Peri-operative use of oestrogen containing medications and deep vein thrombosis--a national survey

To determine the practice of New Zealand orthopaedic surgeons when women taking hormone replacement therapy (HRT) or a combined oral contraceptive pill (COC) present for major surgery. Current practice is compared with recently produced guidelines and manufacturers advice.

A postal survey was sent to all New Zealand orthopaedic surgeons.

The response rate was 80% (118/148). There was wide variation in beliefs surrounding the peri-operative use of both of these medications. 44% of surgeons indicated that they would routinely advise discontinuing the COC pill peri-operatively for major surgery. 24% indicated that they would routinely advise discontinuing HRT peri-operatively. Recently released guidelines recommend that HRT should be stopped for at least 30 days prior to elective surgery and withheld for 90 days following surgery. Less than 3% of surgeons appeared to be routinely following this recommendation. Most manufacturers of COC pills recommend stopping the medication for at least four weeks prior to elective surgery. Only 25% of surgeons routinely practice in accordance with these recommendations.

This survey clearly demonstrates substantial differences between current clinical practice, recently revised HRT guidelines and oral contraceptive manufacturers advice. These differences need to be brought to the attention of surgeons and guideline producers. Particular medico-legal caution in this area is advised.