A Novel Approach to Infraclavicular Brachial Plexus Block: The Ultrasound Experience
Bibliographic record
Abstract
To the Editor: We read with interest the recent article by Klaastad et al. (1) which describes a novel approach to infraclavicular block where the needle is inserted immediately medial to the coracoid process and directed posteriorly with a 15 degree angle to the coronal plane. We have also modified our approach in a similar manner for coracoid infraclavicular block when we are using an ultrasound-guided technique. In our experience, inserting the needle adjacent (2 cm medial) to the coracoid process at the inferior border of the clavicle and advancing posteriorly with a 15 degree angle to the coronal plane consistently localizes the cords, which are often situated superior and posterior to the axillary artery at a depth of 4–6 cm. The trajectory of this approach appears to avoid puncture of the axillary vessels while the cords are encountered 2–3 cm cephalad to the pleural cavity (Fig. 1). This is in contrast to the traditional “blind” coracoid approach that would appear to invite vascular or pleural puncture in order to reach the cords of the brachial plexus in a proportion of cases. The use of ultrasound in combination with nerve stimulation with this approach has enabled us to improve our block success and decrease morbidity.Figure 1.: Ultrasound-guided infraclavicular brachial plexus block. Ultrasonography performed with Philips ultrasound model HDI® 5000 SonoCT® using a 50 mm linear 4–7 MHz transducer (Philips Medical Systems, Bothell, WA). Short closed arrow identifies needle. Long dashed arrow represents needle trajectory of traditional “blind” coracoid approach. A = axillary artery; LC = lateral cord; P = pleura; PC = posterior cord; PM = pectoralis minor; PMJ = pectoralis major; V = axillary vein.Richard Brull, MD, FRCPC Colin J. L. McCartney, MBChB, FRCA, FCARCSI Vincent W. S. Chan, MD, FRCPC Department of Anesthesia, Toronto Western Hospital, University Health Network, University of Toronto, Toronto, Canada
Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.
How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.001 | 0.006 |
| Meta-epidemiology (narrow) | 0.001 | 0.001 |
| Meta-epidemiology (broad) | 0.001 | 0.001 |
| Bibliometrics | 0.001 | 0.001 |
| Science and technology studies | 0.001 | 0.001 |
| Scholarly communication | 0.002 | 0.003 |
| Open science | 0.001 | 0.001 |
| Research integrity | 0.007 | 0.007 |
| Insufficient payload (model declined to judge) | 0.003 | 0.002 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".