Evaluation of Continuous Saphenous Nerve Block to Supplement a Continuous Sciatic Nerve Block After Ankle Surgery
| Status: | Completed |
|---|---|
| Conditions: | Orthopedic |
| Therapuetic Areas: | Orthopedics / Podiatry |
| Healthy: | No |
| Age Range: | 18 - 75 |
| Updated: | 9/2/2018 |
| Start Date: | July 2010 |
| End Date: | September 7, 2017 |
Evaluation of a Continuous Saphenous Nerve Block to Supplement a Continuous Sciatic Nerve Block for Postoperative Analgesia Following Ankle Surgery
A nerve block catheter is a small tube placed next to a nerve through a needle, and the
needle is then removed. Numbing medicine is dripped through the tube to reduce pain sensation
from the nerve.
The purpose of this research study is to test whether the placement of a second nerve block
catheter, rather than a single injection for the saphenous nerve block will improve pain
relief and/or reduce pain medication needed after surgery enough to justify two nerve block
catheters.
There are two nerves that carry pain sensations from the ankle, the large (sciatic) nerve and
the smaller (saphenous) nerve. Patients undergoing ankle fusion or fracture surgery at Wake
Forest University typically have a nerve block catheter placed next to the sciatic nerve to
give local anesthetic (numbing medicine) for 24-72 hours. In addition, a single injection of
local anesthetic is usually performed to block the saphenous nerve for 12-16 hours
postoperatively.
needle is then removed. Numbing medicine is dripped through the tube to reduce pain sensation
from the nerve.
The purpose of this research study is to test whether the placement of a second nerve block
catheter, rather than a single injection for the saphenous nerve block will improve pain
relief and/or reduce pain medication needed after surgery enough to justify two nerve block
catheters.
There are two nerves that carry pain sensations from the ankle, the large (sciatic) nerve and
the smaller (saphenous) nerve. Patients undergoing ankle fusion or fracture surgery at Wake
Forest University typically have a nerve block catheter placed next to the sciatic nerve to
give local anesthetic (numbing medicine) for 24-72 hours. In addition, a single injection of
local anesthetic is usually performed to block the saphenous nerve for 12-16 hours
postoperatively.
Interventions and Interactions Study participants will be asked to report a preoperative
baseline pain score (Numeric Pain Scale (0-10)), and have quadriceps strength measured (see
below) prior to any sedation being administered. Patients will undergo placement of a
continuous subgluteal sciatic nerve catheter, and dosage with 25ml of 0.25% bupivacaine with
epinephrine 1:200,000 and clonidine 25 mcg per usual technique after sedation. A perineural
catheter will then be placed for primary saphenous nerve block and postoperative saphenous
infusion. This continuous saphenous catheter will be placed using ultrasound guidance
(Sonosite Turbo ™, Bothell, WA) (6-13MHz linear probe). The superficial femoral artery will
be identified in short axis at approximately the midpoint or distal third of the femur as the
artery lies deep to the sartorius muscle in the adductor canal. Using aseptic technique, an
18 gauge tuohy needle will be inserted in-plane from lateral to the transducer and advanced
to a position anteromedial to the artery, between sartorius and vastus medialis muscles.
Proper positioning will be confirmed by injection of saline, a 20g multiorifice catheter will
be inserted 3-4 cm beyond the needle tip and the catheter will be tunneled and taped up the
medial surface of the thigh. The catheter will be test dosed with 1.5% lidocaine with
1:200,000epinephrine to confirm position and rule out IV injection. The primary saphenous
nerve block will be produced by incremental injection through the catheter of 10ml of 0.25%
bupivacaine with epinephrine 1:200,000 and clonidine 15 mcg. Successful saphenous block will
be defined as loss of sensation to pinprick in the mid, anteromedial leg measured at 15 and
30 minutes post-block. A 3-point scale will be used to define sensory block: 0=full
sensation, 1= touch without sharp sensation, 2=absent sensation.
