Chapter 23: Restrictive Pulmonary Disorders Flashcards
Fibrotic Interstitial Lung Disease
- Group of disorders (more than 180 disease entities)
- Characterized by acute, subacute, or chronic infiltration of alveolar walls by cells, fluid, and connective tissue
- If left untreated, may progress to irreversible fibrosis
Diffurse Interstitial Lung Disease
- Also called diffuse interstitial pulmonary fibrosis and other names
- Characterized by thickening of alveolar interstitium
Pathogenesis of and pathological patterns of Diffuse Interstitial Lung Disease
- Begins with injury to alveolar epithelial or capillary endothelial cells
- Persistent alveolitis leads to obliteration of alveolar capillaries, reorganization of lung parenchyma, irreversible fibrosis
- Leads to large air-filled sacs (cysts) with dilated terminal and respiratory bronchioles (honey-comb lung)
- Pathologic patters include inflammation, fibrosis, and destruction
Clinical Manifestations of Diffuse Interstitial Lung Disease
- Progressive dyspnea with irritating, nonproductive cough
- Rapid-shallow breathing
- Clubbing of nail beds
- Bibasilar end-expiratory crackles
- Cyanosis (late finding)
- Anorexia, weight loss
- Inability to increase cardiac output with exercise
Diagnosis of Diffuse Interstitial Lung Disease
- Chest x-ray
- PFTs (decreased VC,
- TLC, diffusing capacity)
- Open lung biopsy
- Transbronchial biopsy
- Gallium-67 scan
- High resolution computed tomography (HRCT) and bronchoalveolar lavage: primary tests
Treatment of Diffuse Interstitial Lung DIsease
- Smoking cessation
- Avoid environmental exposure to cause
- Anti-inflammatory agents
- Immunosuppressive agents
- Oxygen for hypoxemia
- Lung transplant
Sarcoidosis (Etiology)
- Acute or chronic systemic disease of unknown cause
- Immunologic basis is most likely cause
- Activation of alveolar macrophage to unknown trigger
- First degree relative increases risk 5 fold
Pathogenesis of Sarcoidosis
- Development of multiple, uniform, noncaseating epithelioid granulomas
- Affects multiple organs
- Abnormal T cell function
Clinical Manifestations of Sarcoidosis
- Malaise, fatigue
- Weight loss
- Fever
- Dyspnea of insidious onset
- Dry, nonproductive cough
- Erythema nodosum
- Macules, papules, hyperpigmentation, and subcutaneous nodules
- Hepatosplenomegaly, lymphadenopathy
Diagnosis of Sarcoidosis
- Leukopenia, anemia
- Increased eosinophil count, elevated sedimentation rate
Increased Ca++ levels - Elevated liver enzymes
Anergy - Elevated angiotensin-converting enzyme in active disease
- Gallium-67 scan (Localize areas of granulomatous infiltrates)
- PFTs
- Transbronchial lung biopsy (Noncaseating granulomas (definitive diagnosis))
- Bronchoalveolar lavage
- Stages 0-4 (Progressing from normal to advanced fibrosis with evidence of honeycombing, hilar retraction, bullae, cysts, and emphysema)
Treatment of Sarcoidosis
- Management of symptoms
- Corticosteroids
- Immunosuppressive agents
- Hydroxychloroquine: for disfiguring skin lesions, hypercalcemia, and neurologic involvement
Acute (Adult) Respiratory DIstress Syndrome (ARDS) Etiology
- Damage to the alveolar-capillary membrane (Causes widespread protein-rich alveolar infiltrates and severe dyspnea)
- Occurs in association with other pathophysiologic processes
- More than 150,000 cases/year in United States
- Mortality rate 30% to 63%
- Associated with a decline in the Pao2 that is refractory (does not respond) to supplemental oxygen therapy
Causes of ARDS
- Severe trauma
- Sepsis (>40%)
- Aspiration of gastric acid (>30%)
- Fat emboli syndrome
Shock
Characteristics of ARDS
- Increased permeability of the pulmonary vasculature
- Flooding of the alveoli with proteinaceous fluid
- Leads to development of protein-rich pulmonary edema (noncardiogenic pulmonary edema)
- Triggers the immune system to activate the complement system and to initiate neutrophil sequestration in the lung
Pathogenesis of ARDS
- Injury to alveoli from a wide variety of disorders
- Changes in alveolar diameter
- Injury to pulmonary circulation
- Atelectasis and decrease in lung compliance from lack of surfactant
