Comparison of different doses of intranasal nitroglycerine in attenuation of pressor response to laryngoscopy and intubation

AIMS: To observe the various pressor responses to laryngoscopy and intubation in normotensive patient undergoing elective surgery under general anesthesia and use of three different attenuating doses (400, 800, 1200 mcg) of intranasal nitroglycerine administered five minutes before laryngoscopy and intubation, to observe the efficacy and safety. SETTINGS AND DESIGN: Randomized study. MATERIALS AND METHODS: The study was carried out in a total of 60 patients. ASA grade 1 and II patients posted for elective surgeries under general anesthesia were included. Patients received different doses of intranasal nitroglycerine five minutes before induction as given below Group 1-received 400 micrograms-20 patients Group 2-received 800 micrograms-20 patients Group 3-received 1200 micrograms-20 patients. STATISTICAL ANALYSIS: Student's t test. RESULTS AND SUMMARY: Results were statistically analyzed. All three groups effectively attenuated the pressor response to laryngoscopy and intubation. Maximum rise in heart rate was seen in group III (23.86%). Maximum fall in systolic (19.6%), diastolic (30.76%), and mean arterial blood pressure (25.53%) was observed in group III at 10(th) minute of laryngoscopy and intubation. CONCLUSION: Best results of attenuation of pressor response were seen with 400 and 800 micrograms of intranasal nitroglycerine. One thousand and two hundred micrograms dose caused maximum increase in heart rate and caused maximum fall in blood pressure, hence it is advisable to use increased dose with caution in attenuation of pressor response to laryngoscopy and intubation.