The Use of an Oxygen Dissociation Curve Analyzer in Transfusion Therapy

Abstract

Two automatic apparatuses utilizing a dual wavelength spectrophotometric method were developed to perform O2 dissociation curves on microsamples of blood. This method provides a complete printout of an O2 dissociation curve in 15-20 min and the P50 [50% O2 saturation] values obtained agree closely with those obtained by classical methods. This technique was used as part of a routine clinical evaluation in assessing O2 delivery in anemic patients. These apparatuses allowed identification of patients with well-compensated anemia, patients with no compensatory decrease in O2 affinity, and several patients with a paradoxical increase in O2 affinity. Knowledge of the O2-releasing capacity of the blood permitted a more thorough evaluation of O2 transport in anemic patients than the Hb level and a more precise assessment of the need for transfusion therapy. The ready availability of an O2 dissociation curve by this method is feasible for routine clinical evaluation and permits more judicious use of blood products.