Abstract 266: The Impact of Chest Compression Release Velocity on Outcomes From Out-of-Hospital Cardiac Arrest
Bibliographic record
Abstract
BACKGROUND: Previous studies have demonstrated significant relationships between CPR quality metrics and survival to hospital discharge from out-of hospital (OHCA) cardiac arrest. Recently a new metric, chest compression release velocity (CCRV) has been associated with improved survival from OHCA. OBJECTIVE: To determine the impact of CCRV on clinical outcomes from OHCA. METHODS: We performed a retrospective review of prospectively collected data on all treated adult OHCA occurring over a one year period (Jan 2012 - Jan 2013) in two Canadian EMS agencies. CPR metrics of chest compression fraction (CCF), compression rate, compression depth, shock pause duration and CCRV were abstracted from impedance channel measurements during each resuscitation. Cases of public access defibrillation, EMS witnessed arrest and those missing any Utstein variable or discharge status data were excluded. We performed a multivariable regression analysis to determine the impact of CCRV on survival to hospital discharge. Secondary outcome measures were the impact of CCRV on return of spontaneous circulation (ROSC) and neurologically intact survival (MRS ≤ 3). RESULTS: Among 908 treated OHCA, 611met inclusion criteria. The median (IQR) age was 71.7 (60.7, 81.6) with 395 (64.6%) being male. 140 (22.9%) presented in ventricular fibrillation, 122 (20%) pulseless electrical activity and 349 (57.1%) asystole. The median (IQR) CPR quality metrics were: CCF 0.81 (0.73, 0.85), compression rate 105/minute (101, 115), compression depth 49.9 mm (42.5, 56.7), pre-shock pause 13.5 secs (8, 19) and post-shock pause 3.5 secs (2.8, 5). The median (IQR) CCRV (mm/sec) amongst 49 survivors was 135.9 (115.4, 156.5) compared to 120 (102.9, 140) in 562 non survivors (p=0.009). When adjusted for CPR metrics and Utstein variables, the odds of survival to hospital discharge for each 5 mm/sec increase in CCRV was 1.02 (95% CI: 0.97, 1.08). Similarly the odds of ROSC and neurologically intact survival were 1.02 (95% CI: 0.99, 1.05) and 1.03 (95% CI: 0.98, 1.08), respectively. CONCLUSIONS: When adjusted for Utstein variables and CPR quality metrics, CCRV was not significantly associated with outcomes from OHCA. Our findings may have been impacted by the sample size of our study.
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 | 0.008 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.001 |
| Bibliometrics | 0.001 | 0.002 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.001 | 0.000 |
| Open science | 0.001 | 0.000 |
| Research integrity | 0.000 | 0.001 |
| Insufficient payload (model declined to judge) | 0.003 | 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".