A comparison of syringes to collect blood for analysis of gases, electrolytes and glucose

We studied the interchangeability of two blood gas syringes (Johns, Hardie Health Care Products Pty Ltd and Marksman, Martell Medical Products Inc) for the collection of blood for the analysis of PCO2, PO2, pH, sodium, potassium and glucose in 71 intensive care unit patients. The interchangeability of these two syringes with a specially designed syringe (Radiometer, Radiometer A/S) for the collection of blood for the analysis of ionized calcium was also studied. Analysis of pH, sodium, potassium and glucose showed no clinically significant differences between samples collected with Johns and Marksman syringes. However, differences in PCO2 and PO2 in samples collected with these syringes may be clinically significant if the PO2 is less than 100 mmHg. There were no clinically significant differences in ionized calcium levels in blood samples collected with Johns, Marksman and Radiometer syringes. We conclude that Johns and Marksman syringes are interchangeable for the collection of blood for the analysis of PCO2, PO2, pH, sodium, potassium and glucose and they are also interchangeable with Radiometer syringes for the collection of blood for ionized calcium analysis.