Cardiovascular Responses of General Anesthesia with Nalbuphine - Diazepam - O2 - 1/2 MAC Halothane and Awareness during Operation for Adult Open Heart Surgery

Moon, Hyun Soo; Kwon, Jin Hyung; Lee, Sang Min

Abstract

Recently, nalbuphine has been used for reversal of opioid indueed respiratory depression. Because of its structural chsracter, nalbuphine has been known as a better nareotic antagonist with keeping analgesic potency and without considerable cardiovascular responses. Some investigators reported nalbuphine can decrease minimum alveolar concentration(MAC) of major inhalation anesthetic agents and can be a intravenous anesthetic adjuvant but can accompany several adverse reactions such as hypertension and tachycardia etc. To evaluate the eligibility and efficacy of nalbuphine as a intravenous narcotic adjuvant for cardiac anesthesia, we selected 24 adult cardiac patients and divided them into 3 groups. Valvular surgerys were performed for group I patients, aorto-coronary-bypass surgerys(CABG) for group II and correction of congenital heart disease for group III, respectively, All patients were inducted general anesthesia with 0.3 mg/kg nalbuphine+0.1 mg/kg diazepam+2 mg/kg thio- pental sodium and maintained with intermittent injection of 0.3-0.5 mg/kg nalbuphine and O.l mg/kg diazepam just before the time of most stressful surgical stimuli with 1/2 MAC halothane inhalation under vecuronization for muscle relaxation. We measured heart rate(HR), systolic blood pressure(BP), central venous pressure(CVP) at pre-induction as a control data, and just after endotracheal intubation, skin incision, sternotomy, and skin closure respectively to compare basic cardiovascular responses of patients at surgical stimuli with control data. We also checked recovery time of consciousness and presence of awareness during operation. The results were as follows: 1) Significant HR changes occurred in group I at just after intubation time from 104+/-18.6 to 134+/-25.9 and in group II from 83+/-10.5 to 115+/-32.3 respectively. 2) There were few significant changes of systolic blood pressure during anesthesia of all groups except just after intubation in group II from 135+/-32.8 torr to 168+/-37.9 torr.3) A significant CVP decrease occurred only in group I at the time of skin closure from 13+/-3. 5 cmHO to 10+/-3.8 cmH2O because of operative correction of tricuspid regurgitation of group I patients rather than anesthesia effects. 4) Recovery of consciousness needed average 1 hr 30 mins in group I and 2 hr 45 mins in group II. None of patients complained awareness during operations. Above results demonstrate that Nalbuphine-Diazepam-O2-1/2 MAC Halothane can be a anesthetic method for open heart surgery without any significant cardiovascular responses at surgical and anesthetic stimuli except intubation stimulus, but for more evaluation study of Nalbuphine-Diazepam-O2 Anesthesia will be needed.