Before you jump to the trach. Does your husband sleep on his side or back? Chronic regurgitation during sleep could result in small amounts being aspirated into his lungs.
I have similar issues and found that sleeping with my torso at 25 degrees or greater angle from horizontal (floor) mostly resolved the problem. (Sleeping in a recliner is not great, but then again, I haven't had to deal with pneumonia since I started to do this.)
Also talk to your doctor about using a crushable version of Previcid or similar medication to reduce the reflux.
Good Luck