BREATH ALCOHOL ANALYZER WITH ELECTROCHEMI CAL SENSOR - MEASURING ACCURACY WITH ARTIFICIAL-RESPIRATION IN A LUNG MODEL

Absorption of irrigating fluid by blood vessels during endoscopic urol ogical surgery may result in cardiac insufficiency, impairment of elec trolyte metabolism and neurological disorders. For detection and quant ification of the volume absorbed, ethanol is added to the irrigating f luid. The resulting blood alcohol concentration can be obtained by mea suring the alcohol concentration in the expired air. For artificially ventilated patients receiving a general anesthetic, electrochemical se nsors that remain uneffected by volatile anaesthetics are used. In the present study, the measuring accuracy of three different alcohol anal yzers using electrochemical sensors was tested against an infrared ref erence sensor during simulated ventilation in a lung model, and the op timal trigger time point for sampling determined. All three devices te sted show the same degree of accuracy as the reference. For manual end expiratory triggering devices with short sampling times are best suita ble. Portable devices powered by rechargeable batteries and usable wit h both spontaneously breathing and ventilated patients are recommended for clinical application.