What is the management for suspected microaspiration?

From the Guidelines

Management of suspected microaspiration should prioritize the use of antiacid medication, such as proton pump inhibitors (PPIs) or histamine-2 blocker receptor antagonists (H2RAs), to decrease the risk of microaspiration-associated lung injury or damage. This approach is based on the evidence that abnormal gastroesophageal reflux (GER) is a risk factor for aspiration and microaspiration, which can cause pneumonitis and worsen idiopathic pulmonary fibrosis (IPF) 1.

The use of antiacid medication has been shown to have a potential survival benefit and decrease the progression of disease in patients with IPF, with one retrospective analysis suggesting a survival benefit for patients receiving antiacid medication (HR, 0.47; 95% CI, 0.24–0.93; adjusted analysis) 1. Additionally, an aggregate analysis of patients with IPF showed a significantly smaller decrease in FVC during the study period for those receiving antiacid treatment at baseline (mean difference, 0.07 L; 95% CI, 0–0.14; P = 0.05) 1.

Key interventions for suspected microaspiration include:

• Using antiacid medication, such as PPIs (e.g., pantoprazole 40mg IV/PO daily) or H2RAs (e.g., famotidine 20mg IV/PO twice daily), to decrease gastric acid production
• Elevating the head of the bed to 30-45 degrees to reduce the risk of gastric contents flowing into the airway
• Implementing oral care with chlorhexidine 0.12% solution twice daily to reduce bacterial colonization
• Maintaining endotracheal cuff pressure at 20-30 cmH2O and using continuous subglottic suctioning if available for patients on mechanical ventilation
• Considering post-pyloric feeding for patients at high risk of aspiration
• Initiating empiric antibiotics if infection is suspected, with adjustments based on culture results
• Promoting physical therapy and early mobilization to clear secretions.

From the Research

Management of Suspected Microaspiration

The management of suspected microaspiration involves several considerations, including the identification of underlying causes and the implementation of preventive measures.

• Identifying and managing underlying conditions that may contribute to microaspiration, such as gastroesophageal reflux disease (GERD) 2
• Withholding certain medications that may increase the risk of aspiration pneumonia, such as benzodiazepines and antipsychotics, in high-risk populations 3
• Implementing general measures to reduce the risk of aspiration, such as maintaining a semirecumbent position during sleep and feeding 3
• Considering the use of medications that may reduce the risk of aspiration pneumonia, such as angiotensin-converting enzyme inhibitors, although more research is needed to confirm their effectiveness 3

Diagnostic Considerations

Diagnosing microaspiration can be challenging, and it is often suspected in patients with refractory respiratory symptoms, such as unexplained chronic cough, asthma, and chronic obstructive pulmonary disease (COPD) 2.

• Gastric biomarkers obtained directly from the airways may be used to confirm the association between reflux and respiratory disease, although results are limited by methodologic flaws and correlation 2
• Histopathologic detection of foreign bodies may provide the best evidence of aspiration directly causing respiratory disorders 2

Treatment Approaches

Treatment approaches for suspected microaspiration may vary depending on the underlying cause and severity of symptoms.

• Aggressive treatment for GERD may be considered, although clinical trials have not demonstrated a clear impact on outcomes, and there may be potential for harm 2
• In cases of suspected aspiration of foreign objects, such as a capsule endoscope, immediate intervention may be necessary to prevent major airway compromise and obstructive pneumonitis 4
• Cough induction may be an effective method for removing aspirated objects, such as a capsule endoscope 4
• In patients with respiratory failure requiring mechanical ventilation after presumed aspiration, aggressive bacteriologic surveillance and the administration of IV antibiotics may be recommended to prevent early infectious complications 5