The Impact of a Systemwide Policy for Emergent Off-Hours Venous Duplex Ultrasound Studies

Background: We evaluated the impact of an after-hours policy regulating venous duplex ultrasound (VDU) for deep vein thrombosis (DVT) diagnosis on resource utilization and patient care. Methods: On July 1, 2007, we altered the approach to emergent VDU of patients with potential DVT during off-hours (defined as 5: 00 p. m. to 7: 00 a. m. weekdays, after 3: 30 p. m. Saturdays and Sundays). Instead of 24 hr access, we permitted a venous duplex study in the noninvasive vascular laboratory (NIVL) only after meeting set criteria developed collaboratively across services. In the emergency department (ED), we based all VDU requests on a preset modified Wells score (MWS) as determined by the ED physician. Those patients with MWS 0 or 1 and those above 1 who could receive empiric single-dose low-molecular weight heparin (LMWH) received next-morning imaging unless consultation with a vascular surgeon created an emergent imaging plan. In parallel, inpatient emergent VDU was permitted only after contact with an attending vascular surgeon and where empiric short-term anticoagulation could not occur safely. We tracked NIVL utilization, patient morbidity, sonographer retention, and satisfaction. Results: The number of overall off-hours emergent VDUs decreased from 59 to 19/month after implementation. Testing was deferred in 52 ED patients: 15 stayed in the ED for testing in the morning and 37 were discharged to be tested the following day. Thirty-one of 37 patients returned for testing as outpatient follow-up. Twenty-eight received ED LMWH while awaiting testing. No adverse events were noted with the delay. The mean MWS for ED after-hours studies was 2.9 +/- 1.6 and that for deferred ER studies was 2.4 +/- 1.3 (p = 0.005). Incidentally, overall off-hours inpatient and ED VDU requests decreased 64% with no clinical adverse events in the first year. The rate of overall positive studies done off-hours increased from 6.7% to 20% (p < 0.0001). Sonographer satisfaction was maintained with regulation of call. Conclusion: Our collaborative approach allowed off-hour VDU utilization to decrease without any measurable negative care impact.