Umbilical blood gas analysis: I. Effect of storage of samples on outcome.

The pH and blood gas values of umbilical blood samples must be determined as soon as possible after birth to avoid changes in pH, oxygen pressure (PO2) and carbon dioxide pressure (PCO2). Since a continuous around-the-clock laboratory service is not available in every hospital, a method of reducing these changes is desirable. Determination of pH and blood gas values at different time intervals while the samples were stored on ice showed that pH decreased by a mean of 0.003 unit/hr, whereas PCO2 and PO2 increased. A method of reducing glycolysis in blood cells must be found to make postponement of analysis acceptable.