AM24-SN-13-O: Diagnostic Blood Loss: An Ignored Component of the Multidisciplinary Pillar of Patient Blood Management (Enduring)

Diagnostic-Blood-Loss not only includes MICRO-liters of blood aspirated by an analyzer, or MILLI-liters of blood collected in sample tube, but also the discard-volumes, especially when sampling happens from lines, and also failed draws, unnecessary draws/tests etc. Diagnostic-Blood-Loss, estimated to be ~12 ml/day in medical wards & 40-50 ml/day in Intensive care Unit (ICU) in mid-1980s, increased over the years. A 2021 study shows that estimations of a 2019 study missed the discard-volumes, underestimating loss by 18%. Irrespective of initial Hemoglobin, 90-100% ICU admissions have anemia in 3 days to 3 weeks. Thus ICU-admission itself can be a cause for Hospital-acquired anemia (HAA), aggravating morbidity & mortality. Phlebotomy guidelines of WHO & European federation of Laboratory Medicine (EFLM) don't cover line-draw. CLSI recommends large discard-volumes (2-6 times dead-space) for line draws. Neither guidelines sufficiently sensitize users to large discard-volumes & sampling frequency in ICUs. We will discuss various techniques, gadgets, logistics and practice updates, that help reduce diagnostic blood loss. Large number of lines/catheters make direct phlebotomy challenging in ICUs, leaving drawing from lines as the only choice left. Until recently CLSI guidelines (eg GP41) stress the need for the discard-volume, eg 6 times dead-space when doing coagulation or platelet tests. It is too large when the catheter is long or patient is small, and likely unnecessary. Re-samplings to resolve pre/post-analytic issues, for sake of safety, contribute to anemia, a mortality risk factor. Choosing wisely, Society for Advancement of Patient Blood management (SABM), Test-Utilization (TU) and Minimum-Retesting-Interval (MRI) guidelines explore multipronged collaborative efforts. Minimum Retesting Interval is a very important part of the Test Utilization Tool-Box in practice in the UK for about a decade but not yet covered by Choosing wisely. Accessories like closed-sampling devices, low-volume/pressure tubes, pediatric cups etc, environment-friendly practices, and our practice-survey results, will be discussed with pictures and quizzes. It is high time laboratorians and clinicians join hands to curb this ongoing Diagnostic-Blood-Loss, an often invisible pillar of Patient Blood management (PBM).