Fig. 1.

Intervention with a direct thrombin inhibitor in persistent circuit clotting occurring in COVID-19 patients on CRRT. Five patients with SARS-CoV-2 infection and critical disease, involving respiratory failure and acute kidney injury, were followed from the time of ICU admission (hospital day 1). Day of institution of continuous renal replacement therapy (CRRT) is marked by an asterisk. Day of first recognition of a circuit clot, which persisted after dialysis membrane flushes, is marked by an arrow. Anticoagulation regimens are indicated as: argatroban, red solid line; therapeutic intravenous heparin, red dashed line; prophylactic enoxaparin (0.5mg/kg body weight, once daily), black dotted line; intermediate dose enoxaparin (0.5mg/kg body weight twice daily), black dashed line; therapeutic dose enoxaparin (1mg/kg body weight twice daily), black solid line. The gap in anticoagulation for Case 4 on days 15–17 related to concern for a bleed following an acute drop in hemoglobin. (For interpretation of the references to colour in this figure legend, the reader is referred to the Web version of this article.)