Comprehensive Notes on Respiratory Disorders and Dental Hygiene

Human Respiratory System Structure and Anatomy

• The human respiratory system is composed of several critical structures that facilitate the exchange of gases:
  • Nose and Nasal Cavity: The primary entry point for air.
  • Mouth and Tongue: Secondary entry point for air; the tongue plays a role in airway obstruction in certain disorders.
  • Throat (Pharynx): The passage connecting the nasal/oral cavities to the larynx.
  • Epiglottis: A flap of tissue that prevents food from entering the trachea.
  • Larynx: The voice box, located above the trachea.
  • Esophagus: Located posterior to the trachea; the passage for food.
  • Trachea: The main airway (windpipe) leading to the lungs.
  • Right Lung and Left Lung: The primary organs of respiration, protected by the rib cage.
  • Bronchi and Bronchioles: A branching network of tubes that distribute air throughout the lungs.
  • Alveoli: Tiny air sacs where gas exchange occurs. These are surrounded by an arteriole capillary network and venules.
  • Pleural Membranes: Serous membranes that surround the lungs.
  • Diaphragm: The primary muscle of respiration located at the base of the chest cavity.

Acute Respiratory Failure (ARF)

• Definitions and Terms:
  • ARF: Acute Respiratory Failure.
  • WOB: Work of breathing.
  • CNS Depression: Central Nervous System depression, often caused by drug overdoses ($OD$).
  • NM: Nerve and muscle problems affecting respiration.
  • V/Q: Ventilation/Perfusion ratio; issues arise when there is poor blood flow to the lungs relative to air flow.
• Common Causes of ARF:
  • Drug overdose.
  • Amyotrophic Lateral Sclerosis ($ALS$) and muscular dystrophy.
  • Drowning.
  • Blood clots (pulmonary embolism).
  • Smoke inhalation.

Chronic Obstructive Pulmonary Disease (COPD)

• Definition of the Acronym:
  • Chronic: The disease lasts a long time and is always present. Symptoms may take years to develop, and severity varies, but it is a persistent condition.
  • Obstructive: The ability to move air in and out of the lungs is blocked or obstructed, typically caused by swelling and extra mucus in the airways.
  • Pulmonary: The disease is located specifically within the lungs.
  • Disease: The lungs have sustained damage. While not currently curable, symptoms are treatable.
• Primary Components of COPD:
  • COPD is an umbrella term that primarily includes Emphysema and Chronic Bronchitis. It is also closely associated with Asthma.
• Etiology and Epidemiology:
  • Causes: Smoking accounts for $75 \%$ of cases in the United States. Other causes include inhaled pollutants (fumes, dust), secondhand smoke, and genetics.
  • Statistics: COPD is the most common chronic pulmonary disease and the $5\text{th}$ leading cause of death in the $US$.
  • Prevalence: Approximately $16 \text{ million}$ people have Chronic Bronchitis, Emphysema, or both. An additional $16 \text{ million}$ are estimated to be underdiagnosed.
  • Risk Factors: Current or former smokers, history of asthma, women, adults aged $65+$, Native Americans, Alaska Native populations, and individuals of more than one race. Economic factors include earning less than $\$25{,}000$ annually, unemployment, or lower education levels.

Comparison: Chronic Bronchitis vs. Emphysema

• Chronic Bronchitis (Blue Bloater - Obstructive Type B):
  • Clinical Diagnosis: A daily productive cough lasting for at least $3 \text{ months}$ in at least $2 \text{ consecutive years}$, with other causes excluded.
  • Pathophysiology: Damage to bronchial tubes and cilia. Irritation causes coughing; damaged cilia prevent mucus clearance, leading to buildup and further damage.
  • Physical Characteristics: Overweight and cyanotic (blue-tinged skin), elevated hemoglobin, peripheral edema ($swelling$), rhonchi, and wheezing.
• Emphysema (Pink Puffer - Obstructive Type A):
  • Pathologic Diagnosis: Permanent enlargement and destruction of airspaces distal to the terminal bronchiole.
  • Pathophysiology: Permanent damage to the alveoli (air sacs). Air becomes trapped, making it impossible to exhale properly, resulting in shortness of breath.
  • Physical Characteristics: Older and thin appearance, severe dyspnea ($shortness of breath$), quiet chest sounds.
  • X-Ray Findings: Hyperinflation with flattened diaphragms.

