NCT07824713

Brief Summary

The purpose of this study is to determine the 50% and 90% effective doses (ED50 and ED90) of prophylactic phenylephrine infusion for preventing spinal anesthesia-induced hypotension during elective cesarean delivery, in the supine position and in the left-lateral-tilt 15° position, respectively. Two hundred parturients with singleton term pregnancies will be randomized 1:1 to the supine group or the left-tilt 15° group, and within each position 1:1:1:1 to one of four fixed phenylephrine infusion rates (0.2, 0.4, 0.6, or 0.8 μg/kg/min; 25 per group), with the rate allocation masked by concentration blinding (identical pump rate, different solution concentrations). Spinal anesthesia consists of hyperbaric bupivacaine 12 mg plus morphine 0.15 mg. The primary outcome is the incidence of hypotension (systolic blood pressure \< 80% of baseline or \< 90 mmHg) from completion of the intrathecal injection to delivery. ED50 and ED90 will be estimated by probit regression within each position.

Trial Health

63
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Trial Health Score

Automated assessment based on enrollment pace, timeline, and geographic reach

Enrollment
200

participants targeted

Target at P75+ for phase_4

Timeline
4mo left

Started Sep 2026

Shorter than P25 for phase_4

Geographic Reach
1 country

1 active site

Status
not yet recruiting

Health score is calculated from publicly available data and should be used for screening purposes only.

Trial Relationships

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Study Timeline

Key milestones and dates

Study Progress11%
Sep 2026Jan 2027

First Submitted

Initial submission to the registry

September 15, 2026

Completed
2 days until next milestone

First Posted

Study publicly available on registry

September 17, 2026

Completed
3 days until next milestone

Study Start

First participant enrolled

September 20, 2026

Completed
4 months until next milestone

Primary Completion

Last participant's last visit for primary outcome

January 31, 2027

Expected
Same day until next milestone

Study Completion

Last participant's last visit for all outcomes

January 31, 2027

Last Updated

September 17, 2026

Status Verified

September 1, 2026

Enrollment Period

4 months

First QC Date

September 15, 2026

Last Update Submit

September 16, 2026

Conditions

Hypotension After Spinal Anesthesia

Keywords

HypotensionCesarean DeliveryPhenylephrine

Outcome Measures

Primary Outcomes (1)

  • hypotension incidence of hypotension from completion of intrathecal injection to delivery of the infant

    Hypotension defined as systolic blood pressure \< 80% of baseline (measured in the assigned study position) or \< 90 mmHg

    From completion of spinal anesthesia to fetal delivery

Secondary Outcomes (5)

  • Umbilical artery and umbilical vein blood gas values

    At delivery

  • Apgar scores at 1 and 5 minutes after delivery

    From fetal delivery to 5 minutes after delivery

  • Time to first rescue vasopressor

    From completion of intrathecal injection to delivery

  • Serial systolic blood pressure values within 12 minutes after intrathecal injection

    From completion of spinal anesthesia to 12 minutes after completion of spinal anesthesia

  • Incidence of hypertension before delivery

    From completion of intrathecal injection to delivery

Study Arms (8)

Supine Position - Phenylephrine 0.2 μg/kg/min

EXPERIMENTAL

Participants in the supine position (maintained from completion of spinal anesthesia until delivery) receiving prophylactic phenylephrine infusion 0.2 μg/kg/min (pump rate 0.6 mL/kg/h, concentration-blinded solution 20 μg/mL) from completion of spinal anesthesia until delivery.

Drug: Phenylephrine hydrochloride infusion

Supine Position - Phenylephrine 0.4 μg/kg/min

EXPERIMENTAL

Supine position as Arm 1; phenylephrine infusion 0.4 μg/kg/min (concentration-blinded solution 40 μg/mL).

Drug: Phenylephrine hydrochloride infusion

Supine Position - Phenylephrine 0.6 μg/kg/min

EXPERIMENTAL

Supine position as Arm 1; phenylephrine infusion 0.6 μg/kg/min (concentration-blinded solution 60 μg/mL).

Drug: Phenylephrine hydrochloride infusion

Supine Position - Phenylephrine 0.8 μg/kg/min

EXPERIMENTAL

Supine position as Arm 1; phenylephrine infusion 0.8 μg/kg/min (concentration-blinded solution 80 μg/mL).

