Respiratory System and Disorders

Aims & Learning Objectives

• After this session you will be able to explain the parts of the respiratory system
• After this session you will be able to describe pulmonary ventilation and perfusion
• After this session you will be able to define respiratory disorders
• After this session you will be able to evaluate types of lung diseases
• After this session you will be able to explain the pathophysiology of common respiratory disorders like Asthma
• After this session you will be able to describe management of respiratory related medical emergencies
• After this session you will be able to evaluate how dental treatments can be affected by respiratory conditions
• After this session you will be able to describe relevant medications for patients with respiratory conditions

Why Study Respiratory Disorders

• Respiratory disease effects 1 in 5 people
• Respiratory disease is the 3rd largest cause of death in England
• 25% of patients suffer from a respiratory disorder
• Lung cancer, COPD, and pneumonia have the biggest death rates in the UK
• Smoking is a huge risk factor in these cases and are seen more in low socioeconomic groups
• Dental professionals need to understand how such disorders can impact oral health

GDC Training

• Dental hygienists and therapists need to describe relevant and appropriate physiology and its application to patient management
• Dental hygienists and therapists need to describe the properties of relevant medicines and therapeutic agents, as well as discuss their application to patient management
• Dental hygienists and therapists need to recognize psychological and sociological factors affecting oral health, the course of the disease, and success of treatment
• Dental hygienists and therapists need to explain the impact of mental and medical conditions in patients
• Dental hygienists and therapists need to recognize and manage medical emergencies

Lecture Structure

• How respiratory systems work, with focus on anatomy, physiology, ventilation, and perfusion
• Explanations into respiratory disease, classifications, common lung conditions, signs and symptoms, and treatments
• Insight into asthma and COPD including pathophysiology, signs and symptoms, and treatments
• Patient management, clinical considerations, smoking cessation, prevention, and potential medical emergencies associated with lung disorders

Four Main Parts of the Respiratory System

• Airway: breathing air in and out of the body
• Lungs: the role of the lungs
• Muscles: breathing in and out
• Blood vessels: oxygen to the calls

Ventilation

• The process of airflow in and out of the lungs

Perfusion

• Moving oxygen from the air into our blood vessels
• Removing carbon dioxide from the blood vessels which we then expire
• The gas exchange process
• Occurs in the lungs between the alveoli and the pulmonary capillaries

Common Lung Diseases

• Asthma
• Chronic Obstructive Pulmonary Disease (COPD)
  • Chronic Bronchitis
  • Emphysema
• Lung Cancer
• Pneumonia
• Pleural Effusion
• A respiratory disorder is anything that affects the body's ability to carry out pulmonary ventilation and perfusion

Types of Respiratory Disease

• Airway Disease: compromised ability to move air in and out of the lungs
  • This compromises the body’s ability to exchange oxygen and carbon dioxide
  • Caused by narrowing or blockage of airways
  • Examples: asthma, COPD
• Lung tissue disease: affects the lungs and their structure
  • Scarring or inflammation of the lung tissue affects their ability to expand and take air in and out
  • Examples: tuberculosis, Covid-19
• Lung circulation disease: affects the pulmonary blood vessels
  • Caused by clotting, scarring, or inflammation
  • Affects ability of the lungs to take up oxygen and release carbon dioxide into the vessels (gas exchange)
  • May affect heart function, as seen in pulmonary hypertension

Lung Cancer

• Common and serious
• In the UK, 47,000 people are diagnosed with it every year
• The majority of people are over 75 years of age
• Symptoms include; cough, pain, coughing up blood (haemoptysis), breathlessness, weight loss, fatigue
• Forms includeprimary/secondary, non-small/ small cell lung cancer
• The most common form of non-small cells are SCC, adenocarcinoma, and large cell carcinoma
• Smoking is major risk factor
• Treatments include; surgery, radiotherapy, or chemotherapy

