Anesthesia for Mitral Commissurotomy
THE margin of safety during anesthesia for mitral commissurotomy is extremely narrow. In most patients undergoing this operation, pathologic changes in the cardio-respiratory system have resulted in pulmonary hypertension. The major pulmonary arteries show atheromatous changes; the small vessels show various changes ranging from simple muscular hypertrophy to hyalinization and fibrosis. Unless these serious anatomicophysiologic changes are understood, anesthetic agents might cause death before valvulotomy is accomplished.
All of the ability and skill of the anesthesiologist is required to administer anesthesia successfully to one of these patients. Anoxia is prevented by supplying the alveoli with an oxygen-rich atmosphere; blood pressure is maintained and adequate respiratory excursions guaranteed. Most important of all the functions of the anesthesiologist are: determination and maintenance of the optimum plane of anesthesia for successful completion of mitral commissurotomy; and the use of the least amount of anesthetic agents and technic as possible. When deep levels are reached, the strain on the cardiac patient is too great for his compensatory ability; serious arrhythmias appear or a progressive bradycardia threatens cardiac arrest. Light anesthesia is characterized by its lack of influence upon the cardiac mechanism.
Adequate oxygenation must be guaranteed in all anesthetized patients. During intracardiac procedures, an already deficient oxygen saturation caused by anatomic changes of the disease itself is partially remedied by filling the alveoli with an oxygen-rich mixture. Full expansion of the lungs not only insures delivery of these mixtures but also accomplishes the removal of any carbon dioxide which may have accumulated. Distention of. . .