A 40-year old 50 kg woman with well-controlled myasthenia gravis is scheduled for a radical hysterectomy for cancer. She has completed a course of chemotherapy and radiation therapy. She is currently on Mestinin (pyridostigmine) 60 mg qid. Blood pressure is 105/95 mmHg, pulse is 96 bpm, and hematocrit is 30 gm/dl.
I. Evaluation of myasthenia
1. What is the etiology of myasthenia?
2. What is the treatment for myasthenia?
3. How does pyridostigmine work?
4. What is the difference between pyridostigmine and physostigmine?
5. What are signs of cholinergic crisis?
6. What is the management?
II. Assessment of respiration
1. Are pulmonary function tests indicated? Why or why not?
2. What are your expected findings?
3. How does this influence your treatment?
I. Selection and management of anesthesia
1. What anesthetic technique will you use?
2. What induction agents will you use?
3. How will you intubate the patient? Explain.
4. Which maintenance agent will you use? Explain your choice.
5. Are neuromuscular properties important? Explain.
6. The surgeon requests deliberate hypotension. How does this affect your anesthetic choice? 7. What are the pros and cons of myocardial depression vs vasodilation?
II. Provision of relaxation
1. Do you expect a problem with using succinylcholine in this patient? Explain.
2. Can vecuronium or atracurium be used safely for relaxation? Explain.
3. Is a nerve stimulator needed? Why or why not?
4. What is the significance of stimulating with the stimulator?
III. Management of arrhythmias
1. The patient develops premature atrial contractions. What is the etiology?
2. What is the significance?
3. Should they be treated?
4. What is your treatment?
5. Atrial fibrillation occurs. What is your treatment?
IV. Evaluation of hematuria and oliguria
1. For two hours postoperatively, the patient has only 50 ml of urine. What is your differential diagnosis?
2. The urine sodium is 8 mEq/l, and is pink. What is your differential diagnosis?
3. How do you establish a diagnosis?
4. What is the significance of this occurrence?
5. Would you order other tests?
6. What is your treatment?
I. Management of ventilation
1. What are your criteria for extubation?
2. Describe the rationale behind each criterion.
3. Vital capacity is 400 ml with the endotracheal tube in place while the patient is spontaneously breathing. pH=7.42, paCO2=40mmHg, and paO2=100mmHg on 30% FIO2. How would you proceed?
II. Management of postoperative pain
1. The surgeon suggests continuous epidural for pain relief. Do you agree?
2. Describe the hazards of epidural narcotics vs local anesthetics.
3. What protocol do you use?
III. Evaluation of postoperative nerve injury
1. On postoperative day one, the patient complains of numbness and weakness of the right leg. What is your differential diagnosis?
2. What are the signs of obturator nerve damage?
3. What are the signs of femoral nerve damage?
4. What are your recommendations?