Drug: Phenylephrine hydrochloride infusion

Left-Tilt 15° - Phenylephrine 0.2 μg/kg/min

ACTIVE COMPARATOR

Participants in the left-lateral-tilt 15° position (sponge wedge 7.5 × 28 × 50 cm under the thoracolumbar region, maintained from completion of spinal anesthesia until delivery) receiving prophylactic phenylephrine infusion 0.2 μg/kg/min (pump rate 0.6 mL/kg/h, concentration-blinded solution 20 μg/mL).

Drug: Phenylephrine hydrochloride infusion

Left-Tilt 15° - Phenylephrine 0.4 μg/kg/min

EXPERIMENTAL

Left-tilt 15° position as Arm 5; phenylephrine infusion 0.4 μg/kg/min (concentration-blinded solution 40 μg/mL).

Drug: Phenylephrine hydrochloride infusion

Left-Tilt 15° - Phenylephrine 0.6 μg/kg/min

ACTIVE COMPARATOR

Left-tilt 15° position as Arm 5; phenylephrine infusion 0.6 μg/kg/min (concentration-blinded solution 60 μg/mL).

Drug: Phenylephrine hydrochloride infusion

Left-Tilt 15° - Phenylephrine 0.8 μg/kg/min

ACTIVE COMPARATOR

Left-tilt 15° position as Arm 5; phenylephrine infusion 0.8 μg/kg/min (concentration-blinded solution 80 μg/mL).

Drug: Phenylephrine hydrochloride infusion

Interventions

Phenylephrine hydrochloride infusionDRUG

Prophylactic fixed-rate IV infusion (pump rate 0.6 mL/kg/h, concentration-blinded), from completion of spinal anesthesia until delivery

Left-Tilt 15° - Phenylephrine 0.2 μg/kg/minLeft-Tilt 15° - Phenylephrine 0.4 μg/kg/minLeft-Tilt 15° - Phenylephrine 0.6 μg/kg/minLeft-Tilt 15° - Phenylephrine 0.8 μg/kg/minSupine Position - Phenylephrine 0.2 μg/kg/minSupine Position - Phenylephrine 0.4 μg/kg/minSupine Position - Phenylephrine 0.6 μg/kg/minSupine Position - Phenylephrine 0.8 μg/kg/min

Eligibility Criteria

Age18 Years+
Sexfemale
Healthy VolunteersNo
Age GroupsAdult (18-64), Older Adult (65+)

You may qualify if:

  • Singleton term pregnancy scheduled for elective cesarean delivery
  • Height 150-180 cm
  • ASA physical status II-III
  • Body mass index \< 35 kg/m2

You may not qualify if:

  • Transverse lie or suspected macrosomia
  • Uterine abnormalities (e.g., large uterine fibroids, bicornuate uterus)
  • Polyhydramnios
  • Ruptured membranes or oligohydramnios
  • Fetal growth restriction
  • Gestational or pregestational hypertension, diabetes mellitus, or preeclampsia
  • Diseases associated with autonomic neuropathy (e.g., diabetes mellitus \> 10 years) or renal failure
  • Contraindications to spinal anesthesia
  • Refusal to provide written informed consent-

Contact the study team to confirm eligibility.

Sponsors & Collaborators

Study Sites (1)

Department of Anesthesiology，Xuzhou HeJia Hospital, Xuzhou, Jiangsu, China

Xuzhou, Jiangsu, 221000, China

Location

MeSH Terms

Conditions

Hypotension

Condition Hierarchy (Ancestors)

Vascular DiseasesCardiovascular Diseases

Central Study Contacts

Feng Feng, Dr.

CONTACT

13601083503doc_yifeng@163.com

Study Design

Study Type
interventional
Phase
phase 4
Allocation
RANDOMIZED
Masking
QUADRUPLE
Who Masked
PARTICIPANT, CARE PROVIDER, INVESTIGATOR, OUTCOMES ASSESSOR
Masking Details
Position allocation was open label; rate allocation was masked by concentration blinding (identical pump rate 0.6 mL/kg/h; solution concentrations 20/40/60/80 μg/mL prepared in identical syringes)
Purpose
PREVENTION
Intervention Model
PARALLEL
Sponsor Type
OTHER
Responsible Party
PRINCIPAL INVESTIGATOR
PI Title
Director of Anesthesiology

Study Record Dates

First Submitted

September 15, 2026

First Posted

September 17, 2026

Study Start

September 20, 2026

Primary Completion (Estimated)

January 31, 2027

Study Completion (Estimated)

January 31, 2027

Last Updated

September 17, 2026

Record last verified: 2026-09

Locations

CN(1)