-SWS wrote:I also favor the general theory that autoSV "ventilation" itself indirectly helps to keep DSM's leg cramps at bay. And that's essentially the theory DSM has been maintaining for quite some time, regarding inefficient gas exchange w/out SV. Along those lines, DSM mentioned feeling "stretched" on APAP (pulmonary stretch, right??). So one possibility along that gas-exchange theory is excessive inspiratory stretch followed by inadequate elastic recoil---thus not all CO2 is adequately expelled. This stretch-without-full-recoil theory essentially converts part of the lungs' capacity into additional CO2-retaining dead space. So there's a hypothetical possibility for CO2 buildup toward those leg cramps with pulmonary stretch followed by inadequate CO2 expel. The SV machines can help DSM avoid that hypothetical etiology with adequate (and on-demand) inspiratory volumes and much easier expiration facilitated via EPAP/EEP's instantaneous pressure drops (the core purpose of servo "ventilation").
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Very interesting thinking. To describe the cramp onset it goes like this ...
Wake, feel the need to do a big stretch (extend legs, breathe deep) no cramps at that point. Then having stretched right out, wham !, cramp will occur.
On Cpap/Apap they could be very painful & might even have me getting up to walk around & massage legs. One other observation is that I am pretty sure there is a 'tingling' feeling in my legs before & during the whole process.
The wanting to stretch & the cramps seem to go hand in hand. These past mornings I would wake in a similar fashion & was consciously aware I didn't feel the need to stretch out.
One other loose theory I have had is that what I am experiencing is likely age related. at 64 this year I am pretty sure that my respiratory system is not as elastic nor as effective as it was say 20-30 years ago. Support for this would be if other 60+ year olds were experiencing similar patterns of both loss of cpap therapy effectiveness or cramping etc:
DSM
