Head elevating device and cricothyroid membrane position in pregnant women with obesity class 3: an observational study
Bibliographic record
Abstract
BACKGROUND: Obesity and pregnancy are risk factors for difficult intubation. A head-elevating positioning device increases functional residual capacity and improves direct laryngoscopy. It is unclear what effect such device has on the airway anatomy. The primary aim of this study was to determine the change in distance from the sternal notch to the cricothyroid membrane (CTM) mid-point among pregnant women with class 3 obesity, comparing the supine positioning and the head-elevated position. METHODS: In this prospective observational study, 50 pregnant women with class 3 obesity provided their consent for participation, and airway anatomy was assessed with ultrasound when presenting either for elective cesarean delivery or in early stages of labor. The CTM's depth and height were measured in supine (Time 1) and head-elevated (Time 2) positions. The CTM midpoint was established and the distance from this point to the sternal notch was obtained. The primary outcome was change in distance from sternal notch to CTM midpoint. Secondary outcomes included changes in CTM depth and height. RESULTS: The median (± standard deviation) sternal notch to CTM midpoint distance increased significantly from 41.07 mm (± 8.35 at Time 1 to 45.40 mm ± 8.97) at Time 2 (mean difference 4.33 mm, 95% CI 3.06 to 5.61, P <0.0001). No differences were observed in CTM depth (mean difference -0.15 mm, P =0.66) or height (mean difference 0.34 mm, P =0.20). CONCLUSION: Head elevation increased the distance from the sternal notch to the CTM midpoint but did not affect CTM depth or height in pregnant women with class 3 obesity. Further research is needed to assess neck ultrasound anatomy in high-risk patients for difficult intubation.
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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 | 0.000 | 0.002 |
| Meta-epidemiology (narrow) | 0.000 | 0.001 |
| Meta-epidemiology (broad) | 0.001 | 0.001 |
| Bibliometrics | 0.001 | 0.001 |
| Science and technology studies | 0.001 | 0.001 |
| Scholarly communication | 0.001 | 0.001 |
| Open science | 0.000 | 0.001 |
| Research integrity | 0.001 | 0.002 |
| Insufficient payload (model declined to judge) | 0.002 | 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".