Factors associated with pulmonary edema in severe scorpion sting patients--a multivariate analysis of 428 cases.

OBJECTIVE

To determine clinical and routine laboratory factors associated with pulmonary edema secondary to scorpion envenomation.

DESIGN AND SETTING

Retrospective study covering 13 years (1990-2002) in the medical Intensive Care Unit of a university hospital (Sfax-Tunisia).

PATIENTS

428 patients older than 3 years who were admitted to the intensive care unit for scorpion envenomation were included in this study. Patients were stratified into two groups according to the presence or absence of pulmonary edema as assessed by a medical committee.

MEASUREMENTS AND RESULTS

The mean (+/- SD) age was 17.5 +/- 17.7 years, ranging from 3 to 76 years. The pulmonary edema group included 294 patients (68.7%). A multivariate analysis found the following factors to be correlated with a pulmonary edema: age less than 5 years (p = 0.04), sweating (p = 0.004), agitation (p = 0.01), leukocytes of 25000 cells/mm3 or more (p = 0.02), and a plasma protein concentration of 72 g/L or more (p < 0.0001). In addition, a plasma protein concentration of 72 g/L or more predicted the presence of pulmonary edema with a sensitivity of 78% a specificity of 88%, a positive predictive value of 93%, and negative predictive value of 64%. Almost 84% of patients having a respiratory rate of > or = 30 breaths/minute associated with agitation and sweating were classified in the pulmonary edema group. This clinical association indicates the presence of pulmonary edema with a specificity of 84.3% and a positive predictive value of 87.5%.

CONCLUSION

In scorpion envenomation patients older than 3 years, the association of a respiratory rate of > or = 30 breaths/minute, agitation, sweating, or the presence of high plasma protein concentrations suggest the presence of pulmonary edema.