Acute compartment syndrome in Bothrops atrox envenomation: a case-control study in the Brazilian Amazon

Abstract Background: Bothrops snakebite is common in the Amazon region and can lead to severe complications in the affected limb, including secondary bacterial infections, blisters, necrosis, and acute compartment syndrome (ACS) in extreme cases. Many of these patients reside in remote areas with limited resources, where early recognition of clinical indicators is decisive for the timely identification of ACS and subsequent decision-making by healthcare professionals. The aim of this study was to identify risk factors associated with ACS following Bothrops atrox envenomation in the Brazilian Amazon. Methods: A case-control study was conducted in three health units of Manaus, Western Brazilian Amazon. The allocation ratio was 1:3, with cases defined as B. atrox-envenomed patients developing ACS, and a control group consisting of patients who did not develop ACS. Results: A total of 37 ACS cases and 111 controls were included in the study. Living in rural areas [OR = 4.59 (95%CI = 1.51-20.0; p = 0.017)], bites in the lower limbs [OR = 7.6 (95%CI = 3.18-19.3; p < 0.001)], time to medical care of 7-12 hours [OR = 4.23 (95%CI = 1.63-11.1; p = 0.003)], blisters [OR = 3.24 (95%CI = 1.12-9.25; p = 0.027)], and secondary bacterial infection [OR = 15 (95%CI = 3.54-103; p < 0.001)] were associated with ACS. Mean values of creatine kinase were significantly higher in ACS patients on the first (p = 0.022) and second (p = 0.013) days of hospitalization. Conclusion: This study presents, for the first time, the factors associated with ACS from B. atrox envenomation, providing a basis for early diagnosis and treatment, and enabling prompt medical intervention. This may reduce adverse events, promote faster recovery, and lower the rate of disability.