Superior Trunk Block Provides Noninferior Analgesia Compared with Interscalene Brachial Plexus Block in Arthroscopic Shoulder Surgery
Bibliographic record
Abstract
BACKGROUND: Interscalene brachial plexus block of the C5-C6 roots provides highly effective postoperative analgesia after shoulder surgery but usually results in hemidiaphragmatic paresis. Injection around the superior trunk of the brachial plexus is an alternative technique that may reduce this risk. The authors hypothesized that the superior trunk block would provide noninferior postoperative analgesia compared with the interscalene block and reduce hemidiaphragmatic paresis. METHODS: Eighty patients undergoing arthroscopic shoulder surgery were randomized to receive a preoperative injection of 15 ml of 0.5% ropivacaine and 5 μg · ml epinephrine around either (1) the C5-C6 nerve roots (interscalene block group) or (2) the superior trunk (superior trunk block group). The primary outcome was pain intensity 24 h after surgery measured on an 11-point numerical rating score; the prespecified noninferiority limit was 1. Diaphragmatic function was assessed using both ultrasonographic measurement of excursion and incentive spirometry by a blinded investigator before and 30 min after block completion. RESULTS: Seventy-eight patients completed the study. The pain score 24 h postoperatively (means ± SDs) was 1.4 ± 1.0 versus 1.2 ± 1.0 in the superior trunk block (n = 38) and interscalene block (n = 40) groups, respectively. The mean difference in pain scores was 0.1 (95% CI, -0.3 to 0.6), and the upper limit of the 95% CI was lower than the prespecified noninferiority limit. Analgesic requirements and all other pain measurements were similar between groups. Hemidiaphragmatic paresis was observed in 97.5% of the interscalene block group versus 76.3% of the superior trunk block group (P = 0.006); paresis was complete in 72.5% versus 5.3% of the patients, respectively. The decrease in spirometry values from baseline was significantly greater in the interscalene block group. CONCLUSIONS: The superior trunk block provided noninferior analgesia compared with interscalene brachial plexus block for up to 24 h after arthroscopic shoulder surgery and resulted in significantly less hemidiaphragmatic paresis.
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How this classification was reachedexpand
Full frame distilled prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. Learned from the 10,348 direct Codex labels and 10,348 direct Gemma labels. Candidate is the union of thresholded teacher heads; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels or direct frontier model labels.
Codex and Gemma teacher scores by category
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.001 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.000 | 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 teacher head, 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".