The Potency of Prophylactic Norepinephrine and Phenylephrine Boluses for Postspinal Anesthesia Hypotension
- Registration Number
- NCT05035472
- Lead Sponsor
- General Hospital of Ningxia Medical University
- Brief Summary
The purpose of this study is to investigate the potency between prophylactic norepinephrine and phenylephrine boluses for postspinal anesthesia hypotension in patients with severe preeclampsia during caesarean section.
- Detailed Description
Preeclampsia, which affects 5% to 7% of patients, 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 patients with preeclampsia are apparently higher than healthy patients, placental hypoperfusion is more common. Spinal anesthesia is still the preferred mode of anesthesia in patients with preeclampsia for cesarean section. In preeclampsia patients, spinal anesthesia improve intervillous blood flow (provided that hypotension is avoided) which contribute to increase placental perfusion. Even so, 17-26% patients 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 patients undergoing cesarean section. However, the ED50 (prevent postspinal hypotension in 50% of patients) and ED90 of prophylactic norepinephrine bolus is still unknown. The purpose of this study is to investigate the potency between prophylactic norepinephrine and phenylephrine boluses for postspinal anesthesia hypotension in patients with severe preeclampsia during caesarean section.
Recruitment & Eligibility
- Status
- UNKNOWN
- Sex
- Female
- Target Recruitment
- 80
- 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
- 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
Study & Design
- Study Type
- INTERVENTIONAL
- Study Design
- PARALLEL
- Arm && Interventions
Group Intervention Description Norepinephrine group Norepinephrine Prophylactic norepinephrine bolus simultaneous with spinal anesthesia Phenylephrine group Phenylephrine Prophylactic phenylephrine bolus simultaneous with spinal anesthesia
- Primary Outcome Measures
Name Time Method The dose that would be effective in preventing postspinal anesthesia hypotension in 50% (effective dose, ED 50) and 90% (ED90) of patients 1-15 minutes after spinal anesthesia Systolic blood pressure (SBP) \< 80% of the baseline
- Secondary Outcome Measures
Name Time Method The incidence of nausea and vomiting. 1-15 minutes after spinal anesthesia Presence of nausea and vomiting in patients after spinal anesthesia
The incidence of hypertension. 1-15 minutes after spinal anesthesia Systolic blood pressure (SBP) \>120% of the baseline.
pH Immediately after delivery From umbilical arterial blood gases.
The incidence of bradycardia. 1-15 minutes after spinal anesthesia Heart rate \< 60 beats/min.
Base excess (BE) Immediately after delivery From umbilical arterial blood gases.
APGAR score 5 min after delivery A= Appearance P=Pulse G=Grimace A=Attitude R=Respiration
The incidence of severe post-spinal anesthesia hypotension. 1-15 minutes after spinal anesthesia Systolic blood pressure (SBP) \< 60% of the baseline
The incidence of post-spinal anesthesia hypotension 1-15 minutes after spinal anesthesia Systolic blood pressure (SBP) \< 80% of the baseline
Partial pressure of oxygen (PO2) Immediately after delivery From umbilical arterial blood gases.