hospital-acquired pneumonia

Hospitals are full of sick people and the antibiotics used to treat them, which over time breeds tougher, more resistant germs in that environment. Hospital-acquired pneumonia is the lung infection a patient picks up after being admitted — and because the culprit germs are often these hardened hospital strains, it tends to be more serious and harder to treat than pneumonia caught at home.

By convention, hospital-acquired pneumonia is pneumonia that develops 48 hours or more after admission, when it could not have been brewing on arrival. Patients in hospital are vulnerable because illness, surgery, sedation and reduced mobility weaken normal lung defenses, and a breathing tube — when present — bypasses the airway's natural filters. Common organisms include Gram-negative bacteria such as Pseudomonas and resistant Staphylococcus aureus (MRSA).

Because resistant organisms are likely, initial antibiotic therapy is usually broader than for community-acquired pneumonia and is then narrowed once cultures identify the specific germ and its drug sensitivities. Prevention matters greatly: good hand hygiene, elevating the head of the bed, careful oral care and getting patients up and breathing deeply all reduce the risk.

A related and especially severe form occurs in ventilated patients and is treated as its own entity, ventilator-associated pneumonia, because the breathing tube so strongly drives the risk.