The efficacy of Labetalol versus Nitroglycerin for induction of controlled hypotension during sinus endoscopic surgery. A prospective, double-blind and randomized study.

OBJECTIVE: To assess the efficacy of labetalol versus nitroglycerin for induction of controlled hypotension during sinus endoscopic surgery.

DESIGN: A prospective, double-blind and randomized study.

SETTING: Carried out in operating room in university hospital.

PATIENTS: 60 patients of both sexes, American Society of Anesthesiologists (ASA) physical status I and II, age range from 20 to 60years; scheduled for elective sinus endoscopic surgery under general anesthesia (GA).

INTERVENTIONS: Patients were divided into two groups (30 each). NTG group received nitroglycerin infusion at a dose of 2-5μg/kg/min, LAB group received labetalol infusion at a dose of 0.5-2mg/min.

MEASUREMENTS: Surgical condition was assessed by surgeon using average category scale (ACS) of 0-5, a value of 2-3 being ideal. In both groups mean arterial blood pressure (MAP) was gradually reduced till the ideal ACS for assessment of surgical condition, the target of ACS was 2-3 or lower.

RESULTS: Both studied drugs achieved desired hypotension and improved visualization of surgical field by decreasing bleeding in the surgical site, but ideal surgical conditions were created at mild hypotension (MAP 70-75) in LAB group while same conditions were created at MAP of 65-69mmHg in NTG group. Mean heart rate (HR) was significantly higher in NTG group as compared to LAB group. Blood loss decreased significantly in LAB group.

CONCLUSION: Both labetalol and NTG are effective and safe drugs for induction of controlled hypotension during sinus endoscopic surgery. While, labetalol was better as it offered optimum operative condition with mild decrease in blood pressure, decreased surgical bleeding and less tachycardia during the surgery.