A 76-year-old woman is being evaluated for recurrent fever and cough. The patient was admitted to the hospital from a skilled nursing facility 7 days ago due to urinary tract infection and was treated with intravenous ceftriaxone. The patient has a history of dementia, and her hospital course has been complicated by delirium. She has received several doses of an antipsychotic medication to control agitation and anxiety. Over the past 2 days, she has had productive cough and recurrent fever. Temperature is 38.4 C (101.1 F), blood pressure is 120/70 mm Hg, pulse is 106/min, and respirations are 20/min. Oxygen saturation is 96% on room air. On physical examination, the patient appears somnolent. Dentition is poor. Lung auscultation reveals right-sided rhonchi and crackles. Heart sounds are normal. Chest x-ray shows infiltrate in the apical segment of the right lower lobe. Sputum Gram stain shows many neutrophils, gram-positive cocci in chains, and gram-positive rods. Which of the following was the most likely underlying trigger for this patient's current condition?
Conditions associated with aspiration pneumonia | |
Trigger | Related conditions |
Reduced |
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Dysphagia |
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Pharyngeal or |
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Dental issues |
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This patient developed fever, cough, and pulmonary infiltrate >48 hours after being admitted to the hospital, indicating hospital-acquired pneumonia (HAP). The presence of poor dentition, an apical right lower lobe infiltrate, and polymicrobial sputum gram-stain results suggest the underlying cause is bacterial aspiration pneumonia.
Bacterial aspiration pneumonia develops when oropharyngeal or gastric microbes are introduced into the lower airways and subsequently overwhelm host defense mechanisms due to large inoculum size or organism pathogenicity. Risk is increased in hospitalized patients due to the following:
Use of sedative and antipsychotic medications: These medications impair the cough reflex and often directly impair glottal function, which increases the quantity and frequency of aspiration.
Use of gastric acid suppression medications: These medications increase the pH of the stomach, which creates a more permissive environment for microbe growth.
Glottal or pharyngeal disruption: Intubation, tracheostomy, nasogastric feeding, and anesthesia impair the ability to protect the airway and/or coordinate muscle movement with swallowing, which increases the frequency of aspiration and inoculum size.
Other common risk factors for aspiration include poor dentition, dementia/delirium, and older age.
Bacterial aspiration pneumonia generally causes fever, productive cough (often with a putrid odor), and a pulmonary infiltrate in a dependent portion of the lung (eg, apical segment right middle lobe). Most cases are caused by aerobic upper respiratory organisms, but anaerobes are often present in the setting of lung abscess or empyema.
(Choice A) Advanced age impairs the innate and adaptive immune responses, which increases risk for infection and malignancy. Although advanced age is associated with an increased risk for aspiration, this patient's greatest risk factor was likely the use of antipsychotic medications for delirium.
(Choices B and D) Inadequate hand hygiene increases risk of hospital-acquired infections with multi–drug-resistant and highly pathogenic organisms. Although these organisms are more likely to cause bacterial aspiration pneumonia due to their pathogenicity (lower inoculum sizes can trigger infection), this patient likely developed a polymicrobial lung infection due to aspiration of multiple pathogens in the setting of antipsychotic medications.
(Choice C) Impaired esophageal motility is a common cause of aspiration, but patients generally have progressive difficulty with solids and liquids over weeks or months. It is unlikely this patient had an acute change in esophageal motility while hospitalized that led to aspiration.
Educational objective:
Bacterial aspiration pneumonia is a common cause of hospital-acquired pneumonia, particularly in the setting of sedative or antipsychotic medications, gastric suppressive medications, intubation, anesthesia, or nasogastric feeding. Patients typically develop fever, productive cough, and infiltrate in a dependent portion of the lung.