Reduction of intraocular pressure by intranasal nitroglycerine used to ameliorate the pressor response to laryngoscopy and intubation

ABSTRACT

Twenty health adult patients undergoing non-opthalmic operation, classified into two groups, were studied to evaluate the effect of intranasal nitroglycerine [NTG] used to ameliorate the pressor responses to laryngoscopy and intubation, on the intraocular pressure [IOP]. 1.5ml of nitroglycerine solution, prepared locally, were instilled in each nostril of patients of group II before induction of anaesthesia while patients of group I received nothing. Heart rate [HR], mean arterial blood pressure [MABP] and [IOP] were measured before premedication, after premedication [by diazepam and atropine], after induction by thiopentone Na, after muscle relaxation [by atracurium] then 1 minute, 2 minutes and 5 minutes after laryngoscopy and intubationin in both groups. It was found that intranasal NTG produced insignificant changes in HR, MABP, and IOP below its preoperative value in patients of group II compared to patients of group I. It is therefore, recommended to use NTG especially in hypertensive patients where ophthalmic operations are to be done, especially if no increase in IOP is desired. Intranasal route of NTG administration is reliable especially when the intravenous or oral route is difficult