PHARMACOLOGICAL THROMBOPROPHYLAXIS IN HIP AND KNEE SURGERY - A SURVEY OF NEW-ZEALAND ORTHOPEDIC SURGEONS

A survey was conducted of the attitudes and practices of New Zealand orthopaedic surgeons on the use of pharmacological thromboprophylaxis (PT) for patients undergoing major hip or knee surgery. A questionnaire was sent to all 106 consultant surgeons known to perform hip or knee surgery and a response rate of 89% was obtained. The results suggested that while almost all surgeons used PT at some time, only about one-third of elective surgery patients and just a few per cent of patients with neck of femur fracture (NOFF) receive PT. For about three-quarters of surgeons, heparin (usually low molecular weight) was the most frequently used PT. About half of the surgeons began prophylaxis pre-operatively and about half stopped it when the patients were mobile postoperatively. Previous venous thromboembolism was felt by almost all surgeons to be a very important indication for PT; gross obesity, prolonged pre-operative immobility and active malignancy were thought to be very important factors by approximately one-half of the surgeons. The presence of a major bleeding diathesis or active peptic ulcer was cited as a contraindication to PT by more than two-thirds of all surgeons. Fear of bleeding complications and the rarity of thromboembolic complications were cited as reasons for limited use of PT by about one-third of surgeons. The results suggest that most surgeons usually rely on non-pharmacological methods of thromboprophylaxis, particularly for NOFF patients. The minimal use of PT in NOFF patients, despite their very high risk of thrombotic complications, was difficult to explain as more than one-half of all surgeons felt that age, dependency or dementia were not very important in the decision as to whether or not to give PT.