Week 4. Swallowing Disorders_Neurogenic & Respiratory

Dysphagia - Miriam Carroll-Alfano, Ph.D., CCC-SLP

Agenda

• Week 4:
  • Watch Lecture 4: Neurogenic & Respiratory Disorders
  • Complete Assignment 4
  • Complete Quiz 4
• Reminders
  • Work on MBSImP
  • Midterm exam June 26th at 5:00 pm

Learning Outcomes – Causes of Dysphagia

• Define and utilize vocabulary associated with swallowing disorders.
• Name & discuss a variety of causes of dysphagia and their consequences for health and nutrition.
• Examine case studies of patients with various causes of dysphagia and identify risks and issues.

Causes & Characteristics of Dysphagia

• Neurogenic Disorders & Swallowing
• Respiratory Disorders & Swallowing
• Dysphagia in Head and Neck Cancer
• Esophageal Disorders & Swallowing
• latrogenic Disorders & Swallowing

Neurogenic Disorders

• Any pathology in the nervous system can produce neurogenic dysphagia.
• The relationship between site of lesion and dysphagia is not always as distinct as the site of lesion for speech and language disorders.
• Complexity of cortical and subcortical loops can lead to patients with similar lesions having different swallowing patterns.

Neurological Etiologies of Dysphagia

• Cerebrovascular accident (stroke)
• Traumatic brain injury (TBI)
• Neoplasm
• Infection
• Toxins
• Degenerative diseases (ALS, MS, Parkinson’s, dementia, etc.)
• Metabolic diseases
• Collagen vascular diseases (Rheumatoid arthritis, Lupus, scleroderma, etc.)

Neurological Disorders

• Damage in the cerebral cortex
• Cranial nerve damage or other peripheral nerves
• Damage vs. Sever
  • A damaged nerve may be able to heal
  • There are not many options for a severed nerve
• Neuroplasticity – the capacity of neurons and neural pathways in the brain to change their connections and behavior in response to new information, sensory stimulation, development, damage, or dysfunction.

Oral Phase Signs & Symptoms

• Weakness
• Paralysis
• Incoordination of oral structures
• Drooling
• Pocketing of food in labial or buccal sulci
• Difficulty manipulating the bolus
• Difficulty chewing
• Prolonged oral preparation time
• Loss of control of the bolus

Oral Preparation & Oral Phase Disorders

Oral Preparation & Oral Phase Disorders (Cont.)

Pharyngeal Signs & Symptoms of Dysphagia

• Pharyngeal phase deficits increase risk of choking and aspiration
• Delay in triggering the pharyngeal swallow
• Penetration of liquids/solids
• Aspiration of liquids/solids
• Reduced hyolaryngeal elevation
• Residue in the valleculae
• Residue in the pyriform
• Pharyngeal stasis

Aspiration

• Before the swallow
  • Delayed or absent initiation of swallow
  • Poor bolus control and formation
• Aspiration during the swallow
  • Poor airway closure
  • Reduced hyolaryngeal elevation
• Aspiration after the swallow
  • Oral residue/pocketed material falls into the airway
  • Residue from the valleculae and/or pyriform
  • Reduced hyolaryngeal elevation may lead to food remaining at the top of the larynx

Pharyngeal Phase Disorders

Pharyngeal Phase Disorders (Cont.)

Stroke

• Fifth leading cause of death in the United States after heart disease, cancer, accidents, & Covid
  • Leading cause of long-term adult disability
• After declines from 2002-2012, the annual stroke death rate has increased 12% through 2021
• The estimated direct and indirect cost of stroke in the United States in 2016 is over $100 billion
• Strokes can be prevented! CDC, 2024; www.stroke.org

Dysphagia in Stroke

• Dysphagia is highly prevalent in acute stroke, with estimates that well over 50% of all patients are affected
• Majority of patients recover functional swallow within the first 1-6 months after stroke
• Acute and chronic swallowing problems in stroke patients are associated with:
  • Dehydration, malnutrition, aspiration, chest infections (pneumonia), and potentially death
• Dysphagia during acute stroke is associated with poor long-term outcome

Dysphagia in Stroke (Respiratory)

• Acute stroke patients are at risk for respiratory abnormalities which put them at increased risk of aspiration
  • Weakness in expiratory muscles which reduces ability to cough
  • Increased episodes of oxygen desaturation
  • Deviations in respiratory rate
  • Difficulty coordinating respiration and swallowing
• Dysphagia, especially dysphagia accompanied by aspiration, is significantly correlated to the presence of pneumonia

