Clinical Trial Details
— Status: Completed
Administrative data
NCT number |
NCT04396548 |
Other study ID # |
Midodrine and SA |
Secondary ID |
|
Status |
Completed |
Phase |
N/A
|
First received |
|
Last updated |
|
Start date |
June 8, 2020 |
Est. completion date |
December 29, 2020 |
Study information
Verified date |
January 2021 |
Source |
Mansoura University |
Contact |
n/a |
Is FDA regulated |
No |
Health authority |
|
Study type |
Interventional
|
Clinical Trial Summary
Neuraxial blockade such as spinal anaesthesia can cause severe hypotension due to
pharmacological sympathectomy resulting in potential deleterious consequences for the
patient. Prevention of this spinal anaesthesia induced hypotension is of utmost importance.
Techniques currently in use for preventing hypotension include intravenous fluid
prehydration, sympathomimetic drugs, and physical methods such as leg bindings and
compression stockings. Midodrine is a direct acting α1-adrenoceptor agonist which causes
venous and arterial vasoconstriction through stimulation of α1- receptors located in the
vasculature. The aim of this study is to evaluate the efficacy and safety of prophylactic
midodrine use with preoperative fluid hydration before spinal anesthesia in the prevention of
hypotension in patients undergoing elective orthopedic surgery. We hypothesize that
intraoperative hypotension would be less in patients given midodrine and intravenous fluid
prehydration preoperatively before spinal anesthesia.
Description:
Neuraxial blockade such as spinal anaesthesia can cause severe hypotension due to
pharmacological sympathectomy resulting in potential deleterious consequences for the
patient. Prevention of this spinal anaesthesia induced hypotension is of utmost importance.
Several techniques and methodologies have been adopted for the prevention of this neuraxial
hypotension with varying degree of success. Techniques currently in use for preventing
hypotension include intravenous fluid prehydration, sympathomimetic drugs, and physical
methods such as leg bindings and compression stockings. Midodrine is a direct acting
α1-adrenoceptor agonist which causes venous and arterial vasoconstriction through stimulation
of α1- receptors located in the vasculature. The net result is an increase in vascular tone
and systolic blood pressure. Cardiac β-receptors are unaffected and there is no significant
blood brain barrier penetration. We hypothesize that intraoperative hypotension would be less
in patients given midodrine and intravenous fluid prehydration preoperatively before spinal
anesthesia. The study will include 80 patients who will be scheduled for elective orthopedic
surgery on the lower extremities undergoing spinal anesthesia. It will be conducted in
Mansoura University Hospital after getting approval from Institutional Review Board (IRB),
Faculty of medicine, Mansoura University. Informed written consents will be obtained from all
subjects in the study after ensuring confidentiality. Patients will be randomly allocated
using computer generated random numbers to either treatment with midodrine (group M) or
control (group C) using the sealed opaque envelope technique. Patients in group M will
receive oral 10 mg tablet of midodrine with small sips of water one hour before arrival in
the operation room while patients in group C will receive inert tablet containing sugar
(placebo) at the same time. All patients will be monitored in with noninvasive blood pressure
as well ascontinuous electrocardiogram (ECG) and pulse oximetry (SpO2). Before placement of
spinal anesthesia, all patients will receive an IV bolus of 10mL/kg of Lactated Ringer's.
Spinal anesthesia (midline puncture) will be performed in sitting position by a staff
anesthetist at L3-L4 or L4-L5 with a 25-gauge Withacre needle injecting 12.5 mg of hyperbaric
0.5% bupivacaine (2.5 mL) with 10μg fentanyl. After injection,the patients will be turned
supine. The baseline arterial blood pressure (mean) will be calculated as the average of 3
consecutive measurements before placement of the SA every 15 min after taking midodrine and
every 5 min for 30 min after spinal anesthesia. Any vasovagal syncopes will be recorded.
After placement of the SA, the patient's heart rate will be obtained every five minutes for
30 minutes and thereafter, in accordance with standard clinical practice, every 5 minutes
until the end of surgery. The dermatome level of the sensory block using loss of pinprick
will be checked every 5 minutes for 20minutes. The modified Bromage scale (0 = no motor
block, 1 = straight leg hip flexion blocked, 2 = knee flexion blocked, 3 = complete motor
block) will be used to quantify the degree of motor block at 20 minutes. Reqirements of
ephedrine and atropine and fluide intake will be recorded. time to onset of the first
hypotension, the proportion of patients without hypotension, and the number of bradycardic
episodes per patient will also be recorded. Perioperative copmlications such as reactive
hypertension, nausea, vomiting, hypothermia, shivering and postdural puncture headache will
be recorded. An investigator who is blind to type of intervention wil be responsible for
collection of data.