Testing of the Eschweiler 2500-11 blood gas analyser during inflight conditions

Measurement of blood gas values during air transport of intensive care patients must take into account the extreme inflight variations in pressure. We tested the accuracy and reliability of the Eschweiler 2500-11 apparatus, with its incorporated pressure transducer, on four different gas mixtures equilibrated with fresh blood at two different altitudes simulated in a decompression chamber. Results for the pressure transducer show: 1) concordance of pressure values with those of ground instrumentation; 2) stable response; and 3) absence of hysteresis. Gas measurement electrodes were shown to have linear responses and were accurate for all tested values except very low PCO2 and very high PO2 figures. We conclude that the performance of this device is satisfactory during inflight conditions.