What complication is an older adult with type 2 diabetes mellitus and pneumonia at highest risk for?

An older adult with type 2 diabetes mellitus and pneumonia is at highest risk for hyperosmolar hyperglycemic state (HHS). HHS is characterized by extremely high blood glucose levels and significant dehydration, which can occur due to illness or infection, such as pneumonia. In this scenario, the stress of the infection can lead to increased insulin resistance and higher blood sugar levels.

Older adults are particularly vulnerable because they may have other comorbid conditions, impaired renal function, and an overall decreased ability to manage their blood glucose levels during times of stress. Unlike diabetic ketoacidosis, which is more common in individuals with type 1 diabetes and is accompanied by ketosis, HHS does not typically involve significant ketone production but can be life-threatening if not promptly identified and treated.

Additionally, while hypoglycemia can occur in diabetes management, the risk is often higher for individuals actively managing their diabetes than for those experiencing an acute illness like pneumonia. Neuropathy, while a common complication of long-term diabetes, is not an immediate or direct risk associated with an acute infection. Thus, with the combination of type 2 diabetes and pneumonia, HHS is the most likely and concerning complication to arise.