A simplified method of obtaining umbilical cord blood for pH using a heparinized vacutainer versus heparinized syringe.

Two experimental methods for collecting cord blood for acid-base analysis using green top vacutainer tubes were compared with a standard method using heparinized syringes. Paired samples from 30 newborn infants were collected using one of the vacutainer methods and the standard heparinized syringe method. No significant differences in pH, pCO2, base deficit, or pO2 were noted when comparing the two vacutainer methods with the standard syringe method. Both vacutainer methods were substantially easier to use than the heparinized syringe method. A green top vacutainer may be used to obtain an accurate cord blood sample for assessment of an infant's acid-base status at birth, and to aid the neonatologist as an indicator of intrapartum asphyxia.