Abstract 292: Time Course of Epinephrine Administration During Cardiac Arrest Shows Transient Increase in Aortic Pressure at the Cost of Persistent Decrease in Carotid Flow
Bibliographic record
Abstract
Epinephrine is routinely used during treatment of cardiac arrest. Administration may improve immediate resuscitation at the cost of long term survival. We hypothesized that epinephrine transiently increases aortic pressure, but decreases blood flow to the brain during cardiopulmonary resuscitation (CPR). Methods: Six anesthetized Yorkshire pigs (31±4 kg) underwent 1 minute of untreated ventricular fibrillation (VF), followed by 9 minutes of guideline based CPR with mechanical compressions, then defibrillation. Epinephrine (1 mg IV) was administered 1-3 times per pig (median 2.5) at ≥3 minute intervals. Hemodynamic parameters were measured continuously with a micromanometer in the abdominal aorta and a perivascular flow probe around the carotid artery. Results: After 10 minutes of VF, 5 of 6 pigs were successfully defibrillated, but all 5 became asystolic or lacked pulsatile aortic pressure 30 minutes after defibrillation. During CPR prior to epinephrine injection, aortic systolic and diastolic pressures were 72±26 and 17±3 mmHg respectively, coronary perfusion pressure was 15±5 mmHg and antegrade carotid blood flow was 141±77 mL/min. Epinephrine produced a repeatable, transient effect on both aortic pressure and carotid blood flow (see Table). Aortic systolic and diastolic pressures increased above pre-injection values with peak pressures reached approximately 80 seconds after injection and stabilizing after 180 seconds. Carotid flow decreased below pre-injection values with nadir flow reached approximately 80 seconds after injection, and remained below baseline for 100 additional seconds or longer. Conclusions: The effect of epinephrine on hemodynamics during CPR is not consistent over time. Epinephrine produces differential effects on aortic pressure and carotid flow. Although epinephrine may transiently improve coronary perfusion, it may do so at the cost of brain perfusion.
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 | 0.000 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 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 | 0.001 |
| Insufficient payload (model declined to judge) | 0.002 | 0.001 |
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".