%0 Journal Article %A Paul Duchateau %A Claude Guérin %T Tidal volume delivery from ICU ventilators in BTPS condition. A bench study. %D 2012 %R 10.4187/respcare.01915 %J Respiratory Care %P respcare.01915 %X Background. We measured tidal volume (VT) delivered from ICU ventilators after adding an external filter to the expiratory limb of the breathing circuit. This latter may protect the expiratory valve from water saturation in case of nebulisation and the environnement in case of lung infection with multi-drug-resistant micro-organisms or H1N1 influenza, even though it is not a common practice. Methods. Six ICU ventilators, two with built-in expiratory filter (Avea, PB 840) and 4 without (Engström, Evita XL, Evita V500, Servo-i) set in volume controlled mode, BTPS condition with a heated humidifier on, were connected to a lung model (compliance 16 ml.cmH2O-1 and resistance 20 cm H2O.L-1.s) placed inside a neonatal incubator. The temperature was targeted at 37°C for both heated humidifier and incubator. The set-up was run continuously for 24 hours. In the four last ICU ventilators, Hygrobac or Sterivent S external filter was placed upstream the expiratory valve for an additional 24-hour period for each. At the end of this period, VT was measured at four nominal VTs (300, 400, 500 and 800 ml) by using Fleish 4 pneumotachograph. The volume error computed from the ratio of set to measured VT (% set VT) was the primary end-point. Results. In present warm and wet conditions, volume error averaged 96±3% for Avea, 100±7% for PB 840, 90±2% for Evita XL, 100±7% for Evita V500, 105±2% for Servo-i, and 108±4% for Engström (P<.0001). With Hygrobac, the values were 93±1% for Evita XL, 94±4% for Evita V500, 110±4% for Servo-i, and 99±2% for Engström, (P<.0001). With Sterivent, the corresponding values were 95±2%, 105±2%, 112±5%, and 98±2%, respectively (P<.0001). Conclusions. In BTPS condition, volume error differed substantially across ICU ventilators for VT delivery with further significant changes occurring after adjunction of filter at the distal expiratory limb. %U https://rc.rcjournal.com/content/respcare/early/2012/11/09/respcare.01915.full.pdf