Sonoanatomy of the Lumbar Spine in Patients With Previous Unintentional Dural Punctures During Labor Epidurals
Bibliographic record
Abstract
BACKGROUND AND OBJECTIVES: Preprocedural lumbar ultrasound is a valuable tool to assess anatomical landmarks and predict the depth of the epidural space. Variations of the ligamentum flavum sonoanatomy are occasionally observed; however, no literature is available as to their incidence or clinical significance. We hypothesize that abnormal sonoanatomy of the lumbar spine detected by ultrasound can be associated with an increase in unintentional dural punctures. This study was undertaken to determine if the sonoanatomy of the lumbar spine of patients who had documented unintentional dural punctures differs from that of patients with a history of uneventful epidural placement for labor analgesia. METHODS: Ultrasound of the entire lumbar spine was performed on 18 patients with a documented history of unintentional dural punctures, and 18 volunteers with a history of uneventful labor epidurals. At each interspace, we studied the quality of the ligamentum flavum (normal or abnormal), the symmetry of the bony structures (symmetric or asymmetric), and the distance from the skin to the ligamentum flavum. These parameters were compared in both groups. RESULTS: The incidence of asymmetric sonoanatomy and the distance from the skin to the ligamentum flavum was similar in both groups. The incidence of abnormal ligamentum flavum sonoanatomy was higher in the dural puncture group (overall odds ratio for the 5 interspaces was 8.21, 95% confidence interval 3.07-22.0, P < .0001). CONCLUSIONS: Abnormal sonoanatomy of the ligamentum flavum may represent anatomical variations of this structure, which may be related to an increased incidence of unintentional dural punctures during epidural placements.
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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 | 0.001 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.001 | 0.000 |
| Bibliometrics | 0.000 | 0.001 |
| Science and technology studies | 0.000 | 0.001 |
| 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".