Clinical trial NCT06151522: 90% Effective Dose of Phenylephrine Infusions Under Intensive and Standard Treatment
Official title: 90% Effective Dose of Phenylephrine Infusions for Preventing Postspinal Anesthesia Hypotension Under Intensive and Standard Treatment During Cesarean Section
Study type: INTERVENTIONAL
Overall status: NOT_YET_RECRUITING
Phase: NA
Conditions: Adverse Effect
Lead sponsor: General Hospital of Ningxia Medical University
Sponsor class: OTHER
First posted: 2023-11-30
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 objective of this study is to investigate the 90% effective dose of phenylephrine infusions for preventing postspinal anesthesia hypotension under intensive and standard treatment during cesarean section

Detailed description: Post-spinal anesthesia hypotension is a frequent complication during spinal anesthesia for cesarean section. The incidence of post-spinal anesthesia hypotension is as high as 62.1-89.7% if prophylactic measures are not taken. The 2016 ASA guidelines for obstetric anesthesia suggest avoiding hypotension following spinal anesthesia in women and emphasize the use of vasopressors, specifically alpha-receptor agonists, as the preferred strategy to prevent and manage post-spinal anesthesia hypotension. The 2018 International Consensus in the United Kingdom and Northern Ireland recommends maintaining maternal systolic blood pressure above 90% of the baseline value following lumbar anesthesia, while avoiding dropping below 80% of the baseline value. Currently, the threshold for maintaining blood pressure above 80% of the baseline value is widely adopted as a standard; however, limited evidence supports the advantage of sustaining maternal blood pressure above 90% of the baseline value. The objective of this study is to investigate the 90% effective dose of phenylephrine infusions for preventing postspinal anesthesia hypotension under intensive and standard treatment during cesarean section.

Eligibility criteria: Inclusion Criteria:

* 18-45 years
* Primipara or multipara
* Singleton pregnancy ≥37 weeks
* American Society of Anesthesiologists physical status classification I to II
* Scheduled for cesarean section under spinal anesthesia

Exclusion Criteria:

* Body height \< 150 cm
* Body weight \> 100 kg or body mass index (BMI) ≥ 40 kg/m2
* Eclampsia or chronic hypertension or baseline blood pressure ≥180 mmHg
* Hemoglobin \< 7g/dl

Primary outcomes:
measure: ED50 and ED90
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: Base excess
timeFrame: Immediately after delivery
measure: Partial pressure of oxygen (PO2)
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: Yi Chen, M.D.
role: STUDY_CHAIR
References: