I wanted to pass on some information regarding CPAP users. I have terrible air trapping, as well as bloating, as well as gerd. I found myself in the hosptal on a BiPAP machine. I realized it worked different from my CPAP. Made me curious.
Through a little google research, I found that CPAP can contribute to air trapping. With the continuous pressure our expiatory breath is against pressure contributing to air trapping. A BiPAP machine reduces its pressure for the expiatory breath relieving the pressure and contributes less to air trapping. Further, CPAP can contribute to aerophagia or swallowing of air. Air is pushed down the esophagus into the stomach, resulting bloating, burping etc. Further that trapped air can come back up contributing top GERD.
http://www.sleep-apnea-guide.com/cpap-gas-problem-...
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC25763...