pathophysiology chapter 23

CHAPTER 23

RESTRICTIVE PULMONARY DISORDERS

RESTRICTIVE PULMONARY DISORDERS

Result from Decreased Lung Expansion• Alterations in lung parenchyma, pleura,

chest wall, or neuromuscular function• Represent acute or chronic patterns of lung

dysfunctions (not a single disease)• Classifications• Pulmonary, extrapulmonary

RESTRICTIVE PULMONARY DISORDERS (CONT.)

Characteristics• Decrease in vital capacity (VC), lung

capacity (TLC), functional residual capacity (FRC), residual volume (RV)

• The greater the decrease in lung volume, greater the severity of disease

• ABG• Decreased PaO2• Normal or decreased PaCO2

LUNG PARENCHYMA DISORDERS

Fibrotic Interstitial Lung Disease• Diffuse interstitial lung disease

• Diffuse interstitial pulmonary fibrosis• Etiology

• Characterized by thickening of alveolar interstitium• 5:100,000

LUNG PARENCHYMA DISORDERS (CONT.)

Diffuse Interstitial Lung Disease• Pathogenesis

• Immune reaction• Begins with injury to alveolar epithelial or

capillary endothelial cells• Interstitial and alveolar wall thickening• Increased collagen bundles in interstitium



• Immune reaction • Lung tissue becomes infiltrated• Persistent alveolitis leads to obliteration of

alveolar capillaries, reorganization of lung parenchyma, irreversible fibrosis

• Lead to large air-filled sacs (cysts) with dilated terminal and respiratory bronchioles



• Inflammation• Occurs early, reversible• Triggering event leads to inflammatory response and

increased inflammatory cells• Injury leads to increased membrane permeability and

movement of fluid/debris into alveoli



• Fibrosis• Fibroblastic proliferation and deposition of large

amount of collagen• Caused by increased mesenchymal cells and

fibroblasts in interstitium• Alveolar walls become thickened with increased

amounts of fibrous tissue



• Destruction• End-stage disease• Loss of alveolar walls


Diffuse Interstitial Lung Disease• Clinical manifestations

• Progressive dyspnea with exercise with desaturation

• Rapid-shallow breathing• Irritating, nonproductive cough• Clubbing of nail beds (40%-80%)


Diffuse Interstitial Lung Disease• Clinical manifestations

• Bibasilar end-expiratory crackles (Velcro rales)• Cyanosis (late finding)• Anorexia, weight loss• Inability to increase cardiac output with exercise


Diffuse Interstitial Lung Disease• Diagnosis

• Chest x-ray• PFT (decreased VC, TLC, diffusing capacity)• Open lung biopsy• Transbronchial biopsy• Gallium-67 scan• Bronchoalveolar lavage


Diffuse Interstitial Lung Disease• Treatment

• Smoking cessation• Avoid environmental exposure to cause• Anti-inflammatory agents• Immunosuppressive agents• Lung transplant


Sarcoidosis• Etiology

• Chronic common in 3rd-4th decade of life• North American blacks (35.5/100,000)• Northern European whites (10.9:100,000)• Acute or chronic systemic disease of unknown

cause• Immunologic • Activation of alveolar macrophage to unknown

trigger


Sarcoidosis• Pathogenesis

• Development of multiple, uniform, noncaseating epithelioid granulomas• Affects multiple organs

• Lymph nodes, lung tissue (most common)• Skin, eyes, spleen, liver, kidney, bone marrow

• Fibrotic and surrounded by large histiocytes• May occur in bronchial airways• Abnormal T-cell function


Sarcoidosis• Clinical manifestations

• Malaise, fatigue• Weight loss• Fever• Dyspnea of insidious onset• Dry, nonproductive cough• Erythema nodosum• Macules, papules, hyperpigmentation, and

subcutaneous nodules• Hepatosplenomegaly, lymphadenopathy


Sarcoidosis• Diagnosis

• Leukopenia, anemia • Increased eosinophil count, elevated

sedimentation rate• Increased Ca++ levels (5%)• Elevated liver enzymes• Anergy (70%) • Elevated angiotensin-converting enzyme in active

disease (40%-80%)



• Gallium-67 scan• Localize areas of granulomatous infiltrates• Pleural effusion noted in 10% of cases

