Immediate extubation in cardiac surgery: evaluation using electroencephalogram

BACKGROUND AND OBJECTIVES:The current techniques of anesthesia employed in cardiac surgery leading to immediate extubation depend on adequate analgesia and titration of anesthetic drugs. We sought to determine the best possible moment of extubation, using the bispectral index of the electroencephalogram. METHOD: Twelve ASA III patients were analyzed. Seven (58.4%) were children (Group I), submitted to correction of congenital cardiac defects with ages ranging from 0 to 7 years. Five adults (Group II), with ages ranging from 30 to 75 years, underwent coronary artery bypass grafts. In Group I spinal anesthesia (L5-S1) using hyperbaric 0.5% bupivacaine (0.5mg/kg) and morphine (5µg/kg) was chosen. In Group II epidural anesthesia (T3-T4) with catheter placement plus ropivacaine (60mg) and morphine (2mg) were employed. For the induction of anesthesia fentanila (4µg/kg), muscle relaxant and propofol (to bring the bispectral index value down to 30) were utilized. General anesthesia was maintained with sevofluorane, maintaining the bispectral index value between 40 and 60. Extubation was programmed at a bispectral index value of 90. RESULTS: All patients were extubated up to one hour after the end of the surgical procedure, 91.6% of them in the operating room. All had the cognitive functions preserved without history of explicit memory or pain (adults and children who were able to speak), nor facial expression of pain (small children). Four (57%) patients in Group I and one (20%) in Group II had post-operative pruritus. Two patients (28%) in Group II had emesis. CONCLUSIONS: The results suggest that the technique employed is safe and effective, as long as the criteria for its use are strictly observed.