Fig. 1. The Narkomed GS and the 6000 ventilator systems were connected to the infant test lung by an endotracheal tube with a 3.5-mm inner diameter. The study consisted of 3 parts—part A: minute ventilation (V̇^E) during time-cycled, pressure-limited and time-cycled, volume-limited ventilation; part B: the effect on V̇^Eof an acute change in test lung compliance (changing from normal infant lung compliance [0.003 l/cm H²O] to low infant lung compliance [0.001 l/cm H²O]); and part C: the effect on V̇^Eof an increase or decrease in fresh gas flow. Variables tested in each part of the experiment are enclosed within boxes bounded by dotted lines. BPM = breath/min. (Modified with permission from Stevenson GW, Tobin MJ, Horn BJ, Sautel M, Chen EH, Hall SC, Coté CJ: The effect of circuit compliance on delivered ventilation with use of an adult circle system for time cycled volume controlled ventilation using an infant lung model. Paediatr Anaesth 1998; 8:139–44.)