Vasopressor Prophylaxis After Spinal Anesthesia

Study Overview
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Brief Summary
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Norepinephrine has been recently introduced as a prophylactic vasopressor during Cesarean delivery with promising results ; However, the optimum dose for efficient prophylaxis with the least side effects is not known. In this study, we will compare three doses (0.05, 0.1, 0.15 mcg/Kg/min) of norepinephrine for prophylaxis against Post-Spinal hypotension during cesarean delivery.

Detailed Description
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Maternal hypotension is a common complication after spinal anesthesia for cesarean delivery (CD). Using vasopressors have been considered a gold standard for prevention of post-spinal hypotension (PSH) during CD. Norepinephrine (NE) is a potent vasopressor characterized by both α adrenergic agonistic activity in addition to a weak β adrenergic agonistic activity; thus, NE is considered a vasopressor with minimal cardiac depressant effect; these pharmacological properties would make NE an attractive alternative to phenylephrine and ephedrine (the most commonly used vasopressors in obstetric anesthesia). Norepinephrine has been recently introduced as a prophylactic vasopressor during CD with promising results; However, the optimum dose for efficient prophylaxis with the least side effects is not known. In this study, we will compare three doses (0.05, 0.1, 0.15 mcg/Kg/min) of norepinephrine for prophylaxis against PSH during CD.

Official Title
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Vasopressor Prophylaxis After Spinal Anesthesia: A Dose Finding Study

Conditions
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Cesarean Section Complications

Intervention / Treatment
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* Drug: Norepinephrine 0.05 mcg /Kg/min
* Drug: Norepinephrine 0.1 mcg /Kg/min
* Drug: Norepinephrine 0.15 mcg /Kg/min
* Drug: Bupivacaine


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: full term singleton pregnant women Scheduled for elective Cesarean Delivery Aged between 18 and 40 years Exclusion Criteria: Cardiac morbidities Hypertensive disorders of pregnancy, Peripartum bleeding Baseline systolic blood pressure (SBP) < 100 mmHg Body mass index > 35

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 40 Years

Sexes Eligible for Study
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Female

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: Prevention
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Triple


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: - 0.05 mcg /Kg/min group<br>will receive norepinephrine 0.05 mcg /Kg/min after spinal anesthesia by bupivacaine till five-minutes after delivery of the fetus | Drug: Norepinephrine 0.05 mcg /Kg/min<br>* Norepinephrine infusion by rate of 0.05 mcg /Kg/min after spinal anesthesia<br>* Other names: noradrenaline infusion;Drug: Bupivacaine<br>* 10 mg Bupivacaine intra-thecal for spinal anesthesia<br>* Other names: marcaine;|
| Experimental: - 0.1 mcg /Kg/min group<br>will receive norepinephrine 0.1 mcg /Kg/min after spinal anesthesia by bupivacaine till five-minutes after delivery of the fetus | Drug: Norepinephrine 0.1 mcg /Kg/min<br>* Norepinephrine infusion by rate of 0.05 mcg /Kg/min after spinal anesthesia<br>* Other names: noradrenaline infusion;Drug: Bupivacaine<br>* 10 mg Bupivacaine intra-thecal for spinal anesthesia<br>* Other names: marcaine;|
| Experimental: - 0.15 mcg /Kg/min group<br>will receive norepinephrine 0.15 mcg /Kg/min after spinal anesthesia by bupivacaine till five-minutes after delivery of the fetus | Drug: Norepinephrine 0.15 mcg /Kg/min<br>* Norepinephrine infusion by rate of 0.05 mcg /Kg/min after spinal anesthesia<br>* Other names: noradrenaline infusion;Drug: Bupivacaine<br>* 10 mg Bupivacaine intra-thecal for spinal anesthesia<br>* Other names: marcaine;|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| incidence of postspinal hypotension | The number of patients who develop hypotension (defined as decreased SBP less than 80% of the baseline reading during the period from intrathecal injection till delivery of the fetus) after spinal block divided by the total number in the group | 30 minutes after spinal anesthesia | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| heart rate | heart rate after spinal anesthesia measured in beat per minute | 90 minutes after spinal anesthesia | 
| vomiting | incidence of vomiting after spinal anesthesia | 120 minutes after spinal anesthesia | 
| nausea | incidence of nausea after spinal anesthesia | 120 minutes after spinal anesthesia | 
| ephedrine consumption | total amount of ephedrine consumed after spinal anesthesia | 60 minutes after spinal anesthesia | 
| Atropine consumption | total amount of atropine consumed after spinal anesthesia | 60 minutes after spinal anesthesia | 
| APGAR score | APGAR score of the delivered fetus | 10 minutes after delivery | 
| incidence of severe postspinal hypotension | The number of patients who develop hypotension (defined as decreased SBP less than 60% of the baseline reading during the period from intrathecal injection till delivery of the fetus) after spinal block divided by the total number in the group | 30 minutes after spinal anesthesia | 
| arterial blood pressure | arterial blood pressure after spinal anesthesia measured in mmHg | 90 minutes after spinal anesthesia |