Intravenous Ketamine for Prevention of Post Anesthetic Shivering In Urological Procedures Done Under Spinal Anesthesia: A Randomized Triple Blinded Placebo Controlled Trial

Author(s):

Karunakaran Mullainayaki, Hermin Sujina A, Gunaseelan Mirunalini and Chinnappan Kuppusamy Swetha Ramani

Background and Aim: Post anesthetic shivering is one of the common complications following spinal anaesthesia. Adding to patient discomfort, it also causes increase in oxygen consumption, metabolic rate, carbon-dioxide production, hinderance in monitoring. The aim of this study is to compare the efficacy of prophylactic intravenous ketamine with 0.9% saline (placebo) in prevention of postoperative shivering in patients undergoing urological procedures under spinal anaesthesia.

Methods: 60 patients between ages 18-65 years, ASA status I–II, scheduled for urological procedures were prospectively studied. In this double-blind, randomized controlled trial, patients were randomly divided into group K(Ketamine 0.3 mg/kg) and group P(0.9% saline). After induction of SA, patients were observed for the incidence and intensity of shivering using a four-point scale by a blinded outcome assessor who is unaware of the drug given. Data collection was done by observation and measurement of various parameters.

Results: Incidence of shivering was increased in group P (93%) compared to group K(60%), with P value >0.0001. The result was very statistically significant. Time of onset of shivering was earlier in group P (29.30 ± 5.35) compared to group K (43.03 ± 4.3). P value equals >0.0001, the result was extremely statistically significant. 13% patients developed hallucination and 20% patients developed delirium and hypersalivation and 6.6% of patients had nystagmus with ketamine.

Conclusion: Incidence of shivering was increased in group P (93%) compared to group K(60%), with P value >0.0001. The result was very statistically significant. Time of onset of shivering was earlier in group P (29.30 ± 5.35) compared to group K (43.03 ± 4.3). P value equals >0.0001, the result was extremely statistically significant. 13% patients developed hallucination and 20% patients developed delirium and hypersalivation and 6.6% of patients had nystagmus with ketamine.