Total intravenous anaesthesia with gamma-hydroxybutyrate (GHB) and sufentanil in patients undergoing coronary artery bypass graft surgery: a comparison in patients with unimpaired and impaired left ventricular function

Abstract

The haemodynamic effects of anaesthesia with gamma-hydroxybutyrate (GHB)/sufentanil for elective coronary artery bypass grafting (CABG) were investigated and compared in patients with unimpaired left ventricular function (ejection fraction ≥45%, left ventricular end diastolic pressure ≤16 mmHg) and patients with impaired left ventricular function. In 38 consecutive patients scheduled for CABG (21 with unimpaired and 17 with impaired left ventricular function), anaesthesia was induced with etomidate, sufentanil and pancuronium. After tracheal intubation, the lungs were normoventilated (end tidal Pco₂ 4.9−5.6 kPa) with an oxygen-air mixture (Fio₂ 0.5). Total intravenous anaesthesia was maintained with GHB (20 mg kg⁻¹ h⁻¹after a ‘priming dose’ of 40 mg kg⁻¹) and sufentanil (2 μg kg⁻¹ h⁻¹). Haemodynamic measurements were made after induction of anaesthesia and at various times in the prebypass period. Patients in both groups showed similar haemodynamic trends. Mean arterial pressure showed a maximum reduction of 10%, whereas heart rate and right- and left-sided filling pressures remained unchanged within the groups after the induction of anaesthesia. Cardiac index remained unchanged in both groups, although values differed between the groups. A total of 14 out of 21 patients (67%) with unimpaired and 10 out of 17 patients (59%) with impaired ventricular function required supplementary administration of opioids to control temporary hypertension after sternotomy. No episodes of myocardial ischaemia were detected during the study period using ST segment analysis (leads II and V₅). The results of this study suggest that GHB provides adequate haemodynamic conditions in the prebypass period and may be a suitable agent for TIVA also in patients with impaired left ventricular function undergoing CABG.