D-dimer Is a Predictor of 28-Day Mortality in Critically Ill Patients Receiving Continuous Renal Replacement Therapy

Continuous renal replacement therapy (CRRT) is an important treatment in the intensive care unit (ICU). Nevertheless, the outcome of CRRT remains unclear. It is important to find a useful and easy indicator to predict the prognosis in patients on CRRT treatment. We undertook this study to observe the association between serum D-dimer level and mortality of ICU patients in the treatment of CRRT.

A total of 149 patients who received CRRT were enrolled in our study. We observed the correlation of D-dimer with the information of biochemical parameters, acute physiology and chronic health evaluation II (APACHE II) score. We analyzed the association between serum D-dimer level before CRRT and 28-d mortality retrospectively. Furthermore, we used Cox regression analysis to assess whether D-dimer could be the independent risk factor for mortality.

There were significant correlations between D-dimer and C-reaction protein (r² = 0.033, p = 0.026), creatinine (r² = 0.066, p = 0.002) and APACHE II (r² = 0.036, p = 0.021). The difference in 28-d mortality risk between elevated D-dimer group and normal D-dimer group was significant (HR 2.872, 95% CI 1.563-5.278, p = 0.001), and the elevated D-dimer level was an independent risk factor for 28-d mortality (HR 2.067, 95% CI 1.104-3.872, p = 0.023). The difference in 28-d mortality was significant between groups (p <0.001). ROC curves showed that the area under the curve (AUC) of D-dimer was 0.763.

The present study demonstrates that serum D-dimer could be a useful and easy prognostic variable of 28-d mortality in critically ill patients who received CRRT.