Paediatric patients require ventilators capable of consistently delivering low tidal volumes at increased ventilatory frequencies. The susceptibility of infants to barotrauma and the use of uncuffed tracheal tubes favour pressure-controlled ventilation. The pneumatic characteristics of the Venturi in the VentiPAC cause it to act as a pressure-generator at flow rates <0.25 litre s with the 'air mix' setting.The VentiPAC, LTV-1000 and Oxylog 3000 can all ventilate infants as small as 5 kg but specialized paediatric ventilators are required beyond this.