Overnight transfusions in New Zealand hospitals: potential risk to patients.

This audit has shown an improvement from 22% to 9% in the rate of OT compared to the 2004 audit. Nevertheless, 42% of transfusions were not considered appropriate based on current guidelines, and there is therefore room for improvement. A mean delay of 9 hours from haemoglobin sampling to transfusion suggests that reasons for this delay could be explored to help optimise transfusion start time. Some aspects of OT were worse than previously, with 12% of the OT exceeding 4 hours duration, double the rate of the previous audit. Results showing poor documentation and a high rate of unreported transfusion reactions (69% of reactions) suggest if an adverse transfusion reaction occurs overnight, there is a significant risk that it is less likely to be recognised, treated and/or reported.