Association Between Capnographic Changes During Pulse Checks of Varying Durations and Clinical Outcomes During Cardiopulmonary Resuscitation: A Multicenter Study From Türkiye (CaPTuRe).

Abstract

Aim: To investigate the association between capnographic changes during pulse checks of different durations and cardiopulmonary resuscitation (CPR) outcomes.

Methods: This multicenter, prospective, controlled, quasi-randomized study categorized patients according to pulse check duration: Group A (≤5 seconds) and Group B (>5 to ≤10 seconds). Five measurements were obtained during the first six CPR cycles. Four capnographic parameters were evaluated for each measurement: Post-CPR end-tidal carbon dioxide (ETCO₂), Pre-CPR ETCO₂, loss rate (percentage decrease between Post- and Pre-CPR ETCO₂), and recovery time (time required to regain the previous cycle's Post-CPR ETCO₂).

Results: The study included 252 cardiac arrest patients (Group A, n=124; Group B, n=128). In Group A, patients with return of spontaneous circulation (ROSC) had markedly lower loss rates and shorter recovery times than non-survivors, together with higher pre- and post-CPR ETCO₂ values (all p<0.001). Group A also had a higher ROSC rate than Group B (36.3% vs. 19.5%; p=0.005). Logistic regression identified pulse check duration as an independent predictor of ROSC, with Group A having 2.39-fold higher odds of ROSC than Group B (odds ratio [OR]=2.39, 95% confidence interval [CI]=1.347-4.242; p=0.003). Pre-CPR ETCO₂ was strongly negatively correlated with loss rate (ρ=-0.770), whereas Pre- and Post-CPR ETCO₂ values (ρ=0.96) and loss rate and recovery time (ρ=0.89) were strongly positively correlated.

Conclusion: Pulse checks completed within 5 seconds were associated with more favorable capnographic dynamics and higher ROSC rates than those lasting 6-10 seconds. These findings are hypothesis-generating and warrant prospective validation.