Integrated and automatic mixing of whole blood: an evaluation of a novel blood gas analyzer.
BACKGROUND
A homogeneous whole blood specimen is essential to produce quality results from blood gas analysis, however achieving an adequately mixed specimen can be difficult due to the absence of any dead space in a blood gas syringe. This study evaluated the efficacy of an automatic mixing feature incorporated into the ABL800 FLEX blood gas analyzer and estimated the systematic error in tests performed by the instrument.


METHODS
Quantitative measurements of pH, PCO(2), PO(2), Na(+), K(+), Ca(+), glucose, lactate, and total hemoglobin were performed on 388 whole blood specimens collected into standard blood gas syringes or specific syringes designed to work in conjunction with the ABL800 FLEX. One hundred eighty specimens were manually or automatically mixed following horizontal storage for 10, 20, or 30 min and total hemoglobin was used as in indicator of specimen homogeneity. Two hundred eight specimens were used to estimate the systematic error of tests performed by the ABL800 FLEX.


RESULTS
Manual mixing produced significantly more variation in paired hemoglobin measurements compared to automatic mixing at all three time points (p<0.0001). All estimates of systematic error were very low and clinically insignificant. Quantitative results showed excellent agreement with a reference analyzer.


CONCLUSIONS
In contrast to manual mixing, automatic mixing by the ABL800 FLEX consistently produces a homogeneous specimen.
Grenache
David G
DG
Department of Pathology and Laboratory Medicine, University of North Carolina at Chapel Hill, School of Medicine, CB # 7525, Chapel Hill, NC 27599-7525, United States. dgrenach@unch.unc.edu
Parker
Christopher
C
D000328:Adult; D001774:Blood Chemical Analysis / Q000295:instrumentation* / Q000379:methods*; D001786:Blood Glucose / Q000032:analysis; D002118:Calcium / Q000097:blood; D002245:Carbon Dioxide / Q000097:blood; D006454:Hemoglobins / Q000032:analysis; D006801:Humans; D019344:Lactic Acid / Q000097:blood; D010100:Oxygen / Q000097:blood; D011188:Potassium / Q000097:blood; D015203:Reproducibility of Results; D012964:Sodium / Q000097:blood; D013048:Specimen Handling; D013594:Syringes
D001786:Blood Glucose; D006454:Hemoglobins; D002245:Carbon Dioxide; D019344:Lactic Acid; D012964:Sodium; D011188:Potassium; D010100:Oxygen; D002118:Calcium