OBJECTIVE

To explore and evaluate the predictive value of coagulopathy in patients with community-acquired pneumonia (CAP) METHODS: A retrospective study was performed by investigating the prothrombin time (PT), activated partial thromboplastin time (APTT), plasma fibrinogen (FIB), thrombin time (TT), platelets (PLT), and D-dimer in 385 patients with CAP, who were admitted to the Respiratory Medical Department of the First Affiliated Hospital of Xiamen University from June, 2010 to May, 2011. The differences of the aforementioned results in patients with different prognostic risks were compared and analyzed. The Pneumonia Severity Index (PSI) was calculated to assess the severity.

RESULTS

The serum levels of PT, TT and D-dimer in high-risk patients with CAP were (15.1 ± 1.4) s, (16.0 ± 1.8) s, (7.5 ± 8.3) mg/L, respectively. They were all increased compared with those in the low-risk group (14.5 ± 0.9) s, (15.4 ± 1.2) s, (1.6 ± 2.0) mg/L]; the differences being statistically significant (P < 0.001), while PLT, APTT, and FIB were not statistically different (P > 0.05). The difference of the abnormal rate of PLT, PT, and D-dimer in high-risk group and the low-risk group were 30% (45/148) and 20% (47/237), 18% (26/148) and 5% (13/237), 99% (146/148) and 85% (202/237), respectively, the differences being statistically significant (χ² value were 5.602, 14.609, 23.442, respectively, P < 0.05), while TT, APTT, FIB were not (P > 0.05). Rank correlation existed between D-dimer and PSI (r = 0.798, P < 0.001), while there was no correlation between PLT and PSI (χ² = 6.040, P > 0.05). D-dimer in patients with respiratory failure was (10.0 ± 9.9) mg/L, which was significantly increased compared with that in patients without respiratory failure (2.4 ± 3.6) mg/L, P < 0.001, and there was no significant difference in PLT (χ² = 3.457, P > 0.05). D-dimer was significantly higher in patients who died of pneumonia as compared to those who survived [(14.0 ± 8.8) mg/L, (2.8 ± 4.6) mg/L, P < 0.001], and there was a significant difference in PLT (χ² = 4.909, P < 0.05). The area under the receiver operator characteristic curve (ROC) of D-dimer, PSI and PLT were 0.962, 0.906, 0.583, respectively. Concerning the predictive value of mortality, both D-dimer and PSI showed ideal predictive accuracy (P < 0.001). The sensitivity of D-dimer was superior to its specificity. PLT showed poor predictive value for mortality.

CONCLUSIONS

D-dimer was significantly higher in patients with CAP. D-dimer level was positively correlated with severity and mortality. D-dimer could be a good biomarker to assess the severity and mortality of patients with CAP.