Comparing Labetalol and Nitroglycerine on Inducing Controlled Hypotension and Intraoperative Blood Loss in Rhinoplasty: A Single-Blinded Clinical Trial.

Background: Uncontrolled bleeding during surgery is one of the main predisposing factors for failure of the surgeon and complications following rhinoplasty. The current study aimed at comparing the effects of nitroglycerine and labetalol on the induction of controlled hypotension and bleeding volume during septorhinoplasty.

Methods: The current randomized, controlled, clinical trial enrolled 60 patients candidate for septorhinoplasty at Firoozgar hospital in Tehran, Iran, in 2 equal groups receiving either 0.1 to 1 mcg/kg/minute nitroglycerine or 2 to 4 mg/minute labetalol to achieve a mean arterial blood pressure of about 60 to 65 mmHg. In case the targeted blood pressure was not achieved, isoflurane was added. Degree of bleeding was evaluated by the volume of suctioned blood and the blood remaining in surgical gauzes. Additionally, the surgeon's satisfaction with the surgical field was evaluated by a scoring system. The collected data were, then, compared between the study groups by the statistical methods.

Results: Based on the current study findings, systolic (P < 0.001), diastolic (P = 0.002), and the mean arterial blood pressures (P < 0.001) were significantly lower in the nitroglycerine group. Ninety percent of the patients in the labetalol group received isoflurane to achieve the targeted blood pressure defined as controlled hypotension. There was no significant difference between the groups regarding the volume of bleeding (P = 0.75); however, the surgeons were more satisfied with nitroglycerine than labetalol (P < 0.001).

Conclusions: It was concluded that nitroglycerine had a better effect, in comparison to labetalol, on inducing the controlled hypotension in septorhinoplasty.