Minimum Effective Dose of Local Anaesthetic With Fentanyl Clinical Trial
Official title:
Determination of the Initial Minimum Effective Dose of 0.5% Bupivacaine With 20mcg of Fentanyl Via a Spinal Catheter for Operative Fixation of Fractured Neck of Femur.
Fractured neck of femur (FNF) is a common cause of admission to hospital in elderly patients
with multiple comorbidities. Anaesthetic management of this patient group is extremely
challenging.Neuraxial anaesthesia with minimum doses of local anaesthetic agents
administered via a spinal catheter leads to better cardiovascular stability.The minimum dose
of local anaesthetic with intrathecal fentanyl was not established yet.We propose to study
and determine the initial minimum local anaesthetic dose (MLAD) of 0.5% bupivacaine with 20
mcg of fentanyl administered via a spinal catheter to achieve a sensory block up to T10 for
the operative fixation of FNF.We will use a previously well established Dixon and Massey
"up-and-down method" to calculate initial MLAD in this prospective, observational trial.
Objectives: We would like to determine the initial MLAD of 0.5% bupivacaine with 20mcg of
fentanyl administered via a spinal catheter required to achieve a sensory block up to T10 on
the side of FNF.
Outcomes
Primary outcome:
1. Initial MLAD of 0.5% bupivacaine with 20mcg of fentanyl required for a sensory block up
to T10 on the side of FNF.
Secondary outcomes:
2. Total dose of 0.5% bupivacaine with 20mcg of fentanyl required for the operative
fixation of fractured neck of femur.
3. The effect on haemodynamic variables (blood pressure, heart rate).
4. Incidence of side effects
5. The length of postoperative analgesia (the time from the last dose of local anaesthetic
administered intrathecally to VAS>3).
6. The time to first rescue analgesic requirement
Study Design Prospective, observational trial.
Study Size Based on the previously well established Dixon and Massey "up-and-down
method"(10), we will recruit patients until a successful spinal block has been achieved in
six consecutive patients who received a specific dose. This is the requirement to calculate
the initial MLAD.
n/a
Observational Model: Cohort, Time Perspective: Prospective