Incidence, risk factors and potential timing of occurrence of pulmonary embolism in fatal trauma: An autopsy based case-control study on 2705 victims.

BACKGROUND

Pulmonary embolism (PE) following trauma is a potentially preventable but highly lethal complication. We sought to investigate the incidence, risk factors and potential timing of occurrence of post-traumatic PE in a large cohort of trauma fatalities.

METHODS

A case-control study on 9266 consecutive trauma fatalities (between 1996 and 2005) from a regional autopsy-based trauma registry. Injuries were classified according to the Abbreviated Injury Scale-1990 edition (AIS-90) and the Injury Severity Score (ISS) was calculated. Hospitalized victims were categorized according to the presence or absence of PE on autopsy. Univariate comparisons and multivariate logistic regression analysis for probabilities of association (odds ratios-OR) were performed.

RESULTS

Out of 2705 subjects who met the inclusion criteria, 116 had autopsy findings of PE and constituted the PE group (incidence of 4,3%), while the remaining victims formed the control group. The survival time of the PE group ranged from 0.66 to 104.73 days. Victims in the PE group were older (median age 69.5 vs 59), had lower ISS values (median 16 vs 26) and longer post-injury survival times (median 13.6 vs 5.7 days). Positively associated risk factors were AIS2-5 pelvic ring injuries (OR:2.23) and secondary deaths following an uneventful hospital discharge (OR:3.97), while AIS2-5 head (OR:0.33) and abdominal injuries (OR:0.23) showed a reverse association.

CONCLUSIONS

Trauma fatalities with autopsy findings of PE were associated with less severe trauma indicating that PE was likely detrimental to the fatal outcome. Both the early and delayed occurrence of PE was reaffirmed. Prophylactic measures should be initiated promptly and extended post discharge for high risk patients to prevent secondary deaths.