• PFTs• Normal or show evidence of restrictive disease and/or

obstructive disease



• Bronchoalveolar lavage• Monitors cell content• Fluid has increased lymphocytes and high CD4/CD8

cell ratio• Transbronchial lung biopsy

• Noncaseating granulomas (definitive diagnosis)• Chest x-ray

• Differentiates stages


Sarcoidosis• Stages

• Stage 0• Normal

• Stage 1• Good prognosis• Hilar adenopathy alone

• Stage 2• Hilar adenopathy and bilateral pulmonary infiltrates


Sarcoidosis• Stages

• Stage 3• Pulmonary infiltrates without adenopathy

• Stage 4• Advanced fibrosis with evidence of honeycombing,

hilar retraction, bullae, cysts, and emphysema


Sarcoidosis• Treatment

• Corticosteroids• Immunosuppressive agents


Hypersensitivity Pneumonitis• Etiology

• Known as extrinsic allergic alveolitis• Restrictive and occupational disease• Predominant in nonsmokers (80%-95%)


Hypersensitivity Pneumonitis• Pathogenesis

• Genetic predisposition• Agent suggested by patient history• Agent confirmed by precipitating antibodies in

serum• Antigen combines with serum antibody in alveolar

walls; leads to type III hypersensitivity reaction


Hypersensitivity Pneumonitis• Pathogenesis

• Antigen-antibody complexes then elicit granulomatous inflammation leading to lung tissue injury

• Must have delayed hypersensitivity (type IV) reaction to antigen to develop pneumonitis


Hypersensitivity Pneumonitis• Clinical manifestations

• Acute • Symptoms start 4-6 hr after exposure and resolve in

18-24 hr• General symptoms

• Chills, sweating, shivering• Myalgias• Nausea• Malaise, lethargy• Headache



• Acute • Respiratory symptoms

• Dyspnea at rest• Dry cough• Tachypnea• Chest discomfort

• Physical findings• Cyanosis (late)• Crackles in lung bases



• Intermediate• Acute febrile episodes• Progressive pulmonary fibrosis with cough• Dyspnea, fatigue • Cor pulmonale (right-sided heart failure related to

lung disorders)• Chronic

• Progressive, diffuse pulmonary fibrosis in upper lobes (hallmark of disease)


Hypersensitivity Pneumonitis• Diagnosis

• Chest x-ray• Acute/subacute

• Transient, bilateral pulmonary infiltrates• Increased bronchial markings with alveolar nodular

infiltrates• Chronic

• Diffuse reticulonodular infiltrates• Fibrosis


Hypersensitivity Pneumonitis• Diagnosis

• Skin testing with causative antigen• Red, indurated hemorrhagic reaction 4-12 hr after

injection• Laboratory

• Increased WBCs• Decreased PaO2

• PFTs• Decreased lung volumes, diffusing capacity,

compliance


Hypersensitivity Pneumonitis• Treatment

• Identify offending agent and prevent further exposure

• Oral corticosteroids


Occupational Lung Diseases• Etiology

• Result from inhalation of toxic gases or foreign particles

• Atmospheric pollutants have large effect on occupational respiratory diseases


Occupational Lung Diseases• Pneumoconiosis

• Caused by inhalation of inorganic dust particles• Greater the exposure, the worse the

consequences• Anthracosis

• “Coal miner’s lung” or “black lung”• Silicosis

• Silica inhalation• Asbestosis

• Asbestos inhalation


Occupational Lung Disease• Predisposing factors

• Preexisting lung disease• Exposure to atmospheric pollutants• Duration of dust exposure• Amount of dust concentration• Particle size of pollutant


Occupational Lung Disease• Pathogenesis

• Pollutants interfere and paralyze cilia• Interference with ciliary action

• Impaired clearance effect • Inability to be removed



• Alveolar macrophages try to engulf and remove• Migrate to small airways to use mucociliary escalator• Engulf dust; exit through the lymph/blood system• Migrate through bronchial walls, depositing dust

particles in extra-alveolar tissue• Destroy the particle



• Macrophages secrete lysozymes to control foreign particle activity

• Enzymes damage alveolar walls causing deposition of fibrous materials


Occupational Lung Disease• Clinical manifestations

• Symptoms depend on predisposing factor• Pneumoconiosis produces no signs or symptoms

in early stage• Usually symptom free up to 10-20 years with

chronic exposure


Occupational Lung Disease• Clinical manifestations

• Late clinical features• Chronic hypoxemia• Cor pulmonale• Respiratory failure


Occupational Lung Disease• Diagnosis

• Chest x-ray• No changes without symptoms• With progression

• Micronodular mottling and haziness• Nodules, fibroses, calcifications


Occupational Lung Disease• Diagnosis

• PFTs• ABG

• Hypoxemia• Hypercapnia


Occupational Lung Disease• Treatment

• Preventive measures are key to limiting onset and severity

• Corticosteroids• Bronchodilators• O2 therapy

ATELECTATIC DISORDERSAcute (Adult) Respiratory Distress Syndrome (ARDS)• Etiology

