Comparison of anaesthesia ventilators using a lung model.

Abstract

The ventilatory performance of six anaesthesia ventilators (Alphavent Drägerwerk; MCM 801 Ventilator Dameca; Ohmeda 7000 Ventilator and Ohmeda 7800 Ventilator Ohmeda; Servo Ventilator 900 D and Ventilator 710 Siemens-Elema) was tested in a lung model and compared with the ventilatory performance of the old Engström 300 (Gambro Engström). The lung model consisted of one tracheal tube, two bronchial tubes which could be partially occluded, and two lungs (glass jars filled with water to a suitable compliance). Dialled (set) minute volume was compared to recorded minute volume. Gas distribution between obstructed and non-obstructed lung was calculated. All ventilators had a linear relationship between dialled and measured volume. Only the Servo Ventilator 900 D produced a gas distribution which was as good as, or better than that produced by the Engström 300.