Sufentanil em infusåo venosa contínua para cirurgias abdominais / Continuous intravenous infusion of sufentanil for abdomianal surgery

RESUMO

Background and Objectives - Sufentanil is 5 to 10 times more potent than fentanyl and this property parallels its greateraffinity for opioid receptors. The aims of thisnon-comparative study were to determine the dose requirements of sufentanil used as part of a balanced technique and to evaluate the cardiovascular consequences and the recovery from anesthesia following its use. Methods - Fifty adult ASA physical status I-II patients, aged 41.02 +- 11.45 years undergoing elective intra-abdominal surgeries were studied. Anesthesia was induced with midazolam 0.2 mg.Kg-1 and sufentanil 3.0 ug.Kg-1, followed by pancuronium and tracheal intubation. Patients received N2O/O2 (50/50 per cenmt) and were maintained under mechanical controlled ventilation in a rebreathing circuit with CO2 absorbant. Sufentanil infusion rate was adjusted in order to avoidsigns of light anesthesia. Both the opioid and N2O were discontinued 10 min before the presumed end surgery. Using non-invasive methods, systolic (SAP), diastolic (DAP) and mean (MAP) arterial pressure, heart rate (HR) and oxygen saturation (SpO2) were monitored throughout the procedure. Total consumption of sufentanil and infusion rate requirements were evaluated, as well as duration and quality anesthesia recovery, residual analgesia and perioperative complications. Results - The mean duration of the procedures was 162.42+-69.16 min, the mean total dose of sufentanil was 6.78+-2.29 ug.Kg-1 and the mean infusion rate was 0.024+-0.06 ug.Kg-1. The mean time for recovery to stage IV (well oriented in time and space) was 39.88+-13.95 min. Forty patients (80 per cent) required naloxone to antagonize respiratory depression 30 minafter the discontinuation of opioid infusion. Despiste the reduction in SAP, DAP and MAP following induction, tracheal intubation and surgical incision, there was good cardiovascular stability. Residual analgesia lasting more than 6 hours after discontinuation of sufentanil was observed in 66 per cent of the patients. Conclusions - The technique provides good anesthesia for intra-abdominal surgeries. In order to avoid light anesthesia, sufentanil infusion rate should be titrated for each patient. The high incidence of respiratory depression in the immediate postoperative period requires special observation of these patients in the recovery room