Postoperative respiratory care
After a completed operation, we receive patients on whom controlled ventilation has usually been performed for several hours during cardiac surgery. Hence, immediately postoperatively we must assess a respirator patient. The first question that I pose postoperatively is not, “Can the patient be extubated?” but rather the questions in the following order: (1) Can the patient be weaned? (2) Was the weaning attempt successful? and (3) Can the patient be extubated?
Immediate postoperative artificial respiration through the endotracheal tube following cardiac surgery with extracorporeal circulation seems purposeful for many reasons.
Preoperative pulmonary alterations
Respiratory insufficiency following cardiac surgery is modified in that pulmonary changes have been already present preoperatively. These preoperative pulmonary conditions can be divided into the following groups: (1) chronic pulmonary congestion, (2) increased pulmonary blood perfusion with pulmonary hypertension, and (3) decreased pulmonary blood perfusion.
Extrapulmonary factors influencing pulmonary function
Postoperative respiratory insufficiency may be caused by extrapulmonary factors. These include depression of the respiratory center as a result of the aftereffect of anesthetic drugs or the residual effect of muscle relaxants. Cerebral complications as well as neuropsychological disorders following extracorporeal circulation may be severe enough to necessitate immobilization of the patient by means of artificial respiration.
Respiratory insufficiency as a secondary result of cardiac insufficiency
Primary heart failure often severely disturbs the gaseous interchange in the lungs leading secondarily to breakdown of pulmonary function.
Basically, we differentiate two types of effects of left ventricular failure on pulmonary function: either the increase in left atrial pressure leads . . .