Anesthesia for Cardiac Surgery in Newborns with Congenital Heart Disease

Abstract

The repair of complex congenital heart disease in the neonatal period is an evolving practice that began a decade ago and has resulted in improved survival and reduced long term morbidity. Surgical techniques and anesthetic, management hare evolved to care for these uniquely challenging infants. Optimal anesthetic care requires a sound basis in normal and pathologic neonatal and dedopmental physiology, cardiac and pediatric anesthesia, and cardiopulmonary bypass management. Typical concerns in neonatal congenital heart patients include a reduced myocardial compliance and poorlydeveloped calcium transport systems. This limits stroke volume and increases calcium requirements in the post-bypass patient. Additionally, abnormal blood flow patterns are common and may be adversely affected by inotropes, inspired oxygen concentration, carbon dioxide tension, and mechanical ventilation. The impact of cardiopulmonary bypass on the neonate is extreme. Infants are commonly cooled to 15°C, their blood volume is hemodiluted by 3-4 fold, and periods of total circulatory arrest for up to 60 min are routine. The physiologic impact of these biologic extremes on organ function must be anticipated. Bypass management must assure optimal distribution of pump flow to minimize any impediment to organ protection. High dose narcotics combined with a benzodiazepine have become an integral part of anesthetic management for the neonate with congenital heart disease. Combined intravenous drug therapy provides a complete anesthetic (sedation amnesia and analgesia), hemodgnamic stability, reduced stress hormone release, and control of pulmonary vascular reactivity. Thii reduces the need for multiple inotropic therapy aimed at decreasing pulmonary vascular resistance and improving myocardial contractility. This manuscript provides an in-depth understanding of the anesthetic management of the neonate with complex congenital heart disease. The overall goal of anesthetic management is to deliver a patient to the ICU with stable hemodynamics and a clear management plan based on intraoperative observations and interventions.