Incidence and risk assessment of venous thromboembolism in cancer patients admitted to intensive care unit for postoperative care.

PURPOSE: The occurrence of venous thromboembolism (VTE) in Chinese cancer patients admitted to intensive care unit (ICU) for postoperative care is poorly characterized. This study was designed to investigate the incidence of VTE in this polulation and to evaluate the utility of the Caprini score in risk stratification.

METHODS: We conducted a retrospective cohort study of 2127 consecutive adult patients admitted to a 10-bed surgical ICU in a tertiary care academic hospital during a 4-year period (January 1,2013 to December 31,2016). Demographic and VTE data were collected. Data for the Caprini risk assessment model (RAM) was used to stratify patients on their risk of VTE.

RESULTS: Of the 2127 patients admitted to ICU after cancer surgery, 66 (3.1%) developed symptomatic VTE. There were a total of 32 patients with pulmonary embolism (PE), 51 patients with deep vein thrombosis (DVT), and 17 patients with both conditions. Based on the original Caprini RAM, 99.5% of the patients scored in the "highest risk" category (score≥5), all patients with VTE were in the "highest risk" category. Further substratification in the "highest risk" category showed the risk of developing VTE events were significantly higher among patients with Caprini score >10 ,as compared with patients with Caprini score of 5 to 6 (OR 5.63; 95%CI 1.27-24.94), 7 to 8 (OR 2.36; 95% CI 1.23-4.52 ) or 9 to 10 (OR 2.28; 95%CI 1.17-4.44). The percentage of patients receiving double prophylaxis was 16.8% (358/2127), 20 of the 66 VTE patients (30.3%) received double prophylaxis before VTE was diagnosed. Patients with higher Caprini score were more likely to receive double thromboprophylaxis than patients with lower Caprini score (23.4% of patients with Caprini score>10 vs 10.8% with Caprini score 5-6).

CONCLUSIONS: Though accompanying with the sub-utilizing of chemoprophylaxis, the overall incidence of VTE was relatively low in Chinese cancer patients admitted to ICU for postoperative care. In contrast, the Caprini score was high in this population. The original Caprini RAM was limited to stratify this population, but further substratification of "highest risk" category demonstrated the risk of developing VTE events was significantly higher in patients with Caprini score >10. Future research with high quality evidence should be performed targeting on the accurate risk stratification and optimizing VTE prophylaxis for this population.