Sedation, pain relief, and neuromuscular blockade in the postoperative cardiac surgical patient.

Abstract

The early postoperative care of the cardiac surgical patient is a natural extension of the intraoperative care in all respects, including anesthetic management. Ideally, the effects of anesthetic drugs are extended until the patient has fully rewarmed, is hemodynamically stable, chest tube drainage is acceptable, and the patient is ready for weaning from mechanical ventilation, If the patient awakens prematurely, it is frequently associated with activation of the sympathetic nervous system manifest as tachycardia, dysrhythmias, and hypertension, which can increase myocardial oxygen consumption as well as disrupt suture lines, with the attendent morbidity of returning to the operating room for reexploration. Premature return of muscular activity can contribute to shivering as the patient rewarms, or lead to ineffective ventilation and barotrauma as the patient “fights” the ventilator. Effective control of postoperative pain improves patient comfort, facilitates respiratory care, and decreases the stress response to surgical trauma. It is imperative that these aspects of extended anesthesia care be addressed to allow for a smooth transition to the recovery phase after cardiac surgery. With the use of intravenous agents, anesthetic management in the postoperative cardiac surgical patient must be “balanced,” using specific drugs to achieve specific components of the anesthetic state: sedation, pain control, paralysis, and control of autonomic reflexes. By using drugs in this fashion, less is given, reducing the severity of side effects and allowing for quicker emergence when the drugs are discontinued. Before initiating any of these drugs, a careful assessment of the patient should be done to assure that the patient’s agitation or hypertension is not the result of inadequate ventilation, low cardiac output, sepsis, or a specific irritant that might be addressed, such as a distended bladder. Therapeutic goals should be defined for each of the drugs used so that therapy can be titrated to achieve the desired effect. Consideration must be given to drugs administered in the operating room that will have an impact on the early postoperative course. The patient who has received a high-dose narcotic anesthetic in the operating room and develops hypertension in the early postoperative period may be profoundly analgetic but awake and paralyzed; the appropriate drug would be a sedative/ hypnotic medication, not necessarily more narcotic.