Prognostic value of early point-of-care blood gas analysis in critically ill non-trauma patients

Background Critically ill non-trauma patients treated in the emergency department have a high risk of in-hospital mortality. While point-of-care diagnostics such as blood gas analysis are established tools for urgent management, data on their prognostic value in this specific patient cohort remain limited. This study aimed to evaluate whether initial blood gas parameters are independently associated with in-hospital mortality in critically ill non-trauma patients. Methods This retrospective cohort study included adult critically ill non-trauma patients treated in the emergency department of a German university hospital. Initial blood gas parameters and clinical data were analyzed using univariate and multivariable logistic regression to assess their association with in-hospital mortality. Results Of 879 screened patients, 542 met the inclusion criteria. In-hospital mortality was 20% (n = 110). In addition to older age and out-of-hospital cardiac arrest, anemia (hemoglobin < 12 g/dL; OR of 2.07, 95% CI 1.20–3.58; p = 0.009), acidosis (pH < 7.35; OR 2.26, 95% CI 1.09–4.95; p = 0.033) and hypobicarbonatemia (< 22 mmol/L; OR 2.79, 95% CI 1.42–5.69; p = 0.004) were independently associated with in-hospital mortality. The association for hyperlactatemia was borderline (> 2.2 mmol/L; OR 1.85, 95% CI 0.93–3.77; p = 0.08). Multivariate analysis did not reveal significant associations between other electrolyte imbalances and in-hospital mortality in this cohort. Conclusion In this retrospective cohort, the presence of anemia, acidosis or hypobicarbonatemia on admission to the resuscitation room were independently associated with an elevated risk of in-hospital mortality in critically ill non-trauma patients. These readily available point-of-care parameters may support early risk stratification. Prospective studies are needed to validate these findings.