Bloodless evaluation of blood oxygenators
Evaluation of blood oxygenators using whole blood is inconvenient and expensive, although it is the ultimate preclinical test. Sodium sulfite solutions have advantages over blood for studying oxygen uptake: They are inexpensive, fewer variables need control, and deoxygenation is unnecessary. Assays and interpretation of results are easy. The kinetics of sulfite oxidation must be fast and the concentration of sulfite must be low to emulate oxygen uptake by blood. The kinetics were studied yielding a first order rate constant in sulfite, zero order in oxygen, of 740/min. Limitations of the technique were evaluated using the experimental rate constant and an adaptation of Lightfoot’s approximation. While the reaction of hemoglobin is reversible and essentially instantaneous, that for sulfite is irreversible and finite. Thus if the approach to saturation is not monotonic or if the mass transfer resistance is significantly lowered, e.g., when blood film thicknesses are thinner than a few hundred microns, deviations may occur. Two TMO oxygenators and several prototypes were tested, with both sulfite and bovine blood. Uptakes of oxygen were comparable and the effect of parameter variations were similar. The use of sulfite for early evaluation of oxygenators is concluded to be very useful.
KeywordsOxygenation Blood oxygenator Sulfite Mass transfer Hemoglobin
Unable to display preview. Download preview PDF.
- 1.Astarita, G., G. Marrucci, and L. Coleti. Ossidazione catalitica del solfito di sodio: Un metodo per la misura di aree interfaciali.Chim. Ind. M. 46: 1021–1026, 1964.Google Scholar
- 2.Ayres, G.H.Quantitative Chemical Analysis. New York: Harper & Row, 1958, pp. 409–628.Google Scholar
- 3.Barron, C.H. and H.A. O’Hern. Reaction kinetics of sodium sulfate oxidation by the rapid-mixing method.Chem. Eng. Sci. 21: 397–404, 1966.Google Scholar
- 4.Bird, R.B., W.E. Stewart, and E.N. Lightfoot,Transport Phenomena. New York and London: John Wiley and Sons, 1960, pp. 532–533.Google Scholar
- 5.Cooper, C.M., G.A. Fernstrom, and S.A. Miller. Gas-liquid contactors.Ind. Eng. Chem. 36: 504–509, 1944.Google Scholar
- 6.Danckwerts, P.V.Gas Liquid Reactions. New York: McGraw-Hill Book Co., 1970, pp. 254–255.Google Scholar
- 10.Galletti, P.M., P.D. Richardson, and M.T. Snider. Blood oxygenator testing and evaluation. Evaluation Techniques, Report NIH-69-2047-1, Artificial Heart Program, NHLI, 1971.Google Scholar
- 11.Greene, G.C. Oxygenation of sodium sulfite and blood. Master’s thesis. Columbia University, New York, 1968.Google Scholar
- 12.Kaufmann, T.G. and E.F. Leonard. Mechanism of interfacial mass transfer in membrane transport.AIChE J. 14: 421–426, 1968.Google Scholar
- 14.Keller, K.H. and K.L. Shultis. Oxygen permeability in ultrathin and microporous membranes during gas-liquid transfer.Trans. Am. Artif. Intern. Organs 25: 469–472, 1979.Google Scholar
- 17.Shah, S.S. Bloodless evaluation of blood oxygenators. Master’s thesis. Columbia University, New York, 1980.Google Scholar
- 19.Travenol Laboratories. Direction sheet accompanying TMO adult membrane oxygenator, 1973.Google Scholar