Reduced bovine hemoglobin solution evaluated for use as a blood gas quality-control material

We evaluated a new commercially available partially purified reduced bovine hemoglobin solution (RBHS) and a new tonometer for use in the quality control of blood gas analyzers. RBHS is manufactured in three different formulations, each corresponding to three different bicarbonate-buffering capacities and concentrations of total hemoglobin (ctHb). The P50 for each formulation of RBHS was determined to be as follows: 30.6 mmHg (4.08 kPa) for Level 1, 29.1 mmHg (3.88 kPa) for Level 2, and 28.2 mmHg (3.76 kPa) for Level 3. When RBHS and human blood samples were tonometered at three clinically significant values of PO2 and PCO2, the recovered values for PO2 and PCO2 in RBHS were comparable with those of the tonometered whole blood. Each level of RBHS also produced precise pH (SD < or = 0.006 pH units) and ctHb (SD = 1.0 g/L) values. In addition, when the temperature of a sample chamber was intentionally altered, the changes in RBHS blood gas values closely approximated the changes seen with human blood. RBHS shows more thermal sensitivity than either perfluorocarbon emulsions or aqueous buffers, which are currently being used as quality-control and proficiency testing materials.