Comparison of four noninvasive tools for predicting sepsis and septic shock mortality: a prospective cohort study

Sepsis, a life-threatening organ dysfunction, is a major global health concern. Early detection remains challenging due to nonspecific symptoms. Noninvasive tools such as the shock index, diastolic shock index, capillary refill time (CRT), and mottling score (MS) could help clinicians assess hemodynamic status and predict mortality, but a comprehensive comparison of their prognostic value is lacking. This study compares the performance of those four tools in predicting mortality in septic patients at 24 hours, 7 days, and 28 days.

A single-center, prospective observational study was conducted from January to September 2024. Adult patients (≥18 years) with suspected infection and a National Early Warning Score-2 of ≥5 were enrolled. Demographic data, vital signs, and CRT and MS results were collected at presentation, and mortality outcomes were recorded at 24 hours, 7 days, and 28 days.

In total, 135 patients were included (median age, 85 years [interquartile range, 79-90 years]; 44.4% female). The mortality rates were 15.6% at 24 hours, 25.2% at 7 days, and 35.6% at 28 days. CRT showed the highest predictive value for 24-hour mortality (area under the curve [AUC], 0.829; 95% confidence interval [CI], 0.755-0.889), and MS had the best performance at 7 days (AUC, 0.732; 95% CI, 0.646-0.806) and at 28 days (AUC, 0.749; 95% CI, 0.662-0.823). No significant differences emerged in pairwise comparisons.

Although no one tool significantly outperformed the others, all four tools may provide useful, noninvasive mortality prediction in sepsis. CRT may be most effective for early risk stratification and MS correlates with mid-term outcomes, supporting their integration into clinical assessments.