[A nicardipine-isoflurane combination in the microsurgery of the middle ear]. / Association nicardipine-isoflurane dans la microchirurgie de l'oreille moyenne.

Middle ear microsurgery requires a bloodless operative field, achieved through deliberate hypotension techniques. The present work was designed to analyze the quality of the deliberate hypotension induced by the combination of isoflurane with nicardipine, an injectable calcium channel blocker. Eleven patients, ASA I, 10 minutes after induction of anaesthesia, received nicardipine as a bolus of 25 mg renewed every five minutes (maximum 4) and as a perfusion (5 mg/hour). The bloodless operative field was excellent in all cases with a 29.7% drop in arterial blood pressure after 15 minutes (heart rate: +22.3% after 25 min); values then remained stable until nicardipine was stopped; then hemodynamic data returned to the preanaesthetic values in 66 +/- 56 minutes. No side effect was registered. As a conclusion, deliberate hypotension induced by isoflurane--nicardipine combination provides good conditions for middle ear microsurgery.