Establishment of Reference Intervals for Umbilical Arterial Blood from Healthy Neonates in the Hulunbuir Area of China.

Background: This study aimed to establish reference intervals for blood gas analyses of umbilical arterial blood from healthy neonates in the Hulunbuir area of China.

Methods: APGAR scores of 8 - 10 (1-min intervals) were obtained for umbilical arterial blood collected from 2,845 healthy newborns during 2,016 - 2,018 based on 10 items - pH, PCO2, PO2, K+, Na+, Cl-, Ca2+, lactic acid (Lac), hemoglobin (Hb), base excess (BE) - using the electrode method. Means ± 1.96 SD were used to establish reference ranges.

Results: Reference intervals obtained were pH 7.25 ± 0.13, PCO2 53.8 ± 20.6 mmHg, PO2 20.8 ± 10.3 mmHg, K+ 4.34 ± 1.32 mmol/L, Na+ 132.4 ± 4.30 mmol/L, Cl- 105.22 ± 5.51 mmol/L, Ca2+ 1.35 ± 0.13 mmol/L, Lac 3.36 ± 1.75 mmol/L, Hb 15.62 ± 3.06 g/dL, BE -4.62 ± 3.28 mmol/L.

Conclusions: These results can help evaluate hypoxia associated with neonatal ischemia in the clinical setting and provide a basis for establishing references for umbilical arterial blood gas in other geographic regions.