Maternal Cardiac Output Response to Rescue Norepinephrine and Phenylephrine Boluses in Patients With Severe Preeclampsia

General Hospital of Ningxia Medical University

Status: Completed

Conditions: Hemodynamic Instability

Treatments: Drug: Phenylephrine; Drug: Norepinephrine

Study type: Interventional

Funder types: Other

Identifiers

NCT05035485

Yi Chen-2021-2

Details and patient eligibility

About

The purpose of this study is to investigate the maternal cardiac output response to rescue norepinephrine and phenylephrine boluses for 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. As a potential substitute drug for phenylephrine and ephedrine, norepinephrine has gained traction for use in parturients undergoing cesarean section. However, hemodynamic effects of the rescue norepinephrine bolus is still unknown. The purpose of this study is to investigate the maternal cardiac output response to rescue norepinephrine and phenylephrine boluses for postspinal anesthesia hypotension in parturients with preeclampsia undergoing cesarean section.

Enrollment: 40 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: Double Blind

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40 participants in 2 patient groups

Phenylephrine group

Active Comparator group

Description:

Rescue phenylephrine (75μg) was given when postspinal anesthesia hypotension occurred

Treatment:

Drug: Phenylephrine

Norepinephrine group

Experimental group

Description:

Rescue norepinephrine (6μg) was given when postspinal anesthesia hypotension occurred

Treatment:

Drug: Norepinephrine