We read with interest the article by Hinds et al1 comparing laboratory and blood gas analyser haemoglobin in their neonatal intensive care unit (NICU). They found a good correlation between laboratory measures and the ABL725 Radiometer blood gas analyser in 127 babies in their unit. However, we feel that the focus of their article was somewhat limited, as they assessed haemoglobin and haematocrit alone. Blood gas analysers have become more sophisticated and are now able to perform many different analyses on a single blood sample including electrolytes, …