Comparative Study between Dexmedetomidine and Nalbuphine for prevention of post spinal shivering in Obstetrics cases- A randomized controlled trial

Background: Shivering is a physiological response to core hypothermia in an attempt to raise themetabolic heat production. The main causes of intra/post-operative shivering are temperature loss,increased sympathetic tone, pain, and systemic release of pyrogens. Spinal anaesthesia significantlyimpairs the thermoregulation system by inhibiting tonic vasoconstriction, which plays a significant rolein temperature regulation. It also causes a redistribution of core heat from the trunk (below the blocklevel) to the peripheral tissues. These factors predispose patients to hypothermia and shivering. Severalpharmacological agents are used for control of Post spinal shivering. Nalbuphine has become afavoured and commonly used drug for post-spinal shivering. However, it has many adverse effects likenausea, vomiting, dizziness etc. Dexmedetomidine is another agent which has gained popularity duringthe last few years. Dexmedetomidine is an α2-adrenergic receptor agonist, has been used as a sedativeagent and is documented to increase the shivering threshold. Objectives: To assess the superiority of Dexmedetomidine over Nalbuphine in prevention of post spinalshivering. Materials & method: This prospective, randomized clinical trial was conducted in Department ofAnaesthesia, Analgesia, Palliative and Intensive Care Medicine, Dhaka Medical College Hospital, from18th October 2019 to 17th April 2020. Total 120 patients were selected and allocated into two groups,group N (Nalbuphine) and group D (Dexmedetomidine). Patients of Group N was given intravenousNalbuphine 0.07 mg/kg mixed with 0.9% normal saline to a volume of 10ml. Patients of Group D wasgiven intravenous Dexmedetomidine hydrochloride 1 μg/kg mixed with 0.9% normal saline to a volumeof 10ml. Then shivering grade and haemodynamic status were recorded at different follow-up time andcompared between groups. Result: Majority of the patients i.e. 58.33% (n=70) were between 25-30 years, mean age was found to26.7±8.4 years and 26.7±8.4 years in Group D & N respectively. The heart rate after 5 min (56, 62beat/min respectively), after 10 min (58, 68 beat/min respectively) and 15 min (63, 72 beat/min respectively)after of anaesthesia were statistically significant. Shivering grade 3 or 4 was existed in bothgroups, but more in group N. Rescue medication for shivering (Inj. Pethedine 25 mg) requirement washigher in Group-N & difference was statistically significant. Shivering was controlled within 15 minutein maximum 13(21.66%) of patients in group D. Comparison of sedation, 45 minute after mean sedationscore was found 2.03±0.07 in group D, but in group N score is reduced and found 1.43±0.127. Meansedation score difference was statistically significant (p<0.05) between two groups. Conclusion: Post spinal shivering is very distressing for patients and may induce a variety of complications.Present study concluded that Dexmedetomidine was more effective compared to Nalbuphineinattenuating the post spinal shivering. JBSA 2022; 35 (2) : 3-11