International Journal of Applied Research
Vol. 1, Issue 12, Part J (2015)
A Study of Pressor Response to Laryngoscopy and Intubation and Its Attenuation by Nitroglycerine
This study evaluated 100 adult patients of either sex belonging to ASA grade 1; aged 20 to 40 years were randomly allocated into 4 groups of 25 each. Group 1- acted as control group (not receiving any pretreatment), group 2- Nitroglycerine intranasal group, group 3- Nitroglycerine topical group, group 4- Nitroglycerine intravenous group. All the patients were prepared by 12 hour preoperative fasting and overnight sedation with 10 mg diazepam orally at bedtime. Patients received 10/c mg diazepam 2 hours before surgery. After checking the patient’s blood pressure, heart rate and ECG, at basal stage, pretreatment was started. Group 2 was pretreated with 2 ml solution 2mg nitroglycerine tablet dissolved in 2ml of distilled water (1 ml in each nostril) 3 minutes before induction of anesthesia. Group 3 was pretreated with 30 mg of 2% nitroglycerine ointment applied by spreading and rubbing on an area of 10 to 15 cm over the forehead using a specially designed dose measuring applicator 20 minutes prior to induction of anesthesia. Group 4 was pretreated with slow intravenous nitroglycerine at the rate of 200mg per minute to be given till the systolic arterial blood pressure fell down by 20-30%. Patients were again checked for heart rate, blood pressure and ECG. This stage of recording was termed pre-induction stage. Patients belonging to all the groups were anaesthetized by routine conventional methods i.e. 3 minutes pre-oxygenation was followed by induction by 4 to 5 mg per kg body weight of sodium thiopentone intravenously followed by suxamethonium 1 to 1.5 mg per kg body weight intravenously. Without any undue delay endotracheal intubation was performed and the drug in Group 3 was immediately removed with a gauze piece. Patients were again checked for heart rate, blood pressure and ECG. This stage of recording was termed intubation stage. For the next 15 minutes these recordings were again taken after every 5 minutes. Anaesthesia was maintained on nitrous oxide, oxygen, 0.5% isoflurane and a long acting muscle relaxant. All the four groups showed highly significant increase in heart rate during laryngoscopy and intubation as compared to basal stage. Hence nitroglycerine had no role in bringing down increased heart rate during intubation. Except for control group no group showed significant rise in systolic and diastolic blood pressure. This suggests that nitroglycerine via various routes safely and effectively attenuates hypertensive response secondary to laryngoscopy and tracheal intubation. ECG changes were observed in all the four groups, most significant being sinus tachycardia. Thus nitroglycerine does not alter cardiac rhythm occurring in response to laryngoscopy and tracheal intubation. It is thus concluded that nitroglycerine can be recommended in patients of cerebral and cardiovascular diseases, where major complications occurring as a result of significant hemodynamics changes are apprehended.
How to cite this article:
Ajai Vikram Singh, Surinder Singh. A Study of Pressor Response to Laryngoscopy and Intubation and Its Attenuation by Nitroglycerine. Int J Appl Res 2015;1(12):683-687.