation, leading to stroke
   D. Metabolic alkalosis precipitating atrial fibrillation, stroke, and aspiration
   E. Dressler's Syndrome precipitating atrial fibrillation, stroke and aspiration

   
   

2. The acid-base disturbance present in this patient is [2]:

   
   A. Pure respiratory alkalosis
   B. Pure metabolic alkalosis
   C. Respiratory alkalosis with metabolic compensation
   D. Metabolic acidosis with respiratory compensation
   E. Metabolic alkalosis and repiratory alkalosis

   
   

3. The most appropriate antibiotic therapy for this hospitalized patient with aspiration pneumonia is [3]:
   

   
   A. Cefuroxime alone
   B. Cefuroxime + Erythromycin
   C. Clindamycin + Ceftazidime
   D. Nafcillin + Gentamicin
   E. Gentamicin + Metronidazole

   
   

4. Over the next 12 hours, the patient's respiratory status deteriorates. Lung exam reveals diffuse rales throughout all lung fields. A pulmonary artery catheter reveals a right atrial pressure of 12mmHg, right ventricular pressure 35/12mmHg, pulmonary artery 35/23mmHg, pulmonary capillary wedge pressure 20mmHg. His systemic blood pressure is 110/60mm Hg and he is on no inotropic agents. On 50% FiO2 non-rebreathing mask, the arterial blood gas shows a pO2 of 90mm, pCO2 32mm, pH 7.32. The most likely explanation for the current condition of this patients is [4]:
   

   
   A. Adult Respiratory Distress Syndrome (ARDS)
   B. ARDS with congestive heart failure (cardiogenic insufficiency)
   C. Congestive heart failure alone
   D. Pneumonia with hypoxemia
   E. Acute mitral regurgitation

   
   

5. A 35 year old woman is brought to the emergency room complaining of dizziness and visual problems after being rescued from a smoke-filled room in a burning house. She is tachypnic (repiratory rate 30/minute) and her lips are cherry red. She is coughing intermittantly. Further examination of her oropharnynx reveals no burns. She appears irritable. A pulse oximiter reads 94% saturation on room air oxygen.Which of following is most likely NOT true [5] ?

   
   A. The patient could not have moderately severe carbon monoxide poisoning
   B. The pulse oximeter reading is accurate
   C. An arterial blood gas would show mixed respiratory alkalosis and metabolic acidosis
   D. Nausea and vomiting are common symptoms of carbon monoxide poisoning
   E. Fetal hemoglobin has a higher affinity for carbon monoxide than adult hemoglobin

   
   

6. A cardiac monitor reveals frequent premature ventricular complexes superimposed on a sinus tachycardia (rate 124 per minute) with mild diffuse ST depressions. The patient's level of consciousness is waxing and waning. The most appropriate next step is [6]:

   
   A. Administer 50% oxygen by face mask and admit patient to critical care unit
   B. Administer 100% oxygen by non-rebreathing face mask and monitor the patient closely for signs of airway edema
   C. Administer lidocaine, 2µg/kg/min intravenously and monitor the patient closely for signs of airway edema
   D. Administer 100% oxygen by non-rebreathing mask, contact a hyperbaric oxygen unit, andmonitor the patient closely for signs of airway edema
   E. Emergently intubate the patient and administer 100% oxygen

   
   

7. A 67 year old man with a history of post-myocardial infarction dilated cardiomyopathy (ejection fraction ~25%) and atrial fibrillation is brought in by his family after passing out over breakfast. He denies chest pain, but is nauseated, diaphoretic and weak. He has been nauseated for about 4 days, and attributed this to increasingly blurry vision (he believes he has a cataract). His pulse is 40 bpm, blood pressure 160/90 mmHg in the right arm, temperature 97.2° tympanic, respiratory rate 28 per minute. An electrocardiogram shows atrial flutter (rate 160 per minute atrial) with 4:1 AV-block. He takes warfarin 2mg/day, digoxin (digitalis) 0.25mg/day, enalapril (Vasotect®) 10mg twice a day, and pravastatin (Pravachol®) 20mg/day. The enalapril was started 2 weeks ago to replace nifedipine. At that time, the patient was in atrial fibrillation with a rate of 80-90bpm, digoxin level was in the normal range, the blood urea nitrogen (BUN) was 40mg/dL (normal <18mg/dL) and the creatinine was 1.7mg/dL (normal <1.3mg/dL). The creatinine on admission is found to be 3.2mg/dL; BUN is pending.The most likely explanation for the patient's syncope is [7]:

   
   A. ACE Inhibitor induced syncope
   B. Progressive cardiac conduction system disease with bradycardia
   C. Cebrovascular accident
   D. Uremic induced bradycardia
   E. Digitalis (digoxin) poisoning with bradycardia

   
   

8. Indications for the use of antibodies to digitalis (digoxin) include all but which ONE of the following [8] ?

   
   A. Shock or Cardiac Arrest or Ventricular Tachycardia
   B. AV Block or Sinus Bradycardia unresponsive to atropine
   C. Digoxin Level >10ng/mL or ingestion of >10mg digoxin
   D. Hyperkalemia with any other signs of digoxin toxicity
   E. Severe nausea and vomiting

   
   

9. All of the following therapies may be used to reduce intracranial pressure EXCEPT [9]:

   
   A. Hyperventilation
   B. Acetazolamide (Diamox®): blocks excretion of bicarbonate (HCO3-)
   C. Nitroprusside
   D. Maintenance of normal or hypothermic temperature (ie. treat fevers)
   E. Glucocorticoids

   
   

10. Which ONE of the following is effective in improving outcome in spinal cord injuries [10] ?

    
    A. Naloxone hydrochloride (Narcan®)
    B. Pentoxyphylline (Trental®)
    C. Phenytoin (Dilantin)
    D. Pegorgotein
    E. Glucocorticoids - high doses used within 24 hours of the injury

    
    

Answers

1. E
2. A
3. C
4. B
5. B (Methemoglobin in the blood is read incorrectly as oxyhemoglobin by the pulse oximeter.)
6. D (The arrhythmias and level of consciousness are indications for hyperbaric oxygen.)
7. E
8. E
9. C
10. A (Glucocorticoids effective only within 8 hours of injury.)