Blood sampling in critical care: Every drop counts

Abstract

Introduction: Frequent blood sampling via arterial catheters can contribute to infection risk and iatrogenic anaemia. This presentation will summarise research related to blood conservation as well as primary studies that audited and surveyed nursing blood sampling practice. Study objectives: The studies collectively aimed to summarise current research and practice related to blood sampling in critical care. Methods: This research used systematic review, audit and a survey research designs. Results: The systematic review identified seven studies evaluating a variety of blood conservation strategies, but varied outcome measures and reporting meant that results were largely inconclusive and not translatable into practice. In the practice audit 940 blood samples from 96 patients were analysed. Arterial blood gas was themain reason for sampling in each unit: AICU 82%, PICU 80% and NICU 47%. The median number of samples per patient per day in each unit was AICU 5.03 (0.81–16.61), PICU 2.3 (0.14–6.86), and NICU 0.7 (0.14–10.64). A survey of 646 nurses in Australia showed just over 50% of nurses discarded line clearance and only a small percentage (13%) reported documenting volume of blood taken. Conclusions: The variation in blood sampling practice within and between critical care settings has implications not only for anaemia but also infection control and healthcare costs. These research studies have laid the foundation for future intervention trial research in the area.