Clinical Trial Details
— Status: Terminated
Administrative data
| NCT number |
NCT03174782 |
| Other study ID # |
20107050 |
| Secondary ID |
|
| Status |
Terminated |
| Phase |
Phase 4
|
| First received |
|
| Last updated |
|
| Start date |
January 1, 2018 |
| Est. completion date |
April 27, 2021 |
Study information
| Verified date |
June 2023 |
| Source |
University of California, San Francisco |
| Contact |
n/a |
| Is FDA regulated |
No |
| Health authority |
|
| Study type |
Interventional
|
Clinical Trial Summary
This study will be a double-blinded randomized controlled trial analyzing all patients who
will undergo major lower extremity amputations by the vascular surgery service at University
of California, San Francisco (UCSF) Fresno between July 2017 and June 2018 to determine if
regional nerve blocks (sciatic and femoral) have any effect on postoperative pain control,
narcotic requirements, and length of stay compared with standard post-operative narcotic
regimens.
Description:
Major lower extremity amputations (above knee amputation or below knee amputation) are common
procedures performed for patients with end stage ischemia, infection, and/or disfiguration.
Patients undergoing major lower extremity amputations have significant morbidity and
mortality. Up to 95% of amputees report chronic pain, and inadequate pre- and postoperative
pain control may increase the risk of chronic amputation pain. Additionally, there is a
growing epidemic of narcotic overdoses in the United States. From 2000 to 2014, the
age-adjusted drug overdose death rate has more than doubled from 6.2 per 100,000 persons to
14.7 per 100,000. The main drugs associated with overdose deaths are prescription pain
medications.
Regional nerve block is part of usual care and may serve as adjuncts for pain control after
major lower extremity amputations. This pain control may be achieved by injecting bupivacaine
into the sciatic and femoral nerves. Bupivacaine is an amide-type local anesthetic approved
by the Food and Drug Administration (FDA) for local or regional anesthesia or analgesia for
surgery. The dosage approved by the FDA for peripheral nerve blocks are 0.25% and 0.5%. The
potential risks are central nervous system and cardiovascular system reactions. The central
nervous system reactions are characterized by restlessness, anxiety, dizziness, or tremors.
The cardiovascular system reactions are characterized by decreased cardiac output, heart
block, hypotension, bradycardia, or arrhythmia. These risks are small and can be minimized
further by slow administration and aspiration prior to administration to avoid intravascular
injection. Other rare but potential risks of regional nerve block are nerve injury and
hematoma formation.
Although bupivacaine is widely used for pain control, there are very few studies looking at
regional nerve blocks as adjuncts for pain control after major lower extremity amputations.
The number of randomized controlled trials is even fewer and none have been conducted in the
United States. Baddoo looked at ten patients undergoing major lower extremity amputations
(nine above knee amputations and one below knee amputation) with regional nerve blocks (a
sciatic nerve block combined with either a 3-in-1 block or a psoas compartment lumbar plexus
block). All ten patients were hemodynamically stable throughout surgery. Seven patients had
good block, and three patients had fair block. Bech et al. presented a case report of four
patients with severe cardiac insufficiency where they successfully utilized peripheral nerve
blocks for trans-femoral amputation. The first patient was an 88-year-old man with American
Society of Anesthesiologists (ASA) class 4. His echocardiogram showed an ejection fraction of
10%, mitral valve insufficiency and aortic valve sclerosis. The second patient was a
90-year-old woman with ASA class 4. Her echocardiogram showed an ejection fraction of 25% and
severe mitral valve insufficiency. The third patient was a 64-year-old man with ASA class 4.
His echocardiogram showed an ejection fraction of 25%, mitral valve insufficiency and
tricuspid valve insufficiency. The fourth patient was a 74-year-old man with ASA class 4. His
echocardiogram showed an ejection fraction of 15%, right-sided heart failure and both mitral
and aortic valve insufficiency. All patients had successful outcomes in the postoperative
course. Palkhiwala et al. looked at combined femoral and sciatic nerve blocks for lower limb
procedures. With a randomized study involving 50 patients, they concluded that combined
femoral and sciatic nerve blocks are effective for pain control with very low incidence of
side effects. Forty-six out of fifty patients had complete block, and none of the patients
had any cardiovascular or neurologic adverse events. Our study design is one of the first
randomized controlled trials that looks at the effect of regional nerve blocks on
postoperative pain and length of hospital stay.
This study will be a double-blinded randomized controlled trial analyzing patients undergoing
major lower extremity amputation by the vascular surgery service at UCSF Fresno between July
2017 and June 2018 at Community Regional Medical Center, Clovis Community Medical Center, and
Fresno Heart and Surgical Hospital. All patients who have been evaluated by the vascular
surgery service and have had lower extremity amputation deemed necessary based on ischemic
disease, infectious disease, and/or disfiguration will be included. Patients will be excluded
if they are less than 18 years of age, pregnant, undergoing emergency amputations, staged
amputations, or amputations by non-vascular surgeons, have known allergies to bupivacaine,
are unable to communicate symptoms of pain, or refuse to participate in the study. Eligible
patients may be identified by the vascular surgery service in their private office or
following a consultation by the vascular surgery service in the hospital. Upon
identification, eligible patients or their surrogate decision maker will be approached for
consent by a member of the study team.
To randomize patients, consent forms will be pre-labeled with a random subject identification
number. This number will serve as the participants' study identification (ID) for all data
collection in order to maintain privacy and confidentiality. Additionally, this number will
be linked to a sealed envelope containing the random treatment group. The study coordinator
will create the labels and assemble the envelopes to ensure all investigators remain blind to
the treatment groups. This sealed envelope will be given to the anesthesia providers for the
amputation. The anesthesia team will then administer the assigned treatment prior to
induction of general anesthesia. Half of the patients will be randomized into the treatment
group, and half of the patients will be randomized into the control group.
Patients randomized to the treatment group will receive regional nerve blocks (sciatic and
femoral) with bupivacaine at the dose of 1 mg/kg. The anesthesiologists are experts in pain
management, and they are trained to perform regional nerve blocks. Femoral and sciatic nerve
blocks are within their scope of practice, and they have been performing them quite
frequently especially in orthopedic operations. Patients randomized to the control group will
receive two needle sticks (in the sciatic and femoral distributions) with normal saline to
maintain the double-blinded investigation. The anesthesiologists are not blinded in this
study, and they will be able to provide the appropriate billing for the saline and the
bupivacaine injections.
The remainder of the operation and post-operative course will proceed per the standard of
care. Post-operative pain will be evaluated daily until discharge by the vascular surgery
service using the McGill pain questionnaire. Additional data collected will include age,
gender, race, BMI, ASA class, length of operation, hospital length of stay, oral and
parenteral narcotic pain requirements. Any adverse events will immediately be reported to the
Principal Investigator (PI) and the Institutional Review Board (IRB). A Medical Monitor with
suitable expertise will be provided with all the study data on a monthly basis. The medical
monitor will use that data especially the unforeseen adverse events and complications to
ensure the study safety. The patients will be monitored and the data will be collected until
six months after discharge.