Dysphagia in Stroke (Deficits)

• Swallowing deficits in hemispheric strokes can be caused by:

Dysphagia in Stroke (Swallowing Deficits)

• Swallowing deficits include:
  • Reduced ability to initiate a saliva swallow
  • Delayed triggering of pharyngeal swallow
  • Incoordination of oral movements
  • Increased pharyngeal transit time
  • Reduced pharyngeal constriction
  • Aspiration
  • Pharyngoesophageal segment dysfunction
  • Impaired lower esophageal sphincter relaxation
• Majority of patients who are NPO have pharyngeal dysphagia

Dysphagia in Stroke (Left Hemisphere)

• Left hemisphere stroke
  • May cause apraxia of the swallow
  • Mild delays in oral transit (3-5 seconds)
  • Mild delays in the initiation of the pharyngeal swallow (2-3 seconds)
  • The pharyngeal stage should be normal once it is initiated since it does not require a lot of cortical input
    • Logemann, 1998

Dysphagia in Stroke (Right Hemisphere)

• Right hemisphere stroke
  • Mild oral transit delays (2-3 seconds)
  • Slightly longer pharyngeal delays (3-5 seconds)
  • Delayed laryngeal elevation
• The dysphagia produced by RH damage, while anatomically and physiologically no more severe than those resulting from left hemisphere damage, have poorer outcomes
  • Patients with RHD tend to have attentional problems and exhibit poor judgment including impulsivity which reduces ability to use strategies

Dysphagia in Stroke (Brain Stem)

• Brain stem stroke typically causes the most severe cases of dysphagia
  • Damage to the medulla is particularly devastating since it is the swallowing center and the nuclei (NTS & NA) and most of the cranial nerves involved in swallowing are located there
• Patients with unilateral medullary lesions may have functional or even normal oral control; however, they usually have significant problems with the pharyngeal stage of the swallow

Dysphagia in Stroke (Brain Stem Cont.)

• Brain stem stroke
  • Oral transit difficulty
  • Pharyngeal muscle function asymmetry
  • Unilateral laryngeal paresis or paralysis resulting in dysphonia
  • Reduced duration and extent of laryngeal elevation
  • Reduced cricopharyngeal opening
  • Valleculae & pyriform sinus residue
  • Penetration and/or aspiration
    • Crary, 1995; Horner et al., 1991; Huckabee & Cannito, 1999

Dysphagia in Stroke (Brain Stem Outcomes)

• Despite the high incidence of dysphagia in patients with brain stem lesions, the long-term outcomes are favorable for 80% if patients receive aggressive intervention (Crary, 1995; Horner et al., 1991; Huckabee & Cannito, 1999; Meng et al., 2000)
• Interventions that target increased cortical involvement (conscious thought) have proved to be successful for these patients

Traumatic Brain Injury (TBI)

• The NIH defines traumatic brain injury as a form of acquired brain injury
  • Occurs when a sudden trauma causes damage to the brain
  • TBI can result when the head suddenly and violently hits an object, or when an object pierces the skull and enters brain tissue
• Open Head Injuries
  • Traumatic event causes opening in skull such that brain is exposed Ex: gunshot, other penetrating wounds
• Closed Head Injuries
  • Exterior bones of cranium remain intact, preventing direct exposure of brain
  • Motor vehicle accidents, assaults, sporting accidents, falls

Traumatic Brain Injury in U.S.

• 69,473 deaths
• 214,110 hospitalizations
• 2. 5 million ER visits
• ?? Receiving other medical care or no care

Dysphagia in TBI

• Traumatic brain injury typically results in diffuse neurologic deficits, as well as potential physiologic deficits
  • Studies have indicated that the prevalence of dysphagia following TBI may be as high as 93%. (Hansen et al. 2008, Lee et al., 2016; Mackay et al. 1999, & Terre & Mearin, 2007)
• Primary factor related to the presence of dysphagia in TBI patients is the severity of neurotrauma assessed by clinical scales including: GCS, RLAS, or FIM

Dysphagia in TBI (Deficits)

• Deficits in cognition, motor function, perception, speech, language, and social skills may affect the ability to eat normally
• Swallow deficits seen in patients with TBI include:
  • Delayed pharyngeal swallow response
  • Reduced lingual control
  • Silent aspiration
    • (Lazarus & Logemann, 1987)
• Severity of the initial injury is a strong predictor of the presence of swallowing deficits & recovery of functional swallowing ability

