Purpose: We assessed the performance of heated wire humidifiers (HWHs), which should avoid water condensation in the circuit.
Methods: We evaluated the efficiency of 3 HWHs, MR850 (Fisher & Paykel, Auckland, New Zealand), CONCHATHERM IV (Hudson RCI, Temecula, Calif), and DAR HC 2000 (Mallinckrodt DAR, Mirandola, Italy), in comparison with that of the MR730 heated humidifier (HH), which has a standard circuit. We measured gas temperature and absolute humidity (AH) at the Y piece of the ventilatory circuit using a test lung ventilated at 2 minute ventilation volumes (5 and 15 L/min).