Chronic Aspiration

What is Chronic Aspiration?

Aspiration happens when substances like saliva, food, or stomach fluids mistakenly enter the windpipe or lungs, causing an inflammation reaction. Such a problem can affect both healthy and sick individuals. If this happens over a long period, it’s called chronic aspiration, which is typically seen in elderly people, children with specific neurological disorders, and patients who have to be constantly connected to a breathing tube.

Aspiration can be classified into two types, depending on the amount that enters the lungs: microaspiration, when a tiny bit of foreign substance is inhaled, and macroaspiration, when a sizeable amount is inhaled. However, there isn’t a precise cutoff between the two. Chronic aspiration usually results from repeated microaspiration.

The consequences of one aspiration incident can range from harmless to very severe, depending on the nature and volume of the substance that is inhaled. However, if it happens repeatedly, or becomes chronic, it suggests an underlying problem with basic functions like speaking, swallowing, breathing, or maintaining a protected airway. This condition often affects children, elderly, and patients in intensive care units, and can lead to significant health complications and even death. In children with neurological impairments, chronic aspiration is a leading cause of death. Moreover, patients with swallowing difficulties are three times more likely to get pneumonia and have nearly a 3% increased chance of dying in hospital.

What Causes Chronic Aspiration?

Anything that causes the nerves and muscles used for speaking, swallowing, breathing, and keeping the airway open to break down could lead to chronic aspiration (the entry of food or liquids into the lungs) and the health problems it can cause. The main risk factors are nerve damage, lung diseases, abnormal conditions above the vocal cords (supraglottic disease), and other conditions.

Nerve damage could be general or targeted. In children, common risk factors include brain diseases, problems with the specific nerves like CHARGE syndrome, muscle diseases like Duchenne muscular dystrophy, paralysis of the vocal cords, and cerebral palsy. Each condition leads to aspiration differently. For example, muscle diseases might cause general weakness when swallowing solid food, while cerebral palsy might cause problems with handling oral secretions and thin liquids. Recurrent lung infections due to aspiration are strongly linked in children to problems swallowing, such as penetration, aspiration, reflux, and abnormal esophageal function.

In adults, nerve damage caused by stroke, dementia, diseases like amyotrophic lateral sclerosis (ALS), multiple sclerosis, Parkinson’s disease, and Guillain-Barre syndrome are amongst the causes. Adults usually show an overall weakness of the swallowing muscles, which can become worse due to the decline of neurological functions, like what happens in dementia or a stroke. Swallowing difficulties in these patients often lead to a higher rate of health complications. For instance, patients with Parkinson’s disease are more than three times more likely to be hospitalized for aspiration pneumonia, a risk that increases as the disease progresses and their ability to cough and swallow deteriorates.

Pulmonary or lung diseases can also increase the risk of aspiration. Patients with poor expiratory volume, inadequate cough, or those who require a ventilator are at an increased risk. Patients in the ICU for extended periods often develop weakness and flaccidity in the muscles. This coupled with physical deconditioning, weak airway muscles, prolonged intubation, and poor airway protection, contributes to an increased risk for significant swallowing disorders and aspiration-related pneumonia. Similarly, weakened respiratory and vocal cord muscles seen in end-stage patients and those suffering from multi-system chronic diseases such as kidney disease, heart failure, and chronic obstructive pulmonary disease often lead to aspiration.

With supraglottic disease, people who have poor dental health, abnormalities in the throat, impaired swallowing, or abnormal esophagus movements also have a higher risk of aspiration. In children, fistulas (abnormal connections between the esophagus and trachea), laryngomalacia (a condition where the larynx is malformed), and other abnormalities that prevent normal swallowing function can increase the risk. Abnormal facial anatomy and obstructive lesions can lead to lingering food particles after swallowing, which increases the risk of aspiration. In adults, conditions like achalasia, Zenker diverticulum, and head and neck cancers can also increase the risk.

Other conditions that increase the risk include position changes, vomiting large amounts, numbness of the throat and/or larynx, procedures involving the oral cavity, esophagus, or airway like the placement of a nasogastric tube, trauma, and certain medications. For instance, prolonged use of proton pump inhibitors can lead to an increase in stomach bacteria. Antipsychotic drugs can affect the muscles involved in swallowing. Antihistamines and antidepressants can reduce oral lubrication. Anticonvulsants can cause drowsiness and unsteady movements. These medications can all affect stomach movements, potentially increasing reflux.