Dysphagia in TBI (Pneumonia)

• Pneumonia is frequently seen in patients with TBI, especially early in posttraumatic treatment
• Clinical factors associated with the presence of pneumonia include:
  • Severity of brain injury (GCS, RLAS)
  • NPO on admission
  • Presence of tracheostomy tube
  • Presence of feeding tube
  • Presence of communication and cognitive deficits
  • Presence of physical deficits that may interfere in self feeding ability

Dysphagia in TBI (Recovery)

• Recovery of swallow function is good for patients with TBI
• Most patients regain some degree of swallow functioning within the first 3-6 months after injury
• As cognition improves, swallowing function also tends to improve

Dementia

• Not a specific disease. A description of a collection of symptoms
• The hallmark of all dementias is progressive deterioration in cognitive abilities
• Memory, judgment, abstract reasoning, personality changes
• Apraxia and aphasia can also be seen
  • Swallowing deficits are well documented in advanced dementia, but they can also be seen in earlier stages of dementia
  • According to the NIH, it is estimated that 45% of institutionalized patients with dementia have dysphagia (2008)

Types of Dementia

• Alzheimer’s disease
• Vascular dementia
• Lewy body dementia
• Frontotemporal dementia
• Huntington’s disease
• Creutzfeldt-Jacob disease

Stages of Dementia (Mild)

• Mild Dementia
  • Memory loss of recent events
  • Personality changes, such as becoming more subdued or withdrawn
  • Setting lost or misplacing objects
  • Difficulty with problem-solving and complex tasks, such as managing finances
  • Trouble organizing or expressing thoughts

Stages of Dementia (Moderate)

• Moderate Dementia
  • Increasing confusion or poor judgment
  • Greater memory loss, including a loss of events in the more distant past
  • Needing assistance with tasks, such as getting dressed, bathing, and grooming
  • Significant personality and behavior changes, often caused by agitation and unfounded suspicion
  • Changes in sleep patterns, such as sleeping during the day and feeling restless at night

Stages of Dementia (Severe)

• Severe Dementia
  • Loss of the ability to communicate
  • Need for full-time daily assistance with tasks, such as eating and dressing
  • Loss of physical capabilities, such as walking, sitting, and holding one’s head up and, eventually, the ability to swallow, to control the bladder, and bowel function
  • Increased susceptibility to infections, such as pneumonia

Dysphagia in Dementia (Deviations)

• Swallowing & Feeding Deviations in Dementia
  • Swallowing Deviations
    • Slow oral movement
    • Slow or delayed pharyngeal swallow response
    • Overall slow swallowing duration
  • Feeding Deviations
    • Require increased self feeding cues (Specifically related to food preparation or utensil use)
    • Direct assistance with utensil use for food preparation or convenience
    • Imitation of feeding behavior from the meal partner

Dysphagia in Dementia (Deficits)

• Swallowing deficits seen in patients with dementia:
  • Unexplained weight loss
  • Oral stage dysfunction
  • Pharyngeal stage dysfunction
  • Combined oral and pharyngeal dysfunction
  • Aspiration
  • Feeding limitations
• Dependency for feeding can contribute to dysphagia related health problems, including pneumonia (Langmore et al. 2002; Rothan-Tondeur et al. 2003; Wada et al. 2001)

Dysphagia in Dementia (Study)

• Study by Ikeda et al., 2002, compared patients with frontotemporal lobe dementia vs. patients with Alzheimer’s disease
• Evaluated five categories:
  • Swallowing problems
  • Appetite change
  • Food preferences
  • Eating habits (including table manners & behaviors)
  • Other oral behaviors
• Found differences in all of these areas by dementia type indicating underlying neurologic disease affects clinical presentation

Neurological/Neuromuscular Diseases

• Parkinson’s Disease
• Huntington’s Diease
• Amyotrophic Lateral Sclerosis (ALS)
• Guillain-Barré Syndrome
• Myasthenia Gravis
• Multiple Sclerosis
• Muscular Dystrophy
• Polyneuropathy
• Polymyositis
• Sjogren’s Syndrome

Parkinson’s Disease

• Slow progressive disease that affects the substantia nigra of the basal ganglia
  • This area controls and regulates activities of the motor and premotor cortical areas so that movements can be performed smoothly
  • Degeneration of these cells causes reduction in the neurotransmitter dopamine

Parkinson’s Disease (Statistics)