COPD Management in Dental Hygiene

• Positioning and Comfort:
  • Orthopnea: Difficulty breathing when lying flat. Patients may require treatment in a vertical or semi-supine position (approximately $30 ^\circ$).
  • Patients may need frequent breaks and additional suctioning for excessive mucus.
• Medication Side Effects:
  • many COPD medications lead to Xerostomia (dry mouth).
  • Oropharyngeal Candidiasis (Thrush) is common, especially with inhaled steroids.
  • Increased caries risk due to the use of $\beta\text{-agonists}$, which decrease salivary secretions and change saliva composition.
  • Increased risk of gingivitis and aspiration of microorganisms from periodontal conditions.
• Procedural Modifications:
  • Rubber dams should be used with caution as they may create a suffocating sensation.
  • Standard precautions: Specialized clinics may offer oxygen equipment and trained personnel.
• Drug Interactions and Contraindications:
  • Avoid: Hypnotics, narcotics, antihistamines, and anticholinergic agents.
  • Antibiotics: If the patient is taking Theophylline, avoid macrolide antibiotics such as Erythromycin and Clarithromycin.
  • Anesthesia: Ambulatory general anesthesia is totally contraindicated.

Asthma: Pathophysiology and Dental Implications

• Mechanism of Asthma:
  • Smooth muscle constriction of bronchial airways (bronchospasm).
  • Bronchial wall inflammation leading to fibrosis.
  • Eosinophils infiltrate the mucosa, causing swelling up to $3 \text{ times}$ normal thickness.
  • Proliferation of goblet cells leads to excessive production of thick, whitish bronchial secretions.
  • Mucus plugging can lead to atelectasis (lung collapse) and hyperinflation of alveoli (air trapping).
• Symptoms: Dyspnea, coughing (especially night cough), wheezing, weakness, headache, tachycardia, and shortness of breath.
• Epidemiology: Over $25.7 \text{ million}$ Americans suffer from asthma. Most have allergies. Annually, it causes approximately $1.8 \text{ million}$ ED visits, $189{,}000$ hospitalizations, and $4{,}000$ deaths.
• Demographics: In young children, it is $2 \text{ times}$ more prevalent in boys; after puberty, it is more common in girls.
• South Carolina Statistics: $1 \text{ in } 11 \text{ children}$ and $1 \text{ in } 12 \text{ adults}$ have asthma. It is the leading cause of school absences in $SC$.
• Dental Management:
  • Recommended pre-treatment: Patients should use a bronchodilator (such as Albuterol or Xopenex) prior to dental work.
  • Treatment should only be performed on asymptomatic or controlled patients.
  • Managing an Attack: STOP treatment, raise the patient upright, administer a bronchodilator, and give $100\% \, O_2$ via mask. If no improvement, administer subcutaneous epinephrine and notify $EMS$.
  • Triggers: Attacks are often triggered immediately after local anesthetic injection or during stressful maneuvers like extractions or surgery.

Cystic Fibrosis (CF)

• Etiology: A life-shortening autosomal recessive gene disorder affecting secretory glands (mucus and sweat). There are more than $1{,}500 \text{ types}$ of mutations for the CF regulator gene.
• Pathophysiology:
  • Thick mucus clogs the lungs, leading to chronic respiratory infections.
  • Mucus obstructs pancreatic ducts, preventing digestive enzymes from reaching the intestines.
• Epidemiology:
  • Affects $1 \text{ in every } 2{,}500 \text{ births}$ per year.
  • Most common fatal recessive inherited disease among Caucasians in the $US$.
  • $30{,}000 \text{ cases in the US}$; $70{,}000 \text{ worldwide}$.
  • Survival: Median survival age was $27 \text{ years}$ in $1987$; it is now $40 \text{ years}$. Children born today may live more than $50 \text{ years}$.
• Dental Considerations:
  • Oral Conditions: High tooth decay risk due to high-fat, high-carb diets; enamel defects (found in $90\% \text{ of cases}$), including opacities and hypoplasia.
  • Paradox: Often show less plaque and less gingival bleeding than those without CF.
  • Medication Side Effects: Chronic antibiotic use (e.g., Tetracycline) causes staining and discoloration. Long-term steroid use increases the risk of osteoporosis in alveolar bone.
  • Clinical Care: Update medical history every $3 \text{ months}$. Monitor blood pressure and blood glucose (risk of hypoglycemia in CF-related diabetes). Use semi-supine or upright positioning.
  • Preventive Care: Sealants and topical fluoride. Recommend rinsing with sodium bicarbonate or Xylitol after using inhalers or consuming sugary foods.

