Pre-operative Phentolamine Vs Intraoperative Esmolol Efficacy for Hypotensive Anesthesia in Functional Endoscopic Sinus Surgery

Functional endoscopic sinus surgery (FESS) is becoming a widely performed operation. Its introduction associated with enhanced illumination and visualization has dramatically improved surgical dissection. However major complications have been reported for FESS under general anesthesia resulting from impaired visibility due to excessive bleeding.

Esmolol is a selective β1-adrenoreceptor antagonist involved in the control of heart rate (HR), contractility, and atrioventricular conduction. Currently, the use of β-blockade for hemodynamic stability and cardiac protection is well accepted among anesthesia providers, but recently, researchers have begun to explore the perioperative use of esmolol as an anesthetic adjunct. Esmolol was found to produce desired hypotension without tachycardia and improved surgical condition by reducing operative field bleeding.

Phentolamine is well known selective α1-blocker which is used to treat hypertensive emergency by producing profound vasodilatation. The reduced blood pressure will induce response in the arterial baroreceptors leading to release of adrenal catecholamine, eventually inducing reflex tachycardia. The reflex tachycardia is less profound in the selective α1-blockers such as phentolamine. Phentolamine is a short acting drug with a context sensitive half-life of 15 minutes which makes it ideal for rapid control of blood pressure.