• Second most common neurodegenerative disease (Alzheimer’s dementia #1)
  • Dysphagia has been demonstrated in 63 to 81% of patients with Parkinson’s Disease (ECRI, 1999)
• Patients with Parkinson’s Disease exhibit:
  • Resting tremor
  • Generalized slowness of movement initiation (bradykinesia)
  • Stiffness in limbs (rigidity)
• Patients with Parkinson’s Disease often deny awareness of dysphagia symptoms, despite signs of swallowing abnormalities (Bushmann et al., 1989; Jankovic, 2008; Logemann et al., 2008)

Dysphagia in Parkinson’s Disease

• Patient’s may exhibit the following:
  • Impaired lingual movement
  • Minimal jaw opening
  • Abnormal head and neck posture
  • Increased oral transit time characterized by tongue pumping and piecemeal deglutition
  • Impaired sensorimotor integration
  • Delayed pharyngeal swallow
  • Pooling in the valleculae and/or pyriform
  • Reduced pharyngeal contraction
  • Silent aspiration

Huntington’s Disease

• Hereditary degenerative brain disease affecting the basal ganglia
  • Results in deterioration of intellectual ability, emotional control, balance, speech and chorea (involuntary movements of the body, including oral structures and larynx)
• Dysphagia stems from:
  • Impaired bolus control & formation
  • Impaired voluntary swallow initiation
  • Delayed pharyngeal swallow
  • Pooling in the pyriform sinuses
  • Penetration/aspiration

Amyotrophic Lateral Sclerosis (ALS)

• Progressive neurodegenerative disease of unknown etiology
  • Attacks brain and spinal cord nerve cell bodies that control voluntary movement, affecting both upper and lower motor neurons
  • The pattern of dysphagia symptoms closely reflects the location of degenerative changes
  • Dysphagia eventually occurs in all types of ALS
  • Patients with ALS often develop malnutrition and weight loss due to their dysphagia which accelerates their muscle weakness (Bedore, 2013; Harkawik & Coyle, 2012)

Amyotrophic Lateral Sclerosis (ALS cont.)

• Swallowing deficits are characterized by:
  • Difficulty with chewing
  • Anterior spillage
  • Reduced tongue mobility and bolus control
  • Delayed pharyngeal swallow response
  • Reduced pharyngeal contraction
  • Reduced laryngeal elevation
  • Residue in the valleculae and pyriform
  • Residue on the pharyngeal walls
  • Penetration and aspiration
    • Logemann, 1998

Myasthenia Gravis

• Chronic autoimmune neuromuscular disease
• Causes weakness in skeletal muscles
  • Eye and eyelid movement
  • Facial expression
  • Chewing
  • Talking
  • Swallowing
  • Breathing
  • Limb movements
• Muscle weakness worsens after periods of activity and improves after periods of rest

Sjögren’s Syndrome

• An autoimmune disorder
  • Results in severe dryness of mucous membranes in the mouth, eyes, pharynx, larynx, and digestive tract, along with other neurological symptoms
• Can occur with other autoimmune diseases such as Multiple Sclerosis, Raynaud’s Syndrome, and scleroderma
• Dysphagia presents as a complicating factor
• Rosus-Pulia and Logemann (2011) looked at the relationship between dysphagia symptoms of patient’s with Sjogren’s on VFSS
  • Patients perceived their swallowing to be more impaired than the VFSS suggested

Case Study 1

• A 72-year-old female with a PMHX of HTN, hyperlipidemia, and hypothyroidism presented to the ER with right sided weakness and slurred speech. A Stroke Alert was called. CXR showed lungs were clear, no active pulmonary disease and CT scan revealed an evolving infarct. There is no hemorrhage, mass effect, or midline shift. She was admitted to the Neuro ICU and the RN reports patient’s speech is difficult to understand and patient exhibits drooling on the R side. The patient is NPO pending results of the clinical swallow evaluation.
  • What do you suspect is happening with this patient?
  • Is she at risk for dysphagia? Why?
  • What problems with eating and drinking do you suspect she might have? Why?
  • Provide 2 additional questions you would ask the nurse to learn more?

