VARIABILITY IN VENOUS THROMBOEMBOLISM PROPHYLAXIS FOR INPATIENT MEDICAL PATIENTS: A DESCRIPTION OF DIFFERENCES IN PRACTICE ACROSS THE PRAIRIE PROVINCES

Background: Venous thromboembolism is the most common preventable cause of in-hospital mortality. Despite this, thromboprophylaxis practices vary related to order sets and special populations. Aim: To describe thromboprophylaxis strategies and awareness of institutional policies. Methods: Electronic survey of pharmacists having general medicine institutional practices within Alberta, Saskatchewan and Manitoba in 2017. Results: Amongst 88 (24.2%) respondents, the majority (60.2%) had practiced >5 years, and were working full time (81.8%) as staff pharmacists (94.3%). The majority (80.7%) used institutional order sets. In patients with normal weight and renal function, agents used were: dalteparin (36.4%), enoxaparin (31.1%), unfractionated heparin (UFH) (15.4%) and tinzaparin (11.3%), while for those with CrCl<30mL/min or hemodialysis, UFH (55.7% and 65.2%) and enoxaparin (23.5% and 26.3%) were used. Escalating doses for obesity were used by 86.7%, with upper weight extremes, defined in kilograms by 50.0% (median 100kg [range 100-150]), and BMI by 29.5% (median 40 [30-40]). Reduced doses were used for emaciation by 72.3%, with lower weight extremes defined in kilograms by 63.6% (median 40kg [30-50]). Prophylaxis was discontinued at discharge (58.0%) or once mobile (37.5%). However, 55.7% reported no standard mobility definition. When available, mobility was defined as home activity (46.2%) and bathroom use/walking distance (38.5%). Conclusion: Enoxaparin or dalteparin were most commonly used for thromboprophylaxis, while UFH was favored in those with severe renal dysfunction. Despite 80.7% having institutional order sets, mobility was not defined for the majority and some pharmacists identified not having weight cut off points for obese (29.5%) or emaciated (35.2%) patients.