Capillary leak syndrome in Daboia russelii bite-a complication associated with poor outcome

Capillary leak syndrome (CLS) has been previously observed as a complication of Daboia russelii bite but not clearly defined or studied in length. This observational case-control study evaluates the mortality along with associated clinical and laboratory features. Twenty-five patients who developed CLS were compared with 25 patients without CLS following Daboia russelii (Russell's viper) bite. Development of CLS is associated with a significantly high risk of mortality; 11 (44%) patients with CLS died compared with 1 (4%) control (odds ratio 18.8 [95% confidence interval 2.2 to 161.99], p=0.002). Disease-defining manifestations included myalgia (22 [88%]), thirst (20 [80%]), parotid swelling (15 [60%]), conjunctival chemosis (19 [76%]) and hypotension (22 [88%]), which were unobserved in controls. Although several clinical and laboratory parameters were found to be predictive for development of CLS in univariate analysis, none of them had independent predictive value in multivariate analysis. Similarly, development of parotid swelling was the only factor with independent predictive value for mortality in multivariate analysis. Even though the number of vials of snake antivenom used is more in CLS, it seems unlikely to improve the mortality in CLS. This study proves that CLS is a well-defined complication of Russell's viper bite with high mortality but with clear predictors for the development of CLS and mortality.