Pulmonary Pathophysiology: Restrictive Lung Dysfunction Flashcards
Define restrictive lung dysfunction (RLD)
- Abnormal reduction in pulmonary ventilation caused by restricted expansion of the chest wall or the lungs
- Decreased volume of air or gas moving in & out of the lungs
Pathophysiology of RLD is related to what 3 factors
- Decreased compliance of both the lung & the chest wall
- Decreased lung volumes & capacities
- Increased work of breathing
What are some causes of increased work of breathing
- Increased airway resistance
- Increased flow rates
- Decreased lung or chest wall compliance
Greater ___________ pressure is required to achieve a normal TV in RLD
- Transpulonary
6 classic signs of RLD
- Tachypnea (increased RR)
- Hypoxemia (low blood O2 concentration)
- Decreased breath sounds with dry inspiratory crackles
- Decrease in lung volumes & capacities
- Decreased diffusing capacity of lung for carbon monoxide (DLCO)
- Cor pulmonale (R sided HF): due to pulmonary HTN or hypoxia
What are the 3 hallmark signs of RLD
- Dyspnea
- Irritating, dry, & nonproductive cough
- Wasted, emaciated appearance as the disease progresses
If etiological factors of RLD are permanent or progressive, then treatment consists of supportive measures:
- Supplemental O2 to support the PaO2
- Antibiotic therapy to fight 2ndy pulmonary infection
- Measures to promote adequate ventilation & prevent the accumulation of pulmonary secretions
- Good nutritional support
If etiological factors are reversible, treatment is _____________ and ____________
- Corrective and supportive
What does diffusing capacity of the lung for carbon monoxide (DLCO) measures
- Measures how well the lungs transfer O2 from the air into the blood
- Normal: 75-140% predicted
- Mildly Reduced= 60-75% predicted
- Severely Reduced= <40% predicted
Describe what low and high DLCO indicates are may be seen in
- Low DLCO means the lungs aren’t getting O2 from the air to the blood efficiently
- Low DLCO with restrictive pathology may indicate interstitial lung disease (ILD)
- Reduced DLCO with obstructive pathology could suggest emphysema
- High DLCO may be seen in asthma or obesity
Define atelectasis
- Incomplete expansion
- Clinical manifestation of several lung & chest disorders
- Region of lung parenchyma is collapsed & non-aerated
What are the 5 types of atectasis
- Resorptive/obstructive: most common, often caused by an obstruction
- Passive: loss of volume in lungs caused by pneumothorax or diaphragmatic dysfunction; lack of deep breathing, under general anesthesia
- Adhesive: surfactant deficiency (greater tendency for alveoli to collapse)
- Compressive: caused by space occupying lesion, pleural effusion/tumor, or empyema
- Cicatrization: volume loss caused by decreased pulmonary compliance bc of fibrosis
Define pneumonia
- Inflammatory process of the lung parenchyma
- Usually begins with an infection in the lower respiratory tract
Causative agents of pneumonia
- Bacteria
- Viruses
- Fungi
- Mycoplasmas
Symptoms of a bacterial pneumonia
- High fever
- Chills
- Dyspnea
- Tachypnea
- Productive cough
- Pleuritic pain
Symptoms of a viral pneumonia
- Moderate fever
- Dyspnea
- Tachypnea
- Non-productive cough
- Myalgias (pain in muscle/muscle group)
What is adult respiratory distress syndrome (ARDS)/acute lung injury
- Widespread inflammatory condition affecting pulmonary tissue
- Leads to increased pulmonary vascular permeability/lung weight and loss of aerated tissue
- All pts develop some muscle wasting/weakness that continues past 1yr post discharge
Pulmonary triggers of ARDS
- Pneumonia
- Inhalation injury
