Comparación de dos alfa-2 agonistas intravenosos como adyuvantes anestésicos en cirugía endoscópica nasosinusal. Ensayo clínico aleatorizado de clonidina versus dexmedetomidina

Abstract

NTRODUCTION: The presence of intense bleeding in the surgical field is a critical factor in the potential success or failure in nasosinusal endoscopic surgery (FESS). Anesthesia that includes α₂ intravenous agonists as anesthetic adjuvants may reduce intraoperative bleeding. The present project was aimed to compare two of the anesthetic regimens based on α₂ agonist hypotensors (clonidine / dexmedetomidine) in FESS. OBJECTIVES: Primary objective: To compare surgical field bleeding during FESS, in patients receiving hypotensive anesthetic treatment based on clonidine or dexmedetomidine by means of a modified Boezaart scale, evaluated by an external evaluator blind to the identity of the treatments administered. Secondary objectives: To systematize the available information on the efficacy of α₂ agonist drugs as anesthetic adjuvants in FESS. To evaluate the secondary objectives of the clinical trial including: to compare surgical field during FESS by estimating the amount of blood aspirated during the intervention, surgical field during FESS by estimating the intensity of bleeding during surgery by subjective scales (visual analog scale- VAS- and Boezaart scale) evaluated by the surgeon, and by an external evaluator blinded to the identity of the treatments administered, the duration of the FESS and the anesthesia, peroperative and postoperative complications (hemodynamic, severe bleeding, hematoma or orbital emphysema, CSF leak) and the time to discharge of the patient after FESS, in patients receiving hypotensive anesthetic treatment based on clonidine or dexmedetomidine. METHODS: 1. Systematic review of published clinical trials comparing the use of α₂ agonists to improve the surgical field in FESS. 2. Randomized clinical trial to compare the efficacy of hypotensive anesthesia with clonidine or dexmedetomidine during FESS (open-label study for the anesthesiologist and blind for the external evaluator who evaluated video-recorded surgeries). RESULTS: 1.- Systematic review: Thirteen clinical trials have been analyzed, concluding that α₂ agonists improve the visibility of the surgical field, without reducing the duration of surgery and without evidence on reduction of complications. 2.- Clinical trial: In the analysis of the main variable of the study, the proportion of patients who had an average value of the Boezaart scale> 2 (heavy bleeding) by the external evaluator who assessed bleeding in the surgical field through video recordings was not different for clonidine -42.6% (n = 20/47)- and dexmedetomidine -42.6% (n = 20/47)-. No differences were observed in the secondary variables of bleeding, duration or complications. Differences were observed in the mean values ​​of the heart rate, reflecting possible differences in the pharmacological profile of the products of uncertain clinical relevance. CONCLUSIONS: The use of α₂ adrenergic agonists as anesthetic adjuvants in the FESS significantly reduces intraoperative bleeding, improving the visibility of the surgical field. We have not found significant differences between clonidine and dexmedetomidine used as anesthetic adjuvants in the reduction of su

Date of Award	25 Oct 2018
Original language	Spanish
Supervisor	Caridad Pontes Garcia (Director), Manuel Bernal-Sprekelsen (Director) & Alda Cardesin Revilla (Director)