Phenylephrine Prophylaxis for Postspinal Anesthesia Hypotension in Parturients With Preeclampsia

General Hospital of Ningxia Medical University

Status: Not yet enrolling

Conditions: Adverse Effect

Treatments: Drug: Phenylephrine; Drug: Normal saline

Study type: Interventional

Funder types: Other

Identifiers

NCT04576663

Yi Chen-2020-6

Details and patient eligibility

About

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.

Full 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.

Enrollment: 95 estimated patients

Sex: Female

Ages: 18 to 45 years old

Volunteers: No Healthy Volunteers

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

Trial design

Primary purpose: Treatment

Allocation: Randomized

Interventional model: Parallel Assignment

Masking: Triple Blind

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95 participants in 4 patient groups, including a placebo group

Control group

Placebo Comparator group

Description:

Normal saline infusion simultaneous with subarachnoid block

Treatment:

Drug: Normal saline

0.3125 μg/kg/min group

Experimental group

Description:

A maintenance dose of phenylephrine (0.3125 μg/kg/ min) infusion simultaneous with subarachnoid block

Treatment:

Drug: Phenylephrine

0.625 μg/kg/min group

Experimental group

Description:

A maintenance dose of phenylephrine (0.625 μg/kg/ min) infusion simultaneous with subarachnoid block

Treatment:

Drug: Phenylephrine

0.9375 μg/kg/min group

Experimental group

Description:

A maintenance dose of phenylephrine (0.9375 μg/kg/ min) infusion simultaneous with subarachnoid block

Treatment:

Drug: Phenylephrine