Less than 5% of Australian patients having hip or knee arthroplasty receive guideline-recommended therapy to prevent venous thrombosis, a study at the Royal Hobart Hospital has concluded.

Ms Corinne Mirkazemi, from the University of Tasmania School of Pharmacy, and colleagues reviewed the records of 300 patients treated between 2007 and 2009.

There were two cases symptomatic deep vein thrombosis or pulmonary embolism occurring during the initial hospital admission and another six cases after discharge (but all within one month of surgery). The overall incidence of 2.7% was similar to that reported in other studies.

“All inpatients received pharmacological thromboprophylaxis, predominantly injectable anticoagulants,” the researchers said. However, only 37% continued to receive treatment after discharge.

The accepted guidelines at the time of the study were those of the American College of Chest Physicians (ACCP). The most common departure from the guidelines was an inadequate duration of therapy, which was recommended to continue for at least 10 days after knee arthroplasty and 28 to 35 days after hip arthroplasty.

The NHMRC released guidelines on thromboprophylaxis in hospital patients in 2009, after data collection for the Hobart study was completed. It acknowledged that surgeons were often reluctant to persist with treatment because of the perceived and actual risks of major bleeding.

“In response, the Arthroplasty Society of Australia released an article with recommendations for surgeons to conduct risk assessments for each patient,” the researchers said.

The Society suggested that aspirin, or no chemo-prophylaxis, combined with mechanical prophylaxis might be appropriate for some patients with a relatively low risk of thrombosis.

Lack of consensus on optimal care meant that many patients failed to receive thromboprophylaxis conforming to any of the current guidelines, Ms Mirkazemi and colleagues said.

“Implementation of guidelines requires that more be done than simply publishing them,” they concluded.

Internal Medicine Journal. doi: 10.1111/j.1445-5994.2012.02864.x