Point-of-care ultrasound of the diaphragm after proximal brachial plexus block for shoulder surgery: a prospective observational study
Bibliographic record
Abstract
INTRODUCTION: This observational study evaluates diaphragmatic excursion and thickening fraction before and after proximal analgesic brachial plexus block in 99 patients undergoing shoulder surgery. METHODS: This study has a prospective, observational, blinded design and evaluates three methods of sonographic assessment: (1) the excursion of the dome of the diaphragm, (2) the thickening fraction of the zone of apposition, and (3) the excursion of the zone of apposition. All three methods of assessment were used prior to and within 30 min of a proximal brachial plexus block for shoulder surgery. The blocks were all ultrasound-guided and were either an interscalene block or a superior trunk block with 15-20 mL of ropivacaine 0.5% or bupivacaine 0.25% with 1:400 000 epinephrine. The type of block was not randomized and was left to the discretion of the anesthesiologist performing the nerve block. RESULTS: Assessment of the excursion of the zone of apposition and the thickening fraction was possible bilaterally in all patients. Assessment of the excursion of the dome of the diaphragm was consistently possible on the right side but only possible in about half of the patients (48.8% preblock and 46.3% postblock) on the left hemithorax. The median decrease in diaphragmatic function was between 42% and 82% dependent upon the type of nerve block, patient sex, and method of evaluation. One patient developed complete plegia, and three-quarters of all patients developed >50% weakness. Female sex and interscalene block were associated with greater weakness. CONCLUSION: The data suggest that the assessment of the excursion of the zone of apposition on the lateral aspect of the chest using a linear probe is consistently successful in measuring both baseline and postblock values of diaphragmatic excursion, and thus it may be a helpful tool in the perioperative period. Future studies are needed to establish use in other clinical settings as well as assessment of learning curves and reliability of this emerging technique.
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 | 0.002 | 0.006 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.001 | 0.001 |
| Bibliometrics | 0.001 | 0.001 |
| Science and technology studies | 0.001 | 0.001 |
| Scholarly communication | 0.001 | 0.001 |
| Open science | 0.000 | 0.001 |
| Research integrity | 0.001 | 0.001 |
| Insufficient payload (model declined to judge) | 0.001 | 0.000 |
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".