Controlled hypotensive anesthesia for functional endoscopicsinus surgery: a new protocol for dexmedetomidineadministration

ObjectiveThe aim of the study was to conduct a comparative investigation to evaluate the efficacy of dexmedetomidine as a hypotensive agent by presenting a new protocol for administration versus the conventional protocol in functional endoscopic sinus surgery (FESS). Materials and methodsForty patients of ASA grade I–II scheduled for FESS were equally randomly assigned to twogroups: the DEX group and the DEXnew group. The DEX group received dexmedetomidine at 1 ❍g/kg diluted in 10 ml normal saline 10 min before surgical incision (SI), followed by intravenous infusion of dexmedetomidine at 0.2–0.7 ❍g/kg/h according to the hemodynamic status and BIS. The DEXnew group received dexmedetomidine at 1 ❍g/kg diluted in 10 ml normal saline 10 min before SI, followed by intravenous top-up doses of 1/4 of the loading dose over 2 min in the form of intravenous shots to maintain MAP between 65 and 70 mmHg. Mean arterial blood pressure (MAP), heart rate (HR), cortisol level, fentanyl consumption, emergence time, and recovery from anesthesia (modified Aldrete score) were recorded. The sedation score and time to first analgesic request were recorded.ResultsIn the DEX group there was a statistically significant decrease in MAP at 30, 45, 60, and 90 min after SI in comparison with preoperative MAP. In the DEXnew group also there was a statistically significant decrease in MAP at 30, 45, 60, and 90 min after SI in comparison with preoperative MAP. There was a nonsignificant difference as regards intraoperative fentanyl and postoperative pethidine consumption between the two groups. There was a significant decrease in the total amount of consumed dexmedetomidine in the DEXnew group (118 ± 14.6 ❍g) compared with the DEX group (189.4 ± 22.7 ❍g). Emergence time was significantly shorter in the DEXnew group (5.34±1.83 min) compared with the DEX group (9.45 ± 2.02 min).ConclusionThis modified protocol of dexmedetomidine administration is safe and effective for controlled hypotension, providing an ideal surgical field during FESS. Compared with the conventional protocol of dexmedetomidine administration, the modified protocol offers fewer side effects; significant decrease in dexmedetomidine consumption, faster emergence time, and bettermodified Aldrete scores.