Abstract
Koch CG, Reineks EZ, Tang AS, et al.
Ann Thorac Surg 2015; 99: 779–784.
This intriguingly titled article takes a fresh look at nosocomial anaemia, specifically in the context of cardiac surgery, although the findings may be more generally applicable. A retrospective review of laboratory test records revealed a median cumulative blood draw of 454 mL per hospital admission, two-thirds of which was in the cardiac intensive care unit – blood discarded to clear lines may have contributed here. One patient had over 16 L of blood taken for testing. There was a clear correlation between volume of blood drawn and risk of developing anaemia requiring transfusion. The authors also mention a higher mortality rate, but it is not clear whether increased testing was the cause or consequence of sicker patients.
Three main suggestions are made for how to reduce cumulative blood draw: (1) careful consideration of rationale for each test – for example, greater use of oximetry and capnography to guide ventilator weans; (2) avoiding discarding of blood to clear lines, for example, by using closed loop devices which return blood to the patient; and (3) transition to smaller sample containers.
In summary, this is a timely reminder that both clinicians and laboratories should consider if changes can be made to refine testing practices.