Pulmonary Pathophysiology

What is COPD?

Chronic Obstructive Pulmonary Disease (COPD) describes airflow limitation that is not fully reversible. Emphysema and Chronic Bronchitis both result from damage to the lungs over many years and predominantly affect former and current smokers. They are the most common causes of respiratory failure.

COPD High Risk Populations

All smokers 45 y.o. and older
Past smokers with a 20--pack year hx of smoking
Pt's w/ recurrent or chronic respiratory sx including cough and breathlessness on exertion.
Pt's w/ family hx of COPD
Pt's w/ significant occupational exposure to respiratory irritants.

X-ray findings of COPD

Flattened diaphragm, Increased A-P distance, Vertical heart.
Lungs are large and hyperinflated
Signs of hyperinflation may be seen in emphysema, chronic bronchitis and asthma.

Emphysema Etiology

Abnormal and permanent enlargement of the gas exchange airways. Destructive changes to the alveolar wall, without obvious fibrosis. Obstruction occurs as a result of changes in lung tissue and loss of elastic recoil.

Alveoli collapse during expiration.

Obstructive

Emphysema S&Sx

Genetics: Alpha-1 antitrypsin deficiency
Air pollutants
Infection
Cigarette smoking

May be called "pink puffers"
Malnourished
Cachexia: Weakness and wasting of the body due to sever chronic illness.

Chronic Bronchitis Etiology

Chronic cough lasting longer than three months for 2 consecutive years.

-Airways become swollen and partially clogged w/ mucous.
-May have mm spasms in the airways.
-Most common cause is smoking.
-Chronic inflammation of the bronchial mucosa. Airway narrowing. Decreased ciliary function.

Obstructive

Chronic Bronchitis S&Sx

Described as "Blue Bloaters"
Spasmodic cough + sputum production
Chronic Bronchitis can lead to emphysema.
High incidence of infection d/t trapped secretions.

More Emphysema

Pink Puffer
-Low BMI
-Few co-morbidities
-Less mm mass
-Hyperinflation
-Low diffusion capacity for CO
-More dyspnoea
-Decreased exercise capacity
-Worst health status

Less Emphysema

Blue Bloater
-High BMI
-More co-morbidities
-Cardiac Compromise
-Less hyperinflation
-More chronic bronchitis
-Increased exacerbations
-More normal diffusion capacity

Asthma Etiology

Inflammatory disorder of the airways characterized by periodic attacks of wheezing, SOB, chest tightness and/or coughing

Increased reactivity of the tracheobronchial tree to different stimuli.

Attacks may be relieved with medications and are episodic in nature.

Contributing factors: Environmental, genetic predisposition, diet, respiratory tract infections, ANS imbalance, Mucosal damage

Obstructive

Asthma S&Sx

-Episodes of bronchoconstriction resulting in wheezing and dyspnea.
-Nonproductive cough, prolonged expiration, Increased HR and breathing rate.
-Accessory mm use.
-May have inspiratory and expiratory wheezes.
-X-ray may show hyperinflation

Asthma Tx

Identification and avoidance of triggers
Sx Management
-Bronchodilator medication
-Anti-inflammatory meds

Bronchiectasis Etiology

Defined as permanent pathologic enlargement of airways (normal diameter > 2mm)
Results in fibrosis and ulceration of bronchioles, chronically retained secretions, atelectasis and infection.

Obstructive.

Bronchiectasis Mechanism: Bronchial wall injury/structural weakness of bronchial walls

Can occur following infection or inhalation accidents.
May be from genetic condition causing structural defects of the airway or abnormal mucociliary clearance.
Exaggerated immune response disorders.

Bronchiectasis Mechanism: Traction froma adjacent lung fibrosis

Ex: Sarcoidosis or interstitial fibrosis
Airway pulled outward by local retractile forces resulting in fixed dilation of airways.

Bronchiectasis Mechanism: Bronchial Lumen Obstruction

Related to slow-growing tumors in airway. Could be due to fibrotic structures related to prior infection (TB).
Can develop pna or atelectasis distal to these obstructions.

Cylindrical Bronchiectasis

Smooth parallel bronchial walls that end squarely and abruptly, commonly seen after pna

Saccular Bronchiectasis

Bronchial dilation progressively increasing toward the periphery, may form honeycomb pattern, most severe.

Varicose Bronchectasis

Bronchi distorted and bulging

Bronchiectasis S&Sx

-May have recurrent URI's and copious secretions.
-Dyspne, fatigue, hypoxia
-Dec VC and expiratory flow rates
-Possible hemoptysis secondary to erosion of bronchial wall
-Auscultation: crackles over involved lobes. Rhonchi during periods of mucous retention. May have wheezing.
-Shallow breathing pattern common to avoid coughing. May caused diminished breath sounds

COPD Stage 1

Very Mild.
With a FEV1 about 80% or more of normal. Commonly, in this stage, COPD causes slight airflow limitation.

