Inter-Instrument Comparison of Blood Gas Analyzers and Assessment of Tonometry Using Fresh Heparinized Whole Human Blood

Because of limitations associated with commercial blood gas quality controls and tonometry of stored blood, fresh heparinized blood was used to compare Po 2 and Pco 2 performance of ten blood gas analyzers. Function of nine gas mixer/tonometer systems was evaluated. These were used to create blood samples with target values for Po 2 and Pco 2 . All ten analyzers had high precision; this magnified small differences between observed results and target values. Grand mean results from all ten analyzers were within 0.8 mm Hg of the target for Po 2 of 40.0 and 100.0 and for Pco 2 of 20.0 and 70.0 mm Hg. Eight automated blood gas analyzers gave clinically indistinguishable results for Po 2 and Pco 2 that were sufficiently accurate for clinical purposes. Also reported is the practicality of using tonometry of fresh heparinized blood in a per shift quality control program for Po 2 and Pco 2 .