Intravenous Administration of Magnesium Sulfate in Hysterectomy Cases

Study Overview
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Brief Summary
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In our study, it was aimed to show the contribution of intraoperative intravenous magnesium sulfate administration to peroperative opioid consumption and postoperative analgesia.

Detailed Description
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Postsurgical pain is one of the most important issues that could impress on postoperative peace and comfort. Abdominal hysterectomy associated with intense inflammatory response, resulting in moderate to severe postoperative pain perception The major goal in postoperative pain management is to minimize the dose of medications and lessen side effects, while still providing adequate analgesia. Postoperative pain relief leads to earlier mobilization, shortened hospital staying, reduced hospital costs, and increased patient satisfaction Narcotics are the most common analgesics which are used after the surgeries. But anesthetists are always looking for replaceable methods with fewer side effects and cost . It seems adjuvant analgesics are those desirable replacements. Nowadays there have been many debates on the role of adjuvant analgesics on postoperative pain relief. One way to use adjuvant analgesics is preventive method Preventive analgesia is a method initiated before anesthetic procedure in order to reduce the physiological consequences of nociceptive stimulation and medical adverse effects and has been defined as an antinociceptive treatment that prevents establishment of altered central processing ofafferent input from injuries. One of the intravenous adjuvant that has been shown potential in preventive analgesia is magnesium sulfate that could be administered with multiple routes or methods Mg has been used for many years in anesthesia and cardiology as an anticonvulsant or antiarrhythmic drug. The mechanism of the analgesic effect of Mg is not clear but inter- ference with calcium channels and N-methyl-D-aspartate (NMDA) receptor seem to play an important role. It seems that analgesic mechanism of NMDA-antagonists is made by preventing nociceptive central sensitization. Another suggesting mechanism is the role of it on reduction of catecholamine release with sympathetic stimulation, thereby decreasing peripheral nociception or the stress response to the surgery. Data illustrate that the NMDA receptor antagonists like Mg sulfate have an effect on pain threshold and could prevent pain perception even with low doses (preventive doses) In our study, investigators aimed to determine the contribution of magnesium sulfate to postoperative analgesia in abdominal hysterectomy by considering its mechanism of action. The patients were divided into two groups as magnesium sulfate administered and non-administered The magnesium group received a bolus of 20 mg/kg of magnesium sulfate in 100 mL of saline for 15 minutes before induction, followed by a continuous infusion of 20 mg/kg/hr until the skin was closed. The same volume of isotonic saline for the control group was administered as indicated in the magnesium group.

Official Title
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The Effect of Intravenous Magnesium Sulfate Use on Intraoperative Remifentanil Consumption and Postoperative Pain in Abdominal Hysterectomy Cases

Conditions
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Abdominal Hysterectomy, General Anesthesia, Magnesium Sulfate

Intervention / Treatment
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* Drug: magnesium sulfate group
* Drug: control group saline


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Patient undergoing abdominal hysterectomy Between the ages of 20-70, ASA I- II Exclusion Criteria: Presence of hepatic and renal dysfunction, Presence of cardiac arrhythmia or other cardiac comorbidity, Neurological and psychiatric disorder, Chronic use of calcium and beta blockers, Drug or alcohol abuse, Pregnancy and lactation status, Patients with a history of allergy to any drug included in the study protocol

Ages Eligible for Study
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Minimum Age: 20 Years
Maximum Age: 70 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: Supportive Care
Allocation: Randomized
Intervention Model: Parallel Assignment
Interventional Model Description: The patients were randomly divided into two groups according to a 1:1 randomization ratio using opaque sealed envelopes before surgery. Study randomization was performed using computer generated randomization codes by SPSS v23.0 (IBM, New York, USA). Each patient was asked to choose an envelope and the patients were assigned to the study according to the group specified in the envelope. The drugs to be used were prepared 30 minutes before the surgery by the nurse who did not participate in the study in the drug preparation room. Everyone involved in this study, including patients, researchers, the anesthesiologist responsible for anesthesia management, and the surgeon, remained blind to group distribution during the study.
Masking: Double


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Active Comparator: Magnesium sulfate<br>Before induction, a bolus of 20 mg/kg magnesium sulfate in 100 mL saline was administered for 15 minutes, followed by a continuous infusion of 20 mg/kg/hour until the skin was closed. | Drug: magnesium sulfate group<br>* Anesthesia induction was provided with propofol (2mg/kg), fentanyl (2mcg/kg). Intubation was performed after administration of 0.6 mg/kg rocuronium with an appropriate endotracheal tube. Anesthesia was maintained using AIR/O2 (50%/50%), 1 minimum alveolar concentration (MAC) sevoflurane, 0.1-0.25 mcg/kg/min remifentanil infusion. The target BIS value was kept between 40 and 50. Systolic blood pressure (SBP) <90mmHg or <20% of baseline was considered hypotension; remifentanil infusion was reduced. If no response was obtained, 5-10 mg of IV ephedrine was administered. HR < 45 beats/min was evaluated as bradycardia; IV atropine 0.5 mg was planned The magnesium group received a bolus of 20 mg/kg of magnesium sulfate in 100 mL of saline for 15 minutes prior to induction, followed by a continuous infusion of 20 mg/kg/hr until skin closure.<br>* Other names: magnesium sulfate;|
| Active Comparator: Placebo<br>The control group received only 100 ml of saline 15 minutes before induction. | Drug: control group saline<br>* Anesthesia induction was provided with propofol (2mg/kg), fentanyl (2mcg/kg). Intubation was performed after administration of 0.6 mg/kg rocuronium with an appropriate endotracheal tube. Anesthesia was maintained using AIR/O2 (50%/50%), 1 minimum alveolar concentration (MAC) sevoflurane, 0.1-0.25 mcg/kg/min remifentanil infusion. The target BIS value was kept between 40 and 50. Systolic blood pressure (SBP) <90mmHg or <20% of baseline was considered hypotension; remifentanil infusion was reduced. If no response was obtained, 5-10 mg of IV ephedrine was administered. HR < 45 beats/min was evaluated as bradycardia; IV atropine 0.5 mg was planned The same volume of isotonic saline for the control group was administered as indicated in the magnesium group.<br>* Other names: saline;|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Fentanyl consumption in the first 24 hours after surgery | Fentanyl consumption in the first 24 hours was measured. Patients were able to request opioids via a PCA device when their VAS score is above 4 at rest and during activity (coughing and walking). | Postoperative Day 1 | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Post-operative acute pain | Pain status at rest and while activity (coughing and walking) was assessed by VAS scores at 0, 2, 4, 6, 8, 12 and 24 hours after surgery. The VAS is an 11-point numeric scale which ranges from 0 to 10 at rest and during activity. | Postoperative Day 1 | 
| The incidences of post-operative nausea and vomiting (PONV) | The severity of postoperative nausea and vomiting (PONV) was assessed using a Verbal Descriptive Scale(VDS) at 0, 2, 4, 6, 8, 12 and 24, hours after surgery. If a score of 3 or more is recorded, ondansetron 0,1 mg/kg iv was administered. | Postoperative Day 1 | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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postoperative pain, intravenous magnesium sulfate