- Aspiration of gastric contents
- Chest trauma/pulmonary contusion
- Near drowning
Extrapulmonary triggers of ARDS
- Sepsis
- Major trauma
- Burns
- Pancreatitis
- Fat embolism
- Hypovolemia
- Transfusion related acute lung injury (TRALI)
- Cardiopulmonary bypass
- Drug induced
Symptoms of ARDS
- Appear acutely ill
- Dyspneic at rest & with any activity
- Breathing pattern fast & labored
- Cyanotic
- May have impaired mental status, restlessness, HA, & increased anxiety
Causes of ARDS
- Hyaline membrane damage
- Ruptured alveolar walls
- Intra-alveolar edema
What is interstitial lung disease
- A group of lung disorders that cause problems with diffusion of O2 into the blood stream as a result of progressive scarring & fibrosis of the lung tissue
Common causes of interstitial lung disease (ILD)
- Exposures in the environment
- Autoimmune disease
- Medication effects
- Genetics
- Idiopathic or unknown reasons
Describe idiopathic pulmonary fibrosis (IPF)
- Most common idiopathic interstitial pneumonia
- Worst prognosis of the ILDs
- Bc of poor diffusion capacity individuals with ILD often require supplemental O2 as the disease progresses & especially with exercise
Symptoms of pulmonary fibrosis
- SOB that gets worst over time
- Dry cough that doesn’t improve
- Achy joints & muscles
- Feeling tired or weak
- Losing weight slowly & without trying
Describe idiopathic pulmonary fibrosis (IPF)
- Progressive, irreversible, & usually lethal lung disease
- Progressive worsening of dyspnea & lung function
- Most important environmental risk factors: cigarette smoking, exposure to metal & wood dust
What is sarcoidosis
- Idiopathic granulomatous inflammatory disorder that affects many organ systems (lungs, heart, skin, CNS, & eyes)
- Lungs are most involved organ
- Typically affects young adults
What are the 3 distinct features of sarcoidosis
- Alveolitis
- Formation of well-defined round or oval granulomas
- Pulmonary fibrosis
Fibrotic lung disease that affects the smaller airways; Produces restrictive and obstructive lung dysfunction describes
- Bronchiolitis obliterans
Bronchiolitis obliterans is characterized by
- Necrosis of the respiratory epithelium in the affected bronchioles
Causes/association of Bronchiolitis obliterans in children versus adults
- Pediatrics: often caused by viral infection
- Adults: associated with toxic fume inhalation or by viral, bacterial, or mycobacterial infectious agents, particularly M. pneumonia
What are the 7 ways RA can affect the lungs
- Pleural involvement
- Pneumonitis
- Interstitial fibrosis
- Development of pulmonary nodules
- Pulmonary vasculitis
- Obliterative bronchiolitis (OB)
- Increased incidence of bronchogenic CA
Characterized by various antigen–antibody reactions; May involve the skin, joints, kidneys, lung, nervous tissue, and heart describes
- Systemic lupus erythematosus (SLE)
What is the most common lung dysfunction with SLE
- Pleurisy: pain with deep breathing
- Diaphragmatic weakness is relatively common
Progressive fibrosing disorder that causes degenerative changes in skin, small blood vessels, esophagus, intestinal tract, lungs, heart, kidney, and articular structures; In lung, appears as progressive diffuse interstitial fibrosis describes
- Scleroderma
Systemic connective tissue disease characterized by symmetric proximal muscle weakness and pain; May involve lung parenchyma; Aspiration pneumonia—most common abnormality describes
- Polymyositis
Systemic connective tissue disease characterized by inflammatory and degenerative changes in the skin; Pulmonary involvement mirrors that of polymyositis.
