Abstract Sun706: Association of Diastolic Blood Pressure Trends and Thresholds with Return of Spontaneous Circulation Across Full CPR Duration

Introduction: Pediatric resuscitation guidelines support using diastolic blood pressure (DBP) as a marker of CPR quality. However, studies establishing DBP thresholds (≥25 mmHg in infants and ≥30 mmHg in children) only used data from the first 10 minutes of CPR, regardless of CPR duration. We aimed to describe DBP trajectories over the full course of IHCA and evaluate associations between DBP thresholds and ROSC in CPR events ≥10 minutes in duration (prolonged CPR). Hypothesis: DBP can be maintained above threshold during prolonged CPR and higher DBP throughout CPR will be associated with ROSC. Methods: Single-center retrospective cohort study of pediatric IHCAs with prospectively collected physiologic and event data (2017-2023). Invasive arterial BP waveforms were manually reviewed; only periods of CPR with evaluable data were included in DBP calculations. Events with ≥1 minute of data were included in the trends analysis and events with ≥1 minute of data after 10 minutes of CPR in the prolonged CPR analyses. Linear regression and mixed-effects models evaluated DBP trends and their association with ROSC. Univariate logistic regression determined the association between attaining DBP thresholds in prolonged CPR and ROSC. Results: Of 118 events with invasive BP data, median age was 0.4 [IQR: 0.1-2.3] years; 70% had congenital heart disease; and shock was the cause of arrest for 76%. On average, DBP rose early, then plateaued and remained above threshold throughout CPR; 37/46 prolonged events maintained average DBP above threshold. Higher average DBP (p=0.003) and rapid early rise in DBP (p<0.001) were associated with ROSC within 10 minutes. In prolonged CPR, upward DBP trend was associated with ROSC (p<0.001). Achieving current targets was not significantly associated with ROSC (OR 3.38; 95% CI: 0.52–66.64; p=0.222), but achieving higher targets (≥30 in infants and ≥35 mmHg in children) later in CPR was associated with ROSC (OR 7.14; 95% CI: 1.58–51.35; p=0.009). Conclusion: DBP is sustained above age-specific targets during prolonged CPR in most patients. Early DBP rise is associated with early ROSC. In prolonged CPR, upward DBP trajectory and reaching higher thresholds than currently recommended are associated with ROSC. These findings suggest that meeting existing DBP thresholds is necessary but potentially insufficient in prolonged arrests. Future study should explore dynamic, patient-specific, and time-dependent DBP goals to inform physiology-directed CPR.