Respiratory Disorders

Respiratory System

• The respiratory system includes three major parts:
  • Airway
    • Mouth, nose, pharynx, larynx, trachea
  • Lungs
  • Muscles of respiration

Respiration and Swallowing

• Respiration and swallowing are linked by their anatomy (common use of the mouth and pharynx) and their neuro-anatomic controls (brainstem-medulla)
• Respiration is inhibited by swallowing. Breathing stops when the bolus is passing through the pharynx (Swallow apnea)
• Disorders of breathing can be a cause for dysphagia or can exacerbate it

Ventilation and Respiration

• Ventilation
  • Transfer of air into and out of the lungs
  • Three requirements for ventilation:
    • Pumping mechanism (muscles, diaphragm-pump)
    • Pump attached to the lungs (pleural membrane keeps lungs attached to ribs and muscles)
    • Easy to inflate lungs (lungs stay partially inflated at all times)
• Respiration
  • Gas movement across membranes
  • Trading of atmospheric gas with blood gases and blood gases with organ produced gases

Respiratory Disorders

• Respiratory Failure
  • Respiratory failure happens when not enough oxygen passes from your lungs into your blood
  • Respiratory failure can also happen if your lungs can’t move enough carbon dioxide out of your blood
• Some patients enter the hospital with primary respiratory tract disease, while others enter the hospital for other medical reasons and have pulmonary complications

Respiratory Disorders (Causes)

• Respiratory failure can be acute or chronic
• Caused by:
  • Lung diseases such as COPD & asthma
  • Pneumonia, pulmonary embolism, cystic fibrosis, infections/sepsis
  • Conditions that affect the nerves and muscles that control breathing, such as spinal cord injuries, muscular dystrophy, and stroke
  • Damage to the tissues and ribs around the lungs due to an injury to the chest
  • Drug or alcohol overdose
  • Injuries from inhaling smoke or harmful chemicals

Artificial Airways

• Patients with compromised respiratory status may require special intervention to support basic life functions
• Intubation (endotracheal)
  • Procedure by which a tube is inserted through the mouth down into the trachea
  • This is done before surgery or during emergency situations
  • They are designed to be attached to a ventilator, a machine that mechanically breaths for the patient
  • An intubated patient cannot talk or swallow

Post-Extubation

• Structural & Mechanical problems post-extubation
  • Oro-pharyngeal atrophy
  • Reduced laryngeal elevation
  • Alterations of the receptors of the pharyngeal and laryngeal mucosa
  • Epiglottal dysfunction
  • Laryngeal atrophy
  • Reduced VF closure/VF immobility

Tracheostomy

• Patients who have difficulty weaning from endotracheal intubation require the surgical placement of a tracheostomy tube
• Tracheotomy
  • Surgical procedure which consists of making an incision on the anterior aspect of the neck and opening a direct airway through an incision in the trachea
  • Advantages include: allowing access to the lungs for suctioning, less trauma to the vocal folds, and the possibility of speaking and swallowing

Tracheostomy (Parts)

• Stoma – hole made in the neck and trachea
• Parts of a tracheostomy tube:
  • Outer cannula
  • Inner cannula
• Tracheostomy tubes can be cuffed or cuffless
• Cuff
  • Portion at the end of the tracheostomy tube that can be inflated with air externally using a syringe
  • When the cuff is inflated it can seal off the entrance to the lungs to reduce food or secretions entering
  • Ensures that volume of air being delivered via mechanical ventilation is accurate

Tracheostomy and Swallowing

• Studies have found a higher prevalence of aspiration events in patients with tracheotomy compared with those without (Bonano, 1971; Elpern et al., 1987; Nash, 1988)
• Factors that increase risk for aspiration include:
  • Loss of subglottic air pressure
  • Poor laryngeal elevation
  • Loss of upper airway sensitivity
  • Loss of normal laryngeal closure reflex
  • Inability to coordinate normal swallow

Passy-Muir Valve

• One-way valve which redirects air flow through the vocal folds, mouth and nose enabling voice and improved communication
  • Closes the respiratory system and restores positive airway pressure and subglottic pressure which can help restore a more normal swallow
  • Directs airflow back over the vocal folds and through the oral cavity for communication
  • Studies of tracheostomized patients showed improvement in swallowing with PMV (Blumenfeld, 2012; Dettlebach et al., 1995; Lian et al., 2022; Manzano et al., 1993; www.passy-muir.com)

Chronic Obstructive Pulmonary Disease (COPD)

• COPD is a progressive disease that makes it hard to breathe
  • COPD can cause coughing that produces large amounts of mucus, wheezing, shortness of breath, chest tightness, and other symptoms
  • Cigarette smoking is the leading cause of COPD. Most people who have COPD smoke or used to smoke
  • Long-term exposure to other lung irritants—such as air pollution, chemical fumes, or dust—also may contribute to COPD