Risk Factors and Frequency for Chronic Aspiration

Chronic aspiration, a condition where foreign material is inhaled into the lungs, is a problem that affects an unknown number of people. It can happen to anyone, but it is more often seen in children, older adults, and patients in the intensive care unit (ICU). These groups are more at risk because they have a higher chance of experiencing factors that can lead to aspiration. Even though the number of hospitalizations in the U.S. due to aspiration pneumonia, a common consequence of chronic aspiration, is decreasing, it still presents a significant strain on the healthcare system, particularly for patients over 65.

• Chronic aspiration is more frequently seen in children, the elderly, and ICU patients.
• In the US, hospitalizations due to aspiration pneumonia is decreasing but still burdens the healthcare system.
• This issue is particularly significant for people over 65.

In children, swallowing and feeding issues, which can lead to aspiration, are more widespread than one might think. It’s estimated that up to a quarter of all children have these issues. The percentage increases to 40% for infants born prematurely and goes as high as 78% for children with developmental delays. Such children, along with those who have multiple medical conditions, account for most hospitalizations and ICU admissions related to aspiration. The cost of their care is on average 2.4 times higher than that of hospitalizations related to community-acquired pneumonia (a type of pneumonia caught outside of healthcare settings).

• Swallowing and feeding disorders are prevalent in up to 25% of all children, 40% of prematurely born infants, and 78% of children with developmental delays.
• These children often represent the majority of hospitalizations and ICU admissions due to aspiration.
• The cost of care for these cases is, on average, 2.4 times higher than community-acquired pneumonia-related hospitalizations.

Signs and Symptoms of Chronic Aspiration

Aspiration syndrome is a condition that affects breathing. Some of the common symptoms usually include:

• Wheezing
• Chronic cough
• Cough at night
• Repeated pneumonia
• Poor weight gain or slow growth in children

These symptoms might become more obvious after eating. In babies, if there is a weak sucking reflex or frequent coughing after feeding, it may suggest the presence of a nerve or muscle disease.

During a physical examination, early warning signs can be noticed. These may include the symptoms above, unusual lung sounds like wheezing, snoring sounds or crackling sounds when listening to the lungs. If there’s a blockage, there might be reduced or no airflow or lung sounds. A drop in oxygen levels recorded by a pulse oximeter could indicate an advanced stage of aspiration syndrome. This signifies that a significant part of the respiratory tract is affected, causing a decrease in overall oxygen levels. For patients in intensive care units, especially those who have been on a ventilator for a long period, a sudden drop in oxygen levels or increased effort to breathe could be an early sign of aspiration. This should always be considered as a possible cause of these symptoms.

Testing for Chronic Aspiration

Plain x-rays can show signs of bronchial inflammation, but a CT scan (computerized tomography) provides a clearer picture of the disease’s presence, location, and severity. Signs that point towards disease includes thickening of interstitial areas, lines that are more visible than they should be, small nods of tissue, spots of opacities that looks like ground glass, and areas with bronchiectasis.

Chronic aspiration conditions, like aspiration bronchiolitis and pneumonia, can also be viewed using CT scans. The scans can show increased areas of brightness, small nodules, and uneven patches of bronchial areas. Additional complications such as lung abscess and empyema (fluid filled lungs) can also be identified via imaging. CT scans can further provide differentiating features like the shape of the attached wall, the angle the disease makes with the lining of the lung and how it affects surrounding structures.

When there is a risk of chronic aspiration, it is important to carry out speech and swallow studies, as failures in breathing, swallowing, and speaking mechanisms are directly connected. If children are unable to perform these classic tests, a feeding tube may be placed, and they may be put on a diet progression.

The next step is a videofluoroscopic swallow study (VFSS), also known as a barium swallow, where a patient swallows food or liquid mixed with barium. This allows doctors to observe anything unusual, such as penetration (food or liquid passing into the larynx), aspiration (the barium showing up in the trachea or bronchioles), or lack of coughing when barium is in the lungs (known as silent aspiration). A score is then derived to signify any abnormalities.

Alternative methods like fiberoptic endoscopic evaluation of swallowing (FEES) or radionucleotide salivary scans can also be used, particularly in children or those unable to tolerate VFSS. The use of scopes, tubes, or tagged tracers helps to observe the swallowing process more clearly.

Determining the risk of aspiration can also involve direct observation of the throat area using procedures such as laryngoscopy or bronchoscopy. These procedures are used to rule out any anatomical irregularities. However, for some procedures, patients must be awake, which some may find uncomfortable. In cases where minor sedation is needed, rigid laryngoscopy with bronchoscopy is used. Finally, a flexible bronchoscopy with lavage (BAL) enables medics to assess if a patient is preventing further aspirations.