COPD Stage 2

Moderate.
With a FEV1 btwn 50-80% of normal. Usually, during this stage, most people seek help for COPD sx of coughing, wheezing and shortness of breath.

COPD Stage 3

Severe.
Emphysema with FEV1 between 30-50% of normal. Typically, in this stage, COPD sx worsen, causing decreased quality of life.

COPD Stage 4

Very Severe.
With a lower FEV1 than Stage 3, or those with Stage 3 FEV1 and low blood oxygen levels. End stage COPD, meaning the disease has progressed, lung function has deteriorated and flare-ups could be life threatening.

BODE Index for COPD Survival Prediction

(B) BMI
(O) Airway Obstruction (FEV1)
(D) Dyspnea
(E) Exercise Tolerance (6MWT)

Dyspnea scale

Are there negative effects cognitively for COPD?

Memory Loss
Poor attention
Visual processing

Restrictive Lung Dysfunction

An abnormal reduction in pulmonary ventilation caused by the restriction of expansion by the chest wall or the lungs.

Lung expansion restricted, therefore volume of air moving in and out is decreased.

Atelectasis Etiology

Partial or total collapse of the alveoli, lung segments or lobes.

Commonly results from hypoventilation and decreased secretion clearance.

Restrictive

Causes and conditions that may contribute to atelectasis

Common Causes:
-Hypoventilation
-Compression
-Airway obstruction
-Adhesions

Conditions:
Inactivity
-Upper abdominal/thoracic incisional pain
-Compression of lung tissue
-Pneumonia
-Diaphragmatic Restriction
-Presence of a foreign body

Pneumonia

Multi-staged inflammatory reaction of the distal airways. Typically begins with infection of the lower resp tract.
-Bacteria
-Viruses
-Foreign substances
-Gastric contents
-Fungi, mycoplasms
-Radiation therapy
-Pollutants/irritants

What are the four categories of Pneumonia?

Community Acquired
Healthcare Associated
Hospital Acquired (nosocomial)
Ventilator Associated (nosocomial)

Pneumonia Presentation

-Dec lung volumes, Dec lung compliance, dec gas exchange, Inc work of breathing
-Dec PaO2, may have dec PaCO2 if hyperventilating.
-May have bronchial sounds above lobnar pna, absent breath sounds over pna and dull to mediate percussion.
-May have bubbling rales, rhonchi, dec or absent sounds, egophony, whispering pectoriloquy

Pneumonia S&Sx

Bacterial
-high fever, chills, dyspnea, Inc RR, productive cough, pleuritic pain

Viral
-Moderate fever, dyspnea, Inc RR, nonproductive cough, myalgias

Viral vs Bacterial Pneumonia

Viral:
More likely to impact healthy people with strong immune systems. Antibiotics don't work. Can be fatal.

Bacterial:
More likely to affect someone with a lowered immune system, or someone who is recovering from a respiratory infection. Antibiotics work. More aggressive and difficult to treat.

Aspiration PNA

Foreign substance (food, secretions, environmental compound) enters the lung and causes inflammation. Severity of injury directly related to amount of substance aspirated.

May be found in:
-Dysphagia
-Fused cervical extension
-Intoxication
-Impaired consciousness
-Neuromuscular disease
-Recent anesthesia

Aspiration PNA

Cough progresses from dry to productive
Dyspnea
Cyanosis
Tachypnea
Wheezes with crackles, decreased breath sounds
Fever
Hypoxemia
CXR shows pneumonitis

PNA 0-3 days

Alveolar edema and exudate formation

PNA 2-4 days

Alveolar infiltration w/ bacterial colonization, RBC, WBC, and macrophages

PNA 4-8 days

Alveolar infiltration & consolidation w/ dead bacteria, WBC and fibrin

PNA >8 days

Resolution w/ expectoration or enzymatic digestion of infiltrative cells.

PNA up to 6 wks

Complete clearance of pna. Increased time with older age, + smoking, poor nutritional status, previous pna or coexisting illness.

Acute Respiratory Distress Syndrome/Acute Lung Injury

Result of disease that causes inflammation. Pulm VC can contribute to RHF --> resp failure

3 Stages:
-Exudative: capillary leak cause alveoli to fill with neutrophilic exudate and edema.
-Proliferative
-Fibrotic

Inflammation debris causes issues with diffusion, V/Q mismatch and decreased compliance. Thrombi may cause dead space.

Interstitial Lung Diseae

General term for destruction of the respiratory membranes in multiple lung regions. Inflammation --> Fibrosis --> Alveolar Scarring.

Causes:
Occupational and environmental factors
Infections
Autoimmune disease
Radiation
Genetics
Idiopathic
Medications
-Antibiotics
-Chemotherapy
-Psych meds

Interstitial Lung Disease Sx

Dyspnea
DOE
Dry cough
Fatigue
Decreased exercise tolerance
Crackles.rales on auscultation
Possible: Cyanosis/clubbing if hypoxia

Pulmonary Fibrosis

Progressive interstitial inflammation and fibrosis.