• Occurs in association with other pathophysiologic processes

• 125,000-150,000 cases/year in United States• Mortality rate 30%-60%

ATELECTATIC DISORDERS (CONT.)

ARDS• Causes

• Severe trauma• Sepsis (>40%)• Aspiration of gastric acid (>30%)• Fat emboli syndrome• Shock


ARDS• Pathogenesis

• Widespread pulmonary inflammation leads to:• Noncardiogenic pulmonary edema associated with

“leaky” pulmonary capillaries• Atelectasis associated with lack of surfactant

• Decreases surface tension in small alveoli and prevents them from collapsing

• Fibrosis (hyaline membranes)• Associated with inflammatory deposition of proteins



• Characteristic abnormalities• Injury to alveoli from a wide variety of disorders• Changes in alveolar diameter• Injury to pulmonary circulation• Disruptions in O2 transport and utilization



• Common findings• Severe hypoxemia caused by intrapulmonary

shunting of blood• Perfusion of large numbers of alveoli that are poorly

(areas of low ventilation-perfusion) or not ventilated (areas of shunt)



• Common findings • Decrease in lung compliance

• Due to loss or inactivation of surfactant with subsequent increased recoil pressure

• Proteinaceous fluid fills alveoli and impairs ventilation



• Common findings • Decrease in FRC

• Very stiff, noncompliant lungs associated with alveolar edema and exudate exaggerate surface tension forces

• Alveolar closure leads to atelectasis and loss of lung volume

• Diffuse, fluffy alveolar infiltrates• Noncardiogenic pulmonary edema


ARDS• Clinical manifestations

• Early• Sudden marked respiratory distress• Slight increase in pulse rate• Dyspnea• Low PaO2• Shallow, rapid breathing


ARDS• Clinical manifestations

• Late• Tachycardia• Tachypnea• Hypotension• Marked restlessness• Crackles, rhonchi on auscultation• Use of accessory muscles• Intercostal and sternal retractions• Cyanosis


ARDS• Diagnosis

• Hallmark is hypoxemia refractory to increased levels of supplemental O2

• ABG• Hypoxia• Acidosis• Hypercapnia


ARDS• Diagnosis

• PFTs• Decrease in FVR• Decreased lung volumes• Decreased lung compliance• VA/Q mismatch with large right-to-left shift


ARDS• Diagnosis

• Chest x-ray• Normal with progression to diffuse “whiteout”

• Open-lung biopsy shows• Atelectasis• Hyaline membranes• Cellular debris• Interstitial and alveolar edema


ARDS• Treatment

• Mostly supportive • Enhance tissue oxygenation until inflammation

resolves• Identify underlying cause• Address cause (ex: sepsis)• Maintain fluid and electrolyte balance

• Increased fluid administration can produce or intensify pulmonary edema

• Block system inflammatory cells


ARDS• Treatment

• Adequate oxygenation• 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


ARDS• Treatment

• Adequate oxygenation • 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


Infant Respiratory Distress Syndrome (IRDS)• Etiology

• Hyaline membrane disease• Similar to ARDS• Syndrome of premature neonates• 60% infants born <30 weeks not treated with

corticosteroids• 35% for infants receiving antenatal steroids• 5% infants <34 weeks


IRDS• Etiology

• High risk factors • Birth prior to 25 weeks gestation• Birth at advanced gestational age• Poorly controlled diabetes in mother • Deliveries after antepartum hemorrhage


IRDS • Etiology

• High-risk factors • Cesarean section without antecedent labor• Perinatal asphyxia• Second twin• Previous infant with RDS• Rh factor incompatibility


IRDS• Causes

• Primary cause is lack of surfactant • Premature neonate has difficulty maintaining high

pressures needed for adequate oxygenation• Related to soft, compliant chest that’s drawn inward

with each inspiratory contraction of diaphragm


IRDS• Pathogenesis

• The neonate with IRDS must generate high intrathoracic pressures (25-30 mm Hg) to maintain patent alveoli• Leads to increased alveolar surface tension and

decreased lung compliance



• Increased work of breathing and decreased ventilation • Progressive atelectasis• Increased pulmonary vascular resistance• Profound hypoxemia• Acidosis



