the Use of Magnesium Sulfate for Prevention of Postspinal Shivering

Study Overview
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Brief Summary
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Shivering is an unpleasant experience after spinal anesthesia. Shivering is defined as an involuntary, repetitive activity of skeletal muscles. The mechanisms of shivering in patients undergoing surgery are mainly intraoperative heat loss, increased sympathetic tone, pain, and systemic release of pyrogens. Spinal anesthesia significantly impairs the thermoregulation system by inhibiting tonic vasoconstriction, which plays a significant role in temperature regulation. Spinal anesthesia also causes redistribution of core heat from the trunk (below the block level) to the peripheral tissues. These two effects predispose patients to hypothermia and shivering. The median incidence of shivering related to regional anesthesia observed in a review of 21 studies is 64.4%. Shivering increases oxygen consumption, lactic acidosis, carbon dioxide production, and metabolic rate by up to 400%. Therefore, shivering may cause problems in patients with low cardiac and pulmonary reserves. The best way to avoid these intraoperative and postoperative shivering-induced increases in hemodynamic and metabolic demands is to prevent shivering in the first place. Although magnesium is among several pharmacological agents used for the treatment of shivering, its effects on prevention of shivering during central neuraxial blockade have not been evaluated to date. Henceforth, the aim of this study was to evaluate the effect of magnesiume on shivering during spinal anesthesia. Aim: to compare the efficacy of intravenous versus intrathecal magnesium sulphate for prevention of post spinal shivering in adult patients undergoing elective lower limb orthopedic surgeries.

Official Title
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Intravenous Infusion Versus Intrathecal Injection of Magnesium Sulfate for Prevention of Postspinal Shivering During Lower Limb Fracture Surgery. A Randomized Comparative Study

Conditions
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Prevention of Postspinal Shivering

Intervention / Treatment
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* Drug: Magnesium Sulfate 1000 MG


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Age between 20-45 years old Both genders ASA I, II Exclusion Criteria: Patients with hemodynamic instability cardiopulmonary renal , liver disease hypo or hyperthyroidism cerebrovascular insufficiency coagulation defects those with psychiatric disorder patients receiving vasoactive drugs or beta blockers BMI > 35 allergic to study drug height <160 cm or >190 cm basal body temperature >38°C or <36°C those who received blood transfusion or >2000 mL fluid intra-operatively surgery duration > 3 hours

Ages Eligible for Study
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Minimum Age: 20 Years
Maximum Age: 45 Years

Sexes Eligible for Study
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All

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: The patients will be randomly allocated to Groups ([T], Intrathecal MgSo4 and [M], IV infusion MgSo4 groups) on the basis of computer-generated random numbers. Patients belonging to Group T (n = 45) will receive 50 mg intrathecal MgSo4 added to 0.5% hyperbaric bupivacaine [131],while those belonging to Group M (group, n = 45) will receive IV magnesium sulfate 50 mg/kg in 100 mL isotonic saline over 20 min as a bolus then 2 mg/kg/h infusion using a separate infusion set after administering spinal anesthesia. Axillary temperature and grades of shivering will be noted every 10 min by the same anesthesiologist who performed the spinal anesthesia using Crossley and Mahajan scale,[8] If grade III, IV shivering persisted for >10 min pethidine 25 mg IV will be administered as a rescue drug and number of patients required rescue drug will be recorded.
Masking: Single


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Intrathecal Mg group<br>45 patients will receive 50 mg intrathecal MgSo4 added to 0.5% hyperbaric bupivacaine | Drug: Magnesium Sulfate 1000 MG<br>* intrathecal versus IV infusion of Magnesium sulfate for prevention of postspinal shivering<br>|
| Experimental: IV Mg infusion group<br>45 patients will receive IV magnesium sulfate 50 mg/kg in 100 mL isotonic saline over 20 min as a bolus then 2 mg/kg/h infusion using a separate infusion set after administering spinal anesthesia | Drug: Magnesium Sulfate 1000 MG<br>* intrathecal versus IV infusion of Magnesium sulfate for prevention of postspinal shivering<br>|
| No Intervention: control<br>0.5% heavy bupivacaine in the spinal with no additives | |

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| incidence of postspinal shivering | the efficacy of the use of MgSo4 IV infusion versus intrathecal injection in decreasing the incidence of postspinal shivering using Crossley and Mahajan scale which is 0, no shivering; 1, piloerection or peripheral vasoconstriction (cyanosis) but no visible shivering; 2, muscular activity in only one muscle group; 3, muscular activity in more than one muscle group but not generalized shivering; and 4, shivering involving the whole body | up to 5 months | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Magnesium Sulfate - postspinal shivering -intrathecal - infusion