Definitions:
Therapeutic anticoagulation was defined as low molecular weight heparin
(LMWH) dosed as 1 mg/kg subcutaneously (SQ) every 12 hours to attain
anti-FXa levels between 0.5 to 1, or unfractionated heparin (UFH)
administered intravenously to attain anti-FXa levels of 0.3 to 0.7
and/or PTT of 70 to 110 seconds. Prophylactic anticoagulation was
defined as LMWH 0.5 mg/kg SQ every 12 hours to attain anti-FXa level
between 0.2 to 0.4 or adult dose of 40 mg SQ daily.
Bleeding was defined per International Society on Thrombosis and
Hemostasis (ISTH) guidelines. Non major or minor bleeding was defined as
overt bleeding requiring blood product transfusion (not directly
attributable to the patient’s underlying condition), bleeding requiring
medical or surgical intervention to restore hemostasis other than in the
operating room, other bleeding for which medical attention has been
sought and/or any overt macroscopic evidence of bleeding not fulfilling
above criteria for major bleeding7. Major bleeding
defined as fatal bleeding, symptomatic bleeding in a critical area or
organ (like intracranial, intraocular, pericardial), and/or bleeding
causing a fall in hemoglobin by 2 g/dL or more requiring transfusion of
2 or more units of while blood or red blood cells8.