Avaliaçåo do risco de complicaçöes em duas técnicas de hipotensåo controlada em cirurgia ortognática / Risk evaluation of two techniques of controlled hypotension in ortognathic surgery

RESUMO

Background and Objectives - Some surgical procedures require a reduction of bleeding in order to obtain a better exposure of the surgical field. Controlled hypotension is the most used technique for this purpose, but the risk-benefit of such technique should always be considered for each patient, This study was propesed in order to analyse the complications associated with two anesthetic techniques of controlled hypotension used for ortognathic surgery. Methods - Thirty-two patients aged 14 to 53 years, submitted to ortognathic surgery, were studied. Patients were randomised into two-groups in which the variable was the halogenated agent used (halothane or isoflurane). The studied parameters were: BP, HR, CVP, ECG, diuresis, temperature and pulse oxymetry. Measurements were obtained at the following moments: pre-induction, 2 and 4 hours intraoperativelly. Results - Complications were more frequent with halothane, which determined a higher incidence of arrythmias, hypotension and vasopressor consumption. In this group, 60 per cent of the patients received vasopressors and 20 per cent developed junctional rhythm. Conclusion - The technique which used isoflurane determined less complications and proved to be safer than the one in which halothane was used.