- Dermatomyositis
Characterized by Interstitial or intraalveolar hemorrhage, Glomerulonephritis, Anemia; Caused by antiglomerular basement membrane antibodies that react with vascular basement membranes of the alveolus and glomerulus describes
- Goodpasture syndrome
- Coughing up and peeing blood is a sign
Treatment for good pasture syndrome
- Plasmapheresis & immunosuppressive therapy to lower the levels of anti-GBM antibodies; cyclophosphamide with prednisone
Multisystem disease characterized by granulomatous vasculitis of upper and lower respiratory tracts, glomerulonephritis, and small vessel vasculitis; Often starts in upper respiratory tract with necrotizing granulomas and ulceration in the nasopharynx and paranasal areas describes
- Wegener granulomatosis
Treatment of choice for Wegener granulomatosis
- Cyclophosphamide
Interstitial lung disease caused by accumulation of coal dust in the lungs and the subsequent reaction by the surrounding tissue; Caused by repeated inhalation of coal dust over a long period of time (10 to 12 years) describes
- Coal workers’ pneumoconiosis (aka Black Lung)
What is the pathologic hallmark of coal workers’ pneumonsoniosis
- Coal macule
- Focal collection of coal dust with little tissue reaction either in terms of cellular infiltration of fibrosis
Fibrotic lung disease caused by the inhalation of free crystalline silicon dioxide or silica; Industries associated with exposure—mining, tunneling through rock, quarrying, grinding and polishing rock, sandblasting, ship building, foundry work, hydraulic fracturing (fracking) of oil and gas wells describes
- Silicosis
- Even after the pt is no longer exposed, lung function impairment worsens as the disease progresses
Pneumoconiosis caused by the inhalation of asbestos; Plaques (localized fibrous thickenings of the parietal pleura) and pleural effusions may occur describes
- Asbestosis
Asbestosis often has a dormancy period after exposure of __________ years
- 20 to 30 years
Describe Radiation pneumonitis and fibrosis
- Primary complication of irradiation to thorax
- Usually occurs 2-6mo after tx
- Pulmonary injury includes acute radiation pneumonitis & chronic radiation fibrosis
Lung cancer is a growth of abnormal epithelial cells in the tracheobronchial tree.
Two main types: Small cell cancer and Nonsmall cell lung cancer describes
- Bronchogenic carcinoma
Primary causative factor of bronchogenic carcinoma
- Tobacco use
Common sites of metastasis for lung cancer
- Liver
- Kidney
- Adrenal
- Brain
- Heart
- Lymph
- Pleura
- Bone
Pleural effusion is when there is an abnormal amount of fluid within the pleural space made up of transudate and exudate define these terms
- Transudate: fluid with low protein content accumulates bc of changes in hydrostatic pressure within pleural capillaries
- Exudate: fluid with high protein content accumulates bc changes in permeability of pleural surfaces
Most common conditions leading to pleural effusion
- Cardiac failure
- Pneumonia
- Malignant neoplasm
How to diagnosis and remove fluid for pleural effusion
- Thoracentesis procedure can diagnosis and remove excess pleural fluid
_______________ is an increase in the pulmonary capillary hydrostatic pressure, often secondary to left ventricular failure.
- Cardiogenic pulmonary edema
Heavy clot burden may cause ______ ventricular dysfunction or acute cor pulmonale
- Right
Eight clinical variables significantly associated with an absence of PE
- Age < 50 years
- Pulse < 100 beats per minute;
- SaO2 > 94%
- No unilateral leg swelling
- No hemoptysis
- No recent trauma or surgery
- No history of VTE
- No oral hormone use
Innervation of the inspiratory muscles
- Diaphragm: C3-C5 (Phrenic nerve)
- External intercostals: T1-T12
- Sternocleidomastoid: Cranial nerve XI (Spinal accessory)
- Scalenes: C1-C2
Innervation of expiratory muscles
- Internal intercostals: T1-T12
- Abdominals: T7-L1
Pacing the diaphragm muscle has decreased pulmonary complication and can also
- decrease pulmonary complication
- improve venous return
- improve breathing, speech, and mobility
- Improve quality of life
Progressive degenerative disease of the nervous system that involves upper and lower motor neurons; Respiratory muscles may be severely affected describes
- Amyotrophic lateral sclerosis (ALS)
Virus is neurotropic and has a predilection for the motor cells of the anterior horn and the brainstem; Can result in muscular paralysis describes
- Poliomyelitis
Demyelinating disease of the motor neurons of the peripheral nerves; Idiopathic polyneuritis linked to the immune system; Characterized by rapid bilateral ascending flaccid motor paralysis and areflexia describes
- Guillain-Barre Syndrome