Pneumonia

• Inflammation and swelling of tissue in the lungs
• Seen in the very young or elderly, smokers, immunocompromised
• Symptoms: (can be chronic or acute) include cough, difficulty breathing, tachycardia, fever, sweating and shivering, loss of appetite, and chest pain
• Causes include bacterial infection, viral infection (e.g. COVID19), aspiration pneumonia, inhaling a harmful agent, and hospital acquired pneumonia
• Treatments include rest, fluids, antibiotics, and hospital admission (severe cases)

Pleural Effusion

• Fluid in the pleural cavity, surrounding the lungs
• Affects lungs' ability to expand and work efficiently
• Potential symptoms may be none, difficulty breathing, fever, cough, and shortness of breath (SOB)
• Aetiology; fluid from other organs, cancer, infections, autoimmune conditions, and pulmonary embolism
• Treatments include methods to drain and treat the cause of the fluid build up

Asthma Key Points

• A common chronic inflammatory disorder of the airways which impacts people of every age
• 12% of people in the UK have asthma, with 4% having severe asthma
• Causes inflammation and narrowing of the airways in response to a stimulus
• Asthma has no current cure
• Causes symptoms such as wheezing, coughing, tight chest, and shortness of breath
• If symptoms are worsened it can cause an acute asthma attack
• Medications can help treat symptoms and prevent attacks.

Asthma

• A chronic inflammatory disorder of the airways
• Inflammation causes recurrent episodes of wheezing, breathlessness, chest tightness, and coughing, particularly at night or in the early morning
• Episodes are associated with widespread and variable airflow obstruction
• Inflammation can cause an associated increase in existing bronchial responsiveness to a variety of stimuli and is often reversible either spontaneously or with treatment

Asthma Pathophysiology

• Patients with asthma show airway changes in response to a stimulus
• Stimuli include allergens, stress, occupational exposure, viruses, cold air, and exercise
• Changes in the airway can occur in a complex manner and many different cells and can cause inflammation and narrowing of the airway

Bronchoconstriction

• Bronchial smooth muscle contraction occurs quickly to narrow the airway
• Allergen induced acute bronchoconstriction can result from cells being activated by mast cells; this causes histamine, tryptase, leukotrienes and prostaglandins released, these directly contract airway smooth muscle
• NSAIDs (eg Aspirin) can cause the same bronchoconstriction affect

Airway Oedema

• The stimulus produces more reaction from the airways, other factors occur which cause further airway difficulty:
• Oedema, inflammation, mucus hypersecretion and structural changes including hypertrophy and hyperplasia of the airway smooth muscle
• These latter changes may not respond to usual treatment
• A positive feedback cycle is produced which enhances further inflammation and narrowing of airways causing more sensitivity of the airways (hypersensitivity)

Medications for Asthma

• Aid to prevent or relieve symptoms: narrowing of airways, oedema, and inflammation
• The type and dose of medication depends on;
  • Patient’s age
  • Symptoms
  • Severity of asthma
  • Any other medical conditions or medication side effects

Asthma Medication Categories, Purposes, and Types

• Long-term asthma control medications: taken regularly to control chronic symptoms and prevent attacks
  • Inhaled corticosteroids
  • Leukotriene modifiers
  • Long-acting beta agonists
• Quick-relief medications (rescue medications): taken as needed for rapid, short-term relief of symptoms
  • Short-acting beta agonists such as albuterol, salbutamol
  • Oral and intravenous corticosteroids (for serious asthma)
• Medications for allergy-induced asthma: taken regularly/PRN to reduce the body's sensitivity to a particular allergy-causing substance allergen
  • Allergy shots (immunotherapy)
  • Allergy medications
• Biologics (for severe asthma): taken with control medications to stop underlying biological responses causing lung inflammation
  • Omalizumab (Xolair)
  • Mepolizumab (Nucala)

