Phenylephrine Prophylaxis for Postspinal Anesthesia Hypotension in Parturients With Preeclampsia Undergoing Cesarean Section: a Randomized, Placebo-controlled Dose-finding Trial
Overview
- Phase
- Not Applicable
- Intervention
- Phenylephrine
- Conditions
- Adverse Effect
- Sponsor
- General Hospital of Ningxia Medical University
- Enrollment
- 95
- Primary Endpoint
- The incidence of post-spinal anesthesia hypotension
- Status
- Not yet recruiting
- Last Updated
- 4 years ago
Overview
Brief Summary
The purpose of this study is to investigate the suitable infusion dose of phenylephrine for prophylaxis against postspinal anesthesia hypotension in parturients with preeclampsia undergoing cesarean section.
Detailed Description
Preeclampsia, which affects 5% to 7% of parturients, is a significant cause of maternal and neonatal morbidity and mortality. Because of constricted myometrial spiral arteries with exaggerated vasomotor responsiveness, though blood pressure in parturients with preeclampsia are apparently higher than healthy parturients, placental hypoperfusion is more common. Spinal anesthesia is still the preferred mode of anesthesia in parturients with preeclampsia for cesarean section. In preeclampsia parturients, spinal anesthesia improve intervillous blood flow (provided that hypotension is avoided) which contribute to increase placental perfusion. Even so, 17-26% parturients with preeclampsia experienced postspinal anesthesia hypotension due to the extensive sympathetic block that occurred with spinal anesthesia. Practical guidelines for obstetric anesthesia from the American Society of Anesthesiologists and an international consensus statement on the management of hypotension with vasopressors indicate either IV ephedrine or phenylephrine may be used to correct hypotension. But the suitable infusion dose of phenylephrine in parturients with preeclampsia is still unknown. The purpose of this study is to investigate the suitable infusion dose of phenylephrine for prophylaxis against post-spinal anesthesia hypotension in parturients with preeclampsia undergoing cesarean section.
Investigators
Eligibility Criteria
Inclusion Criteria
- •18-45 years
- •Primipara or multipara
- •Singleton pregnancy ≥32 weeks
- •American Society of Anesthesiologists physical status classification II to III
- •Scheduled for cesarean section under spinal anesthesia
Exclusion Criteria
- •Baseline blood pressure ≥180 mmHg
- •Body height \< 150 cm
- •Body weight \> 100 kg or body mass index (BMI) ≥ 40 kg/m2
- •Eclampsia or chronic hypertension
- •Hemoglobin \< 7g/dl
- •Fetal distress, or known fetal developmental anomaly
Arms & Interventions
0.625 μg/kg/min group
A maintenance dose of phenylephrine (0.625 μg/kg/ min) infusion simultaneous with subarachnoid block
Intervention: Phenylephrine
Control group
Normal saline infusion simultaneous with subarachnoid block
Intervention: Normal saline
0.3125 μg/kg/min group
A maintenance dose of phenylephrine (0.3125 μg/kg/ min) infusion simultaneous with subarachnoid block
Intervention: Phenylephrine
0.9375 μg/kg/min group
A maintenance dose of phenylephrine (0.9375 μg/kg/ min) infusion simultaneous with subarachnoid block
Intervention: Phenylephrine
Outcomes
Primary Outcomes
The incidence of post-spinal anesthesia hypotension
Time Frame: 1-15 minutes after spinal anesthesia
Systolic blood pressure (SBP) \< 80% of the baseline
Secondary Outcomes
- Overall stability of heart rate control versus baseline(1-15 minutes after spinal anesthesia)
- APGAR score(5 min after delivery)
- The incidence of hypertension.(1-15 minutes after spinal anesthesia)
- pH(Immediately after delivery)
- Partial pressure of oxygen(Immediately after delivery)
- Base excess(Immediately after delivery)
- Overall stability of systolic blood pressure control versus baseline(1-15 minutes after spinal anesthesia)
- The incidence of severe post-spinal anesthesia hypotension(1-15 minutes after spinal anesthesia)
- The incidence of nausea and vomiting(1-15 minutes after spinal anesthesia)
- The incidence of bradycardia(1-15 minutes after spinal anesthesia)