Comparison of blood gas and pH values obtained from arteriovenous fistulae and femoral arteries in chronic renal failure patients managed by hemodialysis
Beasley, C.R.; Neale, T.J.
Clinical Nephrology 23(4): 184-188
1985
ISSN/ISBN: 0301-0430 PMID: 3924458 Document Number: 250062
The validity of obtaining blood directly from arteriovenous (a-v) fistula for blood gas and pH measurements in patients undergoing hemodialysis was examined. In such patients, blood samples were taken simultaneously from both the arterial and venous lines within the a-v fistula and from a femoral artery. We conclude that for clinical application sampling from either the arterial or venous line within an a-v fistula cannot be used for accurate determination of arterial blood gas and pH values. Possible reasons for the differences observed between the values obtained from the alternative sampling sites are suggested. If blood gas and pH measurements are required during hemodialysis, direct arterial puncture must be made to obtain an accurate result for clinical use. However, for sequential comparative studies of acid-base metabolism or respiratory function while on dialysis, repetitive fistula sampling appears valid.