Type And Dose Of Heparin In Covid-19: Reply

We thank the authors for their comments and feedback on the ISTH interim guidance. Hyper-coagulability is indeed a significant issue in COVID-19 and the haemostatic system is shifted markedly towards the procoagulant side in these patients. However, we cannot yet be certain that unfractionated heparin (UFH) is better than low molecular weight heparin (LMWH) in this scenario. Although UFH has been used for several years, it does have practical issues, mainly with respect to the need for frequent monitoring using the activated partial thromboplastin times (aPTT).