- Fibrosis (hyaline membrane)
- Diffuse, fluffy alveolar infiltrates
- Disruptions in O2 transport and utilization (Severe hypoxemia)
Clinical Manifestations of ARDS
- History of a precipitating event that has led to a low blood volume state (“shock” state) 1 or 2 days prior to the onset of respiratory failure
- Early: Sudden marked respiratory distress, Slight increase in pulse rate,Dyspnea
Low PaO2, Shallow, rapid breathing - Late: Tachycardia, Tachypnea
Hypotension, Marked restlessness, Frothy secretions,
Crackles, rhonchi on auscultation, Use of accessory muscles, Intercostal and sternal retractions, Cyanosis
Diagnosis of ARDS
- Hallmark is hypoxemia refractory to increased levels of supplemental O2
- ABG (Hypoxia, Acidosis, Hypercapnia)
- Chest Xray (Normal with progression to diffuse “whiteout”)
- PFTs (Decrease in FVR, Decreased lung volumes, Decreased lung compliance, VA/Q mismatch with large right-to-left shunt)
- Open-Lung biopsy shows (Atelectasis, Hyaline membranes, Cellular debris,
Interstitial and alveolar edema)
Treatments of ARDS
- Mostly supportive (Enhance tissue oxygenation until inflammation resolves)
- Identify and treat underlying cause
- Maintain fluid and electrolyte balance (Increased fluid administration can produce or intensify pulmonary edema)
- Volume ventilator using pressure support
- Mechanical ventilation with positive end-expiratory pressure (PEEP) (Increases FRV and prevents alveolar collapse at end-expiration, Forces edema out of alveoli)
- Supplemental O2 (>60% contributes to ARDS related to absorption atelectasis, FIO2 reduced as soon as possible)
- High-frequency jet ventilation (HFJV)
- Inverse ratio ventilation (IRV)
- Inhaled nitric oxide
Pneumothorax Etiology
- Accumulation of air in the pleural space
- Primary pneumothorax (Spontaneous, Occurs in tall, thin men 20 to 40 years, No underlying disease factors, Cigarette smoking increases risk)
- Secondary Pneumothorax (Result of complications from preexisting pulmonary disease)
- Catamenial pneumothorax (Associated with menstruation, Primarily in right hemothorax, Associated with endometriosis)
- Tension Pneumothorax (Traumatic origin, Results from penetrating or nonpenetrating injury, May also be from iatrogenic causes, Medical emergency)
Pathogenesis of Pneumothorax
- Primary (Rupture of small subpleural blebs in apices; Air enters pleural space, lung collapses, and rib cage springs out)
- Secondary (Result of complications from an underlying lung problem, May be due to rupture of cyst or bleb)
- Tension (Results form buildup of air under pressure in pleural space; Air enters pleural space during inspiration but cannot escape during expiration; Lung on ipsilateral (same) side collapses and forces mediastinum toward contralateral (opposite) side; Decreases venous return and cardiac output)
- Open “sucking” chest wall wound (Air enters during inspiration but cannot escape during expiration leads to shift of mediastinum)
Clinical Manifestations of Pneumothorax
- Small pneumothoraces (
Diagnosis of Pneumothorax
- ABG (Decreased PaO2, acute respiratory alkalosis)
- ECG
- Chest Xray (Expiratory films show better demarcation of pleural line than inspiratory;
Depression of hemidiaphragm on side of pneumothorax)
Treatment of Pneumothorax
- Management depends on severity of problem and cause of air leak
- Lung collapse 15% to 25% (Chest tube placement with H2O seal and suction; Oxygen)
- Chemical pleurodesis (Promotes adhesion of visceral pleura to parietal pleura to prevent further ruptures; For recurrent spontaneous pneumothorax)
- Thoracotomy (Permits stapling or laser pleurodesis of ruptured blebs)
Pleural Effusion Etiology
- Pathologic collection of fluid or pus in pleural cavity as result of another disease process
- Normally, 5-15 ml of serous fluid is contained in pleural space
- Constant movement of pleural fluid from parietal pleural capillaries to pleural space
- Reabsorbed into parietal lymphatics
Five major types of pleural effusion
- Transudates (Low in protein (ratio 0.5 mg/dl); Causes: malignancies, infections, pulmonary embolism, sarcoidosis, postmyocardial infarction syndrome, pancreatic disease)
