10 Vs.15 mcg Norepinephrine Bolus in Severe Maternal Hypotension During Cesarean Delivery

Comparing 10- Versus 15-mcg Norepinephrine Bolus for Management of Severe Post-spinal Hypotension During Elective Cesarean Delivery: A Randomized, Controlled Trial

Data regarding the optimum dose of norepinephrine for management of severe maternal hypotension is lacking. A previous report showed that the use of 10-mcg norepinephrine bolus was not superior to the 5-mcg bolus in the management of severe hypotension in addition the incidence of reactive bradycardia and hypertension was comparable in the two doses. Therefore, we hypothesize that using a higher dose of norepinephrine (15 mcg) would increase the success rate of management of severe hypotensive episode.

Study Overview

• Status: Not yet recruiting
• Conditions: Hypotension; Cesarean Section; Spinal Anesthesia
• Intervention / Treatment: Drug: 10 mcg Norepinephrine; Drug: 15 mcg Norepinephrine

Detailed Description

Upon arrival to the operating room, the patient will be in supine position with left uterine displacement using a wedge below the right buttock. Routine monitoring will be applied (electrocardiography, pulse oximetry, and non-invasive blood pressure monitor). An 18G-cannula will be inserted, and the patients will receive 10 mg metoclopramide. Baseline heart rate and systolic blood pressure will be recorded as the average of three consecutive readings with 2-minutes interval.

Lactated Ringer's solution will be infused at rate of 15 mL/Kg over 10 minutes as a co-load; spinal anesthesia will be achieved by injecting 10 mg of hyperbaric bupivacaine and 20 mcg fentanyl into the subarachnoid space at L3-L4 or L4-L5 interspace using 25G spinal needle.

After subarachnoid block, mothers will be placed in the supine position with left-lateral tilt.

Block success will be assessed after 5 minutes from intrathecal injection of local anesthetic; and will be confirmed if sensory block level is at T4.

The patient would receive the study drug only if she developed severe post-spinal hypotension (defined as systolic blood pressure ≤60% of the baseline reading) as her first hypotensive episode. The management of the hypotensive episode will be considered successful if the systolic blood pressure is > 80% of the baseline within 2 mins of the bolus. If the bolus failed, norepinephrine bolus of 5 mcg will be given.

Any other hypotensive episode (systolic blood pressure <80% of baseline) will be managed with norepinephrine bolus of 5 mcg.

Intraoperative bradycardia (defined as heart rate less than 55 bpm) will be managed by IV atropine bolus (0.5 mg) will be administered.

Fluid administration will be continued up to a maximum of 1.5 liters. An oxytocin bolus (1 IU) will be delivered over five seconds after delivery then infused at a rate of 2.5-7.5 IU/hour.

• Study Type: Interventional
• Enrollment (Estimated): 184
• Phase: Not Applicable

Contacts and Locations

Study Locations

• Egypt
  • Cairo, Egypt
    • Cairo University

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

• full-term singleton pregnant women
• American society of anesthesiologist II, scheduled for elective cesarean delivery,

Exclusion Criteria:

• Patients with uncontrolled cardiac morbidities (patients with tight valvular lesion, impaired contractility with ejection fraction < 50%, heart block, and arrhythmias),
• hypertensive disorders of pregnancy,
• peripartum bleeding,
• coagulation disorders (patients with INR >1.4 and or platelet count < 80000 /dL) or any contraindication to regional anesthesia,
• baseline systolic blood pressure (SBP) < 100 mmHg

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Quadruple

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Active Comparator: 10 mcg group; patient will receive the study dry once developed severe post-spinal hypotension	Drug: 10 mcg Norepinephrine; The assigned dose (10 mcg) will be diluted with normal saline in a 10-cc syringe
Active Comparator: 15 mcg group; patients will receive the study dry once developed severe post-spinal hypotension	Drug: 15 mcg Norepinephrine; The assigned dose (15 mcg) will be diluted with normal saline in a 10-cc syringe.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
the incidence of successful management of severe post-spinal hypotension	systolic blood pressure >80% of baseline after drug bolus	1 min after spinal anesthesia until 5 min after the delivery

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
time to severe hypotensive episode	min	1 min after spinal anesthesia until 5 min after the delivery
reactive bradycardia	heart rate <55 beat/min	1 min after spinal anesthesia until 5 min after the delivery
reactive hypertension	systolic blood pressure >120% of baseline	1 min after spinal anesthesia until 5 min after the delivery
umbilical blood pH	umbilical artery sample	5 min after delivery
Apgar score	assess Breathing effort, Heart rate, Muscle tone, Reflexes, Skin color, Each category is scored with 0, 1, or 2	5 min after delivery
systolic blood pressure	mmHg	baseline, 1 min after spinal anesthesia until 5 min after the delivery
heart rate	beat/min	baseline, 1 min after spinal anesthesia until 5 min after the delivery

Collaborators and Investigators

• Sponsor: Cairo University

Study record dates

Study Major Dates

• Study Start (Estimated): August 1, 2024
• Primary Completion (Estimated): December 1, 2024
• Study Completion (Estimated): December 1, 2024

Study Registration Dates

• First Submitted: July 16, 2024
• First Submitted That Met QC Criteria: July 16, 2024
• First Posted (Actual): July 22, 2024

Study Record Updates

• Last Update Posted (Actual): July 22, 2024
• Last Update Submitted That Met QC Criteria: July 16, 2024
• Last Verified: July 1, 2024

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Cardiovascular Diseases; Vascular Diseases; Hypotension; Physiological Effects of Drugs; Adrenergic Agents; Neurotransmitter Agents; Molecular Mechanisms of Pharmacological Action; Autonomic Agents; Peripheral Nervous System Agents; Adrenergic alpha-Agonists; Adrenergic Agonists; Sympathomimetics; Vasoconstrictor Agents; Norepinephrine
• Other Study ID Numbers: MS-421-2022

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: UNDECIDED
• IPD Plan Description: The datasets used and/or analyzed during the current study are available from the corresponding author upon reasonable request

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No