Randomized clinical trial to compare the efficacy to improve the quality of surgical field of hypotensive anesthesia with clonidine or dexmedetomidine during functional endoscopic sinus surgery.

PURPOSE: Intense bleeding of the surgical field is a potential factor influencing success of functional endoscopic sinus surgery (FESS). Hypotensive anesthesia with α2 intravenous agonists reduces intraoperative bleeding, but which is the best agent is unknown. The main objective of this trial was to compare the current standard adjuvant drug for hypotensive anesthesia, clonidine, with the recently available alternative dexmedetomidine. METHODS: A randomized clinical trial compared the efficacy of clonidine and dexmedetomidine during FESS. Treatment was open label for the anesthesiologist and operating surgeon, but blind for an external evaluator who evaluated video-recorded surgeries. A Boezaart scale was assessed every 30 min during FESS until surgery completion. Main end-point was the proportion of patients with mean Boezaart scores > 2 (heavy bleeding) by external blinded evaluator. Secondary end-points included other bleeding parameters, surgery duration, hemodynamic measures and surgical complications. RESULTS: 94 patients were randomized. There were no significant differences in the proportion of patients with mean Boezaart scores > 2 in clonidine (42.6%) and dexmedetomidine (42.6%). Consistently, no differences were observed in secondary variables of bleeding, duration or complications. Small differences in mean heart rate were observed that might reflect different pharmacological profiles of the products, but are of uncertain clinical relevance. CONCLUSIONS: No significant differences were observed between clonidine and dexmedetomidine when used as anesthetic adjuvants in the reduction of surgical bleeding in FESS. A longer experience with clonidine and its lower costs suggest it may be a preferable option as an adjuvant for hypotensive anesthesia.

A randomised double blind clinical trial to compare surgical field bleeding during endoscopic sinus surgery with clonidine-based or remifentanil-based hypotensive anaesthesia.

BACKGROUND: Significant bleeding during functional endoscopic naso-sinusal surgery (FESS) impairs recognition of anatomical references and may negatively affect surgical outcome. Anaesthesia including clonidine as an adjuntive hypotensive agent may reduce intraoperative bleeding. METHODS: A randomised comparison of clonidine-based vs remifentanil-based hypotensive anaesthetic regimen was conducted in patients undergoing FESS. The main assessment was the proportion of subjects with Boezaart scores of surgical field bleeding, as blindly assessed from video recordings by a third surgeon not involved in patient care. RESULTS: A total of 47 subjects underwent FESS and were randomised to clonidine or remifentanil. A significantly lower proportion of patients in the clonidine arm had blindly-assessed Boezaart scores higher than 2, with significantly lower mean blind Boezaart scores at 60 minutes and at 120 minutes. Similar findings were reported by the operating surgeon, and when Wormald and VAS scores were used. Objective estimates of bleeding and the duration of surgery and anaesthesia did not differ between groups. CONCLUSION: The use of clonidine- based controlled hypotensive anaesthesia achieves lower surgical field bleeding during FESS.

Hypotensive anaesthesia and bleeding during endoscopic sinus surgery: an observational study.

Significant bleeding during functional endoscopic naso-sinusal surgery (FESS) impairs recognition of anatomical references and may negatively affect surgical outcome. Through their hypotensive effect, adjuvant anaesthetic agents may influence intraoperative bleeding. The present study compared intraoperative bleeding in patients undergoing FESS administered a clonidine-based anaesthetic regimen and in patients receiving other an anaesthetic combination with higher acquisition costs. Prospective observational study included 37 subjects undergoing FESS in 2011. Assessment of intraoperative bleeding was according to type of anaesthesia (clonidine vs. opioid derivatives). Patients receiving clonidine (N = 11; 29.7%) presented significantly lower surgical field bleeding scores than those receiving opioid derivatives (N = 26; 70.3%) [mean (SD) Boezaart scores 1.91 (0.53) vs. 2.92 (0.79), p < 0.0001]. The multivariate analysis including baseline characteristics and risk factors related to bleeding intensity showed that the type of drug used for controlled hypotensive anaesthesia was the best predictor of bleeding during FESS, with an OR of 0.03 for clonidine based vs. opioid based anaesthesia (p = 0.014). The anaesthetic combination including clonidine for controlled hypotensive anaesthesia produces lower levels of surgical field bleeding during FESS. Compared with other hypotensive anaesthetics, clonidine is inexpensive and associated with better surgical conditions during FESS. If confirmed through randomized clinical trials, the use of clonidine during FESS can reduce surgical time and improve surgical results through a less bloody field, resulting in lower patient morbidity and improvement of operating room resources.