• Secondary cause is immaturity of capillary blood supply

• Leads to VA/Q mismatch, adding to hypoxemia and metabolic acidosis

• Right-to-left shunt from open foramen ovale or patent ductus arteriosus may increase hypoxemia



• Progressive damage to basement membrane and respiratory epithelial cells• Causes patchy areas of atelectasis

• Increased capillary permeability and leakage of high-protein fluid into alveoli• Related to cellular damage, excess fluid

administration, high levels of FIO2


IRDS• Clinical manifestations

• Early• Shallow respirations, diminished breath sounds• Intercostal, subcostal, or sternal retractions• Flaring of nares• Hypotension, bradycardia• Peripheral edema• Low body temperature• Oliguria• Tachypnea (60-120 breaths/min)


IRDS• Clinical manifestations

• Late• Frothy sputum• Central cyanosis• Expiratory grunting sound• Paradoxical respirations (seesaw movement of chest

wall)


IRDS• Diagnosis

• ABG• Hypoxemia, metabolic acidosis• Hypercapnia and respiratory acidosis with

progression of disease• Chest x-ray

• Diffuse whiteout or ground glass indicative of diffuse bilateral atelectasis and alveolar edema

• Generalized lung hypoinflation


IRDS• Diagnosis

• Lecithin-sphingomyelin (L/S) ratio and desaturated phosphatidylcholine concentration in amniotic fluid

• Determines ability of fetus to secrete surfactant• > 2:1 incidence of RDS <5%• Presence of phosphatidylglycerol = pulmonary maturity• L/S ratio improves with administration of

glucocorticoids before delivery


IRDS• Treatment

• Prevention is primary goal• Maintain adequate oxygen levels (50-90 mm Hg)

• Low FIO2 settings related to high levels over time may result in further alveolar damage, primary persistent pulmonary hypertension, and retrolental fibroplasia

• Mechanical ventilation with PEEP or continuous positive-airway pressure


IRDS• Treatment

• Exogenous surfactant administration (bovine, porcine, or synthetic)• Decreases mortality 50%

• High-frequency ventilation• Provides more uniform lung inflation• Improves lung mechanics• Improves gas exchange


IRDS• Treatment

• Antibiotics (infection after culture done or prophylactically until blood cultures return)

• Supportive therapy• Adequate intravenous nutrition• Fluid and electrolyte balance• Minimal handling• Neutral thermal environment

PLEURAL SPACE DISORDERSPneumothorax• Etiology

• Accumulation of air in the pleural space• Primary pneumothorax

• Spontaneous• Occurs in tall, thin men 20-40 years • No underlying disease factors• Cigarette smoking increases risk

PLEURAL SPACE DISORDERS (CONT.)

Pneumothorax• Etiology

• Secondary pneumothorax• 20,000 new cases annually• Result of complications from preexisting pulmonary

disease• Asthma, emphysema, cystic fibrosis, infectious disease

(pneumonia, TB)


Pneumothorax• Etiology

• Catamenial pneumothorax• Associated with menstruation• Primarily in right hemothorax• Associated with endometriosis

• Tension pneumothorax• Traumatic origin• Results from penetrating or nonpenetrating injury


Pneumothorax• Pathogenesis

• Primary• Rupture of small subpleural blebs in apices• Air enter pleural space, lung collapses, and rib cage

springs out• Secondary

• Result of complications from complications from an underlying lung problem

• May be due to rupture of cyst of bleb



• Tension• Results form buildup of air under pressure in pleural

space• Air enters pleural space but cannot escape during

expiration• Lung on ipsilateral (same) side collapses and forces

mediastinum toward contralateral 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


Pneumothorax• Clinical manifestations

• Small pneumothoraces (<20%) are usually not detectable on physical exam

• Tachycardia• Decreased or absent breath sounds on affected

side• Hyperresonance• Sudden chest pain on affected side (90%)• Dyspnea (80%)


Pneumothorax• Clinical manifestations

• Tension and large spontaneous pneumothorax are emergency situations• Severe tachycardia• Hypotension• Tracheal shift to contralateral side• Neck vein distention• Hyperresonance• Subcutaneous emphysema


