A new preoperative predictor of outcome in ruptured abdominal aortic aneurysms: the time before shock (TBS)

Background: In patients with ruptured abdominal aortic aneurysm (RAAA) and shock, the time lag between the onset of the symptoms due to RAAA and the presence of a full developed shock syndrome was evaluated to assess its prognostic meaning. This time lag was called time before shock (TBS). Methods: Ninety-four patients operated on between 2002 and 2007 have been retrospectively analyzed regarding TBS and the following parameters: presence of shock, severity of bleeding, age, comorbidities, and gender. According to TBS, on a 10-hour cutoff value, three groups of patients were distinguished: patients with TBS of 10 or less (short TBS), patients with TBS greater than 10 (long TBS), and patients without shock. The relationship of these variables with intraoperative and 30-day mortality was analyzed by both univariate and multivariate analyses. Results: In the univariate analysis, patients with short TBS presented with four-fold mortality compared to patients without shock (p = 0.000), whereas the increase in mortality of the patients with long TBS was nonsignificant (p = 0.448). The mortality in patients with shock (presence of shock) was 3.7 times higher than in patients without shock (p = 0.001). The mortality related to massive bleeding was 3.7 times higher than that associated with moderate bleeding (p = 0.001). An increased mortality with borderline significance level was observed in patients older than 75 years (p = 0.052). The relationship of mortality to the presence of comorbidities and gender was not significant. In the multivariate analysis, the mortality among the patients with short TBS was clearly highest, after either massive or moderate bleeding. In the logistic model with TBS, the Wald test showed as significant both short TBS (p = 0.001) and severity of bleeding (p = 0.033) but not age (p = 0.103) and long TBS(p = 0.0401). The model with TBS presented a better performance than that with shock, showing higher sensitivity, higher values of Youden's J, and a greater proportion of the total variation in mortality. Through the model with TBS, two groups of patients (those 75 years or younger with massive bleeding and those older than 75 years with moderate bleeding), both with short TBS, presented with a high risk of death not predicted by the model with shock. Conclusion: TBS seems to complete the information given by the parameter "presence of shock," and its evaluation allows a more effective judgment of the risk of death, at emergency admission of patients with RAAA.