Chemoprophylaxis Plus Early Ambulation

Investigators enrolled 598 patients who were sent to thoracic postoperative intensive care unit (ICU) ward right after surgery from August 8 to September 12 of 2017 and those patients stayed in ICU for at least 24 hours. Excluded non-lung surgery there were 581 lung surgery cases. Investigators adopted the Caprini VTE risk assessment model from Boston Medical Center (BMC) in United States of America (USA). According to different risk level, participants received different thromboprophylaxis strategies. Early ambulation alone was for patients at low risk (Caprini 0-4), early chemoprophylaxis plus early ambulation was for patients at moderate (Caprini 5-8) or high risk (Caprini ≥9). Early chemoprophylaxis means low-molecular weight heparin (LMWH) 3075 IU (WHO Units) injection subcutaneously one time a day no later than 24 hours after surgery. Early ambulation means activity out of bed no later than 24 hours after surgery. Thromboprophylaxis contraindication included chest tube drainage more than 500 ml or major bleeding during operation or surgeons refusing to use thromboprophylaxis because they thought that patients would benefit more from not performing early ambulation or chemoprophylaxis. Some patients received chemoprophylaxis after they moved back to regular ward out of ICU which was called late chemoprophylaxis which means more than 24 hours after surgery. All chemoprophylaxis were used only during hospitalization. When participants were discharged, no extended treatment prescribed. However, they were followed up twice on 30 days and 60 days after surgery by phone call.