Pneumothorax• Diagnosis

• ABG• Decreased PaO2, acute respiratory alkalosis

• Chest x-ray• Expiratory films show better demarcation of pleural

line than inspiratory• Decompression of hemidiaphragm on side of

pneumothorax• Pleural line with absence of vessel markings

peripheral to this line


Pneumothorax• Diagnosis

• ECG• Axis deviations• Nonspecific ST-segment changes• T-wave inversions


Pneumothorax• Treatment

• Management depends on severity of problem and cause of air leak

• Lung collapse <15%• Patient may or may not be hospitalized• Treat symptomatically and monitor closely

• Lung collapse >15%-25%• Chest tube placement with H2O seal and suction


Pneumothorax• Treatment

• Chemical pleurodesis• Promotes adhesion of visceral pleura to parietal

pleura to prevent further ruptures• Thoracotomy

• Patients with further development of spontaneous pneumothorax and blebs

• Surgery 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


Pleural Effusion• Five major types

• Transudates• Low in protein (ratio <0.5)• Low in lactate dehydrogenase (ratio >0.6)• Specific gravity <1.016• Associated with severe heart failure or other

edematous states• Cirrhosis with ascites, nephrotic syndrome, myxedema


• Exudates• High in protein (>0.5 mg/dl) • High in LDH (>0.6)• Causes

• Malignancies, infections, pulmonary embolism, sarcoidosis, post-myocardial infarction syndrome, pancreatic disease

Pleural Space Disorders (Cont.)Pleural Space Disorders (Cont.)


• Empyema due to infection in the pleural space• High-protein exudative effusion

• Results from infection in pleural space• Hemothorax

• Presence of blood in pleural space• Result of chest trauma• Contains blood and pleural flood• Hct of fluid >50% of Hct of peripheral blood



• Chylothorax or lymphatic • Exudative process that develops from trauma

• Results from leakage of chyle (lymph fluid) from thoracic duct

• Rheumatoid pleural effusion• Tuberculous pleuritis


Pleural Effusion• Causes

• Changes associated with various types r/t changes in pleural capillary hydrostatic pressure, colloid oncotic pressure, or intrapleural pressure

• Imbalance in pressure associated with fluid formation exceeding fluid removal


Pleural Effusion• Pathogenesis

• Transudates• Increased hydrostatic or decreased oncotic pressure

• Exudates• Increased production of fluid r/t increased

permeability of pleural membrane • Impaired lymphatic drainage


Pleural Effusion• Clinical manifestations

• Vary depending on cause and size of effusion• May be asymptomatic with <300 ml of fluid in

pleural cavity• Dyspnea• Decreased chest wall movement• Pleuritic pain (sharp, worsens with inspiration)• Dry cough


Pleural Effusion• Clinical manifestations

• Absence of breath sounds• Dullness to percussion• Decreased tactile fremitus over affected area• Contralateral tracheal shift (massive effusion)


Pleural Effusion• Diagnosis

• Chest x-ray• Pleural-based densities• Infiltrates• Signs of CHF• Hilar adenopathy• Loculation of fluid


Pleural Effusion• Diagnosis

• Thoracentesis• Analyze fluid and reduce amount of fluid

• pH, LDH, glucose• Presence of pathologic bacteria

• CT or ultrasonographic tests• Assist in complicated effusions• Distinguish mass from large effusion


Pleural Effusion• Treatment

• 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


Pleural Effusion• Treatment

• Thoracentesis• Ultrasound useful for thoracentesis guidance

• Thoracotomy• Control bleeding (>200 ml/hr)


NEUROMUSCULAR DISORDERSPoliomyelitis• Viral disease in which poliovirus attacks

motor nerve cells of spinal cord and brainstem

• 8 cases/year in United States• All related to polio vaccine

• New cases rare related to mass vaccination and usually occur in unvaccinated immigrants

• 95% infections asymptomatic

NEUROMUSCULAR DISORDERS (CONT.)

