Lidocaine Compared to Magnesium Sulfate to Prolong Spinal Anesthesia: Non-inferiority Randomized Clinical Trial

Study Overview
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Brief Summary
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This study evaluates the addition of continuous infusion of lidocaine or continuous infusion of magnesium sufate in the duration of spinal anesthesia.

Detailed Description
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Both lidocaine and magnesium sulfate have been shown to prolong spinal anesthesia. The number of studies using magnesium sulfate to improve spinal anesthesia is greater than the number of studies using lidocaine, and methodology varies significantly between studies. Adverse effects of lidocaine are different from magnesium sulfate's. Lidocaine has a wider therapeutic interval with fewer side effects, including: Drowsiness, Feeling Anxious, Feeling Cold, Nervous, Numbness And Tingling, Signs And Symptoms At Injection Site, Twitching. Magnesium sulfate's side effects include: heart disturbances, breathing difficulties, poor reflexes, confusion, weakness, flushing (warmth, redness, or tingly feeling), sweating, lowered blood pressure, feeling like you might pass out, anxiety, cold feeling, extreme drowsiness, muscle tightness or contraction, or headache.

Official Title
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Lidocaine Compared to Magnesium Sulfate to Prolong Spinal Anesthesia: Non-inferiority Randomized Clinical Trial

Conditions
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Anesthesia, Pain

Intervention / Treatment
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* Drug: Magnesium Sulfate
* Drug: Lidocaine


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Will receive spinal anesthesia for TURP por Histerectomy Exclusion Criteria: Protocol violation; Severe adverse events; Change to general anesthesia or addition of epidural anesthesia; Complete or partial spinal block failure; Mental status alteration (agitation, confusion, loss of conciousness).

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 120 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

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
Masking: Single


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Active Comparator: Magnesium Sulfate<br>Continuous intravenous infusion of 15mg/kg/h of magnesium sulfate, starting just after spinal anesthesia infusion until the end of surgery | Drug: Magnesium Sulfate<br>* Magnesium Sulfate 15mg/kg/h<br>|
| Experimental: Lidocaine<br>Continuous intravenous infusion of 1.5mg/kg/h of lidocaine, starting just after spinal anesthesia infusion until the end of surgery | Drug: Lidocaine<br>* Lidocaine 1,5mg/kg/h<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Sensitive block duration | Thermal and pinprick level lowering to S2 | 9 hours | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Motor block duration | Time to Bromage return to baseline | 9 hours | 
| Two levels regression | Time from maximal thermal (cold) sensitive block level to lower two levels | 9 hours | 
| Pain at postanesthesia care unit | Maximum pain (0-10 verbal scale) during PACU | 1-3 hours |