Risk Factors for Death from Asthma

• Asthma History including previous severe exacerbation, two or more hospitalizations, or three or more ED visits for asthma
• Social History including low socioeconomic status or inner-city residence, psychosocial problems and possible illicit drug use
• Comorbidities including cardiovascular disease, other chronic lung disease, or chronic psychiatric disease

COPD Key Points

• Chronic Obstructive Pulmonary Disease
• A group of lung conditions where the airways are narrowed/damaged
• Two of these lung conditions are chronic bronchitis and emphysema
• People with these conditions find it difficult to empty air out of the lungs
• In the UK there is approximately 3 million people with COPD (2 million = undiagnosed)
• Prevalence increases with age, typically diagnosed at 50+
• The greatest risk factor for this disease is smoking

Bronchitis

• Means the airways are inflamed and narrowed
• Excessive mucus can be produced

Emphysema

• Affects the alveoli air sacs
• The air sacs are damaged and break down
• Prevents air to be breathed in and out effectively

COPD vs Asthma

• Conditions that narrow the airways, making it harder to move air in and out
• Ultimately affect gas exchange and can be life threatening if not managed
• They are both chronic
• COPD is a progressive lung disease, typically irreversible, and seen in adults
• COPD is mainly caused by damage from smoking
• Asthma is caused by an inflammatory reaction with reactions often reversible

Management of COPD

• Prevention is better than a cure
• Stop smoking services
• Vaccinations (flu)
• Exercise programs
• Tailored management plan
• Managing other health problems and comorbidities
• Medications to improve breathlessness and prevent acute exacerbations
• Further care = oxygen therapy

Dental Management of Patients with Asthma

• It is important to ask the patient the following questions:
  • When were you diagnosed and how long have you had asthma?
  • Do you take any medications and how often?
  • Have you ever been to the hospital for asthma, how many times and what happened?
  • What triggers your asthma?
  • Do you have any allergies?
• Get a detailed social history, paying attention to smoking history
• The questions above will provide an understanding of the severity of the patient’s asthma
• What dental materials could you use and what triggers can be avoided?

Patient Management: COPD in the Dental Setting

• A full and accurate medical history is important for patients with COPD
  • Ask about medications, triggers, the severity of the disease, any oxygen use, and hospital admissions
• If the patient smokes, provide cessation advice and document
• For invasive dental treatments;
  • Check patient SATs before, during and after the procedure
  • Be ready to provide oxygen to patient

Medical Emergencies and GDC Standards

• "A patient could collapse on any premises at any time, whether they have received treatment or not. It is therefore essential that all registrants must be trained in dealing with medical emergencies, including resuscitation, and possess up to date evidence of capability”

Key Points for Preventing Medical Emergencies

• Risk management
  • Take a detailed patient history
• Planning Ahead
  • Have two dental health care professionals in the clinical environment trained in medical emergencies
• Ensure you are aware of the management of medical emergencies
  • Keep CPD up to date with regular revision and training within your team

Anaphylaxis: Signs and Symptoms

• Sudden onset, flushing and pallor, or respiratory distress
• Hypotension and tachycardia
• Rapid progression of symptoms with a high likelihood of being life threatening
• Potential skin and mucosal changes of fear and impending doom

Managing Anaphylaxis

• ABCDE
• Call 999 for emergency services, and place patients flat, elevating legs if breathing is not impaired
• Administer 15L of oxygen per minute, as well as an adrenaline intramuscular injection(IM)

Adrenaline Doses

• The adult dose is 500 micrograms of adrenaline IM, this is 0.5ml of 1:1000, to be repeated every 5 minutes until an adequate response
• Paediatric doses of adrenaline differ by age:
  • Under 6 years receive 150 micrograms, equivalent to 0.15ml of 1:1000
  • Between 6 and 12 years should receive 300 micrograms, or 0.3ml of 1:1000
  • Over 12 years of age, the adult dose, 500 micrograms applies