- Empyema due to infection in the pleural space (High-protein exudative effusion)
- Hemothorax (Presence of blood in pleural space;
Result of chest trauma; Contains blood and pleural fluid: hemorrhagic) - Chylothorax or lymphatic
(Exudative process that develops from trauma)
Causes of Pleural Effusion
- Changes in pleural capillary hydrostatic pressure, colloid oncotic pressure, or intrapleural pressure
- Imbalance in pressure associated with fluid formation exceeding fluid removal
Pathogenesis of Pleural Effusion
- Transudates (Increased hydrostatic or decreased oncotic pressure)
- Exudates increase production of fluid r/t (Increased permeability of pleural membrane; Impaired lymphatic drainage)
Clinical Manifestations of Pleural Effusion
- Vary depending on cause and size of effusion
- May be asymptomatic with
Diagnosis of Pleural Effusion
- Chest X-Ray (Pleural-based, densities, infiltrates,Signs of CHF, Hilar adenopathy, and Location of fluid
- Thoracentesis (Analyze fluid and reduce amount of fluid)
- CT or Ultrasonographic Tests (Assist in complicated effusions, and Distinguish mass from large effusion)
Treatment of Pleural Effusion
- Directed at underlying cause and relief of symptoms
- Tension and spontaneous pneumothorax are medical emergencies requiring treatment to remove pleural air and re-expand lung
- Closed chest tube drainage (adults) (Controversial in pediatrics)
- Thoracentesis, if large amount of effusion (Ultrasound useful for thoracentesis guidance)
- Thoracotomy (Control bleeding (>200 ml/hr))
Guillian Barre Syndrome (Acute Polyneuritis) etiology
- Immunologic basis
- Demyelination of peripheral nerves
- History of recent viral or bacterial illness (66% of cases) followed by ascending paralysis (Infection involving Campylobacter jejuni often precedes diagnosis)
Clinical Manifestations of Guillian-Barre Syndrome
- Weakness and paralysis begin symmetrically in lower extremities and ascend proximally to upper extremities and trunk
- Severe cases show Respiratory muscle weakness accompanied by limb and trunk symptoms
- Usually have full recovery
- Minor residual motor deficits (15% to 20%)
Myasthenia Gravis
- Weakness and fatigue of voluntary muscles
- Those innervated by cranial nerves
- Peripheral and respiratory muscles can be affected
- Hallmark finding: weakness worse with exercise and better with rest
- 2-5 cases/year/million persons in U.S.
- Females more than males (3:2)
- Primary abnormality at neuromuscular junction
- Transmission from nerve to muscle impaired from decreased number of receptors on muscle
- Symptoms often managed by appropriate therapy
- Respiratory failure can be due to increasing severity of illness or overmedication
- Individual episodes of respiratory failure are potentially reversible
Pneumonia
- Inflammatory reaction in the alveoli and interstitium caused by an infectious agent
- Causes include Aspiration of oropharyngeal secretions composed of normal bacterial flora or gastric contents (25% to 35%), Inhalation of contaminants, and Contamination from the systemic circulation
Classifications of Pneumonia
- Community acquired
- Hospital acquired
- Bacterial
- Atypical
- Viral
Those who are at high risk for Pneumonia
- Elderly
- Those with a diminished gag reflex
- Seriously ill
- Hospitalized patients
- Hypoxic patients
- Immune-compromised patients
Types of Pneumonia
- Anaerobic bacteria: present as a lung abscess, necrotizing pneumonia, or empyema; usually caused by aspiration of normal oral bacteria into the lung
- Mycoplasmal pneumonia: commonly seen in the summer and fall in young adults; common between the ages of 5 and 20
- Legionnaires Disease (Organism lives in H2O;
Transmitted by portable H2O, condensers, cooling towers;
Fever, diarrhea, abdominal pain, liver and kidney failure, pulmonary infiltrates; Treatment: macrolide antibiotic) - Opportunistic Pneumonias (Pneumocystis jiroveci & Aspergillus)
- Pneumocystis jiroveci
(Opportunistic fungal infection,