To determine the effect of saphenous block on quadriceps function, patients will have knee
extension muscle strength tested pre-block and 30 min post-block using a Hoggan Health
microFET 2 MT Digital Handheld Dynamometer. After placement of both the saphenous and sciatic
nerve catheters, patients will receive either neuraxial or general anesthesia for surgical
anesthesia at the discretion of the attending anesthesiologist medically directing their
primary anesthetic technique.
Patients with evidence of sciatic and saphenous nerve block will be randomized to receive a
postoperative continuous infusion of either saline (control) or 0.2% ropivacaine by
elastomeric infusion pump at 5ml/h started within 6h of catheter placement. The randomization
will occur by sealed envelope provided to the OR Pharmacy (block randomization in blocks of
10) and the OR pharmacy will prepare the 300 ml elastomeric pump with active or control
solution. The On-Q C-Bloc™(300ml capacity) (I-Flow corporation) pump will be attached to the
saphenous catheter in the PACU, or within 6h of primary block; the catheter will infuse for
60 hours.
The patients, physicians, nurses and investigators will be blinded to treatment group.
The sciatic infusion will be managed per usual practice: postoperatively all patients will
receive 0.2% ropivacaine through their sciatic nerve catheter at a basal infusion rate of
10ml/h, . The sciatic pump will be an On-Q™ pump per usual practice. All patients will have
oral and IV opioids prescribed while hospitalized, and oral opioids prescribed after hospital
discharge. In the event of breakthrough pain, patients will be instructed to adjust the
sciatic nerve pump, and/or to take oral opioids for the pain.
While patients are hospitalized, opioid administration and pain scores will be recorded by
nursing staff on the patient care record. Side effects including nausea, vomiting, or itching
will also be recorded. Patients will be seen on a daily basis while in the hospital by the
acute pain service, and adjustment of their sciatic infusion performed if indicated. They
will be questioned about sleep quality, pain score, opioid side effects, and sensory function
in the sciatic and saphenous distributions. This information will be recorded by the acute
pain management team. On postoperative day 1, all patients will again have their quadriceps
muscle group strength assessed with the hand-held dynamometer, and the catheter sites will be
inspected per standard protocol.
Patients will be generally discharged home with peripheral nerve catheters in place on POD
#1, after receiving written and verbal instructions in perineural catheter management. These
patients will be called at 24 and 48 hours post discharge to determine rest and incident
numeric pain scores, opioid usage, sleep quality (as number of awakenings for pain), and the
presence of nausea or vomiting. Patients will be given contact numbers and instructions to
call with any questions or concerns per usual practice.
Outcome Measure(s) The primary endpoint of this study will be a reduction of the rest and
incident verbal pain scores 48hpost-nerve blockade when the primary saphenous single-shot
block is expected to have resolved. Secondary endpoints of reduction of opioid use, nausea
and vomiting, sleep disturbance (as number of awakenings), and reduction of quadriceps
strength will also be evaluated.
baseline pain score (Numeric Pain Scale (0-10)), and have quadriceps strength measured (see
below) prior to any sedation being administered. Patients will undergo placement of a
continuous subgluteal sciatic nerve catheter, and dosage with 25ml of 0.25% bupivacaine with
epinephrine 1:200,000 and clonidine 25 mcg per usual technique after sedation. A perineural
catheter will then be placed for primary saphenous nerve block and postoperative saphenous
infusion. This continuous saphenous catheter will be placed using ultrasound guidance
(Sonosite Turbo ™, Bothell, WA) (6-13MHz linear probe). The superficial femoral artery will
be identified in short axis at approximately the midpoint or distal third of the femur as the
artery lies deep to the sartorius muscle in the adductor canal. Using aseptic technique, an
18 gauge tuohy needle will be inserted in-plane from lateral to the transducer and advanced
to a position anteromedial to the artery, between sartorius and vastus medialis muscles.
