How the onslaught begins Most patients develop nosocomial pneumonia by either aspirating contaminated substances or inhaling airborne particles. Let's look at each of these causes. Aspiration occurs when food, fluid, or gastric contents enter your patient's lungs, setting the stage for pneumonia. In hospitals, aspiration occurs most frequently in patients who can't swallow normally or when altered level of consciousness, mechanical ventilation, or a gastric or endotracheal tube causes silent regurgitation. A patient who's fed by someone else or who has dementia also is at increased risk.
Studies suggest that protein-calorie malnutrition increases the risk of aspiration too.
Although aspiration can't be proved in Mr. Hudicek's case, his altered mental status makes it a likely cause of his nosocomial pneumonia. Your patient's gastric contents are unlikely to contain bacteria unless his gastric pH is 4.0 or greater. If aspirated, these colonized gastric contents can lead to lung infection. Inhaling airborne particles occurs when contaminated droplets enter your patient's lungs through respiratory or anesthesia equipment, ventilation systems, humidifiers, showers, faucets, or from other people's coughing and sneezing. Pathogens then may proliferate in his respiratory tract.