BMC Emerg Med. 2025 Nov 26;25(1):246. doi: 10.1186/s12873-025-01406-6.

BACKGROUND: The aim was to compare the hemodynamic and metabolic effectiveness of manual chest compressions and a mechanical chest compression device during in-hospital cardiac arrest by monitoring carotid Doppler flow and end-tidal carbon dioxide (ETCO₂) and arterial lactate levels.

METHODS: In this single-center, prospective, observational cohort study, 54 adult patients with nontraumatic cardiac arrest in the emergency department were enrolled between December 2023 and February 2024. Chest compressions were delivered manually for the first three 2-minute cycles and mechanically for the subsequent two cycles. The peak-systolic velocity (PSV) and end-diastolic velocity (EDV) of the common carotid artery and the ETCO₂ and lactate levels were recorded at cycles 1, 3 and 5. The primary and secondary outcomes were the return of spontaneous circulation (ROSC) and 24-h survival, respectively. The predictive performance of physiological markers was assessed with receiver operating characteristic (ROC) analysis.

RESULTS: ROSC was achieved in 41/54 patients (75.9%), and 22/41 patients (53.7%) were alive at 24 h. The ultrasound acquisition time decreased from 39.9 ± 7.2 s in the first (manual) cycle to 25.7 ± 5.5 s in the fifth (mechanical) cycle (p < 0.01). Compared with manual cardiopulmonary resuscitation (CPR), mechanical compression was associated with greater increases in PSV (Δ₃-₅ = 9.0 ± 3.3 cm s⁻¹ vs. Δ₁-₃ = 2.7 ± 2.9 cm s⁻¹; p < 0.01) and EDV, a greater increase in ETCO₂ (3.5 ± 1.7 mm Hg vs. 1.3 ± 1.6 mm Hg; p < 0.01) and a more pronounced decrease in lactate levels (-0.30 ± 0.34 mmol L⁻¹ vs. -0.10 ± 0.19 mmol L⁻¹; p < 0.01). An ETCO₂ value ≥ 35 mm Hg predicted ROSC with 75.6% sensitivity and 53.9% specificity (AUC = 0.70), whereas a lactate level ≤ 5.3 mmol L⁻¹ predicted ROSC with 76.9% sensitivity and 82.9% specificity (AUC = 0.81). Carotid Doppler velocities showed limited discrimination for ROSC (AUC ≈ 0.56-0.58) and should not be used alone for prognostication.

CONCLUSION: Compared with the preceding manual cycles, the mechanical cycles were associated with higher carotid flow velocities and more favorable ETCO₂-lactate trajectories; however, given the fixed sequence and co-interventions, causality cannot be inferred.

PubMed:41299298 | PMC:PMC12659239 | DOI:10.1186/s12873-025-01406-6