Proper positioning will be confirmed by injection of saline, a 20g multiorifice catheter will
be inserted 3-4 cm beyond the needle tip and the catheter will be tunneled and taped up the
medial surface of the thigh. The catheter will be test dosed with 1.5% lidocaine with
1:200,000epinephrine to confirm position and rule out IV injection. The primary saphenous
nerve block will be produced by incremental injection through the catheter of 10ml of 0.25%
bupivacaine with epinephrine 1:200,000 and clonidine 15 mcg. Successful saphenous block will
be defined as loss of sensation to pinprick in the mid, anteromedial leg measured at 15 and
30 minutes post-block. A 3-point scale will be used to define sensory block: 0=full
sensation, 1= touch without sharp sensation, 2=absent sensation.
To determine the effect of saphenous block on quadriceps function, patients will have knee
extension muscle strength tested pre-block and 30 min post-block using a Hoggan Health
microFET 2 MT Digital Handheld Dynamometer. After placement of both the saphenous and sciatic
nerve catheters, patients will receive either neuraxial or general anesthesia for surgical
anesthesia at the discretion of the attending anesthesiologist medically directing their
primary anesthetic technique.
Patients with evidence of sciatic and saphenous nerve block will be randomized to receive a
postoperative continuous infusion of either saline (control) or 0.2% ropivacaine by
elastomeric infusion pump at 5ml/h started within 6h of catheter placement. The randomization
will occur by sealed envelope provided to the OR Pharmacy (block randomization in blocks of
10) and the OR pharmacy will prepare the 300 ml elastomeric pump with active or control
solution. The On-Q C-Bloc™(300ml capacity) (I-Flow corporation) pump will be attached to the
saphenous catheter in the PACU, or within 6h of primary block; the catheter will infuse for
60 hours.
The patients, physicians, nurses and investigators will be blinded to treatment group.
The sciatic infusion will be managed per usual practice: postoperatively all patients will
receive 0.2% ropivacaine through their sciatic nerve catheter at a basal infusion rate of
10ml/h, . The sciatic pump will be an On-Q™ pump per usual practice. All patients will have
oral and IV opioids prescribed while hospitalized, and oral opioids prescribed after hospital
discharge. In the event of breakthrough pain, patients will be instructed to adjust the
sciatic nerve pump, and/or to take oral opioids for the pain.
While patients are hospitalized, opioid administration and pain scores will be recorded by
nursing staff on the patient care record. Side effects including nausea, vomiting, or itching
will also be recorded. Patients will be seen on a daily basis while in the hospital by the
acute pain service, and adjustment of their sciatic infusion performed if indicated. They
will be questioned about sleep quality, pain score, opioid side effects, and sensory function
in the sciatic and saphenous distributions. This information will be recorded by the acute
pain management team. On postoperative day 1, all patients will again have their quadriceps
muscle group strength assessed with the hand-held dynamometer, and the catheter sites will be
inspected per standard protocol.
Patients will be generally discharged home with peripheral nerve catheters in place on POD
#1, after receiving written and verbal instructions in perineural catheter management. These
patients will be called at 24 and 48 hours post discharge to determine rest and incident
numeric pain scores, opioid usage, sleep quality (as number of awakenings for pain), and the
presence of nausea or vomiting. Patients will be given contact numbers and instructions to
call with any questions or concerns per usual practice.
Outcome Measure(s) The primary endpoint of this study will be a reduction of the rest and
incident verbal pain scores 48hpost-nerve blockade when the primary saphenous single-shot
block is expected to have resolved. Secondary endpoints of reduction of opioid use, nausea
and vomiting, sleep disturbance (as number of awakenings), and reduction of quadriceps
strength will also be evaluated.
Inclusion Criteria:
- surgery for unilateral ankle arthrodesis
- surgery for open reduction and internal fixation of bi/tri malleolar fracture
Exclusion Criteria:
- coagulation abnormalities
- history of opioid addiction
- current chronic pain therapy with high dsoe opioid
- allergy to study medication
- failure of the sciatic nerve catheter
We found this trial at
1
site
1 Medical Center Blvd
Winston-Salem, North Carolina 27103
Winston-Salem, North Carolina 27103
(336) 716-2011
Principal Investigator: Robert Weller, M.D.
Wake Forest University Baptist Medical Center Welcome to Wake Forest Baptist Medical Center, a fully...
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