A 31-year old 70 kg woman is scheduled for elective cesarean section because of long-standing mitral stenosis. She is near term, and her only medication is digoxin 0.25 mg bid. She desires to be awake for the case. Blood pressure is 120/85 mmHg, pulse is 90 bpm, and is irregular. Respirations are 22, and temperature is 37 degrees centigrade. Hemoglobin is 13.
I. Mitral stenosis
1. What are the cardiac and pulmonary effects of long-standing mitral stenosis?
2. What is the dysrhythmia?
3. Why does it occur?
4. Will you treat it? Why or why not?
II. Pregnancy and the cardiovascular system
1. How does pregnancy affect the cardiovascular system in this patient?
2. How would you determine if she is in early heart failure?
3. Is a higher dose of digitalis indicated? Explain.
4. What are some signs of digitalis toxicity?
Symptoms include nausea, vomiting, diarrhea, confusion, delerium, and convulsions. Cardiac signs are secondary to increased automaticity of the ventricles or junctions, and atrioventricular block.
5. What is the treatment for digitalis toxicity?
Discontinue digitalis, and correct electrolyte abnormalities. Arrhythmias may need to be corrected with lidocaine, procainamide, phenytoin, propranolol, or cardioversion. To prevent fatal arrhythmias, the lowest setting possible for countershock is used, with lidocaine to suppress further arrhythmias. In cases of urgency, digoxin-immune antibodies can be given.
4. How do you assess therapeutic effect?
5. Are blood levels helpful? Why or why not?
I. Choice of regional anesthesia
1. What are your primary anesthetic concerns in these patients?
2. Would an epidural be appropriate?
3. What advantages would an epidural offer this patient?
4. Should this patient receive a normal fluid preload prior to epidural placement?
II. Selection of drug
1. What local anesthetic would you select? Explain.
2. Are there any special hazards to the mother or infant?
3. Would you use epinephrine? Explain.
III. Cardiovascular monitoring
1. Is a pulmonary artery catheter desirable in this patient? Why or why not?
2. What information will be helpful to you?
3. How will this affect your anesthetic management?
4. What are particular hazards of pulmonary artery catheter placement in this patient?
1. The blood pressure decreases to 80/60 mmHg after block, with no change in heart rate. What are some causes of this?
2. What is the treatment?
3. After resolution of hypotension, the heart rate increases to 130 bpm. What is your management?
V. Inadequate analgesia
1. After delivery, the patient complains of pain in the abdomen. What do you do?
I. Postoperative analgesia
1. What analgesic regimen do you recommend to the obstetrician?
2. Explain your choices.
3. What are the cardiovascular effects of your choice?
1. The patient is dyspenic in the recovery room. What is your differential diagnosis?
2. What is your management?