Treatment Options for Chronic Aspiration

Managing issues with speaking and swallowing begins with adjusting a person’s diet to more easily manageable foods and liquids. Regular checks, reducing portion size, making foods and liquids thicker, and drinking water during meals can help lower the risk of aspirating (inhaling food/liquid) and improve health outcomes. Speech and swallow therapists can work with the patient on postures, positioning, swallowing techniques, and strengthening muscles.

Oral hygiene is an essential aspect of preventing pneumonia caused by aspiration, a leading cause of death; practicing good oral care helps reduce bacteria in the mouth.

If aspiration leads to pneumonia, the treatment includes antibiotics like beta-lactam/lactamase inhibitors, clindamycin, or carbapenem. Supportive care and preventative measures such as oxygen, suctioning, elevating the head of the bed, and utilizing a tube for feeding temporarily may also be required. In patients on a ventilator, draining the subglottic secretions can help reduce pneumonia complications.

Prophylactic antibiotics don’t prevent recurrent pneumonia caused by aspiration. If pneumonia leads to a lung abscess, treatment includes postural drainage and a prolonged course of antibiotics. In the case of empyema (pus in the lungs), the fluid is drained through a procedure.

If attempts at diet modification fail, or if nutritional status is in question, a feeding tube may be considered. Options range from a nasal or oral feeding tube to surgically inserted feeding tubes. It’s important to know that risks for aspiration are still present even with these tubes, so they should be carefully evaluated.

Surgical options are also available for those with medication-resistant swallowing dysfunction. One approach is laryngeal suspension, which involves surgically moving the larynx beneath the tongue to reduce aspiration and make swallowing easier. Unilateral vocal cord medialization, in which the vocal cord is brought closer to the midline of the throat, can be considered in cases of unresponsive or paralyzed vocal cords to restore pressure during swallowing. Finally, in life-threatening cases, a laryngectomy, or removal of the larynx, might be necessary. However, as it eliminates speech completely, this approach is viewed as a last resort.

What else can Chronic Aspiration be?

When a doctor is investigating chronic aspiration (accidentally inhaling food or drink into the lungs), they may also need to consider other conditions. These can include:

• Pneumonia caused by bacteria or viruses
• Blood clot in the lungs, also known as Pulmonary embolism
• A serious lung condition called Acute Respiratory Distress Syndrome (ARDS)
• Heart failure
• Lung cancer
• A bacterial infection known as Tuberculosis
• Heartburn or acid reflux, medically referred to as GERD
• A lung disease in which lung tissues become damaged and scarred, known as Idiopathic Pulmonary Fibrosis

The doctor needs to carefully weigh these possibilities and conduct appropriate examinations to reach a final and accurate diagnosis.

What to expect with Chronic Aspiration

The outcome of aspirating, or accidentally inhaling food or drink, can be quite varied. It depends on several factors such as what caused the aspiration, how long it happened, what was aspirated, and the diagnostic tools used to identify the problem. Changing diet and how the person is fed, along with the use of things like thickened feeds or feeding tubes, can also impact the result. The situation is also improved if the person’s lungs were in better condition before the aspiration occurred.

Conversely, if someone’s cognitive functioning – that is, their ability to think, understand, remember, and reason – isn’t very good, that’s associated with worse outcomes overall. Surgical methods could also be used to manage aspiration and can affect the prognosis.

Possible Complications When Diagnosed with Chronic Aspiration

Common health issues that may follow are:

• Aspiration pneumonia
• Aspiration bronchiolitis
• Obstructive bronchiolitis
• Lung abscess and empyema

Symptoms that suggest the disease is getting worse include early signs of infection like fever, increased white blood cell count, fast heart rate, rapid breathing, low blood pressure, and high lactate levels. This is in addition to the symptoms related to aspiration mentioned above. Constant aspiration is also linked with interstitial lung disease (a group of lung disorders that leads to scarring of the lungs), idiopathic pulmonary fibrosis (a type of lung disease that results in scarring of the lungs for an unknown reason), persistent asthma, and rejection after a lung transplant.

Preventing Chronic Aspiration

For individuals who might be at risk for frequent food or drink going into their lungs (chronic aspiration), it’s crucial to follow several guidelines. These include maintaining good oral hygiene, eating approved foods, and adopting the correct posture and body positioning. However, it’s also important to understand that while different treatment options exist, none are perfect, and there can still be issues with both minor and significant aspiration.

After considering all the treatments, it’s up to the individuals to decide on their choice. They have the right to continue their usual dietary habits, even if there’s a potential risk of developing lung infection caused by aspiration.

For children who are at a higher risk due to developmental delays or problems with nerves and muscles, parents need to be aware of the early signs of aspiration. The same applies to elderly individuals – both they and their caregivers need to understand the signs and symptoms of aspiration to seek timely medical assistance.