Intravenous Dexmeditomidine for Prevention of Spinal Anesthesia Induced Shivering.

Study Overview
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Brief Summary
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Intraoperative and post operative shivering is a common problem encountered in operating rooms and recovery suites. Shivering under spinal anesthesia has an incidence of 40-60%. Shivering is not only uncomfortable for the patient; additionally it increases minute oxygen consumption, subjecting the patient to a higher risk of cardiovascular complications. A variety of drugs like pethidine, fentanyl, alfentanil, sufentanil, buprenorphine, doxapram, clonidine, and ketanserin, are reported to be effective in suppressing postoperative shivering, yet an ideal drug/ method to be explored. Dexmeditomidine, a sedative and analgesic, may control shivering without significant adverse effects, like nausea and vomitting and respiratory depression. The study design will be randomized controlled parallel trials with sample size of 80,They will be randomized into two equal groups. One group will receive 10 microgram Inj. Dexmeditomedine while the other will recieve inj. normal saline as placebo. The participants will be assessed for intra- and postoperative shivering.

Detailed Description
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Intraoperative inadvertent changes in the body temperature are quite common. Incidence of inadvertent hypothermia (up to 90%) is much higher than hyperthermia. The hypothermic patients shiver postoperatively after general anesthesia and both introperatively and post operatively during regional anesthesia. Shivering under spinal anesthesia has an incidence of 40-60%. Shivering is not only uncomfortable for the patient; additionally it increases minute oxygen consumption VO2 at the cost of increased presser hormones level, subjecting the patient to a higher risk of cardiovascular complications. Heat loss from skin and surgical site is mostly by radiation. Dropped body temperature in cesarean section under spinal anesthesia is due to a combination of anesthetic-induced impaired thermoregulation i.e. vasodilation and inhibition of vasoconstriction in the blocked dermatomes, which are due to autonomic and motor blockade caused by spinal anesthesia. General anesthesia also leads to hypothermia due to vasodilation and reduced metabolic rate, in the order of 20%-30%. Additional factors are exposure to cold environment, un-warmed cold irrigants/ intra vascular fluids and ventilation with dry anesthetic gases. In spinal anesthesia, due to blocked motor activity below umbilicus, shivering in response to hypothermia is abolished. It interferes with physiologic heat recovery, as human core body temperature should normally be maintained within the narrow range of 36.5-37.5 °C. A variety of drugs like pethidine, fentanyl, alfentanil, sufentanil, buprenorphine, doxapram, clonidine, and ketanserin, are reported to be effective in suppressing postoperative shivering, yet an ideal drug/ method to be explored. Dexmeditomidine which is an alpha-2 agonist, is a new drug used for analgesia and sedation either in perioperative settings or in intensive care units. It is 7-8 times selective alpha 2 agonist than clonidine and was expected to control shivering like clonidine. There are study demonstrating the favorable effect of Dexmeditomidine via infusion in the intraoperative period on shivering after abdominal hysterectomy. In previous studies, a prophylactic single dose of Dexmeditomidine for prevention or aborting shivering was generally found to be effective after general or regional anesthesia. Dexmedetomidine 0.5 mcg/kg I/v as loading dose was found 100% effective in managing post anesthesia shivering after general anesthesia in children. In another study, it was observed that Dexmedetomidine was equally effective compared to tramadol, and was associated with shorter time for complete shivering control and less incidence of nausea vomiting, but prospects of a single sub loading dose in parturients during spinal anesthesia requires exploration as physiologic volume loaded parturients at term are expected to lose more heat by redistribution due to vasodilation caused by spinal anesthesia. OBJECTIVE: To determine the role of single sub loading dose of Dexmeditomidine i.e. 10 mcg (0.1- 0.2 microgram/kg) administered intravenously for prevention of shivering in participants undergoing Cesarean section under spinal anesthesia in a randomized double-blind, placebo controlled parallel study.

Official Title
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Role of Dexmeditomidine HCL for Prevention of Shivering in Obstetrical Spinal Anesthesia, a Randomized Controlled Double Blind Parallel Study.

Conditions
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Postoperative Shivering, Cesarean Delivery

Intervention / Treatment
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* Drug: Dexmedetomidine Hydrochloride
* Drug: Normal Saline


Participation Criteria
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Eligibility Criteria
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Inclusion criteria: American Society of Anesthesiologists (ASA) physical status I and II ladies Singleton pregnancies. Undergoing elective Cesarean delivery under spinal anesthesia. Systolic blood pressure ≥ 100 mm of Hg after umbilical cord clamping Exclusion criteria: ASA class III or above Hyperthyroidism Cardiopulmonary or respiratory disease A psychological disorder An initial body temperature of >37.5 °C or <36.5 °C Systolic blood pressure <100 mm of Hg after umbilical cord clamping and/or mean arterial pressure (MAP) < 65 mm of Hg after umbilical cord clamping

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 45 Years

Sexes Eligible for Study
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Female

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Prevention
Allocation: Randomized
Intervention Model: Parallel Assignment
Interventional Model Description: Parallel Assignment The study design is prospective double-blinded randomized controlled parallel trial with allocation ratio of 1:1.
Masking: Double


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Active Comparator: Dexmedetomidine<br>This is group D, which will receive 10 micro-gram Dexmeditomidine diluted in 02 ml normal saline to be administered intravenously in 10 minutes after umbilical cord is clamped.. | Drug: Dexmedetomidine Hydrochloride<br>* The parturients will receive 10 micro-gram Dexmedetomidine diluted in 02 ml normal saline to be administered intravenously over 10 minutes after umbilical cord is clamped..<br>* Other names: inj Precidex (brookes pharmaceutical, Pakistan);|
| Active Comparator: Saline<br>This group S will receive 02 ml normal saline intravenously as placebo in 10 minutes after umbilical cord is clamped.. | Drug: Normal Saline<br>* The parturients will receive 02 ml normal saline as placebo, to be administered intravenously over 10 minutes after umbilical cord is clamped.<br>* Other names: Normal Saline 0.9 %;|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Rate of shivering in all parturients who received either Dexmeditomidine HCL or placebo | The intensity of postoperative shivering will be graded using Bedside Shivering Assessment Scale(BSAS) from 0 - 3 with 0= no shivering and 3=severe shivering. | Two hours | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Rate of sedation in all parturients who received either Dexmedetomidine HCL or placebo. | Sedation will be assessed through Richmond agitation sedation scale (RASS) from +4 to - 5 with +4= combative and -5= unarousable. | Two hours | 
| Rate of postoperative pain and analgesia in all parturients who received either Dexmeditomidine HCL or placebo. | Postoperative pain/analgesia will be assessed through visual analogue scale (VAS) with 0= no pain, 100= very severe pain. | Two hours | 
| Incidence of adverse reactions associated with Dexmedetomidine HCL | Incidence of adverse reactions like hypotension and bradycardia in Dexmedetomidine group will be noted and compared with saline group | Two hours |