Phenylephrine Dose and Mode of Administration for Spinal Anesthesia Induced Hypotension

Study Overview
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Brief Summary
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Three different regimens of phenylephrine are being evaluated to see if one is superior over the other in the maintenance of cardiac output while keeping normotension and/or treating hypotension experienced when receiving spinal anesthesia for cesarean delivery.

Detailed Description
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Phenylephrine will be administered in one of 3 regimens: Intermittent bolus of 50 mcg, Intermittent bolus of 100 mcg, or continuous infusion of 100 mcg/min. The infusion will contain either phenylephrine or normal saline (placebo). Subjects who are randomized to receive a bolus dose will receive placebo in the infusion. Subjects who are randomized to receive the phenylephrine infusion will have normal saline (placebo) in the bolus syringe. Baseline blood pressures will be obtained prior to surgery and then maintained using these drugs. Blood pressure and heart rate will be monitored as usual standard of care. Continuous cardiac output and hemodynamic monitoring will be obtained using CNAP (Tm) or similar (equivalent) monitoring device. Blood pressure will be maintained at 90-120% of baseline utilizing infusion and/or bolus with the 3 regimens.

Official Title
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Correlation and Effects on Cardiac Output With Intermittent Phenylephrine Administration of 50 mcg Versus 100 mcg or 100mcg/Min Prophylactic Infusion for Treatment of Hypotension in Parturients After Receiving Spinal Anesthesia for Cesarean Delivery

Conditions
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Complications; Cesarean Section, Spinal Anesthetics Causing Adverse Effects in Therapeutic Use

Intervention / Treatment
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* Drug: Phenylephrine


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: scheduled for cesarean delivery age >/=18 years of age >/= 37 weeks EGA ASA status I-III Exclusion Criteria: allergy to medications used in the study non-English speaking

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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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Treatment
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Triple


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: phenylephrine 50mcg bolus<br>Phenylephrine 50 mcg bolus dosing with continuous placebo infusion | Drug: Phenylephrine<br> <br> |
| Experimental: Phenylephrine 100 mcg bolus<br>Phenylephrine 100 mcg bolus dosing wtih continuous placebo infusion. | Drug: Phenylephrine<br> <br> |
| Experimental: Phenylephrine continuous infusion 100mcg/min<br>Continuous phenylephrine infusion of 100 mcg/min with placebo bolus dosing. | Drug: Phenylephrine<br> <br> |

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Magnitude of cardiac output changes | Magnitude of cardiac output reduction for the duration from preoperative baseline from time of spinal anesthesia to delivery of fetus and placenta. | 0-90 minutes | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| provider intervention | number of provider intervention to treat abnormal hemodynamics | 0-90 minutes | 
| vasopressor requirement | total amount of vasopressor or equivalent required | 0-90 minutes | 
| Emetic symptoms | emetic symptoms - magnitude and/or incidence | 0-90 minutes | 
| hypertension | incidence and magnitude | 0-90 minutes | 
| hypotension | incidence and magnitude | 0-90 minutes | 
| bradycardia | incidence and magnitude | 0-90 minutes | 
| Anesthetic time |  | up to 120 minutes | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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cesarean section, hypotension, phenylephrine