AquaVENT® heated breathing circuits combine technological advances in thermal conductivity and breathing circuit construction to deliver optimal and controlled humidification. Oxygen and medical air delivered invasively as dry gases, over sustained periods of time, will damage the epithelia of the respiratory tract and prevent adequate functioning of the mucosal tissue in contact with the dry gases. Inadequate humidification, in patients with bypassed airways, can disrupt secretion mobility across the mucocilliary transport system, leading to thickening of secretions, infective secretions, atelectasis or systemic infection and has been reported to increase work of breathing and cause dehydration. Maintaining secretion transport across the mucosal epithelium leads to better patient outcomes. This can be achieved by delivering optimal humidification to the mechanically ventilated patient with bypassed airways.