Chronic neuromuscular disease characterized by progressive muscular weakness on exertion; Caused by autoimmune attack on acetylcholine receptors at the postsynaptic neuromuscular junction; Crisis occurs if respiratory muscles are affected; requires mechanical ventilation with treatment in the ICU describes
- Myasthenia Gravis
Disease of the neuromuscular system caused by the neurotoxin produced by Clostridium tetani; Blocks release of inhibitory transmitter; Causes severe muscle spasticity with tonic convulsions; May cause chest wall immobilization, resulting in asphyxia and death describes
- Tetanus
Sex-linked (X chromosome) recessive disorder that occurs only in males; Causes progressive degenerative myopathy describes
- Pseudohypertrophic (Duchenne) muscular dystrophy
Common symptoms appearing before age 6 for Duchenne muscular dystrophy
- Progressive muscle weakness & atrophy
- Calf muscle hypertrophy
- Fatigue
- Toe walking
- Difficulty climbing up stairs
- Frequent falls
- Developmental delay
- Breathing problems
- Learning differences
- Delayed speech & language development
- Scoliosis
- Short stature (height)
Describe the differences between supportive and respiratory treatment for Duchenne muscular dystrophy
- Supportive treatment—preserving the patient’s mobility as long as possible; patient comfort
- Respiratory treatment—prevention of infection with maintenance of good inspiratory effort and good airway clearance to mobilize any secretions
Diaphragm paralysis or paresis is most commonly caused by
- Invasion of the Phrenic nerve by bronchogenic carcinoma
- Pathologic changes are heightened in the supine position
Combination of excessive anteroposterior and lateral curvature of the thoracic spine describes
- Kyphoscoliosis
- Describe the implications with difference severities of curvature angle
- Angle <70º: no pulmonary dysfunction
- Angle 70-120º: some pulmonary dysfunction
- Angle >120º: severe RLD & respiratory failure
Chronic inflammatory disease of the spine; Characterized by immobility of sacroiliac and vertebral joints and ossification of paravertebral ligaments; Pulmonary impairment results from markedly decreased compliance of the chest wall describes
- Ankylosing spondylitis
Describe the differences between pectus excavator and carinatum
- Excavatum (funnel chest): Congenital abnormality characterized by sternal depression and decreased anteroposterior diameter; If deformity is severe, patients may have decreased TLC, VC, and maximum voluntary ventilation
- Carinatum (pigeon breast): Structural abnormality characterized by the sternum protruding anteriorly; Associated with prolonged childhood asthma
How does pregnancy cause RLD
- Growth/position of fetus impairs ventilation to dependent regions
- Decrease in chest wall compliance is caused by decreased downward excursion of the diaphragm
- Work of breathing increases
- Voluntary lung volumes decrease
Describe when a Lung contusion would occur
- Occurs when a lung strikes directly against the chest wall
Describe the differences between pneumothorax and hemothorax
- Pneumothorax: entry of free air into the pleural space
- Hemothorax: presence of blood in the pleural space
Describe a thermal trauma
- Usually caused by inhalation injuries, direct burn injuries to the thorax, or a combination of both
- Often caused by exposure to fire/smoke
Describe a pulmonary laceration
- Laceration directly into the lung parenchyma is usually caused by a penetrating wound
- Results in air/blood escaping from the lung into pleural space & often into the environment
- Most commonly appears in combination with a pneumothorax or hemothorax
Pulmonary dysfunction is caused by three primary factors
- The anesthetic agent
- The surgical incision or procedure itself
- The pain caused by the incision or procedure
Postoperatively, hypoxia can be treated with methods that may include
- Inflation-hold breathing techniques
- PEEP
- CPAP
- Increased oxygen concentration
Common methods to treat postoperative atelectasis
- Deep breathing exercises
- Early mobilization of the patient out of bed
- Incentive spirometry
- CPAP
Most drug-induced ILD is ____________ if recognized early and the drug is discontinued
- Reversible
Drugs capable of inducing interstitial lung disease (ILD)
- Oxygen
- Antibiotics
- Nitrofurantoin
- Sulfasalazine
- Antiinflammatory drugs
- Cardiovascular drugs
- Chemotherapeutic drugs
- Poisons
- Anesthetics
- Muscle relaxants
- Illicit drugs
Drug-induced ILD probably results from a combination of mechanisms, including
- Toxic effects of the drug or its metabolites
- Interference with the oxidant–antioxidant system
- An indirect inflammatory reaction
- Altered immunologic processes
