Evaluation of a novel point of care blood gas analyser

Abstract

IntroductionPoint-of-care testing is becoming increasingly relevant to the practice of anaesthesia and critical care medicine with the recent development of new devices. We performed a prospective observational study to evaluate a novel, in-line, patient dedicated, point of care blood gas analysis device called the Proxima. The sampling volume is flushed into the patient after analysis resulting in no loss of blood during analysis. The device was also subjected it to extreme physiological conditions, specifically deep hypothermic circulatory arrest.MethodsEight patients who were undergoing pulmonary endarterectomy were studied, and had between 7 and 11 samples taken at set intervals were analysed both with Proxima and a conventional blood gas analyser for seven variables (pH, pCO2, pO2, HCO3-, base excess [BE], K+ and haematocrit [Hct]). All patients underwent a process of cooling to 19°C on cardiopulmonary bypass, and subsequent rewarming to normothermia.ResultsSee tableDiscussionIn summary, we have demonstrated that the Proxima device is effective in measuring pH, pO2, pCO2 and [K+], when compared with a conventional, laboratory blood gas analyser. Derived measures calculated by the device ([HCO3-] and (BE) differed substantially from those produced by the benchtop analyser. The advantages of this device is its dedicated nature, quicker analysis and the reduction of sampling anaemia.(1)