Importance of Spont Cycle %

[Sleeprider]

A restrictive condition like severe scoliosis could interfere with respiratory rebound during expiration and have similar effect to poor lung compliance or obstructive problems, but I see your point. Using a long TiMin is useful to prevent premature cycling during the first second of inspiration. I normally try to keep that to 0.8 seconds or less as a full second can get in the way of the normal range of respiration. In your dad's case, TiMin might get him past a "hitch" in respiration that might shut down IPAP without it. It also helps in cases where spontaneous inspiration appears chaotic and a longer inspiration is needed to ensure each breath counts. I think it might help to look at the time of inspiration chart and see how much of it plateaus at 1-second. You can use a dotted line on the Y-axis to create line at 1.0 seconds to see how much of respiration time is actually affected by the 1-second TiMin. As with most PAP titration, the best way to optimize is often trial and error, or trying various settings to see where the best results and comfort reside. I can't pretend to know a general rule for TiMin that should apply to all, or specifically to your dad, and I'll defer to your very good observations.