Continuous measurement of blood gases using a combined electrochemical and spectrophotometric sensor

Abstract

The use of a combined electrochemical and fibreoptic continuous intra-arterial blood gas sensor is described. The purpose of the study was to evaluate the performance of the sensor in 10 patients in the intensive therapy unit following insertion through a femoral arterial cannula. To our knowledge this is the fast published study on the valuation of an intravascular blood gas sensor through a femoral arterial cannula. A total of 71 sets of data comparing the sensor with the blood gas analyser were obtained. The bias and precision for pH, Pco₂ and Po₂ were 0.006 and 0.07pH units, 0.2 and 1.65kPa (4.6% and 29%) and 0.8 and 2.7kPa (5.1 % and 14.3%) respectively. There was a degree of imprecision of the PCO₂ sensor, the reasons for which are discussed. In summary, the intra-arterial sensor functioned well when inserted into the femoral artery in post-cardiopulmonary bypass patients. There were no complications attributable to sensor placement.