Poliomyelitis • Symptoms

• Fever• Headache• Vomiting• Diarrhea• Constipation• Sore throat• Chronic respiratory insufficiency r/t previous

disease• Function generally recovers


Amyotrophic Lateral Sclerosis• Males > females (2:1)• Prevalence 5:100,000• Degenerative disease of nervous system

• Involves upper and lower motor neurons• Progressive muscle weakness and wasting

• Muscles innervated from spinal and cranial nerves affected• Eventually profound weakness of respiratory muscles

and death


Muscular Dystrophies (Duchenne)• Etiology

• Hereditary (X-linked recessive)• Occurs 1/3500 births

• Symptoms• Progressive muscular weakness

• Initially in lower extremities, and wasting


Muscular Dystrophies (Duchenne)• Symptoms

• Respiratory muscles become involved• Later years (20-30s)• Leads to hypoxia, hypercapnia, frequent respiratory

infections


Guillain-Barré Syndrome (Acute Polyneuritis)• Etiology

• Mortality about 3%• 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


Guillain-Barré Syndrome • Clinical manifestations

• Weakness and paralysis begin symmetrically in LEs and ascend proximally to UEs and trunk

• Severe cases• Respiratory muscle weakness accompanies limb and

trunk symptoms• Natural history of disease leads to recovery

• Minor residual motor deficits (15%-20%)


Myasthenia Gravis• Etiology

• 2-5 cases/year/million persons in U.S.• Primary abnormality at neuromuscular junction

• Impairment by decreased number of receptors on muscle

• Weakness and fatigue of voluntary muscles• Those innervated by cranial nerves• Peripheral and respiratory muscles can be affected


Myasthenia Gravis • Symptoms often managed by appropriate

therapy• Respiratory failure can be due to increasing

severity of illness or medication• Individual episodes of respiratory failure are

potentially reversible

CHEST WALL DEFORMITIESKyphoscoliosis• Etiology

• Neuromuscular• Muscular dystrophy• Marfan syndrome• Neurofibromatosis• Friedreich ataxia• Poliomyelitis

CHEST WALL DEFORMITIES (CONT.)

Kyphoscoliosis• Etiology

• Idiopathic • Found in adolescents >11 years• Female (7:1)

• Congenital • Pott disease


Kyphoscoliosis• Pathogenesis

• Bone deformity of chest wall resulting from kyphosis and scoliosis

• Higher deformity in vertebral column, greater compromise of respiratory status

• Lung volumes compressed • Atelectasis, VA/Q mismatch, hypoxemia


Kyphoscoliosis• Clinical manifestations

• Dyspnea on exertion• Rapid, shallow breathing• Chest wall deformity

• Ribs protruding backward, flaring on convex side, crowded on concave side

• Hypoxia , CO2 retention (late)


Kyphoscoliosis • Diagnosis

• Screening for scoliosis and kyphoscoliosis in school-aged children is an excellent method

• PFTs• Hypercapnia, hypoxia• Decreased lung volumes and capacities• Increased pulmonary arterial pressures

• Chest x-ray• Accentuated bony curves


Kyphoscoliosis • Treatment

• Depends on severity and age of patient• Curvatures <20 degrees

• Monitor on regular basis• Postural exercise program• External braces for moderate scoliosis


Kyphoscoliosis • Treatment

• Curvatures >40 degrees• Electrical stimulation of paraspinal muscles• Spinal fusion• Spinal instrumentation (Harrington rod) placement for

surgical stabilization• Curvatures >60 degrees

• Correlate with poor pulmonary function in later life


Ankylosing Spondylitis• Etiology

• More common in males (10:1)• Common in 2nd or 3rd decade of life• Cause is unknown• 90% have positive HLA-B27 antigen• Transient acute arthritis of peripheral joints (50%)


Ankylosing Spondylitis• Etiology

• Chronic inflammation at site of ligamentous Insertion into spine or sacroiliac joints

• Respiratory system affected by limited chest expansion and formation of pulmonary fibrosis in upper lobes


Ankylosing Spondylitis • Pathogenesis

• Progressive, inflammatory disease• Immobility of vertebral joints and fixation of ribs• Inflammation affects articular processes,

costovertebral joints, sacroiliac joints• Fibrotic response leads to joint calcification, ligament

ossification, and skeletal immobility


Ankylosing Spondylitis • Clinical manifestations

• Low to mid-back pain and stiffness increased with prolonged rest• Pain and stiffness decrease with exercise

• Restrictive lung dysfunction• Rib cage movement reduction • Chest wall muscular atrophy

• Breathing by excursion of diaphragm with rib cage immobilization


Ankylosing Spondylitis • Diagnosis

• PFTs• Decreased VC, TLC, compliance of respiratory system

(chest wall)• Chest x-ray

• Changes are seen in sacroiliac joints• Destruction of cartilage• Erosion of bone• Calcification• Bony bridging of joint margins


