Rattlesnake Roundup: Point-of-Care Thrombelastographic Methods Define the Molecular Impacts on Coagulation of Venom Toxins In Vitro and In Vivo.

A malalignment between rattlesnake-envenomed patients' degree of compromised coagulation and the data generated by standard hematological determinations generated with blood samples anticoagulated with calcium (Ca) chelating agents is almost certain. Many rattlesnake venom toxins are Ca-independent toxins that likely continue to damage plasmatic and cellular components of coagulation in blood samples (anticoagulated with Ca chelation) during transportation from the emergency department to the clinical laboratory. The most straightforward approach to abrogate this patient-laboratory malalignment is to reduce "needle to activation time"-the time from blood collection to commencement of laboratory analysis-with utilization of point-of-care (POC) technology such as thrombelastography. The workflow and history of standard and POC approaches to hematological assessment is reviewed. Further, using a preclinical model of envenomation with four different rattlesnake venoms, the remarkably diverse damage to coagulation revealed with POC thrombelastography is presented. It is anticipated that future investigation and potential changes in clinical monitoring practices with POC methods of hematological assessment will improve the management of envenomed patients and assist in precision care.