Determination of ED50 and ED95 of Isobaric Bupivacaine for Post-Partum Bilateral Tubal Ligation
Description:
This prospective study proposes to enroll 40 post-partum women who are undergoing elective
post-partum bilateral tubal ligation. The patient will be positioned sitting, and combined
spinal anesthesia will be performed at L2-3 or L3-4 level. The presence of an epidural
catheter enables the provider to supplement the spinal anesthetic if required. The starting
dose of isobaric bupivacaine will be 10 mg based on prior similar studies1,4 and our
institution’s current practice. The dose of intrathecal isobaric bupivacaine was decided by
using the up-down sequential method.
The motor block will be graded by a modified Bromage score: Score 1 = complete block, unable
to move feet or knees; 2 = almost complete block, able to move feet only; 3 = partial block,
just able to move knees; 4 = detectable weakness of hip flexion while supine, full flexion of
knees; 5 = no detectable weakness of hip flexion while supine; and 6 = able to perform
partial knee bend. The score of 1 or 2 within 10-15 minutes of injection will be evaluated as
successful motor block.
The success of the sensory spinal block will be noted when bilateral T6 sensory level to
pinprick is attained after 10 mins from the intrathecal drug administration, this is in
accordance with previous studies1.
If spinal anesthesia is inadequate, the epidural catheter will be dosed up for
supplementation. All observations, including block characteristics and the associated outcome
(i.e., adequate or inadequate block), will be evaluated by a dedicated anesthesia provider.
Intraoperative adverse effects, such as hypotension, bradycardia, nausea, or vomiting,
pruritus, or shivering were noted. Hypotension is defined as a decrease of more than 20% in
basal systolic blood pressure within 30 minutes of intrathecal injection. The management of
blood pressure including dose of pressor: phenylephrine and ephedrine will be at the
discretion of the attending anesthesiologist. The use of pressor and anti-emetics will also
be recorded.
The study will be take place in standard clinical context. The study does not deviate from
our current practice, which includes the use of combined spinal anesthesia where the epidural
catheter is available if supplemental local anesthetic is required.
Condition:
Anesthesia, Local
Treatment:
Dose adjustment of bupivacaine
Start Date:
February 25, 2019
Sponsor:
University of Texas Southwestern Medical Center
For More Information:
https://clinicaltrials.gov/show/NCT03779568