Ankylosing Spondylitis • Diagnosis

• Laboratory• Elevated sedimentation rate (85%)• Decreased RBC• Increased WBC• HLA-B27 antigen (90%)


Ankylosing Spondylitis • Treatment

• Development of exercise program• Breathing and mobility exercises

• Medications• NSAIDs


Flail Chest• Etiology

• Results from multiple rib fractures r/t trauma to chest wall

• Ribs fractured at two distant sites• Results in unstable, free-floating chest wall segment• Moves paradoxically inward on inspiration• Sternal fractures can cause flail segment


Flail Chest • Pathogenesis

• Fracture leads to impairment of negative intrapleural pressure generation• Causes decreased lung expansion on inspiration

• Lung parenchymal injury• Pulmonary contusion• Decreased lung compliance• Respiratory failure

• Interstitial and alveolar hemorrhage• VA/Q abnormalities


Flail Chest • Clinical manifestations

• Paradoxical motion of chest wall• SOB, cyanosis• Pain on inspiration• Hypotension• Hypoxemia, low arterial PO2• Pneumothorax, hemothorax, subcutaneous

emphysema are common


Flail Chest • Diagnosis and treatment

• ABG• Managed with mechanical ventilation

• Causes entire chest to move as unit rather than paradoxically

• Pain management


Disorders of Obesity• Etiology

• Excessive body fat • BMI >30 kg/m2 based on body weight and height• Men (19.9%); women (25.1%)• Blacks > whites• BMI >30 kg/m2 have increased mortality of 50%-

100% of those with BMI between 20 and 25 kg/m2


Disorders of Obesity• Pathogenesis

• Several hormones act on brain receptor to regulate appetite and metabolism• Leptin binds to brain receptors, causes releases of

neuropeptides• Increase metabolic rate

• Ghrelin stimulates appetite


Disorders of Obesity• Pathogenesis

• May be associated with hypoventilation and airway obstruction• Pickwickian syndrome

• Increased abdominal size forces thoracic contents upward into chest cavity

• Decreases lung expansion and diaphragmatic shortening• Sleep apnea syndrome

• Soft tissue deposits in neck and tissue predispose person to upper airway obstruction


Disorders of Obesity • Clinical manifestations

• Decreased alveolar ventilation, severe hypoxemia• Somnolence (daytime)• Shortness of breath• Polycythemia• Cor pulmonale• Impotence• Headache• Enuresis


Disorders of Obesity • Diagnosis

• Self-evident on exam• Laboratory

• Increased RBC• Identify comorbid factors

• Hypothyroidism, Cushing syndrome, insulinoma, diabetes, hyperlipidemia


Disorders of Obesity • Diagnosis

• ABG• Hypoxemia, hypercapnia

• PFT• Decreased chest wall compliance, VC, TLC, ERV


Disorders of Obesity• Treatment

• O2 (morbid obesity)• Weight loss program

• Caloric intake promotes energy deficit of 500-1000 kcal/day

• Aerobic exercise• Surgical intervention

• Gastric bypass

INFECTION OR INFLAMMATION OF THE LUNG

Pneumonia• Inflammatory reaction in the alveoli and

interstitium caused by an infectious agent• Causes

• Aspiration of oropharyngeal secretions composed of normal bacterial flora or gastric contents (25%-35%)• Present as lung abscess, necrotizing pneumonia,

empyema• Bacteroides, fusobacterium

Pneumonia• Causes

• Inhalation of contaminants• Virus• Mycoplasma

• Contamination from the systemic circulation

Infection or Inflammation of the Infection or Inflammation of the Lung (Cont.)Lung (Cont.)

Pneumonia• Classifications

• Community acquired• Hospital acquired• Bacterial

• Gram positive• Staphylococcus• Streptococcus



• Bacterial • Gram negative

• Haemophilus influenzae• Klebsiella • Pseudomonas aeruginosa• Serratia marcescens, Escherichia coli, Proteus spp



• Viral• Legionella

• Lives in H2O • Transmitted by portable H2O, condensers, cooling towers• Fever, diarrhea, abdominal pain, liver and kidney failure,

pulmonary infiltrates• Treatment: macrolide antibiotic



• Viral • Mycoplasma pneumoniae

• Common in summer and fall• Young adults

• Pneumocystis jiroveci• Common in patients with cancer or HIV


Pneumonia • Causes

• Fungal • Aspergillus

• Released from walls of old buildings under reconstruction


Pneumonia • Pathogenesis

• Acquired when normal pulmonary defense mechanisms are compromised

• Organism enters lung, multiply, and trigger pulmonary inflammation

• Inflammatory cells invade alveolar septa


Pneumonia • Pathogenesis

• Alveolar air spaces fill with exudative fluid • Consolidates and difficult to expectorate

