Evaluation of d-dimer as outcome biomarker in COVID-19 acute respiratory distress patients

Abstract

Acute respiratory distress syndrome is a significant complication in critical care patients. COVID-19 (C19)-associated severe respiratory failure is related to it, and d-dimer rise predicts a worse outcome. To investigate the association between d-dimer and the severity of this respiratory syndrome, we conducted a study in C19 intubated patients. A retrospective, single-center observational study was conducted with 64 C19 adult intubated patients. Strata of d-dimer results between patients was evaluated using survival analysis. Survival was higher in mild respiratory distress patients. D-dimer showed poor sensitivity and specificity in predicting respiratory failure severity. Risk assessment for death showed a higher prevalence of admission d-dimer results (HR 1.335; 95% CI 0.695-2.564). Our sample confidently represented the medical profile of C19 severe patients. Sepsis development in C19 is associated with the inflammatory storm in respiratory distress syndrome. As the receiver operating curves show, the increase in d-dimer results is consistent with inflammation rather than a prognostic biomarker. As expected, severe respiratory distress patients presented higher mortality. In summary, d-dimer results are not associated with the prognosis of C19 respiratory distress syndrome patients.

Figure 1. Participant flowechart. ICU = Intensive Care Unit; IMV = Invasive Mechanical Ventilation.

Figure 2. Kaplan-Meier curve in COVID-19 ARSD patients: 1) Mild ARDS; 2) Moderate ARDS; 3) Severe ARDS. ARDS = acute respiratory distress syndrome.

Figure 3. ROC curves of d-dimer: a) initial d-dimer; b) average d-dimer; c) higher d-dimer for the prognostic marker in study subjects.

Figure 4. Severity of ARDS and d-dimer results: a) initial d-dimer; b) average d-dimer; c) higher d-dimer. TP = True positive; TN = True negative; FP = False positive; FN = False negative.