[Prevention of thromboembolism and survival after trauma]

Thromboembolism (TE) is a well-known and potentially fatal complication after injury and orthopedic surgery. Thromboembolic prophylaxis is generally recognized as a factor of significant interest concerning posttraumatic comorbidity and mortality. In this context, the aim of the study was to analyze hospital mortality 24 hours after injury, and to assess the proportion of fatal pulmonary embolism in overall hospital mortality. Finally, the purpose of the study was to explore the possible correlation between different prophylactic approaches and hospital mortality.

A retrospective-prospective study was conducted at the University Hospital of Traumatology, Zagreb, over a 14-year period (1988-2001). The study was based on documented clinical and autopsy findings and comprised all trauma patients admitted for hospital treatment. The overall and thromboembolic mortality were analyzed for each individual year during the study period. These two variables were compared and expressed as a proportion for each year. Further analysis included comparison of the data obtained between years and sequences of years. The modes of TE prophylaxis in various periods were analyzed as well. Differences in the mortality rates were tested for statistical significance. Results obtained for each period of time were compared and expressed as a function of different approaches to thromboembolic prevention.

Results obtained in the study demonstrated a clear tendency towards the decrease in the overall mortality as well as in the mortality due to fatal pulmonary embolism. Mortality rates showed significant differences during the study period. The most prominent difference was found between the first and final year of investigation. In 1988, the overall mortality was 3.78% and TE mortality 2.05%, whereas in 2001 the respective rates were 1.17% and 0.3% (p < 0.001). A continuous significant mortality decrease in trauma patients was recorded for some years and sequences of years (p < 0.05). The proportion of TE fatality in the overall mortality was > 50% in 1988 and about 25% in 2001. Our results demonstrated a 70% reduction in the overall mortality and even 85% reduction in the fatal TE rate. Finally, a significant reduction of TE fatality by 55% independently of overall mortality reduction was observed. The decreasing mortality rate correlated with different approaches to TE prophylaxis during the 14-year-period.

Thromboembolism accounted for a considerable proportion of the mortality rate in trauma patients during the study period. The observed dynamics, expressed as a 70% reduction in the overall hospital mortality and an 85% decrease in the fatal PE rate reflected significant improvement in trauma treatment. Further, independently of the overall mortality, TE mortality was reduced by more than 55%, which was obviously related to the changing approaches to TE prevention. At the beginning, physical methods of prophylaxis prevailed. Prophylactic anticoagulation with heparin was started sporadically around 1991 and have been enhanced over time. In 1995, it was included in the routine treatment of specific patient categories. Since 1998, low molecular weight heparin has become the gold standard in TE prophylaxis, with more prominent application in severe multiple injuries. With the recent approach, we have managed to overcome the controversies in the treatment of severe injuries, primarily concerning bleeding and TE, and achieved considerable improvement.

A significant reduction in the mortality, especially due to fatal pulmonary embolism after injury, was clearly demonstrated. This could be explained by improvements in the management of trauma and organized TE prevention.