Prospective Study to Determine Possible Correlation Between Arterial and Venous Blood Gas Values

Abstract

Arterial blood gas analysis is an iatric component factor in the clinical evaluation of patients, but arterial puncture has many complications. Our study aimed to determine a correlation between arterial and venous blood gas values. A prospective comparison of 200 samples from 100 patients undergoing lumbar disc surgery was conducted. Arterial and venous samples were obtained simultaneously from each patient. The samples were analyzed and compared using SPSS version 16 software, with Pearson's correlation and 95% confidence intervals (CIs) of the difference. Arterial and venous values for pH, bicarbonate (HCO(3)), base excess (BE), buffer base (BB) and partial pressure of carbon dioxide (PCO(2)) showed close and direct correlation. The comparison showed the following: pH, r = 0.938, p <0.001 (95% CI, 0.019 to 0.032); HCO(3), r = 0.884, p <0.001 (95% CI, -2.65 to -1.99); BE, r = 0.861, p <0.001 (95% CI, -1.89 to -1.17); BB, r = 0.849, p < 0.001 (95% CI, -2.35 to -1.60); and PCO(2), r = 0.899, p < 0.001 (95% CI, -5.97 to -4.66). Pearson's correlation coefficients for partial pressure of oxygen and oxygen saturation were 0.092 and 0.345, respectively. The mean difference between arterial and venous values for pH was 0.025 pH units, for HCO(3) was 2.327 mmol/L, for PCO(2) was 5.32 mmHg, for BE was 1.533 mmol/L, and for BB was 1.983 mmol/L. Venous blood gas values are an acceptable alternative to arterial blood gas values in patients undergoing lumbar disc surgery.