Common in patients with cancer or HIV) - Aspergillus (Opportunistic fungal infection, Released from walls of old buildings under reconstruction)
Pathogenesis of Pneumonia
- Acquired when normal pulmonary defense mechanisms are compromised
- Organisms enter lung, multiply, and trigger pulmonary inflammation
- Inflammatory cells invade alveolar septa
- Alveolar air spaces fill with exudative fluid (Consolidates and difficult to expectorate)
- Viral pneumonia doesn’t produce exudative fluids
Clinical Manifestations of Pnemonia
- Severity of disease and patient age cause variation in symptoms
- Crackles (rales) and bronchial breath sounds over affected lung tissue
- Chills
- Fever
- Cough, purulent sputum
- Viral (Upper respiratory prodrome: Fever, nonproductive cough, hoarseness, coryza accompanied by wheezing/rales)
- Chlamydia Pneumonia (Cough, tachypnea, rales, wheezes, and no fever)
- Mycoplasma (Fever, Cough, Headache, Malaise)
Diagnosis of Pneumonia
- Chest x-ray (Parenchymal infiltrates (white shadows) in involved area)
- Sputum C&S (Sputum from deep in lungs)
- CURB-65
- Laboratory (WBC >15,000 (acute bacterial)
Treatment of Pneumonia
- antibiotic therapy based on sensitivity of culture
Pulmonary Tuberculosis Etiology
- Estimated 10 million infected in United States
- High-risk individuals include those with Prior infection (90%), Malnourishment, immunosuppression, Living in overcrowded condition, Incarcerated persons, Immigrants, and Elderly
- Multidrug-resistant TB
- Cases are reported to local and state health departments
Causes of Pulmonary Tuberculosis
- Mycobacterium tuberculosis (Acid-fast aerobic bacillus Infects lungs and lymph nodes)
- Infection (Inhalation of small droplets containing bacteria;
Droplets expelled with cough, sneeze, or talking) - Involvement of distant organ systems (Hematogenous spread during primary or reactivation phase)
- Disseminated disease
(Miliary tuberculosis causes hematogenous dissemination of organisms)
Classifications of Pulmonary Tuberculosis
- Primary (usually clinically/radiographically silent)
(May lie dormant for years or decades) - Reactivating (May occur many years after primary infection;
Impaired immune system causes reactivation; HIV, corticosteroid use, silicosis, and diabetes mellitus have been found to be associated with reactivation)
Pathogenesis of Pulmonary Tuberculosis
- Entry of mycobacteria into lung tissue
- Alveolar macrophages ingest and process microorganisms (Microorganisms destroyed OR persist and multiply)
- Lymphatic and hematogenous dissemination (T-cells and macrophages surround organisms in granulomas)
- Reactivation occurs if immunosuppressed
- Pathologic manifestation is Ghon tubercle or complex
Clnical Manifestations of Pulmonary Tuberculosis
- History of contact with infected person
- Low-grade fever
- Chronic cough (most common); as disease progresses becomes productive with purulent sputum
- Night sweats
- Fatigue
- Weight loss
- Malaise
- Anorexia
- Apical crackles (rales)
- Bronchial breath sounds over region of consolidation
- Malnourished
Diagnosis of Pulmonary Tuberculosis
- Sputum culture (definitive diagnosis) (Three consecutive, morning specimens; Identify slow-growing acid-fast bacillus:
Takes 1-3 weeks for determination) - DNA or RNA amplification techniques (diagnosis)
- PFTs
- Chest x-ray (Nodules with infiltrates in apex and posterior segments)
- TB skin test (Mantoux or PPD test) (Doesn’t distinguish between current disease or past infection; False-positive PPD results may occur in persons with other mycobacterial infections or if they have received bacille Calmette-Guérin vaccine)
Treatment of Pulmonary Tuberculosis
- Administer multiple drugs (antibiotics) to which organism is susceptible (Therapy is for 9-12 months for active disease;
Therapy shorter in persons exposed with no active disease) - Add at least 2 new agents to drug regimen when treatment failure is suspected
- Providing safest, most effective therapy for shortest period of time
- Ensuring adherence to therapy by using directly observed therapy (Nonadherence to therapy is major cause of treatment failure; Negative pressure isolation room to prevent spread)