ET 50 for Post Caesarean Section Spinal Hypotension (ET-50)
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.
|Study Design:||Allocation: Randomized
Endpoint Classification: Efficacy Study
Intervention Model: Factorial Assignment
Masking: Double Blind (Subject, Caregiver, 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|
- 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 ] [ Designated as safety issue: No ]The time required so that 50% of patients to not experience hypotension
- Bupivicaine dose [ Time Frame: We will test for blockade level till 40 min after spinal ] [ Designated as safety issue: No ]
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.
|Study Start Date:||March 2012|
|Estimated Study Completion Date:||January 2014|
|Estimated Primary Completion Date:||December 2013 (Final data collection date for primary outcome measure)|
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.
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