Routine blood test ordering for patients in intensive care.

Current practice is for a number of blood tests to be routinely performed on intensive care unit (ICU) patients. A survey of routine blood testing amongst ICUs in Australia and New Zealand was conducted. Ninety-six ICUs completed the survey form. Blood electrolytes, liver function, arterial blood gases and full blood count were the most frequently ordered tests. Routine blood testing was not practised in 12.6% of ICUs. The presence or absence of written guidelines did not influence the frequency of the most commonly performed routine blood tests. Clinical and operational factors specific to each ICU appear to impact on such blood tests and guidelines for their use.