Excessive amount of fibrous or connective tissue in the lung. Marked decrease in compliance, lungs stiff.

May be idiopathic (IPF)

Poor prognosis

Sarcoidosis

Idiopathic, granulimatous inflammatory disorder, multi-system disease

Lungs: alveolitis

Granuloma, mass or nodule formations in the affected organs. Develop a progressive, restrictive lung disease.

SOB, cough chest discomfort

Scleroderma

Progressive system sclerosis: progressive fibrosing disorder that causes degenerative changes.
-skin, small blood vessels esophagus, intestines, lung, heart, kidneys

interstitial pulm fibrosis.

No cure.

Coal Worker's Pneumoconiosis (CWP)

Accumulation of coal dust in lungs and subsequent reaction of surrounding tissue.

Coal macules: local collection of coal dust

Pleural space appears black – used be called “Black Lung” disease

Body Habitus: Obesity

Increased body mass = extra tissue that requires additional O2 from the lungs.

Decreased chest wall compliance, Increased WOB, Diaphragm in a higher resting position

Decreased lung expansion, early closure of the small airways and alveoli (may result in hypoxemia)

Body Habitus: Pregnancy

During the 3rd trimester, ventilation in dependent regions of the lungs is impaired by growth of the fetus.

Decreased chest wall compliance. ERV decreased. WOB increased.

Increased levels of progesterone→increased ventilator drive→ increased TV and respiratory rate → increased minute ventilation.

Body Habitus: Kyphoscoliosis

If severe, lungs are compressed, alveoli are restricted from full expansion
• Causing hypoventilation and atelectasis. Decreased chest wall
compliance.

Sx’s: DOE, decreased exer. Tolerance, mm spasms, accessory mm use.

Body Habitus: Ankylosing Spondylitis

Chronic inflammatory disease of the spine.
Marked decreased compliance of the chest wall.
Ventilation becomes dependent upon diaphragmatic movement.

• Sx’s: DOE, pleuritic chest pain, progressive dyspnea, may have LBP, weight loss and anorexia

Empyema

Infected pleural effusion = anaerobic bacterial pus in pleural space
• Complication of URI: Pna, lung abscess
-Infec crosses the visceral pleura or chest wall & parietal
pleura penetration from trauma, sx or CT placement

May have cyanosis, fever, tachycardia, cough and pleural pain

Tuberculosis

• Infection caused by Mycobacterium tuberculosis
Transmitted via airborne droplets

Bacteria lodge in lungs, primarily upper lobes.

Associated with:
• Immuno-compromised pts
• Homelessness
• Alcoholism
• Health care workers
• Poor socioeconomic status

Tuberculosis S/Sx

May be asymptomatic. Otherwise, sx’s may develop
gradually
• Fatigue
• Wt. loss
• Lethargy
• Anorexia
• Low-grade fever
• Cough that produces purulent sputum
• Night sweats

Lung Cancer Chest Sx

 Non-smoker’s cough that persists for more than two weeks
 Persistent chest, shoulder, or back pain unrelated to pain from coughing
 Change in color of sputum
 Increase in volume of sputum
 Blood in sputum
 Wheezing
 Recurrent pneumonia or bronchitis
 Difficult or labored breathing
 Shortness of breath
 Hoarseness
 Stridor (a harsh sound with each breath)

Lung Cancer other Sx

◼ Loss of appetite
◼ Headache, bone pain, achy joints
◼ Unsteady gait or memory loss
◼ Neck and facial swelling
◼ Unexplained weight loss

Surgical Interventions: Pleura

Pleurectomy, excision of portion of pleura.

Surgical Interventions: Rib

Rib resection, excision of rib.

Surgical Interventions: Trachea and Bronchi

Tracheal repair and reconstruction and sleeve reconstruction. Excision of trachea and part of main bronchus.

Surgical Interventions: Lung

Pneumonectomy, lobectomy, wedge resection. Excision of entire lung.

Pulmonary Embolus

SOB/Rapid breathing
Rapid HR
Chest Pain

Other signs/sx:
Low BP
Low O2 sat

Pulmonary HTN

Pulmonary arteries and capillaries become narrowed, blocked or
destroyed.

More difficult for pulmonary circulatory flow therefore raising the
pulmonary artery pressure.
-Normal PA pressure
-PA pressure of a pt w PHTN

Increased pulmonary artery pressure leads to right-sided heart
failure.

Can't be cured

Pulmonary HTN S/Sx

• SOB/DOE
• Fatigue
• Syncope
• Chest pressure or pain
• LE edema and ascites
• Cyanosis
• Tachycardia and palpitations

Cystic Fibrosis

Most common life shortening genetic illness in Caucasian population

Decreased transport of chloride, sodium and water in epithelial cells of
• Respiratory tract
• Pancreas
• GI
• Reproductive tract
• Hepatobiliary tract