In this section we will summarise the complex process of laboratory and point-of-care testing of patient blood samples, comprising three phases:

1. The pre-analytic phase – that is, sample collection, handling and transportation of the blood sample
2. The analytic phase – the analysis of the sample by the computer
3. The post-analytic phase – that is, transmission and interpretation of the test result, as well as clinical response to the test result in terms of patient management

The pre-analytics is considered the stage prior to analysing the blood sample. The pre-analytic stage includes various steps from the initial request for the test and finishes with the introduction of the sample to the blood gas analyser. This phase accounts for up to 70% of all errors in the process of testing patient ELCBG samples, so it’s important we are all following an appropriate protocol which has been designed to minimised the risk of error.