Study the impact of ketamine, clonidine and combination of ketamine-clonidine on cardiovascular system during pre and postoperatively: A double blind, placebo controlled study

Abstract

Background: The use of ketamine as a sole anesthetic induces marked central sympathetic stimulation, causing increased heart rate, blood pressure (BP), and oxygen consumption (VO2). Both alpha 2-agonists and benzodiazepines have been used to attenuate these potentially harmful ketamine-induced responses.  Materials and Methods: After approval from institutional ethical committee and written informed consent, 120 adult patients, ASA physical status I and II, undergoing elective surgeries e.g. Open abdominal surgery, laparoscopic surgery, open urological surgery were included in this controlled, prospective, randomized, double-blind study. Patients were randomly (envelop randomization) allocated in 4 groups (n=30): Group K received IV ketamine (0.5mg/kg), Group C received IV clonidine (1.5μg/kg), Group KC received combination of IV ketamine (0.25mg/kg) and IV clonidine (0.75μg/kg) and Group P received IV normal saline (placebo). One envelop at a time was chosen by an anaesthesiologist, who was blinded to the preparation of study agents and administered the study drugs in the envelope one after the other, intravenously approximately 20 minutes before extubation. Results: Pre operative haemodynamic parameters like mean arterial pressure (MAP) and heart rate are comparable across the groups. There was statistically significant (two tailed p value < 0.001) rise in intra operative heart rate following intubation in groups K, KC and P. There was statistically significant increase in systolic blood pressure (SBP) in groups K and P (two tailed p value < 0.001). In group C and KC, there were significant fall in SBP, from the baseline values, following induction. Conclusion: The unwanted effects of the individual drugs like, haemodynamic alteration, hallucination or lower incidences of nausea and vomiting could be achieved by using half of the dose of each of the drugs in combination.