Ultrasound-guided popliteal sciatic nerve blockade in the severely and morbidly obese: a prospective and randomized study

Neurological injury following peripheral nerve blocks: a narrative review of estimates of risks and the influence of ultrasound guidance

BACKGROUND

Peripheral nerve injury or post-block neurological dysfunction (PBND) are uncommon but a recognized complications of peripheral nerve blocks (PNB). A broad range of its incidence is noted in the literature and hence a critical appraisal of its occurrence is needed.

OBJECTIVE

In this review, we wanted to know the pooled estimates of PBND and further, determine its pooled estimates following various PNB over time. Additionally, we also sought to estimate the incidence of PBND with or without US guidance.

EVIDENCE REVIEW

A literature search was conducted in six databases. For the purposes of the review, we defined PBND as any new-onset sensorimotor disturbances in the distribution of the performed PNB either attributable to the PNB (when reported) or reported in the context of the PNB (when association with a PNB was not mentioned). Both prospective and retrospective studies which provided incidence of PBND at timepoints of interest (>48 hours to <2 weeks; >2 weeks to 6 weeks, 7 weeks to 5 months, 6 months to 1 year and >1 year durations) were included for review. Incidence data were used to provide pooled estimates (with 95% CI) of PBND at these time periods. Similar estimates were obtained to know the incidence of PBND with or without the use of US guidance. Additionally, PBND associated with individual PNB were obtained in a similar fashion with upper and lower limb PNB classified based on the anatomical location of needle insertion.

FINDINGS

The overall incidence of PBND decreased with time, with the incidence being approximately 1% at <2 weeks' time (Incidence per thousand (95% CI)= 9 (8; to 11)) to approximately 3/10 000 at 1 year (Incidence per thousand (95% CI)= 0. 3 (0.1; to 0.5)). Incidence of PBND differed for individual PNB with the highest incidence noted for interscalene block.

CONCLUSIONS

Our review adds information to existing literature that the neurological complications are rarer but seem to display a higher incidence for some blocks more than others. Use of US guidance may be associated with a lower incidence of PBND especially in those PNBs reporting a higher pooled estimates. Future studies need to standardize the reporting of PBND at various timepoints and its association to PNB.

Evaluation of the effectiveness of artificial intelligence for ultrasound guided peripheral nerve and plane blocks in recognizing anatomical structures

BACKGROUND

We aimed to assess the accuracy of artificial intelligence (AI) based real-time anatomy identification for ultrasound-guided peripheral nerve and plane block in eight regions in this prospective observational study.

METHODS

After obtaining ethics committee approval and written informed consent from 40 healthy volunteers (20 men and 20 women, between 18 and 72 years old), an ultrasound device installed with AI software (Nerveblox, SmartAlfa, Turkey) were used to scan regions of the cervical plexus, brachial plexus, pectoralis (PECS), rectus sheet, femoralis, canalis adductorius, popliteal, and ESP by three anesthesiology trainees. During scanning by a trainee, once software indicates 100 % scan success of associated anatomic landmarks, both raw and labeled ultrasound images were saved, assessed, and validated using a 6-point scale between 0 and 5 by two expert validators. Evaluation scores of the validators for each block were compared according to demographics (gender, age, and BMI) and block type exists.

RESULTS

The scores were not different except ESP, femoralis, and cervical plexus regions between the experts. The mean scores of the experts for the PECS, popliteal and rectus sheath were significant between males and females (p < 0.05). In terms of BMI, significant differences in the scores were observed only in the canalis adductorius, brachial plexus, and ESP regions (p < 0.05).

CONCLUSIONS

Ultrasound guided AI-based anatomy identification was performed in commonly used eight block regions by the trainees where AI technology can successfully interpret the anatomical structures in real-time sonography which would be valuable in assisting anesthesiologists.

Case Report of a Massive Thigh Hematoma after Adductor Canal Block in a Morbidly Obese Woman Anticoagulated with Apixaban

Hematoma formation after peripheral nerve block placement is a rare event. We report a case of a morbidly obese patient who was anticoagulated with apixaban and developed a massive thigh hematoma after an ultrasound-guided adductor canal block. Despite continuous visualization of the block needle, an unrecognized vascular injury occurred leading to a 14-cm hematoma in the anterolateral thigh. Morbid obesity warrants additional risk consideration when placing nerve blocks in an anticoagulated patient. In addition, early recognition and expert consultation are both important in the management of block-related hematomas.