Reducing unnecessary diagnostic phlebotomy in intensive care: a prospective quality improvement intervention.

Abstract

Critically ill patients receive frequent routine and recurring blood tests, some of which are unnecessary. To reduce unnecessary routine phlebotomy in a 30-bed tertiary medical-surgical intensive care unit (ICU) in Toronto, Ontario. This prospective quality improvement study included a 7-month preintervention baseline, 5-month intervention and 11-month postintervention period. Change strategies included education, ICU rounds checklists, electronic order set modifications, an electronic test add-on tool and audit and feedback. The primary outcome was mean volume of blood collected per patient-day. Secondary outcomes included the number blood tubes used and red cell transfusions. Balancing measures included the timing and types of blood tests, ICU length of stay and mortality. Outcomes were evaluated using process control charts and segmented regression. Patient demographics did not differ between time periods; total number of patients: 2096, median age: 61 years, 60% male. Mean phlebotomy volume±SD decreased from 41.1±4.0 to 34.1±4.7 mL/patient-day. Special cause variation was met at 13 weeks. Segmental regression demonstrated an immediate postintervention decrease of 6.6 mL/patient-day (95% CI 1.8 to 11.4 p=0.009), which was sustained. Blood tube consumption decreased by 1.4 tubes/patient-day (95% CI 0.4 to 2.4, p=0.005) amounting to 13 276 tubes (95% CI 4602 to 22 127 tubes) saved over 11 months. Red blood cell transfusions decreased from 10.5±5.2 to 8.3±4.4 transfusions/100 patient-days (incident rate ratio 0.56, 95% CI 0.35 to 0.88, p=0.01). There was no impact on length of stay (2 days, IQR 1-5) and mortality (18.1%±2.0%). Iterative improvement interventions targeting clinician test ordering behaviour can reduce ICU phlebotomy and may impact red cell transfusions. Frequent stakeholder consultation, incorporating stewardship into daily workflow, and audit and feedback are effective strategies.