Clonidine-sufentanil versus remifentanil in endoscopic sinus surgery

Patients are randomized in two group using minimization. For both groups patients are positioned 15 degrees reverse trendelenburg. The trachea is intubated. Mechanical ventilation parameters are set to Peep: 3cmH2O, Respiratory rate: 12, Tidal volume: 6-8ml/kg. These parameters are then adjusted for a target EtCO2 of 30-35mmHg Cata group Anesthesia induction: 1. Lidocaine 1mg/kg I.V. bolus 2. Sufentanil 0.15mcg/kg I.V. bolus 3. Intravenous Propofol titrated to loss of eye lid reflex 4. Rocuronium 0.3mg/kg I.V. bolus 5. Clonidine 2mcg/kg slow I.V. bolus (for 5 min) Anesthesia Maintenance: sevoflurane 1 MAC (inhalation) 15 min from the start of surgery, the Fromme score is assessed, if it's higher than 4 and the mean arterial pressure (MAP) is greater than 65mmHg and the last sufentanil injection occurred more than 45min ago then a new bolus of sufentanil 0.15mcg/kg is injected I.V. If the last sufentanil injection occurred within the last 45 minutes then a new bolus of clonidine 1mcg/kg I.V. is slowly injected (for five minutes) to a maximum total clonidine dose of 3mcg/kg. If, during the procedure, the surgeon complaints about bleeding and the MAP is greater than 65mmHg and the last sufentanil injection occurred more than 45min ago then a new bolus of sufentanil 0.15mcg/kg is injected I.V. If the last sufentanil injection occurred less than 45 min ago then a new bolus of clonidine 1mcg/kg I.V. is slowly injected (for five minutes) to a maximum total clonidine dose of 3mcg/kg If,during the procedure, the patient’s MAP fall below 55mmHg then ephedrine is titrated intravenously by 3mg for a MAP greater than 55mmHg. In all cases, if ephedrine fails to raise the MAP the patient should receive neosynephrine or norepinephrine and leave the study. If the surgeon is unable to perform the procedure due to bleeding despite a well followed protocol, the patient leaves the study.