Chronic Obstructive Pulmonary Disease (COPD)(Effects)

• In COPD, less air flows in and out of the airways because of one or more of the following:
  • The airways and air sacs lose their elastic quality
  • The walls between many of the air sacs are destroyed
  • The walls of the airways become thick and inflamed
  • The airways make more mucus than usual, which can clog them
• In the U.S., the term COPD usually refers to emphysema or chronic bronchitis

Chronic Obstructive Pulmonary Disease (COPD)(Emphysema)

• Emphysema
  • The walls between many of the air sacs are damaged
  • As a result, the air sacs lose their shape and become floppy
  • This damage also can destroy the walls of the air sacs, leading to fewer and larger air sacs instead of many tiny ones
  • This leads to a reduction in the amount of gas exchange in the lungs

Chronic Obstructive Pulmonary Disease (COPD)(Bronchitis)

• Chronic bronchitis
  • The lining of the airways is constantly irritated and inflamed
  • This causes the lining to thicken
  • Lots of thick mucus forms in the airways, making it hard to breathe
• According to the National Heart, Lung & Blood Institute, most people have both emphysema and chronic bronchitis
  • COPD is the sixth leading cause of death in the United States (CDC, 2024)

Treatment of COPD

• Medications
  • Bronchodilators (inhalers)
  • Anti-inflammatories (steroids)
  • Antibiotics
  • Vaccinations
• Oxygen therapy
• Pulmonary rehabilitation
• Life style changes
  • Quit smoking
  • Avoid exposure to irritants
• Surgery (transplants, lung reduction)

Pneumonitis

• Pneumonitis
  • Inflammation of the lungs
  • Caused by infections, chemicals, irritants, allergens, radiation therapy, medications, gastric contents
• Trauma to the alveoli and airway cause inflammation and edema
• Pneumonia is a type of pneumonitis
  • Caused by a pathogen/bacteria/virus/debris
• Pneumonia = infection + inflammation
• Not all pneumonias are related to dysphagia!

Pneumonia

• Pneumonia is an infection in one or both of the lungs
  • Bacteria, viruses, and fungi can cause pneumonia
• The infection inflames your lungs' air sacs, which are called alveoli
  • The air sacs may fill up with fluid or pus, causing symptoms such as a cough with phlegm, fever, chills, and trouble breathing
• Pneumonia and its symptoms can vary from mild to severe

Pneumonia (Seriousness)

• Many factors affect how severity of pneumonia such as the type of germ causing the infection and your age and overall health
• Pneumonia tends to be more serious for:
  • Infants and young children
  • Older adults (people 65 years or older).
  • People who have other health problems, such as heart failure, diabetes, or COPD
  • People who have weak immune systems as a result of diseases or other factors. (HIV, chemotherapy, organ transplant)

Pneumonia (Symptoms)

• Symptoms include:
  • Productive cough
  • Fever
  • Difficulty breathing
  • Chest pain
  • Fatigue
  • Reduced level of consciousness
• Etiologies of pneumonia
  • Community acquired
  • Nosocomial
  • Aspiration

Covid-19

• Severe Acute Respiratory Syndrome (SARS-CoV-2)
• Declared global pandemic in March, 2020, now Covid-19 is endemic
• Infects mucosa of the upper airway
• Spread through droplets and aerosols
• Signs and symptoms can be mild, but it can lead to serious illness

Covid-19 and Swallowing

• Sensory changes – taste and smell
• Other upper respiratory system effects
  • Sore throat, pharyngeal erythema, voice impairments
• Stroke
  • Hypercoagulation, release of microparticles, atrial fibrillation, blood vessel injuries/destabilization of plaques
• Dyspnea
  • Leads to difficulty coordinating breathing and swallowing
• Pneumonia
• Respiratory failure – leads to intubation
• Long-term intubation
  • Typically convert to tracheostomy within 14 days, but with Covid-19, patients were staying orally intubated longer

Pulmonary Clearance Mechanisms

• Two components
• Upper respiratory clearance mechanism
  • Based on the ciliary activity of the tracheobronchial mucosa
    • Cough
    • Muco-ciliary escalator - the ciliated cells transport the mucus together with any deposited particles proximal direction and eventually the mucus is expectorated or swallowed

Pulmonary Clearance Mechanisms (Cont.)

• Alveolar clearance mechanism
  • Alveolar macrophages (WBC) slowly dispose of particles either by:
    • Transporting them along the alveolar surface to the mu