[Nicardipine vs trinitrin for controlled hypotension in maxillo-facial surgery]

In this study we examined perioperative blood losses during maxillo-facial surgery comparing 2 techniques for controlled hypotension using nitroglycerin (NTG) and nicardipine (NICAR). 37 ASA I and II patients electively scheduled for rhinoseptoplasties under general anaesthesia were randomly divided into 2 groups. General anaesthesia was induced with intravenous thiopental and vecuronium following a neuroleptanalgesia consisting of fentanyl (0.053 +/- 0.004 microgram.kg-1.min-1) IV and droperidol (1.98 +/- 0.35 microgram.kg-1.min-1) IV given in bolus doses. The patients were intubated and ventilated (N2O in O2) to maintain normocarbia. Controlled hypotension to maintain a mean arterial pressure (MAP) between 50 and 55 mmHg was induced using an IV infusion of NTG 6 micrograms.kg-1.min-1 in group I and NICAR 10 micrograms.kg-1.min-1 over 10 minutes followed by an infusion at 4 mg.kg-1.min-1 for group II. Measurements of heart rate (HR), systolic blood pressure (SBP), diastolic blood pressure (DBP), MAP using an automated blood-pressure cuff and end tidal carbon dioxide (ETCO2) were recorded prior to induction (PREIND), intraoperatively (PEROP) at 15, 30, 40 and 120 minutes post-induction, and at 15, 30 and 60 minutes postoperatively (POSTOP). Blood loss, graded as minimal or frank, was assessed by the surgeon during the operative period, post-extubation and 3 days postoperatively at dressing removal. The surgeon was unaware of the randomization schedule. Student's test was applied for statistical analysis of measured variables and Fisher's test for qualitative parameters. No statistically significant differences were noted between both groups with respect to demographic data, duration of surgery and total doses of anaesthetic agents (Table I).(ABSTRACT TRUNCATED AT 250 WORDS)