Bothrops snakebites in the Amazon: recovery from hemostatic disorders after Brazilian antivenom therapy

Abstract

Introduction: Bothrops atrox snakebites are a major public health problem in the Amazon region and also cause hemostatic disorders. In this study, we assessed the recovery from hemostatic disorders in Bothrops snakebite patients after being given antivenom therapy.

Methods: This is a prospective study of Bothrops snakebite patients (n = 100) treated at the Fundação de Medicina Tropical Dr. Heitor Vieira Dourado, Manaus, Brazilian Amazon, between January 2016 and December 2017. Blood samples were taken for the measurement of venom concentrations, platelets, clotting time and factors of patients on admission, 12, 24 and 48 h after antivenom therapy, and taken again on discharge. The presence of systemic bleeding was recorded during the follow-up.

Results: On admission, systemic bleeding was observed in 14% of the patients. Thrombocytopenia was noted in 10% of the patients. A total of 54% of the patients presented unclottable blood with low levels of fibrinogen and alpha 2-antiplasmin, and high levels of fibrin/fibrinogen degradation product (FDP) and D-dimers. Unclottable blood and systemic bleeding were overcome in most patients 12 h after the antivenom therapy. Three patients developed systemic bleeding 48 h after antivenom therapy. Levels of fibrinogen and alpha 2-antiplasmin, FDP and D-dimer returned to normal around 48 h after the treatment or on discharge. The frequency of thrombocytopenia with high mean platelet volume increased in the first 24 h after antivenom therapy, and decreased on discharge. Bothrops venom levels in patients decreased 12 h after antivenom therapy and were not correlated with coagulation and fibrinolytic parameters. There were no deaths.

Conclusion: Laboratorial parameters of coagulopathy returned to normal values within 48 h after the antivenom therapy until discharge. A few patients still presented bleeding signs within 48 h after beginning antivenom therapy. However, the Brazilian antivenom was able to overcome the hemostatic disorders in these cases of envenomation.

Keywords:

• Bothrops atrox
• coagulopathy
• systemic bleeding
• thrombocytopenia
• antivenom therapy

Acknowledgments

The authors are grateful to all patients and donors who participated in our study. We acknowledge the assistance of the medical and nursing staff at Fundação de Medicina Tropical Dr. Heitor Vieira Dourado. We also thank Socorro Costa for technical support.

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This work was supported by the Coordenação de Aperfeiçoamento de Pessoal de Nível Superior [CAPES/PROCAD] under Grant number 2992/2014; Conselho Nacional de Desenvolvimento Científico e Tecnológico [CNPQ/UNIVERSAL] under Grant number 428525/2016-4; and Fundação de Amparo à Pesquisa do Estado do Amazonas [FAPEAM/PPSUS] under Grant number 287/2013. Marcus Vinicius Guimarães de Lacerda, Ana Maria Moura-da-Silva and Wuelton Marcelo Monteiro are CNPq fellows.