Comparison of effect of intravenous vs intranasal dexmedetomidine on stress response to pneumoperitoneum in adults undergoing laparoscopic surgery: a double blinded hospital based randomised clinical trial

Laparoscopic surgeries have become popular due to several postoperative benefits allowing quicker recovery, less tissue damage, avoiding big surgical incision, shorter hospital stay with consequent reduction in health care cost.

But anaesthetic management in these patients has become complicated due to cardiopulmonary changes occuring during laryngoscopy, intubation, pneumoperitoneum and patient position required for different laparascopic surgeries. Hence the postoperative benefits of laparoscopy should be balanced against the intra-operative risks.

Various drug combinations have been used with variable success to attenuate the sympathetic responses like: deepening the level of anesthesia with higher concentration of inhalational and intravenous anaesthetics agents, high dose of opioids, antihypertensives and beta adrenergic blockers.

Dexmedetomidine is an alpha 2 adrenergic agonist that is currently being widely used for titrating sedation. It has sedative and analgesic property without causing much respiratory depression. When used as an intravenous adjuvant, it attenuates stress response associated with laryngoscopy, intubation as well as for pneumoperitoneum in laparoscopic surgeries providing haemodynamic stability. However, adverse haemodynamic complications like hypotension, bradycardia and even cardiac arrest may have reduced the widespread use of intravenous dexmedetomidine. Moreover, Delayed recovery with intravenous dexmedetomidine is also documented due to its sedative effect. It has been suggested that alternative routes other than rapid intravenous delivery may help to minimise the adverse effects of Dexmedetomidine while maintaining the advantageous effect of attenuating the stress response to pneumoperitoneum.  Intranasal route is more convenient, effective, reduces first pass metabolism and has a high rate of patient acceptance.

After obtaining the approval of ethical committee a total of 64 patients undergoing laparoscopic surgeries under General Anaesthesia will be included in the study.

After having met inclusion and exclusion criteria and having obtained informed consent, patients will be randomized based on computer generated randomization table into two groups (32 each).

GROUP 1: will receive 1.5 mcg/kg of intranasal dexmedetomidine

GROUP 2: will receive 0.5 mcg/kg of intravenous dexmedetomidine

Hemodynamic parameters will be monitored. Sedation status in both groups, will also be assessed using the Ramsay sedation scale (RSS) in the pre-operative area. All patients to be induced with IV Inj. propofol 2mg/kg and IV succinylcholine 2mg/kg to facilitate tracheal intubation. Anaesthesia will be maintained with 50% O2-N2O mixture, isoflurane 1-1.2 MAC, loading dose of vecuronium 0.1mg/kg followed by top ups of 1/4th the loading dose. Hemodynamic parameters (MAP, SBP, DBP and HR) will be recorded every 5 minutes.

Hence, this study is planned to investigate the effect of intravenous vs intranasal dexmedetomidine on attenuation of hemodynamic changes that occur after creation of pneumoperitoneum in laparoscopic surgeries.