Prevention of venous thromboembolism in patients hospitalized for more than 24 hours in a medical ward: proposed indications for low molecular weightheparins

OBJECTIVE: The efficiency of venous thromboembolism prophylaxis with low mo lecular weight heparins (LMWH) has not been established in non surgical pat ients, so their official preventive use has been limited in Fiance since 19 95 to surgery. However, a survey conducted in 5 university hospitals in non surgical patients showed that 21-29% of patients still received a LMWH pre scription. It seemed necessary to define the medical conditions for which t he practical use of these heparins would be justified. We contacted externa l experts to obtain a consensus by using the Delphi method. METHODS: The Delphi method, created by the "Rand Corporation" in the USA an d used in medicine since the nineteen seventies, is based on a light logist ic, with questionnaires been sent by mail with a leed-back report A total o f 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 multi-cent red 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 expert s first defined a list of 12 risk or high risk situations and 11 aggravatin g factors. For any high risk situation, prescription is justifed. 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 o f low molecular weight heparins is proposed to prevent deep venous thrombo sis in non surgical inpatients, in most current hospital situations and for more than 24 hours of hospitalization. Clinical trials are needed, to vali date their effectiveness and define the optimal dose in these indications T o date, epidemiological studies should be conducted to evaluate the experts proposals by estimating risk factors ior deep venous thrombosis.