Dose-dependent mortality risk of plasma transfusion in critically ill patients

Plasma transfusion is commonly used in intensive care units, often for non-bleeding indications despite limited evidence. This study aimed to evaluate the association between plasma transfusions and in-hospital mortality among critically ill patients.

A retrospective cohort study was conducted using data from 282 adult intensive care unit patients who received transfusion therapy between January and December 2020. Patients were grouped by their exposure to plasma transfusion and further by the transfusion volume. First, multivariable Cox regression coupled with propensity score matching was used to control for baseline confounders and quantify the independent association of plasma transfusion with in-hospital mortality. Subsequently, Cox models and Kaplan-Meier survival curves were employed to elucidate the dose-response relationship between transfusion volume and mortality risk, with additional subgroup analyses.

In the unadjusted analysis, plasma transfusion was significantly associated with increased in-hospital mortality (Hazard ratio = 4.199; 95% confidence interval: 2.53-6.97; p-value <0.001). This association persisted after propensity score matching adjusted for key confounders (Hazard ratio = 3.271; 95% confidence interval: 1.30-8.21; p-value = 0.012). Kaplan-Meier survival analysis demonstrated significantly lower survival probabilities in the transfusion group (log-rank p-value <0.05). Furthermore, a dose-dependent relationship was revealed: mortality risk increased at higher volumes, reaching statistical significance at >800 mL (Hazard ratio = 4.09; 95% confidence interval: 1.19-14.04; p-value = 0.025). Subgroup analysis indicated that the elevated risk was particularly pronounced among patients who concurrently received red blood cell transfusions.

Plasma transfusion is independently and dose-dependently associated with increased mortality in critically ill patients, particularly when used without clear indications. These findings support a restrictive, evidence-based approach, emphasizing correction of underlying coagulopathy over prophylactic transfusion. Strict adherence to guidelines and an individualized risk-benefit assessment are essential to improve patient safety.