• Viral pneumonia doesn’t produce exudative fluids


Pneumonia • Clinical manifestations

• 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


Pneumonia • Clinical manifestations

• Viral• Upper respiratory prodrome

• Fever, cough, hoarseness, coryza accompanied by wheezing/rales

• Mycoplasma• Fever• Cough• Headache• Malaise


Pneumonia• Diagnosis

• Chest x-ray• Parenchymal infiltrates (white shadows) in involved

area• Sputum C&S

• Sputum from deep in lungs • Laboratory

• WBC >15,000 (acute bacterial)


Pneumonia• Treatment

• Antibiotic therapy• Based on sensitivity of culture


Severe Acute Respiratory Syndrome (SARS)• Etiology

• Coronavirus associated with coronavirus (SARS-CoV)

• Primary mode of transmission through person to person • Respiratory droplets• Contact with contaminated objects/surfaces touching

mouth, nose, eyes


SARS• Pathogenesis

• Virus epidemic associated with milder disease in infants/children

• Severe respiratory forms in adults• Median incubation period 4-6 days• Patients become ill within 10 days of exposure• Overall mortality rate 10%

• 50% > 60 years of age


SARS• Clinical manifestations

• Fever (>100.4)• Myalgias• Headache• Nonproductive cough• Dyspnea


SARS• Diagnosis

• Chest x-ray• Evidence within 1 week of symptom onset

• Laboratory• Lymphopenia• Normal/low WBC• Elevated liver enzymes• Prolonged activated PTT• Presence of SARS virus


SARS• Diagnosis

• Respiratory specimens• Nasopharynx• Oropharynx• Sputum

• Stool specimens


SARS• Treatment

• No definitive treatment recommendations• Symptoms of pneumonia

• Hospitalization• O2 therapy• Mechanical ventilation

• Isolation• Discontinued only after consultation with local public

health authorities


Pulmonary Tuberculosis• Etiology

• Estimated 10 million infected in United States• Multidrug-resistant TB

• 15% of cases• Mortality 70%-90%• Median survival of 4-16 weeks



• High-risk individuals• Prior infection (90%)• Malnourishment, immunosuppression• Living in overcrowded condition• Incarcerated persons• Immigrants• Elderly



• Causes• Infection

• Inhalation of small droplets containing bacteria• Droplets expelled with cough, sneeze, or talking

• Mycobacterium tuberculosis• Acid-fast aerobic bacillus• Infects lungs and lymph nodes



• Causes • Involvement of distant organ systems

• Hematogenous spread during primary or reactivation phase

• Disseminated disease• Miliary tuberculosis causes hematogenous dissemination

of organisms



• Classifications• 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


Pulmonary Tuberculosis• Pathogenesis

• 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• Impairs immune system


Pulmonary Tuberculosis• Pathogenesis

• Reactivation occurs if immunosuppressed• Pathologic manifestation is Ghon tubercle or

complex• Parenchymal complex

• Well-circumscribed necrotic nodule that becomes fibrotic and calcified

• Lymph components


Pulmonary Tuberculosis• Clinical manifestations

• History of contact with infected person• Low-grade fever• Cough• Night sweats• Fatigue• Weight loss• Malaise • Anorexia


Pulmonary Tuberculosis• Clinical manifestations

• Physical examination• Apical crackles (rales)• Bronchial breath sounds over region of

consolidation• Malnourished


Pulmonary Tuberculosis• Diagnosis

• Sputum culture (definitive diagnosis)• Three consecutive, morning specimens

• Identify slow-growing acid-fast bacillus• Take 1-3 weeks for determination

• DNA or RNA amplification techniques (diagnosis)


Pulmonary Tuberculosis• Diagnosis

• Chest x-ray• Nodules with infiltrates in apex and posterior

segments• TB skin test

• Doesn’t distinguish between current disease or past infection


Pulmonary Tuberculosis• Treatment

• 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 agents to drug regimen when

treatment failure is suspected


Pulmonary Tuberculosis• Treatment

• 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


pathophysiology chapter 23

Education