Abstract: Objective To study the correlation in the concentrations of sodium(Na⁺),potassium(K⁺),calcium(Ca²⁺), and hemoglobin (HGB)between venous blood and arterial blood gas. Methods The venous blood samples and arterial blood gas samples of the emergency department observation patients were taken at the same time.Venous blood biochemistry panel and routine test were carried out. The concentrations of Na⁺, K⁺, Ca²⁺,HGB in venous blood and arterial blood gas of 60 patients were selected by the method of random number table for statistical analysis. Results The mean values of K⁺ concentrations in arterial blood gas and venous blood were (3.73±0.52)mmol/L and (3.93±0.58)mmol/L, respectively, with P<0.001.The difference is within the clinically permissible error range, and thus the arterial blood gas results were directly used to estimate the venous K⁺ concentration level.The measured Na⁺ concentration of arterial blood gas and venous blood were (136.7±7.0)mmol/L and (136.49±6.6)mmol/L,respectively, with P=0.6.There was no significant difference, and the results of arterial blood gas were directly used to estimate the Na⁺ concentration level in venous blood. The measured values of Ca²⁺ concentration in arterial blood gas and venous blood were (1.12±0.22)mmol/L and (2.02±0.36)mmol/L, with P<0.001. Difference between the two is beyond the maximum clinical error range, however, the correlation coefficient is 0.88, therefore, the venous Ca²⁺ concentration was calculated with linear equation,venous Ca²⁺ concentration (mmol/L)=0.44+1.42×arterial blood Ca²⁺ concentration.The HGB values of arterial blood gas and venous blood were (101.3±26.6)g/L and (98.8±24.6)g/L, respectively, with P=0.17. Difference between the two was not statistically significant, and the arterial blood gas results were directly used to estimate the HGB concentration level in venous blood.Conclusion In emergency management,the concentrations of electrolytes and hemoglobin concentrations in arterial blood gas are reliable for guiding clinical decisions until laboratory results are available.

Key words: arterial blood gas, venous blood, electrolytes, hemoglobin