Abstract
BACKGROUND AND OBJECTIVES: Recent clinical trials suggest that subfascial (sometimes termed subepineural) injections result in faster block onset and success compared with conventional techniques. This prospective, randomized, observer-blinded study measured and compared the 3-dimensional spread pattern and volume of perineural local anesthetic (LA) in contact with the sciatic nerve after subfascial versus extrafascial lateral popliteal injections. METHODS: Sixty patients were randomly assigned to either the subfascial or the extrafascial injection group. All patients received a single-injection, US-guided lateral popliteal sciatic nerve block for postoperative pain. Depending on group assignment, the needle tip was placed outside or beneath the sciatic fascial sheath for a single injection of 30 mL of ropivacaine 0.5%. Using 3-dimensional ultrasound imaging, postblock scans were acquired to quantify the volume and spread pattern of perineural LA around the sciatic nerve in each group. RESULTS: The mean LA perineural volume for the extrafascial group was 1.48 (SD, 0.50) mL versus a mean of 5.57 (SD, 1.68) mL for the subfascial group, P < 0.05. The mean distance of longitudinal perineural LA spread (along the length of the nerve) for the subfascial group was 66% greater than that observed using the conventional technique (9.3 vs 5.6 cm, P < 0.01). Complete sensory block to pinprick for the extrafascial group was 63% versus 90% (P < 0.05) for the subfascial group. CONCLUSIONS: Placement of the needle tip beneath the complex fascial sheath of the sciatic nerve resulted in significantly greater perineural local anesthetic volume following a single-injection lateral popliteal approach at the nerve bifurcation and was associated with greater sensory blockade and a characteristic laminar LA spread pattern.
| Original language | English |
|---|---|
| Pages (from-to) | 627-632 |
| Number of pages | 6 |
| Journal | Regional Anesthesia and Pain Medicine |
| Volume | 37 |
| Issue number | 6 |
| DOIs | |
| State | Published - Nov 1 2012 |
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ASJC Scopus subject areas
- Anesthesiology and Pain Medicine
Cite this
A 3-dimensional ultrasound study of local anesthetic spread during lateral popliteal nerve block : What is the ideal end point for needle tip position? / Missair, Andres; Weisman, Robyn S.; Suarez, Maria Rene; Yang, Relin; Gebhard, Ralf E.
In: Regional Anesthesia and Pain Medicine, Vol. 37, No. 6, 01.11.2012, p. 627-632.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - A 3-dimensional ultrasound study of local anesthetic spread during lateral popliteal nerve block
T2 - What is the ideal end point for needle tip position?
AU - Missair, Andres
AU - Weisman, Robyn S.
AU - Suarez, Maria Rene
AU - Yang, Relin
AU - Gebhard, Ralf E
PY - 2012/11/1
Y1 - 2012/11/1
N2 - BACKGROUND AND OBJECTIVES: Recent clinical trials suggest that subfascial (sometimes termed subepineural) injections result in faster block onset and success compared with conventional techniques. This prospective, randomized, observer-blinded study measured and compared the 3-dimensional spread pattern and volume of perineural local anesthetic (LA) in contact with the sciatic nerve after subfascial versus extrafascial lateral popliteal injections. METHODS: Sixty patients were randomly assigned to either the subfascial or the extrafascial injection group. All patients received a single-injection, US-guided lateral popliteal sciatic nerve block for postoperative pain. Depending on group assignment, the needle tip was placed outside or beneath the sciatic fascial sheath for a single injection of 30 mL of ropivacaine 0.5%. Using 3-dimensional ultrasound imaging, postblock scans were acquired to quantify the volume and spread pattern of perineural LA around the sciatic nerve in each group. RESULTS: The mean LA perineural volume for the extrafascial group was 1.48 (SD, 0.50) mL versus a mean of 5.57 (SD, 1.68) mL for the subfascial group, P < 0.05. The mean distance of longitudinal perineural LA spread (along the length of the nerve) for the subfascial group was 66% greater than that observed using the conventional technique (9.3 vs 5.6 cm, P < 0.01). Complete sensory block to pinprick for the extrafascial group was 63% versus 90% (P < 0.05) for the subfascial group. CONCLUSIONS: Placement of the needle tip beneath the complex fascial sheath of the sciatic nerve resulted in significantly greater perineural local anesthetic volume following a single-injection lateral popliteal approach at the nerve bifurcation and was associated with greater sensory blockade and a characteristic laminar LA spread pattern.
AB - BACKGROUND AND OBJECTIVES: Recent clinical trials suggest that subfascial (sometimes termed subepineural) injections result in faster block onset and success compared with conventional techniques. This prospective, randomized, observer-blinded study measured and compared the 3-dimensional spread pattern and volume of perineural local anesthetic (LA) in contact with the sciatic nerve after subfascial versus extrafascial lateral popliteal injections. METHODS: Sixty patients were randomly assigned to either the subfascial or the extrafascial injection group. All patients received a single-injection, US-guided lateral popliteal sciatic nerve block for postoperative pain. Depending on group assignment, the needle tip was placed outside or beneath the sciatic fascial sheath for a single injection of 30 mL of ropivacaine 0.5%. Using 3-dimensional ultrasound imaging, postblock scans were acquired to quantify the volume and spread pattern of perineural LA around the sciatic nerve in each group. RESULTS: The mean LA perineural volume for the extrafascial group was 1.48 (SD, 0.50) mL versus a mean of 5.57 (SD, 1.68) mL for the subfascial group, P < 0.05. The mean distance of longitudinal perineural LA spread (along the length of the nerve) for the subfascial group was 66% greater than that observed using the conventional technique (9.3 vs 5.6 cm, P < 0.01). Complete sensory block to pinprick for the extrafascial group was 63% versus 90% (P < 0.05) for the subfascial group. CONCLUSIONS: Placement of the needle tip beneath the complex fascial sheath of the sciatic nerve resulted in significantly greater perineural local anesthetic volume following a single-injection lateral popliteal approach at the nerve bifurcation and was associated with greater sensory blockade and a characteristic laminar LA spread pattern.
UR - http://www.scopus.com/inward/record.url?scp=84868270754&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=84868270754&partnerID=8YFLogxK
U2 - 10.1097/AAP.0b013e31826af511
DO - 10.1097/AAP.0b013e31826af511
M3 - Article
C2 - 23080350
AN - SCOPUS:84868270754
VL - 37
SP - 627
EP - 632
JO - Regional Anesthesia and Pain Medicine
JF - Regional Anesthesia and Pain Medicine
SN - 1098-7339
IS - 6
ER -