dear alexandria,   According to the MS Society, "the most common cause of respiratory problems is loss of muscle strength and endurance"      http://www.nationalmssociety.org/about-multiple-sclerosis/what-we-know-about-ms/symptoms/respiration/index.aspx   Some drugs depress breathing function. Also for many, it is the aspiration of food, water and other drinks, and even salvia or mucus, that causes pneumonia. The food or fluid gets into the lungs and causes the pneumonia infection, which requires hospitalization. The person with MS may not be capable of doing big coughs to get out these fluids...may not even realize it has happened until pneumonia comes on. n MS, the most common cause of respiratory problems is loss of muscle strength unfortunately, UTI 's are very common symptoms of MS and with increasing numbers of UTI's, may require a cathether. However, this is a big operation with recovery time that is longer for a person with MS, than for one who doesn't, so don't let them release your patient too soon from hospital.   there is a lot of info and links to brochures by the National MS Society for caregivers on this website, about what to expect at the end of advanced MS...and you could get in a specialized nurse to evaluate the need for hospice care. your patient is old too...so some of these things happen to older people anyway, but the MS is just as likely to be the source.   http://www.nationalmssociety.org/error.html?aspxerrorpath=/about-multiple-sclerosis/living-with-advanced-ms/index.aspx