Máscara laríngea como coadjuvante da anestesia peridural contínua para a realizaçåo de transplante renal / Use of laryngeal mask airway during continuous epidural anesthesia for renal transplant

RESUMO

Background and objective - The majority of renal transplants at our Institution has been performed under continuous epidural anesthesia. However, 12 years of experience showed that intermitent sedation with intravenous agents determined frequent tespiratory complications and intraoperative rupture of the renal anastomosis duo to cough, hicups and agitation 1. With the purpose of presenting an alternative technique, the laryngeal mask airway (LMA) was used to maintain clear upper airways during continuous espidural anesthesia. The results were compaved to those obtained from a retrospective study of renal transplants performed under epidural anesthesia and intermittent sedation with intravenous agents. Methods - Twenty-four patients undergoing elective renal transplant received 0.1mg.Kh-1 of midazolam as premedication. The continuous epidural anesthesia was performed with 0.5 per cent bupivacaine eith epinephrine, up to 3mg.Kg-1, aiming at a sensory block level of T4-6. The LMA was inserted following a bolus intravenous injection of 2.5mg.Kg-1 of propofol and 0.1mg.Kg-1 of lidocaine. The spontaneous ventilation was mantained with isoflurane in O2+N2O(12). Monitoring included pulse oximetry, capnograph, CVP, ECG and noninvasive blood pressure. The data were compared to those obtained from a retrospective study of 278 patients submitted to renal tranplant in the last 12 years (24.3/year), under epidural anesthesia and intermittend sedation with intravenous agents. Results - In the prospectively studied group, 23 out of 24 patients showed uneventful intraoperative course, the results being superior to those observed in the retrospectively studied group. One patient developed convulsions after the injection of propofol and again after a top up dose of bupivacaine, followed by cardiovascular collapse which was succesfuly managed. Conclusions - The LMA seemed appropriate for the situation, allowing the patient be maintained under spontaneous ventilation with clear airways and wothout agitation. The convulsions seemed not to be related to the use of the LMA. According to the results, the current technique showed to be superior as compared to the one fomerly used at our Institution