The Effects of Height and Weight Adjusted Dose of Local Anesthetic.

NCT02635555 | Completed

• 1 other identifier: 107445
• Study Type: interventional
• Target: 160
• Locations: 1 country
• Sites: 1

Brief Summary

At our centre a conventional dose of 12 mg of hyperbaric bupivacaine in combination with a short acting opioid fentanyl (to increase block density) and a long acting opioid morphine (to provide post-operative pain relief ) is used for spinal anesthesia for cesarean section.However, larger doses of local anesthetic drug when used in caesarean section commonly cause low blood pressure and requires drugs (vasopressors) to treat it. In our study the investigators will standardize the doses of both opioids (fentanyl/morphine) and adjust the dose of local anesthetic (bupivacaine) based on the patients height and weight .One of the obvious challenges anesthesiologists face is providing adequate anesthesia to the patient whilst minimizing harmful side effects. Our primary concern is the low blood pressure as an effect of the spinal anesthetic as it is harmful to both mother and the baby. The investigators propose that the extent of surgical anesthetic block, which is dependent on height and weight in our adjusted dose group, will provide adequate anesthesia for surgery and minimise maternal low blood pressure.

Conditions

Complications; Cesarean Section; Hypotension

Outcome Measures

Primary Outcomes (1)

• Maternal hypotension needing vasopressors.

  Until the end of surgery

Secondary Outcomes (3)

• Time to adequate surgical anesthetic block

  24 hours after the surgery

• incidence of nausea, vomiting, pruritus, and respiratory depression

  24 hours after the surgery

• conversion to general anesthesia due to block failure

  1 hour

Study Arms (2)

Adjusted Spinal Dose

EXPERIMENTAL

Patients in this group receive height and weight adjusted dose for spinal anesthesia.During surgery, phenylephrine/ephedrine is given to maintain blood pressure as necessary. Episodes of hypotension will be treated with these vasopressors .

Drug: Phenylephrine

Standard Spinal Dose

ACTIVE COMPARATOR

Patients in this group receive a fixed standard dose for spinal anesthesia. During surgery, phenylephrine/ephedrine is given to maintain blood pressure as necessary. Episodes of hypotension will be treated with these vasopressors .

Drug: Phenylephrine

Interventions

Phenylephrine DRUG

100 mcg of phenylephrine or 5 mg ephedrine given as deemed necessary for treating episodes of hypotension.

Also known as: Ephedrine

Adjusted Spinal Dose; Standard Spinal Dose

Eligibility Criteria

• Age: 18 Years - 40 Years
• Sex: female
• Healthy Volunteers: Yes
• Age Groups: Adult (18-64)

You may qualify if:

• ASA I and II patients aged 18-40 \> 37 weeks gestation
• Scheduled for an elective c-section under spinal anesthetic
• Singleton pregnancy
• Patients height between 150-180cm and with a BMI of \<35
• Subject understands the study and consents to participate

You may not qualify if:

• Contraindication to neuraxial blockade
• Local anesthetic allergy
• Above or below our defined height and BMI criteria
• Emergency C-Section
• Complicated pregnancy including severe toxemia, pregnancy induced hypertension, and placenta previa

Sponsors & Collaborators

• London Health Sciences Centre Research Institute OR Lawson Research Institute of St. Joseph's: lead

Study Sites (1)

Victoria Hospital

London, Ontario, N6A 5W9, Canada

Location

MeSH Terms

Conditions

Hypotension

Interventions

Phenylephrine; Ephedrine

Condition Hierarchy (Ancestors)

Vascular Diseases; Cardiovascular Diseases

Intervention Hierarchy (Ancestors)

Ethanolamines; Amino Alcohols; Alcohols; Organic Chemicals; Amines; Propanolamines; Propanols; Phenethylamines; Ethylamines

Study Officials

• Shalini Dhir, FRCPC

  Western University

  PRINCIPAL INVESTIGATOR

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: RANDOMIZED
• Masking: DOUBLE
• Who Masked: PARTICIPANT, INVESTIGATOR
• Purpose: PREVENTION
• Intervention Model: PARALLEL
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Associate Professor

Study Record Dates

• First Submitted: December 10, 2015
• First Posted: December 21, 2015
• Study Start: April 1, 2016
• Primary Completion: June 1, 2019
• Study Completion: December 1, 2019
• Last Updated: September 26, 2022

Record last verified: 2022-09

Data Sharing

• IPD Sharing: Will not share

Locations

CA (1)