Clinical trial NCT05035472: The Potency of Prophylactic Norepinephrine and Phenylephrine Boluses for Postspinal Anesthesia Hypotension
Official title: Comparison of the Potency of Prophylactic Norepinephrine and Phenylephrine Boluses for Postspinal Anesthesia Hypotension in Patients With Severe Preeclampsia During Caesarean Section
Study type: INTERVENTIONAL
Overall status: UNKNOWN
Phase: NA
Conditions: Adverse Effect
Keywords: Norepinephrine
Phenylephrine
Postspinal anesthesia hypotension
Preeclampsia
Cesarean section
Lead sponsor: General Hospital of Ningxia Medical University
Sponsor class: OTHER
First posted: 2021-09-05
Enrollment: 80
Sex: FEMALE
Minimum age (years): 18
Maximum age (years): 45
Standard ages: ADULT
Accepts healthy volunteers: no
Allocation: RANDOMIZED
Intervention model: PARALLEL
Primary purpose: TREATMENT

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.

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

Primary outcomes:
measure: The dose that would be effective in preventing postspinal anesthesia hypotension in 50% (effective dose, ED 50) and 90% (ED90) of patients
timeFrame: 1-15 minutes after spinal anesthesia
Secondary outcomes:
measure: The incidence of post-spinal anesthesia hypotension
timeFrame: 1-15 minutes after spinal anesthesia
measure: The incidence of severe post-spinal anesthesia hypotension.
timeFrame: 1-15 minutes after spinal anesthesia
measure: The incidence of bradycardia.
timeFrame: 1-15 minutes after spinal anesthesia
measure: The incidence of nausea and vomiting.
timeFrame: 1-15 minutes after spinal anesthesia
measure: The incidence of hypertension.
timeFrame: 1-15 minutes after spinal anesthesia
measure: pH
timeFrame: Immediately after delivery
measure: Partial pressure of oxygen (PO2)
timeFrame: Immediately after delivery
measure: Base excess (BE)
timeFrame: Immediately after delivery
measure: APGAR score
timeFrame: 1 min after delivery
measure: APGAR score
timeFrame: 5 min after delivery
Other outcomes:
Locations:
Study officials:
affiliation: General Hospital of Ningxia Medical University
name: Xinli Ni, Dr.
role: STUDY_CHAIR
References: