Hospital Harm: Aspiration Pneumonia

Overview

Healthcare Excellence Canada has developed this Hospital Harm Improvement Resource – a compilation of resources to support patient safety and improvement efforts.

There are three causes for aspirations that lead to aspiration pneumonia:

1. Orogastric secretions in patients with marked disturbance of consciousness. For example, acute neurological insult including stroke or head trauma.

2. Misdirected orally ingested liquids and/or foods due to swallowing difficulties secondary to a medical condition or intervention. For example, progressive neurological illnesses including Parkinson's disease, ALS as well as tumours of the head and neck or iatrogenic causes such as head and neck cancer treatments such as surgical ablation, chemoradiation therapy and damage to the laryngeal area following prolonged endotracheal intubation.

3. Misdirected orally ingested liquids and/or foods due to aging process.

Pneumonitis is best defined as acute lung injury following the aspiration of regurgitated gastric contents. This syndrome occurs in patients with a marked disturbance of consciousness, such as drug overdose, seizures, and anesthesia. Drug overdose is a common cause of aspiration pneumonitis, occurring in approximately 10 per cent of patients hospitalized following a drug overdose. The risk of aspiration increases with the degree of unconsciousness (as measured by the Glasgow Coma Scale). Historically, the syndrome most commonly associated with aspiration pneumonitis is Mendelson's syndrome (Marik, 2011).

Aspiration pneumonia occurs when regurgitated gastric contents or oropharyngeal secretions or food are inadvertently directed into the trachea and subsequently into the lungs. As the bacteria and other microorganisms become part of an infiltrate within the lung tissue, the resulting effect is an infection in the lung (Pace & McCullough, 2010). Approximately half of all healthy adults aspirate small amounts of oropharyngeal secretions during sleep. However, if the mechanical, humoral, or cellular mechanisms are impaired or if the aspirated inoculum is large enough, pneumonia may follow. Any condition that increases the volume and/or bacterial burden of oropharyngeal secretions when the host defense mechanism is impaired may lead to aspiration pneumonia (Marik, 2011). Healthy people commonly aspirate small amounts of oral secretions, but normal defense mechanisms usually clear the inoculum without sequelae. Aspiration of larger amounts, or aspiration in a patient with impaired pulmonary defenses, often causes pneumonia and/or abscess. Elderly patients tend to aspirate because of conditions associated with aging that alter the level of consciousness, sedative use, neurologic disorders, weakness and other disorders. Empyema also occasionally complicates aspiration (Sethi, 2014).

Paediatric populations have different causes of dysphagia than in adult populations. These causes include: cerebral palsy; acquired/traumatic brain injury; other neuromuscular disorders; craniofacial malformations; airway malformations; congenital cardiac disease; gastrointestinal disease; ingestional injuries; and preterm birth (Dodrill & Gosa, 2015; Lefton-Greif & Arvedson, 2007).

Aspiration pneumonia represents five per cent to 15 per cent of pneumonias in the hospitalized population (DiBardino, 2015). It has been suggested that dysphagia carries a seven-fold increase risk of aspiration pneumonia and is an independent predictor of mortality (Metheny, 2011).

Critically ill patients have an increased risk for aspirating oropharyngeal secretions and regurgitated gastric contents. For those who are tube-fed, aspiration of gastric contents is of greater concern. While witnessed large-volume aspirations occur occasionally, small-volume clinically silent aspirations are far more common. Because no bedside tests are currently available to detect microaspirations, efforts to prevent or minimize aspiration take on added importance (American Association of Critical-Care Nurses, 2016). Silent aspiration is frequent in the pediatric population (Lefton-Grief et al, 2006).

Aspiration pneumonia generally occurs in elderly, debilitated patients with dysphagia (Marik, 2011). Epidemiological studies have demonstrated that the incidence of pneumonia increases with aging, with the risk being almost six times higher in those over the age of 75, compared to those less than 60 years of age (Marik, 2011).

Aspiration pneumonia is the major cause of death in patients with dysphagia resulting from neurological disorders including cerebrovascular accidents, Parkinson's disease, and dementia (Marik, 2011).

Risk Factors for Aspiration Pneumonia and Pneumonitis

(DiBardino, 2015; Marik, 2011, American Association of Neuroscience Nurses, 2006)

1. Dysphagia/swallowing.

2. Altered mental status or decreased alertness and attention span.

3. Esophageal motility disorders/vomiting.

4. Enteral (tube) feeding.

5. Poor oral hygiene, decrease in salivary clearance.

6. Increased impulsiveness or agitation.

7. Use of medications such as psychotropic, neuroleptic, antidepressants, anticholinergic, or phenothiazine drugs.

8. Hyperextended neck or contractures.

9. Facial or neck reconstruction, cancers and their treatments.

10. Long-term intubation.

11. Advancing age due to decreased muscle mass reducing pharyngeal contraction and bolus drive.

12. Supine position.

Paediatric Risk Factors for Aspiration Pneumonia

(Weir et al, 2007)

1. Trisomy 21.

2. Asthma.

3. Gastroesophageal reflux disease (GERD).

4. Lower respiratory tract infection.

5. Moist cough.

6. Multisystem diagnoses.

Importance to Patients and Families

Aspiration pneumonia and aspiration pneumonitis occurs when foreign material, such as food, drink, gastric secretions and secretions from the mouth are inhaled and cause inflammation in the lungs and bronchial tubes. Aspiration can often be prevented by dietary interventions for dysphagia e.g. adjusting texture, consistency and amount of food and fluids, frequent oral care, post-pyloric tube (tube passes through stomach and into small intestine) feedings, and the semi-recumbent (45 degree angle) position for mechanically ventilated patients (DiBardino, 2015).

Patient Story

A catalogue of mistakes by an out-of-hours GP service and a hospital contributed to the death of a young woman with physical and learning disabilities, the NHS ombudsman says in a highly critical report that has led to fresh claims of prejudicial attitudes leading to poor care for such vulnerable patients.

The report, by NHS ombudsman Dame Julie Mellor, finds that Tina Papalabropoulos, 23, died in Basildon hospital in Essex of aspiration pneumonia in 2009 after a series of blunders by two NHS organisations.

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