ED90 of 0.75% Bupivacaine for Bilateral Tubal Ligation (BTL)

Duke University

Overview

The purpose of this study is to determine the dose of bupivacaine that provides effective pain management in 90% (ED90) of patients undergoing bilateral tubal ligation. This will guide anesthesiologists on the most effective dose to minimize intraoperative pain during this procedure. The goal is to make women as comfortable as possible when they undergo this procedure while also minimizing the amount of time they are required to remain in the hospital afterwards for monitoring.

Study Type

INTERVENTIONAL

Allocation

RANDOMIZED

Purpose

SUPPORTIVE_CARE

Masking

DOUBLE

Conditions

Pain

Interventions

Hyperbaric bupivacaineDRUG

The dose for the first subject (A#X) will be 12 mg 0.75% hyperbaric bupivacaine. Two possible outcomes will be recorded: satisfactory or unsatisfactory anesthesia which is determined by occurrence of intraoperative pain and the need for intraoperative analgesia supplementation. Satisfactory analgesia will be defined as a sensory block to the T8 dermatome and the patient shall require no further supplementation for discomfort during her procedure. Unsatisfactory analgesia will be defined as a block not achieving a T8 dermatomal level or when a patient requests additional medication for discomfort at any time during her procedure. The dose for the next (A#X+1) will be adjusted based on the outcome from previous subjects respectively using up-down sequential allocation method with a biased-coin design. This process will continue in similar fashion with dose adjustments for next subjects to be based on outcome from subjects immediately prior.

Eligibility

Sex: FEMALEMin age: 18 YearsHealthy volunteers:

Medical Language ↔ Plain English

Inclusion Criteria: * ≥ 18 years of age * American Society of Anesthesiology class II or III * bilateral tubal ligation Exclusion Criteria: * patient refusal * BMI ≥ 50 kg/m2 * American Society of Anesthesiology class IV or above * contraindication to neuraxial anesthesia * allergy to bupivacaine

Outcomes

Primary Outcomes

Dose (in mg) of intrathecal 0.75% hyperbaric bupivacaine that provides effective analgesia in 90% of patients undergoing bilateral tubal ligation as measured by patient reported effectiveness.