Bench testing
RH (Figure 1) and AH were significantly lower during HFOV than during IPPV while temperature in the Y-piece was significantly higher during HFOV than IPPV (Table 1). RH was significantly higher with MR-A than MR-B, regardless of the ventilatory mode (89.6% ± 6.7% vs 78.7% ± 6.8%;  = 0.003) and in each ventilatory mode (Table 1, Figure 1).