Iatrogenic Anaemia in the Critically Ill: A Survey of the Frequency of Blood Testing in a Teaching Hospital Intensive Care Unit

Abstract

Anaemia in the critically ill remains a contentious issue. Despite adoption of lower haemoglobin levels as transfusion triggers, many patients on intensive care units (ICUs) still require blood transfusions during their illness. One factor that contributes to the critically ill becoming anaemic is regular phlebotomy. Over a two week period, all blood tests performed on patients in a busy, teaching hospital ICU were surveyed to allow calculation of the total volume of blood that had been taken. On average, 52.4 mL of blood was taken per patient per day, and 366.8 mL per patient per week. The most frequently performed tests were arterial blood gas analyses, performed on average 5.8 times per patient per day (range 0–21 times per day). Arterial blood gas analysis alone accounted for taking of 29 mL of blood per patient per day, ie 203 mL per patient per week. Several methods for reducing the amount of blood taken from ICU patients have been identified and discussed. By implementing some of these simple changes in our institution, it would be possible to reduce the volume of blood taken by 43%.