Low accuracy of microscopic hematuria in detecting coagulopathy from Bothrops pit viper bites, Brazilian Amazon

Abstract

Introduction: The common lancehead snakes (Bothrops atrox) are responsible for up to 90% of snakebites in the Amazon, especially in remote areas. The prevalence of microhematuria is similar to that of coagulopathy in B. atrox envenomation in the Amazon. Thus, this study aimed to assess the reliability of microhematuria as an inexpensive and simple alternative to detect snake-induced consumption coagulopathy.

Methods: We analyzed samples from patients with confirmed B. atrox envenomation in terms of plasma fibrinogen and microhematuria (>3 red blood cells per high power field) in order to access the reliability of microhematuria to detect snakebite-induced coagulopathy, within 12 hours from admission.

Results: A total of 186 patients were recruited. From the total, 85.5% of patients had hypofibrinogenemia and only about 50% (n = 94) had a microscopic examination of urine within 12 hours where microhematuria was present in 39 (41.5%). Diagnostic performance showed 38.6% sensitivity and 36.4% specificity (cutpoint 200 mg/dL). No clear association was seen between microhematuria and hypofibrinogenemia (r: −0.10; p: .34).

Conclusion: In this study, microhematuria presented poor diagnostic performance to detect coagulopathy. Further studies are necessary to screen inexpensive and simple alternative diagnostic tools.

Keywords:

• Microhematuria
• snakebite
• coagulopathy
• sensitivity

Acknowledgements

We would like to thank all patients that kindly agreed to participate in the study. We also thank the clinical personnel at the Fundação de Medicina Tropical Heitor Vieira Dourado for their assistance with patient care and monitoring.

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This work was supported by the Fundação de Amparo à Pesquisa do Estado do Amazonas (FAPEAM PPSUS Call) grant number 287/2013. JDBS is supported by Coordenação de Aperfeiçoamento de Pessoal de Nível superior – Brasil (CAPES) – Finance Code 001. The funders had no role in study design, data collection, manuscript preparation or decision to publish.