title: Randomized clinical trial of low molecular weight heparin with thigh-length or knee-length antiembolism stockings for patients undergoing surgery.
abstract: BACKGROUND
  This was a randomized clinical trial to determine the efficacy and safety of a 'blanket' protocol of low molecular weight heparin (LMWH) and the best length of antiembolism stocking, for every patient requiring surgery under general anaesthesia.
  
  
  METHODS
  Of 426 patients interviewed, 376 agreed to be randomized to receive one of three types of stocking: thigh-length Medi thrombexin climax (Medi UK, Hereford, UK), knee-length thrombexin climax and thigh-length Kendall T.E.D. (Tyco Healthcare UK, Redruth, UK). All patients received LMWH thromboprophylaxis. Duplex ultrasonography was used to assess the incidence of postoperative deep vein thrombosis (DVT).
  
  
  RESULTS
  No postoperative DVT occurred in 85 patients at low or moderate risk. Nineteen DVTs occurred, all in the 291 high-risk patients: two with the Medi thigh-length stockings, 11 with the Medi knee-length stockings (odds ratio 0.18 (95 per cent confidence interval 0.04 to 0.82); P = 0.026) and six with the Kendall T.E.D. thigh-length stockings. No patient developed a pulmonary embolism. Stocking groups were similar for age, sex, thromboembolic risk, type of operation and compliance. One significant bleeding complication occurred.
  
  
  CONCLUSIONS
  A single protocol comprising LMWH and thigh-length stockings abolished DVT in low- and moderate-risk patients, and reduced the rate of DVT to 2 per cent in high-risk patients.
authors.affiliation: Department of Acute and Reconstructive Surgery, Imperial College of Science, Technology and Medicine, Charing Cross Hospital, London W6 8RF, UK.
authors.forename: A
authors.initials: A
authors.lastname: Howard
authors.forename: D
authors.initials: D
authors.lastname: Zaccagnini
authors.forename: M
authors.initials: M
authors.lastname: Ellis
authors.forename: A
authors.initials: A
authors.lastname: Williams
authors.forename: A H
authors.initials: AH
authors.lastname: Davies
authors.forename: R M
authors.initials: RM
authors.lastname: Greenhalgh
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000925:Anticoagulants / Q000627:therapeutic use*; D001458:Bandages; D004867:Equipment Design; D005260:Female; D006495:Heparin, Low-Molecular-Weight / Q000627:therapeutic use*; D006801:Humans; D008297:Male; D008875:Middle Aged; D011182:Postoperative Care / Q000379:methods*; D013923:Thromboembolism / Q000517:prevention & control*; D020246:Venous Thrombosis / Q000517:prevention & control*
chemical_list: D000925:Anticoagulants; D006495:Heparin, Low-Molecular-Weight