A comparative study of the effect of dexmedetomidine and lignocaine on hemodynamic and airway responses following extubation

Background: Dexmedetomidine is the newer highly selective alpha 2-adrenoreceptor agonist. It has sympatholytic, sedative and analgesic properties with no respiratory depression. Various studies have evaluated the usefulness of Dexmedetomidine as an adjuvant to general anesthesia, reducing the requirements of inhalational agents and opioids, and for attenuating the intubation stress. A single dose of Dexmedetomidine has been found effective in attenuation of the airway and circulatory reflexes during extubation. Aim of the study: To compare the effects of intravenous Dexmedetomidine and lignocaine on Attenuation of hemodynamic responses and sedation score, Attenuation of airway responses to extubation after intracranial surgeries under general anesthesia. Materials and methods: This was a prospective, randomized, double-blinded study conducted at our institute between June 2018 and July 2018 in Tirunelveli government medical in the department of anesthesiology after getting institutional Ethical committee approval. Written informed consent was obtained from all subjects participating in the study. 50 patients of ASA Grade I and II undergoing craniotomies for non‑vascular ICSOL under general anesthesia were recruited. Patients were divided into two groups of 25 each by computer-generated random numbers. Group D (n=25) received 0.5 microg/kg Dexmedetomidine intravenously. Group L (n=25) received 1.5 mg/kg Lignocaine intravenously. Anesthesiologist who administered the drug and the observer were blinded to the study. Intravenous drugs were prepared by another anesthesiologist not involved in the study. Results: A decrease in HR, SBP, and DBP were observed up to the A5 stage in group D which was statistically significant. In group L the changes in HR, SBP, and DBP at these stages were statistically insignificant. There was an increase in HR, SBP and DBP in both groups during (E) and immediately after extubation (E1). This was more in group L compared to group D which was statistically significant. Thereafter in group D these values continued to decrease and remained below the pre-drug administration value (A0) at the end of the study (E15). Whereas in group L, these values although decreased from E and E1 values but remained above the A0 values at the end of the study period (E15). This difference was statistically significant (p-value less than 0.05). The degree of sedation was higher in Group D after extubation. 5 patients (20%) showed Grade 2 sedation and 20 patients (80%) showed Grade 3 sedation in Group D. In contrast, only 20% (n=5) patients had mild sedation (Grade 2) whereas 80% (n=20) patients were anxious and agitated or restless or both (Grade 1) in group L. The difference between both groups was statistically significant. Conclusion: From our study, we concluded that administration of a single dose of Dexmedetomidine (0.5 mcg/kg) provides significant attenuation of circulatory and airway responses during extubation when compared to lignocaine in craniotomies for ICSOL. Though patients were sedated in the immediate post-extubation period, the levels of sedation were acceptable without any incidence of desaturation.