Controlled hypotension for functional endoscopic sinus surgery: comparison of esmolol and nitroglycerine

Intraoperative bleeding causing poor visibility of surgical field is of major concern during functional endoscopic sinus surgery (FESS) and impaired visibility may result in many complications. The study aimed to compare surgical conditions for FESS during controlled hypotension provided by esmolol or nitroglycerine (NTG) under general anaesthesia. 52 adult patients of both sexes requiring FESS under general anaesthesia were randomly divided to receive either esmolol (group ESM, n = 26) or NTG (group NTG, n = 26) to provide controlled hypotension. Surgical condition was assessed by surgeon using average category scale (ACS) of 0-5, a value of 2-3 being ideal. In both groups mean arterial blood pressure (MABP) was gradually reduced till ACS for assessment of surgical condition (ACS) of 2-3 or lowest targeted MABP (60 mm of Hg) was achieved. Both the drugs produced desired hypotension and improved surgical condition by reducing operative field bleeding but ideal operative conditions were achieved at mild hypotension (MABP 75-70) in ESM group while same conditions were achieved at MABP of 69-65 mm of Hg in NTG group. Mean heart rate was significantly higher in NTG group as compared to ESM group. Blood loss was significantly less in ESM group. Both NTG and esmolol can be used safely to provide controlled hypotension during FESS. Both the drugs improved visibility of surgical field by reducing capillary bleeding. But esmolol offered better operative conditions with only minimal reduction in MABP. No reflex tachycardia and less intraoperative haemorrhage were additional advantages of esmolol.