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ET 50 for Post Caesarean Section Spinal Hypotension (ET-50)

This study has been completed.
Information provided by (Responsible Party):
Albert Moore, McGill University Health Center Identifier:
First received: March 20, 2012
Last updated: June 20, 2014
Last verified: June 2014
Hypotension is extremely common after induction of spinal anesthesia for cesarean delivery. Anesthetic blockade of the sympathetic outflow of the spinal cord causes vasodilation, and is one cause of this hypotension. The higher the spread of the blockade will result in a higher incidence of hypotension. Injected hyperbaric medication has about 15 minutes to spread within the intrathecal space before it will be taken up by the nerve roots. The time that a patient remains in one position after medication injection will affect the spread of the resultant anesthetic block. A patient who is left sitting for a longer period of time after injection of hyperbaric medication will have a lower level of block than someone who is placed supine immediately. In this study, the investigators wish to use up down sequential analysis to determine the time period a patient should remain seated after intrathecal injection of hyperbaric bupivacaine that will result in a 50% rate of hypotension.

Condition Intervention Phase
Drug: 2 ml bupivacaine
Drug: 1.5 ml bupivicaine.
Phase 2

Study Type: Interventional
Study Design: Allocation: Randomized
Intervention Model: Factorial Assignment
Masking: Double Blind (Participant, Care Provider, Investigator, Outcomes Assessor)
Primary Purpose: Prevention
Official Title: The Time Required to Remain Sitting After Spinal Anesthesia for 50% of Patients to Not Experience Hypotension

Resource links provided by NLM:

Further study details as provided by McGill University Health Center:

Primary Outcome Measures:
  • The time required to remain sitting after spinal anesthesia [ Time Frame: start with 3 minutes after completion of spinal then we ll go up or down ]
    The time required so that 50% of patients to not experience hypotension

Secondary Outcome Measures:
  • Bupivicaine dose [ Time Frame: We will test for blockade level till 40 min after spinal ]

    To see if ET50 is dependant on the dosage of medication given, we will determine the ET50 for 2 doses of hyperbaric bupivicaine.

    Patients will receive either 2 ml or 1.5 ml of 0.75% hyperbaric bupivacaine, for a total of 15 mg or 12.5 mg of bupivacaine respectively.

Enrollment: 50
Study Start Date: March 2012
Study Completion Date: May 2014
Primary Completion Date: March 2014 (Final data collection date for primary outcome measure)
Arms Assigned Interventions
Active Comparator: 2 ml bupivacaine
2 ml of 0.75% hyperbaric bupivacaine, for a total of 15 mg of bupivacaine.
Drug: 2 ml bupivacaine
2 ml bupivacaine
Active Comparator: 1.5 ml bupivicaine.
1.5 ml of 0.75% hyperbaric bupivacaine, for a total of 12.5 mg of bupivacaine.
Drug: 1.5 ml bupivicaine.
1.5 ml bupivicaine.

  Show Detailed Description


Ages Eligible for Study:   18 Years to 45 Years   (Adult)
Sexes Eligible for Study:   Female
Accepts Healthy Volunteers:   No

Inclusion Criteria:

  • Patients 18 years or older, presenting for scheduled cesarean delivery to the C7 birthing centre.

Exclusion Criteria:

  • Unable to communicate in English or French
  • Multiple gestations
  • Patients with hypertension
  • Patients with contraindications to any drug or techniques used in the study
  • BMI > 35
  Contacts and Locations
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Please refer to this study by its identifier: NCT01561274

Canada, Quebec
Royal Victoria Hospital
Montreal, Quebec, Canada
Sponsors and Collaborators
McGill University Health Center
Principal Investigator: Albert Moore, MD McGill University Health Center
  More Information

Publications automatically indexed to this study by Identifier (NCT Number):
Responsible Party: Albert Moore, Assistant professor, principal investigator, McGill University Health Center Identifier: NCT01561274     History of Changes
Other Study ID Numbers: 11-134-SDR
Study First Received: March 20, 2012
Last Updated: June 20, 2014

Additional relevant MeSH terms:
Vascular Diseases
Cardiovascular Diseases
Anesthetics, Local
Central Nervous System Depressants
Physiological Effects of Drugs
Sensory System Agents
Peripheral Nervous System Agents processed this record on April 21, 2017