Prediction of return of spontaneous circulation in out-of-hospital cardiac arrest with non-shockable initial rhythm using point-of-care testing: a retrospective observational study.

Background: Out-of-hospital cardiac arrest (OHCA) is a public health concern, and many studies have been conducted on return of spontaneous circulation (ROSC) and its prognostic factors. Rotational thromboelastometry (ROTEM), a point-of-care testing (POCT) method, has been useful for predicting ROSC in patients with OHCA, but very few studies have focused on patients with non-shockable rhythm. We examined whether the parameters of POCT could predict ROSC in patients with OHCA and accompanying non-shockable rhythm.

Methods: This is a single-center, retrospective observational study. Complete blood count, blood gas, and ROTEM POCT measurements were used. This study included patients with non-traumatic OHCA aged 18 years or older who were transported to the emergency department and evaluated using POCT between January 2013 and December 2021. The patients were divided into the ROSC and non-ROSC groups. Prehospital information and POCT parameters were compared using receiver operating characteristic (ROC) curve analysis, and further logistic regression analysis was performed.

Results: Sixty-seven and 135 patients were in the ROSC and non-ROSC groups, respectively. The ROC curves showed a high area under the curve (AUC) for K of 0.77 (95% confidence interval []: 0.71-0.83) and EXTEM amplitude 5 min after clotting time (A5) of 0.70 (95%: 0.62-0.77). The odds ratios for ROSC were as follows: female sex 3.67 (95%: 1.67-8.04); K 0.64 (95%: 0.48-0.84); and EXTEM A5 1.03 (95%: 1.01-1.06).

Conclusion: In OHCA patients with non-shockable rhythm, K level and the ROTEM parameter EXTEM A5 may be useful in predicting ROSC.