[Prevention of venous thromboembolism in a non-surgical medical ward. Proposed indications for low molecular weight heparin].

OBJECTIVE

The efficiency of venous thromboembolism prophylaxis with low molecular weight heparins (LMWH) has not been established in non surgical patients, so their official preventive use has been limited in France since 1995 to surgery. However, a survey conducted in 5 university hospitals in non surgical patients showed that 21-29% of patients still received a LMWH prescription. It seemed necessary to define the medical conditions for which the practical use of these heparins would be justified. We contacted external experts to obtain a consensus by using the Delphi method.

METHODS

The Delphi method, created by the "Rand Corporation" in the USA and used in medicine since the nineteen seventies, is based on a light logistic, with questionnaires been sent by mail with a feed-back report A total of 48 experts were chosen by local staff teams in the 5 hospitals. For the 3 rounds, from March to October 1998, questions were devised by a multicentred staff team.

RESULTS

Among the 48 experts contacted, 32 completed the 3 questionnaires, 7 of them did for 2, and 43 did for at least one questionnaire. The experts first defined a list of 12 risk or high risk situations and 11 aggravating factors. For any high risk situation, prescription is justified. For other cases, 2 risk situations are required, or one risk situation with at least 2 aggravating factors, to justify a prescription. If no risk situation is present, prescription is, according to experts, usually not justified.

CONCLUSION

The maximal agreement defines the situations in which one use of low molecular weight heparins is proposed to prevent deep venous thrombosis in non surgical inpatients, in most current hospital situations and for more than 24 hours of hospitalization. Clinical trials are needed, to validate their effectiveness and define the optimal dose in these indications. To date, epidemiological studies should be conducted to evaluate the experts proposals by estimating risk factors for deep venous thrombosis.