Background: Laryngoscopy and tracheal intubation is invariably associated with certain pressor response like hypertension, tachycardia as well as a variation in cardiac arrhythmias. Many pharmaceutical therapies had been applied to attenuate this response with different degree of success. Aims of the Study: To compare the efficacy of one glyceryl trinitarte (GTN) spray versus two sprays in attenuation of pressor response following laryngoscopy and endotracheal tube.
Patients and Methods: This is a prospective single observational study including 150 consecutive patients scheduled for elective general surgery under general anesthesia. Control group, group treated with one GTN sublingual spray as (0.4 mg) and group treated with two metered sprays (0.8mg). Heart rate, blood pressure and oxygen saturation values were recorded at baseline (before induction), after induction, 2, 4, 6, 8 and 10 after intubation.
Results: SBP, DBP and MAP were significantly reduced in GTN groups (either in one or two sprays) compared to the control group in post induction and at 2 minutes post-intubation (for SBP and DBP) and till 4 minutes post-intubation (for MAP). Furthermore, in post induction and 2 min post intubation. Patients treated with 2 sprays had significantly lower SBP, DBP than those treated with one spray and patients treated with two spray had significantly lower MAP in 2 minutes post intubation than patients treated with one spray. In contrast, HR Post induction and at 2, 4 and 6 min post intubation two sprays group had higher mean HR than control group with significant differences.one spray group had higher mean HR than control group post induction with significant difference. Patients treated with two sprays had higher mean HR than patients treated with one spray at 2 minutes and 4 minutes post intubation with significant difference.
Conclusions: The sublingual administration of GTN spray in a dose of 0.4 mg or 0.8 mg prior to intubation in normotensive can attenuate the pressor response to laryngoscopy and intubation. However, one spray GTN is better than two spray considering the attenuation of blood pressure.