The Value of Thromboelastography (TEG) in COVID-19 Critical Illness as Illustrated by a Case Series

OBJECTIVE: To develop a practical thromboelastograph guided (TEG) anticoagulation protocol to guide the management of COVID-19 critically ill patients. DESIGN: An inter disciplinary team reviewed the current literature on hypercoagulability in critically ill COVID-19 patients, clinical management practices and challenges with high rates of thrombotic events despite anticoagulant therapies. SETTING: The largest tertiary care hospital within the Northwell Health System in New York. PATIENTS: COVID-19 invasively mechanically ventilated patients in Medical Intensive Care Unit Settings. METHODS: TEG was monitored in critically ill COVID-19 patients. Patterns were reviewed to guide the development of a treatment protocol leveraging TEG parameters to select anticoagulant therapy. Three patients are reported to highlight TEG profiles that led to the development of the algorithm. Clinical trajectory and treatment decisions were extracted retrospectively from the Electronic Health Record, with input from the intensivists. Anticoagulant use, laboratory and TEG values, and venous/arterial lower extremity (LE) ultrasound results were recorded. MAIN RESULTS: These patients demonstrated hypercoagulable TEG results despite prophylactic or therapeutic dosages of unfractionated heparin or low-molecular-weight heparin (LMHW). TEG surveillance identified functional fibrinogen and maximum amplitude in high-risk patients with hyper inflammatory markers. Anticoagulation assessment, TEG parameters, and LE ultrasound monitoring for venous and arterial thrombus were used to construct an algorithm to guide and escalate anticoagulant therapy. CONCLUSIONS: TEG provides patient-specific evidence for a hypercoagulable state in patients receiving all types of anticoagulant therapy. The proposed TEG algorithm guides anticoagulation management decisions to maintain or escalate anticoagulant dose and/or change choice of anticoagulant. A TEG algorithm may help negotiate the potential harm/benefit balance of full-dose anticoagulation in critically ill COVID-19 patients, by allowing for a more individualized approach that goes beyond the review of activated partial thromboplastin time (aPTT) levels.