Clinical Variables Associated with Mortality in Out‐of‐hospital Patients with Hemodynamically Significant Bradycardia
Bibliographic record
Abstract
OBJECTIVES: To estimate mortality rates and identify clinical variables associated with mortality among patients with hemodynamically unstable bradycardia in an urban emergency medical services (EMS) system. METHODS: This was a retrospective study conducted in a large, urban EMS system. Adult non-cardiac arrest patients transported by advanced life support paramedics from March 1996 to February 1997 with a heart rate < or =60 beats/min and systolic blood pressure < or =90 mm Hg were included. Transcutaneous pacing was not available. Patients under age 18 years, pregnant, or presenting with vital signs absent were excluded from the study population. Multivariate analysis of the association of patient characteristics with 30-day mortality was conducted by using a Cox proportional hazards model. RESULTS: Of the 247 patients studied, 133 (53.9%) received a fluid bolus, 37 (15.0%) were treated with atropine, and 17 (6.9%) received dopamine. Fifty-one (20.7%) died in the 19-month follow-up period (15.6 per 100 person-years); 10.5% died on the same day, 15.8% within 30 days, and 17.8% within one year. Variables associated with 30-day mortality included wide QRS complex (adjusted risk ratio [RR] 2.6 [95% confidence interval (95% CI) = 1.3 to 5.2]), use of heart rate-lowering calcium channel blockers (adjusted RR 2.1 [95% CI = 1.0 to 4.7]), and paramedic assessment of lack of patient improvement over the course of the call (adjusted RR 0.2 [95% CI = 0.1 to 0.6]). CONCLUSIONS: Out-of-hospital patients with hemodynamically unstable bradycardia have a high mortality rate. A wide QRS complex and use of heart rate-lowering calcium channel blockers were associated with 30-day mortality.
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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 | 0.001 | 0.004 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.001 | 0.001 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.001 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 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".