A 68-year old 70 kg man with a history of hypertension and a myocardial infarction nine months ago is scheduled for resection of an abdominal aortic aneurysm. He is taking furosemide and alpha-methyldopa daily. Blood pressure is 170/100 mmHg, pulse is 90 bpm, respirations are 22, temperature is 37 degrees centigrade, and hematocrit is 45.
I. Cardiovascular assessment
1. How would you evaluate the patient's cardiac status?
2. What bedside tests could you use?
3. What laboratory tests could you use?
4. Does a history of myocardial infarction nine months prior increase his anesthetic risk?
5. What will you tell the patient?
6. Is his blood volume likely to be abnormal? Explain.
7. How would you assess it?
8. Would you place a central line preoperatively?
9. Would a pulmonary artery catheter be preferable?
10. What are the risks of pulmonary artery catheter placement?
11. Is there a need to assess the cerebral circulation?
12. How would you do this?
13. He has an asymptomatic bruit present over the left carotid artery. What is your response?
14. Is cerebral angiography indicated?
I. Monitoring requirements
1. What electrocardiogram leads will you monitor? Explain.
2. Could the Dinamap, pulse oximetry, and end-tidal CO2 take the place of an arterial catheter?
3. If an arterial catheter is used, are pulse oximetry and end-tidal oximetry necessary?
II. Choices and management of anesthesia
1. Would you use etomidate for induction? Explain.
2. What is your choice for induction? Explain your rationale.
3. What steps will you take to prevent the hypertensive response to laryngoscopy and intubation?
4. Why is this important?
5. Would halothane be a good choice for maintenance? Explain.
6. Is narcotic only anesthesia preferred? Explain.
7. Compare the circulatory effects of these drugs.
8. Relate these choices to postoperative planning.
III. Management of muscle relaxation
1. Would an atracurium infusion be your choice?
2. What would determine dose requirements?
3. How will you monitor effect?
4. When will you reverse paralysis, and how will you do it?
IV. Special features of aortic surgery
1. What are the hemodynamic effects of cross-clamping the aorta?
2. What is the relation of the level of clamping?
3. How will you assess cardiac function during this period?
4. How will you treat the increased afterload? Explain your rationale.
5. How will you attempt to prevent hypotension when the aorta is unclamped?
6. What are the mechanisms of hypotension?
7. What is the treatment?
8. How will you manage the patient's fluids?
V. Detection and management of myocardial ischemia
1. ST segment depression appears on the electrocardiogram while the aorta is cross-clamped. What further assessment would you do?
2. What therapy would you institute?
3. Do heart rate and blood pressure influence treatment?
I. Management of oliguria
1. The urine output is 10 ml in the first postoperative hour. What is your assessment?
2. What is your management?
II. Evaluation of nerve injury
1. Definite wrist and hand weakness are present in the recovery room. How will you isolate the level of injury?
2. What is the prognosis if ulnar injury has occurred?