Predictors of spontaneous bleeding in patients with acute febrile syndrome from a dengue endemic area.

ABSTRACT

BACKGROUND: Spontaneous bleeding is a common complication of dengue and is associated with an increased mortality. OBJECTIVE: To evaluate early clinical manifestations and simple laboratory tests as predictors of spontaneous hemorrhage in patients with forms of acute febrile syndrome (AFS) such as dengue from an endemic area. STUDY DESIGN: A prospective cohort study was performed including 729 non-bleeding AFS patients who were enrolled during the first 4 days of disease. Basal evaluation included anamnesis, physical examination and complete blood cell count. Follow-up was extended at least until the sixth day of disease. Dengue infection was studied with paired serologic tests and viral isolation. Potential predictors of spontaneous bleeding were evaluated with bivariate and multivariate analysis. RESULTS: Incidence of outcome was not significantly different between the dengue group and those with non-dengue AFS. The tourniquet test was not associated with outcome (p=0.38). In a binomial regression model, the following variables were associated with outcome: age between 12 and 45 years (RR=2.22; 95% CI 1.25-3.94), rash (RR=1.66; 95% CI 1.25-2.2), vomiting (RR=1.46; 95% CI 1.16-1.83), temperature >38 degrees C (RR=2.63; 95% CI 1.6-4.33), leukocyte count <4500/microL (RR=1.87; 95% CI 1.19-2.96), and platelet count <90.000/microL (RR=1.8; 95% CI 1.1-2.94). With these variables a risk score was formulated that showed an area under ROC curve of 70.5% (95% CI 64.9-76.2) to predict spontaneous bleeding. The score was useful for predicting bleeding in both dengue and non-dengue AFS groups. CONCLUSION: Some variables evaluated in the first days of disease helped to predict the risk of spontaneous bleeding in patients with dengue and non-dengue AFS.