Hypocoagulability in severe yellow fever infection is associated with bleeding: results from a cohort study

Abstract

BackgroundSevere yellow fever infection (YFI) may be complicated by a hemorrhagic diathesis. However, the hemostasis profile of YFI has rarely been reported. ObjectivesThe aim of this study was to characterize the hemostatic features of YFI by using a rotational thromboelastometry (ROTEM). MethodsWe evaluated clinical, laboratory, and ROTEM parameters in adults with severe YFI and their correlation with hemostatic variables according to bleeding and death. ResultsA total of 35 patients were included (median age, 49 years). ROTEM was performed in 22 patients, of whom 21 (96%) presented bleeding and 4 (18%) died. All patients who died had major bleeding. Patients who died presented prolonged clotting time (CT; median, 2326 minutes; IQR, 1898-2986 minutes) and reduced alpha angle (median, 12°; IQR, 12°-15°) in comparison with patients who had minor (median CT, 644 minutes; IQR, 552-845 minutes and alpha angle, 47°; IQR, 28°-65°) and major (median CT, 719 minutes; IQR, 368-1114 minutes and alpha angle, 43°; IQR, 32°-64°) bleeding who survived. In patients who had bleeding, CT showed a strong negative correlation with factor (F)V (r = −.68), FIX (r = −.84), and FX (r = −.63) as well as alpha angle showed a strong negative correlation with FIX (r = −.92). In patients who died, the correlations were even stronger. A total of 19/21 (90%) patients presented hypocoagulability assessed by ROTEM. ConclusionHypocoagulabitity is the hallmark of the bleeding diathesis of severe YFI. Abnormal CT and alpha angle associated with death and could be used as potential predictors of adverse outcome in severe YFI.