Efficacy of Esmolol Versus Nitroglycerin in Maintaining the Quality of Bloodless Surgical Fields in Middle Ear Surgery: A Randomized Controlled Trial

Background Middle ear surgeries such as tympanoplasty and mastoidectomy demand a bloodless operative field because even minimal bleeding under high-magnification microscopy can significantly impair visualization, prolong operative time, and increase the risk of iatrogenic injury. Controlled hypotension is widely accepted for minimizing bleeding; however, the optimal pharmacological agent in otological surgery remains debated. Esmolol, a cardio-selective beta-1 blocker, reduces heart rate (HR) and cardiac output without vasodilation, whereas nitroglycerin (NTG) frequently induces reflex tachycardia that may paradoxically increase microvascular bleeding. Objective To compare the efficacy of intravenous esmolol versus nitroglycerin in achieving and maintaining a bloodless surgical field in middle ear surgery under general anesthesia, with primary evaluation of Surgical Site Comfort (SSC) score, surgical and microscope duration, and secondary evaluation of intraoperative HR, mean arterial pressure (MAP), pre and post op hemodynamic variables. Methods A prospective, randomized, double-blind, parallel-group controlled trial was conducted at Kalinga Institute of Medical Sciences, Bhubaneswar. One hundred ASA I-II adult patients undergoing elective middle ear surgery were randomized to esmolol (Group A, n=50) or nitroglycerin (Group B, n=50) targeting MAP 60-65 mmHg. The surgical field was assessed using the six-point Fromme-Boezaart scale every five minutes. HR and MAP were recorded throughout. SSC scores were analyzed using the Mann-Whitney U test; continuous variables by Welch’s independent t-test. Results Both groups were demographically comparable. SSC scores were significantly lower (better field) in the esmolol group from 5 minutes onward (p < 0.001 at all subsequent time points). Group A reached SSC score 1 (slight bleeding, not a surgical nuisance) by 60 minutes; Group B never reached this level. Surgical duration was shorter in Group A (79.9 ± 15.7 vs. 103.5 ± 15.3 min, p < 0.0001), as was microscope use time (48.2 ± 10.1 vs. 75.7 ± 14.8 min, p < 0.0001). Intraoperative HR was consistently lower in Group A (p < 0.001); MAP was comparable between groups for most of the operative period. No clinically significant adverse events were recorded in either group. Conclusion Esmolol is superior to nitroglycerin in achieving a bloodless surgical field in middle ear surgery under general anesthesia. By providing effective HR control alongside adequate MAP reduction, esmolol achieves earlier and more sustained field clarity, significantly shortening surgical and microscope use time without adverse hemodynamic effects.