ATTENUATION OF HAEMODYNAMIC RESPONSE TO LARYNGOSCOPY AND TRACHEAL INTUBATION IN ADULT PATIENTS WITH A SINGLE INTRAVENOUS BOLUS DOSE OF 3 mu g/Kg CLONIDINE: A PROSPECTIVE, RANDOMIZED, DOUBLE BLIND STUDY

BACKGROUND: Laryngoscopy and endotracheal intubation is often associated with hypertension and tachycardia because of sympatho-adrenal stimulation which is usually transient and lasts for up to 5-10 minutes. Many methods have been tried to blunt this haemodynamic response. Clonidine is a centrally acting alpha - 2 agonist which has antihypertensive, sedative, analgesic actions in addition to reducing the anaesthetic drug requirements. Till recently clonidine was available in India as oral preparation only and as such oral preparation was only being used to attenuate the intubation response. Now clonidine has been introduced in parenteral form and can be used through intravenous route for attenuation of sympathetic response to laryngoscopy and intubation. AIMS: The present study was undertaken to study the efficacy of 3 mu g/kg clonidine IV, given 15 minutes before laryngoscopy and intubation in obtunding the haemodynamic response compared to the control. In addition, we also want to evaluate the effect of clonidine on the dose requirement of thiopentone sodium, vecuronium and also to study the sedation and side effects. MATERIAL AND METHODS: STUDY DESIGN AND SETTING: One hundred normotensive patients aged between 18 to 60 years, scheduled for various elective surgical procedures belonging to ASA (American Society of Anesthesiologists) classI and II were assigned randomly into two groups. Group I (n=50) - received 10 ml of normal saline over 120seconds, Group II (n=50)- received injection Clonidine 3 mu g/kg diluted to 10 mlnormal saline over 120seconds, both given15 minutes prior to laryngoscopy and intubation. Haemodynamic changes associated with intubation were noted in both the groups at different time points. RESULTS: The reduction in the heart rate and blood pressure by clonidine in the post-intubation period was statistically highly significant (p<0.001). In addition Clonidine reduced the requirement of thiopentone and vecuronium and produced arousable sedation after extubation without any side effects like bradycardia and hypotension. CONCLUSION: Clonidine in the dose of 3 mu g/kg body weight given 15 minutes before laryngoscopy and intubation was seen to effectively attenuate the haemodynamic response to laryngoscopy and intubation without any side effects.