Effect of nebulised dexmedetomidine versus nebulised lignocaine on laryngoscopy and neuroendocrine stress response following endotracheal intubation: a randomized comparative study

Nebulised dexmedetomidine has been found to be effective in blunting the hemodynamic response that occurs following laryngoscopy at the time of intubation. Hemodynamic response can lead to an increase in heart rate, blood pressure, mean arterial pressure. It can be tolerated by young and healthy individuals but is detrimental in patients with limited cardiac reserve as it may precipitate hypertensive crisis, myocardial ischaemia, arrhythmias or increase in intra-cranial pressure in suspected individuals. Thus, it is vital to blunt these responses.

It has been observed that neuroendocrine response also occurs following laryngoscopy. However, currently there is no existing literature comparing the nebulised dexmedetomidine with nebulised lignocaine for blunting the neuroendocrine response.

Therefore, this study aims to assess the biochemical markers levels and hemodynamic profile following laryngoscopy when nebulised with dexmedetomidine versus lignocaine.

Forty ASA grade I and grade II patients presenting for general anaesthesia will be randomized into two groups, Group D and Group L based on computer generated randomized table. Allocation concealment will be done by sealed envelope technique.

Thorough pre-anaesthetic assessment will be done for all patients. After taking consent, patients will be wheeled in and standard ASA monitors will be attached in the pre-operative area and depending upon the group, the study drug will be administered through the nebuliser.

Group D will receive 4mL of Dexmedetomidine (1mcg/kg) over 10 minutes while Group L will receive 4mL of Lignocaine (4%) over 10 minutes.

Vitals will be noted at the end of 10 minutes. Any adverse event shall also be noted.

After 30 minutes, the patient will be taken up in the operating room, baseline hemodynamic parameters will be noted.

Intravenous access will be secured and 2mL sample for baseline value of cortisol will be taken. Simultaneously, 2mL of saliva sample will also be taken for measurement of salivary alpha amylase levels.

A conventional balanced general anaesthesia will be administered to all patients.

Post intubation hemodynamic parameters will be noted and same hemodynamic parameters will be noted at 2 minutes and 5 minutes (and subsequently every 5 minutes till 15 minutes and then at 30 minutes and 1 hour).

Blood samples will be taken for serum cortisol levels and saliva sample for salivary alpha amylase levels at 5 minutes post intubation.

Sedation will be assessed in post operative period using Ramsay Sedation score 30 minutes post extubation.