Table 6.

CDC and societal recommendations regarding monitoring of anticoagulation in COVID-19

	Monitoring of patients receiving LMWH	Monitoring of patients with elevated PTT receiving therapeutic anticoagulation	Monitoring of patients receiving therapeutic anticoagulation
CDC	Not mentioned	Not mentioned	Per standard of care for patients without COVID-19
ISTH-IG	Advised in patients with severe renal impairment	Not mentioned	Not mentioned
ACF	Do not recommend dosing based on anti-Xa levels given lack of evidence on outcomes for thrombosis or bleeding	Recommend monitoring anti-Xa receiving UFH. LMWH use allows additional monitoring to be avoided.	Recommend monitoring anti-Xa levels to monitor UFH due to potential baseline PTT abnormalities. Reasonable to monitor anti-Xa or PTT in patients with normal baseline PTT levels and do not exhibit heparin resistance (> 35,000 u heparin over 24 h).
ASH	Not mentioned	May necessitate anti-Xa monitoring of UFH given artefactual increases in PTT.	May necessitate anti-Xa monitoring of UFH given artefactual increases in PTT.
ACCP	Body weight adjusted doses for LMWH do not require laboratory monitoring in majority of patients.	Not mentioned	Monitor anti-Xa levels in all patients receiving UFH given potential of heparin resistance.
SCC-ISTH	No specific recommendations. Mentions that LMWH may be advantageous over other agents for parenteral anticoagulation due to lack of routine monitoring.	Not mentioned	No specific recommendations. Mentions that expert clinical guidance statements and clinical pathways from large academic healthcare systems target an anti-factor Xa level of 0.3–0.7 IU/mL for UFH.
ACC	Not mentioned	Not mentioned	Not mentioned

Abbreviations: COVID-19 coronavirus disease 2019, IU international unit, LMWH low molecular weight heparin, mL milliliter, PTT partial prothrombin time, u units