Lack of agreement between two methods of measuring haemoglobin

Haemoglobin values are reported by the current generation of blood gas analysers used in many intensive care units. A comparison of one such machine against a reference found that there was a mean difference of 1.32 g/dL (95% confidence intervals -2.75-0.9 g/dL) between the values reported. Haemoglobin values reported by blood gas machines may be inaccurate.