Obstructive Sleep Apnea (OSA)

• Mechanism: Critical narrowing of the upper airway during sleep resulting in occlusion. This is intensified by obesity, asthma, or COPD.
• Symptoms: Intense snoring, partial or complete awakening, daytime tiredness, and drowsiness. Periods of apnea can occur $5 \text{ to } 100+ \text{ times per hour}$, lasting $10 \text{ to } 90 \text{ seconds}$ each.
• Consequences: Poor cellular regeneration due to lack of oxygen ($hypoxemia$). High risk of stroke.
• Dental Screening:
  • Palpation of head and neck muscles for masses.
  • Checking for nasal septum deviation, Class II malocclusion, large gonial angles, large tongue base, and enlarged uvula or soft palate tissues.
• Treatment in Dentistry:
  • $60\% \text{ of patients}$ do not tolerate $CPAP$ machines.
  • Dental sleep oral appliances are the $No. 1$ nonsurgical alternative.
  • Devices include mandibular advancement devices, tongue retainers, and anti-snoring aids.

Mechanical Ventilation and Professional Hygiene

• Hospital-Acquired Risks: Oral care in the ICU using chlorhexidine antiseptic mouthwash or toothbrushing reduces the risk of Ventilator Acquired Pneumonia (VAP).
• Home Care: Patients on BiPAP or CPAP have a high risk of dry mouth and need specialized mouth rinses and device humidity.
• Periodontitis Link: $35\text{--}50\% \text{ of the world population}$ suffers from periodontitis. There is a high correlation between periodontitis ($PD$) and Cardiovascular Disease ($CVD$). PD increases the risk of death in patients with other existing diseases.

Smoking and Tobacco Dental Consequences

• Oral Health Impact:
  • Weakens enamel and alters the body's response to plaque.
  • Increases bacteria that cause gum disease, potentially leading to tooth loss.
  • Two-thirds of mouth cancer cases are linked to smoking. Secondhand smoke also increases risk.
  • Bruxism: Nicotine acts as a muscle stimulant, causing or worsening teeth grinding.
• Economic Impact: In South Carolina, the cigarette excise tax is only $\$0.57 \text{ per pack}$, compared to $\$7.16$ in Chicago, IL. However, health care costs caused by smoking are estimated at $\$17.26 \text{ per pack}$.

Vaping and E-Cigarettes

• Components: A combination of flavored liquid and nicotine. The base is usually Propylene Glycol.
• Chemical Hazards:
  • Diacetyl: Causes "Popcorn Lung" (narrowing of bronchioles).
  • Carcinogens: Includes acrylonitrile, acrolein, propylene oxide, acrylamide, and crotonaldehyde. Acrylonitrile is a poisonous compound used in rubber and plastics; Acrolein is toxic via inhalation.
• Nicotine Content: One JUUL pod contains as much nicotine as $20 \text{ cigarettes}$.
• Impact on Youth: In the $US$, $11\% \text{ of high school students}$ and $7\% \text{ of 8th graders}$ have vaped. Nicotine harms developing brains (up to age $25$), affecting attention, learning, and impulse control. It can "train" the brain for future addiction to drugs like cocaine and meth.
• Dental Consequences of Vaping:
  • Tissues: Aerosols contact oral tissues at their hottest and most concentrated states.
  • Oral Lesions: Stomatitis on the palate (dark "pin pricks"), ulcerations, palate burns, and mucoceles.
  • Periodontal Health: Nicotine causes vasoconstriction, reducing blood flow and the ability to fight bacteria. Bleeding on probing has been noted after only $2 \text{ weeks}$ of vaping.
  • Viscosity: Thick, viscous vapors are retained on oral tissues and may be highly cariogenic.
  • Safety: Risk of explosions from delivery devices leading to chemical and physical burns.
• Professional Advice: Encourage patients to quit and refer them to resources like the SC QUIT hotline (1-800-QUIT-NOW).