Two clinical cases of unintentionally prolonged sciatic nerve block

This study describes two clinical cases of unexpectedly long duration of motor block after anterior sciatic nerve block. In two patients who underwent total knee replacement, the motor block reversion in the area of sciatic nerve innervation did not occur at the expected time. Ultrasound examination revealed the deposition of a local anesthetic near the sciatic nerve. In these two clinical cases, unintentionally prolonged sciatic nerve blockade was caused by combined age-related factors of reduced tissue perfusion and the vasoconstrictor properties of levobupivacaine. Subsequently, the block was successfully resolved in 3638 h without any neurological consequences.

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Novel compound LL-a produces long and nociceptive-selective regional anesthesia via TRPV1 channels in rodents sciatic nerve block model

Regional Anesthesia and Pain Medicine ◽

10.1136/rapm-2019-101057 ◽

2020 ◽

Vol 45 (6) ◽

pp. 412-418

Author(s):

Cheng Zhou ◽

Lei Tang ◽

Qinqin Yin ◽

Linghui Yang ◽

Deying Gong ◽

...

Keyword(s):

Sciatic Nerve ◽

Regional Anesthesia ◽

Nerve Block ◽

Motor Block ◽

Sensory Block ◽

Sciatic Nerve Block ◽

Block Model ◽

Voltage Gated ◽

Trpv1 Channels ◽

Channel Currents

Background and objectiveLong-acting nociceptive-selective regional anesthesia has remained an elusive clinical goal. We aspired to identify a novel compound that would produce nociceptive-selective regional anesthesia through the transient receptor potential vanilloid 1 (TRPV1) channels.MethodsWe designed and synthesized a novel compound (LL-a) that penetrates the cell membrane through TRPV1 channels and binds to voltage-gated sodium channels. The regional anesthetic effect of LL-a was evaluated in a rodent sciatic nerve block model. Electrophysiological recording was applied to test the inhibition of LL-a on voltage-gated sodium channel currents.ResultsLL-a inhibited sodium channel currents on the dorsal root ganglion neurons of mice and this action was diminished by TRPV1 channel knockout. In a sciatic nerve block model of a rat, 0.2% and 0.4% (w/v) LL-a produced selective sensory block with median (IQR) durations of 42.0 (24.0, 48.0) and 72.0 (69.0, 78.0) hours, respectively. No motor block was found for 0.2% LL-a. 0.4% LL-a produced a motor block with a median (IQR) duration of 3.0 (0.0, 6.0) hours. This selective sensory block was not observed on TRPV1 knockout mice. As a positive control, 0.5% and 0.75% levobupivacaine produced a non-selective sciatic nerve block with median (IQR) durations of 2.8 (2.6, 2.8) and 3.8 (3.8, 4.8) hours, respectively. No systemic or local irritation was observed during injection of LL-a and sensory and motor function completely recovered for all the animals.ConclusionsLL-a is a potential novel local anesthetic for long-lasting nociceptive-selective analgesia.

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Sex-dependent prolongation of sciatic nerve blockade in diabetes patients: a prospective cohort study

Regional Anesthesia and Pain Medicine ◽

10.1136/rapm-2019-100609 ◽

2019 ◽

Vol 44 (9) ◽

pp. 860-865 ◽

Cited By ~ 2

Author(s):

Shuai Tang ◽

Jin Wang ◽

Yi Tian ◽

Xu Li ◽

Qiuju Cui ◽

...

Keyword(s):

Cohort Study ◽

Sciatic Nerve ◽

Nerve Block ◽

Motor Block ◽

Plantar Flexion ◽

Sensory Block ◽

Sciatic Nerve Block ◽

Sensory Threshold ◽

Nerve Blockade ◽

Diabetes Patients

IntroductionDiabetes may affect the duration of nerve block after regional anesthesia. This study aimed to compare the durations of sensory and motor block in diabetes versus non-diabetes patients after lower limb nerve block and delineate any sex-based differences in the duration of sensory and motor blocks of both diabetes and non-diabetes patients.MethodsThis prospective single-blinded cohort study recruited 86 patients who underwent unilateral lower extremity surgery; 52 patients were non-diabetic and 34 were diabetic. Each patient received an ultrasound-guided nerve stimulator-assisted subgluteal sciatic nerve block with 0.75% ropivacaine. Duration of sensory block was assessed with the Semmes-Weinstein monofilament test, and duration of motor block was assessed with dorsal and plantar flexion of the foot.ResultsThe sensory and motor block durations of diabetes patients were significantly prolonged versus non-diabetes patients (19.8±6.0 hours vs 15.6±5.1 hours; p<0.05) and (19.5±8.1 hours vs 14.8±5.7 hours, p=0.005), respectively. The durations of sensory and motor block were comparable between male diabetes and non-diabetes patients, but they were significantly longer in female diabetes patients. Multiple regression analysis further revealed that, after adjustment for age and preoperative sensory threshold, diabetes, fasting plasma glucose and HbA1c levels were signiﬁcantly associated with sensory and motor blocks. Sex analysis showed the association was only present in female diabetes patients, not male diabetes patients.ConclusionThe durations of sensory and motor block are significantly prolonged after subgluteal sciatic nerve block in diabetes patients. Furthermore, the prolonged nerve blockade is present only in diabetes women, not diabetes men.Trial registration numberNCT02482831.

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