title: Delivery of tidal volume from four anaesthesia ventilators during volume-controlled ventilation: a bench study.
abstract: BACKGROUND
  Tidal volume (V(T)) must be accurately delivered by anaesthesia ventilators in the volume-controlled ventilation mode in order for lung protective ventilation to be effective. However, the impact of fresh gas flow (FGF) and lung mechanics on delivery of V(T) by the newest anaesthesia ventilators has not been reported.
  
  
  METHODS
  We measured delivered V(T) (V(TI)) from four anaesthesia ventilators (Aisys™, Flow-i™, Primus™, and Zeus™) on a pneumatic test lung set with three combinations of lung compliance (C, ml cm H2O(-1)) and resistance (R, cm H2O litre(-1) s(-2)): C60R5, C30R5, C60R20. For each CR, three FGF rates (0.5, 3, 10 litre min(-1)) were investigated at three set V(T)s (300, 500, 800 ml) and two values of PEEP (0 and 10 cm H2O). The volume error = [(V(TI) - V(Tset))/V(Tset)] ×100 was computed in body temperature and pressure-saturated conditions and compared using analysis of variance.
  
  
  RESULTS
  For each CR and each set V(T), the absolute value of the volume error significantly declined from Aisys™ to Flow-i™, Zeus™, and Primus™. For C60R5, these values were 12.5% for Aisys™, 5% for Flow-i™ and Zeus™, and 0% for Primus™. With an increase in FGF, absolute values of the volume error increased only for Aisys™ and Zeus™. However, in C30R5, the volume error was minimal at mid-FGF for Aisys™. The results were similar at PEEP 10 cm H2O.
  
  
  CONCLUSIONS
  Under experimental conditions, the volume error differed significantly between the four new anaesthesia ventilators tested and was influenced by FGF, although this effect may not be clinically relevant.
authors: Service d'Anesthésie-Réanimation, Hôpital de la Croix-Rousse, Hospices Civils de Lyon et Université de Lyon, 103 Grande Rue de la Croix Rousse, Lyon 69004, France.
authors: G
authors: G
authors: Wallon
authors: A
authors: A
authors: Bonnet
authors: C
authors: C
authors: Guérin
mesh_terms: D000758:Anesthesia; D006801:Humans; D011175:Positive-Pressure Respiration; D012121:Respiration, Artificial; D013990:Tidal Volume; D012122:Ventilators, Mechanical
keywords: measurement techniques, ventilation volumes; model, ventilatory mechanics; ventilation, fresh gas flow; ventilation, mechanical; ventilators