Nebulized lidocaine with dexmedetomidine controls hemodynamic responses to laryngoscopy and intubation

Acute hemodynamic reactions (HDR) that continue for at least 10 minutes are brought on by laryngoscopy and endotracheal intubation, which is the most stimulating process. The act of stretching the mucosal tissue in the pharynx and larynx leads to a sympathoadrenal reaction, which in turn triggers a hemodynamic response (HDR). This HDR is characterized by many physiological changes, including an elevation in heart rate (HR), blood pressure (BP), and potentially ischemic ST-segment alterations, which may be attributed to the release of catecholamines. These kind of reactions may be deemed acceptable among those who are young and in good health, but they might have negative consequences for patients who have inadequate cardiac reserve. Therefore, it is important to mitigate these reactions. An optimal pharmaceutical agent should possess a rapid start of therapeutic benefits, be conveniently given, and exhibit minimum adverse reactions.

The present research aimed to evaluate the comparative effects of intravenous Dexmedetomidine and nebulized Lidocaine, both individually and in combination, in reducing hemodynamic response (HDR) during laryngoscopy and post-intubation.

The present study was designed as a double-blind, parallel group, randomized clinical trial, with a total of 90 participants. Each group consisted of 30 individuals, all of whom were between the ages of 18 and 55 years and had an ASA grade of 1-2. The experimental group, referred to as Group DL, was administered Dexmedetomidine intravenously at a dosage of 1 μg kg-1, along with nebulized Lidocaine 4% at a dosage of 3 mg kg-1, prior to the procedure of laryngoscopy. Group D was administered intravenous Dexmedetomidine at a dosage of 1 μg kg-1, whereas group L got nebulized Lidocaine 4% at a dosage of 3 mg kg-1. The variables of heart rate (HR), systolic blood pressure (SBP), diastolic blood pressure (DBP), and mean arterial pressure (MAP) were measured and documented at three time points: baseline, immediately after nebulization, and at 1, 3, 5, 7, and 10 minutes after intubation. The data analysis was conducted using SPSS 20.0.

The post-intubation heart rate was shown to be more effectively regulated in the group using direct laryngoscopy (DL) compared to the groups using videolaryngoscopy (D) and laryngoscopy (L) alone. The mean heart rates for the DL, D, and L groups were 76.40 ± 5.61, 95.16 ± 10.60, and 103.90 ± 12.98, respectively. This difference was statistically significant, with a p-value of less than 0.01. The group with dual control of diet and lifestyle (DL) exhibited a statistically significant increase in systolic blood pressure (SBP) compared to the groups with diet-only (D) control and lifestyle-only (L) control. The mean SBP values for the DL, D, and L groups were 118.93 ± 7.70, 131.10 ± 9.20, and 142.66 ± 19.62, respectively. This difference was shown to be statistically significant with a p-value of less than 0.01. At the 7 and 10-minute intervals, it was observed that both group D and group L shown comparable efficacy in mitigating the increase in systolic blood pressure (SBP). Group DL had statistically significant superior control of diastolic blood pressure (DBP) compared to group L and group D until the 7-minute mark (P < 0.01). Group DL had superior control of mean arterial pressure (MAP) upon intubation compared to both group D and group L. The mean MAP in group DL was 92.86 ± 5.50, while group D had a mean MAP of 102.70 ± 6.64 and group L had a mean MAP of 112.66 ± 7.66. This superior control persisted for a duration of 10 minutes.

The authors of the study have reached the conclusion that the administration of intravenous Dexmedetomidine is superior to the use of nebulized Lidocaine in managing the hemodynamic response during the early phase of intubation. However, they have found no further benefits of Dexmedetomidine over Lidocaine at the 7 to 10 minute mark after intubation. Nevertheless, the concurrent administration of intravenous Dexmedetomidine at a dosage of 1 μg kg-1 with nebulized Lidocaine at a concentration of 4% and a dosage of 3 mg kg-1 demonstrates superior efficacy in mitigating the cardiovascular reactions associated with laryngoscopy and intubation compared to the individual administration of intravenous Dexmedetomidine or nebulized Lidocaine.

Reference –

Sriramka, Bhavna; Warsi, Zeeshan Haider; Sahoo, Janmejaya. Effects of adding dexmedetomidine to nebulized lidocaine on control of hemodynamic responses to laryngoscopy and intubation: A randomized clinical trial. Journal of Anaesthesiology Clinical Pharmacology 39(1):p 11-17, Jan–Mar 2023. | DOI: 10.4103/joacp.JOACP_93_21