# High-fidelity minute-level physiologic trajectories after ROSC from linked monitor-defibrillator recordings in out-of-hospital cardiac arrest

## TL;DR

Minute-by-minute data from monitor-defibrillators after ROSC in cardiac arrest shows that maintaining stable blood pressure and oxygen levels improves survival and neurological outcomes.

## Contribution

The study introduces high-fidelity, minute-level physiologic data linked to ROSC, enabling detailed exposure metrics for hypotension, hypoxaemia, and ETCO2.

## Key findings

- Higher SBP/MAP and SpO2 were associated with greater survival to hospital discharge.
- Higher mean ETCO2 was inversely associated with survival.
- Neurological associations among survivors were smaller and mainly limited to SBP.

## Abstract

•Registry-linked, ROSC-aligned, minute-by-minute Zoll® monitor-defibrillator data.•Enables cumulative exposure metrics for hypotension, hypoxaemia and ETCO2.•Higher SBP/MAP and SpO2 were associated with greater survival to hospital discharge.•Higher mean ETCO2 was inversely associated with survival.•Neurological associations among survivors were smaller, mainly limited to SBP.

Registry-linked, ROSC-aligned, minute-by-minute Zoll® monitor-defibrillator data.

Enables cumulative exposure metrics for hypotension, hypoxaemia and ETCO2.

Higher SBP/MAP and SpO2 were associated with greater survival to hospital discharge.

Higher mean ETCO2 was inversely associated with survival.

Neurological associations among survivors were smaller, mainly limited to SBP.

Early post-ROSC physiology changes rapidly, but most studies rely on a single handover set of vital signs, which can miss trajectories and time spent hypotensive or hypoxemic. We aimed to describe minute-level early post-ROSC blood pressure and oxygenation and examine their association with outcomes.

Retrospective cohort study of out-of-hospital cardiac arrest in Victoria, Australia (2019–2023). We linked the Victorian Ambulance Cardiac Arrest Registry to Zoll® monitor-defibrillator recordings, aligned measurements to recorded ROSC, aggregated readings into 1-min bins, and derived per-patient mean, minimum, and minutes below thresholds for SBP, MAP and SpO2. Associations with outcomes were modelled using adjusted logistic regression. Primary outcome was survival to hospital discharge. Secondary outcome was good 12-month neurological outcome among survivors.

Among 3694 patients with sustained ROSC, 1444 survived. Median ROSC-to-arrival was 58 min. Median per patient was 36 blood pressure and 97 SpO2 values. Compared with SBP 100 mm Hg, survival was lower at 80 mm Hg (aOR 0.87, 95% CI 0.79–0.95) and higher at 140 mm Hg (aOR 1.32, 95% CI 1.11–1.59). SpO2 90% versus 95% was associated with lower survival (aOR 0.70, 95% CI 0.63–0.79). Longer time with SBP <90 mm Hg, MAP <65 mm Hg, or SpO2 <90% was associated with lower survival. Associations with good 12-month neurological outcome were smaller and mainly limited to blood pressure.

Minute-level monitor-defibrillator data showed strong associations between early hypotension and hypoxaemia and survival after ROSC and allow cumulative exposure to be quantified.