Reference limits for blood gas analyzes and electrolytes in venous blood from healthy adults

Abstract

There is an increasing demand for venous blood gas analyses to diagnose and treat certain acid-base disorders. Since we have not found well-documented reference limits for venous blood gas analyses, we have estimated such limits for healthy individuals based on samples from 133 blood donors. From each blood donor, we obtained venous samples in both Vacuette Li-heparin vacuum tubes and in safePICO aspirator, a syringe containing electrolyte balanced heparin. All samples were analyzed with ABL 825 Flex. Electrolytes and lactate were also measured. Using safePICO aspirator, the reference range for pH was 7.32-7.41, for pCO2 5.3-8.1 kPa, for standard base excess -0.7-5.8 mmol/L, for bicarbonate 24-31 mmol/L, for anion gap 6-16 mmol/L, and for free calcium 1.16-1.29 mmol/L. Using Vacuette vacuum tube, the reference range for pH was 7.31-7.42, for pCO2 5.3-7.9 kPa, and for standard base excess -1.0-5.4 mmol/L. For bicarbonate and anion gap the reference range was the same as for safePICO aspirator, whereas the reference range for free calcium was lower because the Vacuette tubes contained heparin that was not electrolyte-balanced.

Keywords

• venous blood gas analyses
• reference range
• sample containers