Evaluation of arterial blood gas analysis in diagnosis of neonatal hypoxic ischemic encephalopathy

Objective To evaluate the arterial blood gas analysis of pH and lactic acid level in diagnosis of neonatal hypoxic ischemic encephalopathy (HIE). Methods To retrospectively analyzed the clinical data of 43 neonates with HIE. Neonates were divided into the normal-mild group (without brain injury) and moderate-severe group (with brain injury) according to results of head MRI and video-electroencephalography (VEEG). The arterial blood gas analysis of pH and lactic acid level of two groups were compared. The receiver operating curve (ROC) model was used to evaluate the pH and lactic acid level in diagnosis of HIE. The univariate analysis and multiple logistic regression analysis were used to analyze potential influencing factors of HIE. Results Neonates in the moderate-severe group(with brain injury) had a lower pH value and higher lactic acid level compared with those in the normal-mild group(without brain injury). The ROC analysis showed that the area-under-the-curve (AUC) of pH was 0. 656, with a sensitivity of 78. 0% and specificity of 53. 8%; the AUC of lactic acid level was 0. 877, with a sensitivity of 83. 3% and specificity of 82. 7%. The multiple logistic regression analysis showed that the increased lactic acid level was independent risk factor for brain injury in HIE neonates (OR=7. 504, P=0. 001). Conclusion Findings of the study showed that increased lactic acid was independent risk factor for brain injury in HIE neonates, and was a better index to predict HIE