Effects of nitroglycerine spray and lignocaine spray on the hemodynamic responses to laryngoscopy and endotracheal intubation: A comparative study

Abstract

BACKGROUND: Laryngoscopy and tracheal intubation cause hypertension and tachycardia in anesthetized patients, which is undesirable, especially in patients with cardiovascular or neurosurgical diseases undergoing anesthesia. Various drug regimens and techniques have been used from time to time for attenuating the pressor response to laryngoscopy and tracheal intubation. The aim is to study, evaluate, and compare the efficacy of nitroglycerine (NTG) spray and 10% lignocaine spray in the attenuation of hemodynamic responses to laryngoscopy and endotracheal intubation and to observe and evaluate any side effects if any associated with the use of these drugs and their management. MATERIALS AND METHODS: This study was conducted on ninety patients under the American Society of Anesthesiologists (ASA) I and ASA II scheduled for elective surgeries. The patients were divided randomly into equal groups of 30 patients and received the following drugs before induction of general anesthesia: Group N-30 patients will be given NTG sublingual spray (2 puffs) 800 mcg 60s before laryngoscopy and group L-30 patients will be given lignocaine spray (2 puffs) 20 mg 60s before laryngoscopy. Hemodynamic variables were continuously recorded from baseline until 15 min after intubation and statistically analyzed. RESULTS: The demographic profile was comparable. The heart rate (HR) increased in both groups, although the increase in HR in the lignocaine group is higher than the increase in HR in NTG group. There was a significant difference in HR values immediately after intubation, 1, 3 min, and 5 min after intubation when the values were lower in group N, and the difference was statistically significant (P 0.05). There was a significant difference in systolic blood pressure (SBP) values immediately after intubation, 1, 3, and 5 min after intubation when the values were lower in group N and the difference was statistically significant (P 0.05). At 1, 3, and 5 min after intubation, the SBP values were significantly higher than baseline in the lignocaine group. However, there was a downward trend in SBP observed in the NTG group until 5 min after intubation, and it was statistically significant. There was a significant difference in diastolic blood pressure (DBP) values immediately after intubation, 1, 3 and 5 min after intubation when the values were lower in group N and the difference was statistically significant (P 0.05). The increase in mean DBP observed in the lignocaine spray group was statistically highly significant when compared to the increase in mean DBP in the NTG spray group. There was a significant difference in mean arterial pressure (MAP) values immediately after intubation, 1, 3 and 5 min after intubation when the values were lower in group N and the difference was statistically significant (P 0.05). NTG spray decreases the MAP more effectively as compared to lignocaine following laryngoscopy and endotracheal intubation. CONCLUSION: Based on our study, we conclude that: In lignocaine spray group patients who received a dose of 20 mg (2 puffs), there was a significant rise in HR, SBP, DBP, mean arterial blood pressure. In the NTG spray group patients who received a dose of 800 mcg (2 puffs), there is effective attenuation of the pressor response to laryngoscopy and intubation in normotensive ASA I–II patients. However, NTG is not able to attenuate the rise in HR due to reflex tachycardia due to vasodilation. Thus, it can be a better alternative in attenuating the hemodynamic responses to laryngoscopy and intubation.