The investigation of the log file has revealed that the device passed the system test in the morning of the date of event w/o deviations.The concerned procedure was started in manual ventilation mode at 12:12.Already during this phase the device measured significant deviations between inspiratory and expiratory volumes which indicates a massive circuit leak outside the device.The device alarmed for apnea and fresh gas low or leakage to alert the user about the resulting fresh gas shortage.At this time, a fresh gas flow of 6.00 l/min (100vol% o2) was set and, the measured fio2 was in the upper nineties.Changeover to volume control mode was proceeded at 12.19 in combination with a reduction of fresh gas flow to 2.00 l/min and fio2 to 60vol%.The fresh gas deficit persisted, fio2 declined as expected.At 12:21 the user activated the emergency o2 delivery; fio2 jumped back to 98vol% but the minute volume delivered by the device was decreasing.A minute later the device recognized a sudden drop of fio2 to 21vol% and expsev to almost zero while the etco2 level remained nearly unchanged; values for airway pressure and flow were not measued anymore.Corresponding alarms were posted by the workstation.After approx.60 seconds the fio2 jumped back to 97%, expsev to ~3 vol% and volume and pressure values returned to the former levels.The situation however remained unstable; the patient was disconnected another five minutes later.All in all, no indication for the potential presence of a device malfunction could be found.The ventilation episode was disturbed already from the beginning by a massive leak in the pneumatic circuit.During the initial phase of manual ventilation the effects were measured and alarmed but the user may simply have adapted the way of squeezing the manual breathing bag and equalized the effects.But with switchover to automatic ventilation the leakage became more prominent and, the user-initiated reduction of fio2 and fresh gas flow has even worsened the situation.Between 12:22 and 12:23 the patient was obviously disconnected.Dräger finally concludes that there is no issue with the device which would require repair or correction.Appropriate alarms were posted; all alarms, potential root causes and dedicated remedies are listed in the ifu.
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