Pathology Flashcards
What air obstructive airway diseases?
- Asthma
- COPD (chronic bronchitis, emphysema)
- Bronchiectasis (obstructive or mixed)
- Cystic fibrosis (obstructive or mixed)
What is the definition of asthma?
- chronic inflammatory disorder of the airways resulting in episodes of reversible bronchospasm causing airflow obstruction
- associated with reversible airflow limitation and airway hyper-responsiveness to endogenous or exogenous stimuli
At what oxygen saturation can you detect central cyanosis?
Central cyanosis is not detectable until SaO2 is <85%. It is more easily detected in polycythemia and less readily detectable in anemia
What is the pathophysiology of how someone becomes acidotic in asthma?
• airway obstruction → V/Q mismatch → hypoxemia → increased ventilation → decreased PaCO2 → increased pH and muscle fatigue → decreased ventilation, increased PaCO2/decreased pH
Asthma triggers
- URTIs
- Allergens (pet dander, house dust, moulds, cockroach)
- Irritants (cigarette smoke, air pollution)
- Drugs (NSAIDs, β-blockers)
- Preservatives (sulphites, MSG)
- Other (emotion/anxiety, cold air, exercise, GERD)
Asthma signs and symptoms
- dyspnea, wheezing, chest tightness, cough, sputum
- symptoms usually occur or worsen at night
- symptoms can be paroxysmal or persistent
- signs of respiratory distress
- pulsus paradoxus
Criteria for determining if asthma is well controlled
Daytime symptoms <4 d/wk No asthma-related absence from work/school Night-time symptoms <1 night/wk β2-agonist use <4 times/wk Physical activity unimpared by symptoms FEV1 or PEF >90% of personal best Exacerbations mild, infrequent PEF diurnal variation <10-15%
PFT criteria for asthma diagnosis
FEV1/FVC <0.75-0.8 in adults and <0.8-0.9 in children
AND
Increase FEV1 ≥12% and, 200 mL in adults after bronchodilator or controller therapy
What are challenge tests that can be used to diagnose asthma?
- Methacholine - PCO2 <4 mg/ml (4-16 is borderline, >16 is negative)
- Post exercise decrease in FEV1 10-15%+
Asthma treatment
- environment: avoid triggers
- patient education: features of the disease, goals of treatment, self-monitoring
• pharmacological
■ symptomatic relief in acute episodes: short-acting β2-agonist, anticholinergic bronchodilators, inhaled corticosteroids, addition of a long acting β2-agonist
■ long-term maintenance: inhaled/oral corticosteroids, anti-allergic agents, long-acting β2-agonists (do not use LABA alone), long-acting anticholinergics, methylxanthine, LTRA, anti-IgE antibodies (e.g. omalizumab), anti-IL5 drugs (e.g. mepolizumab)
Emergency management of asthma
- inhaled β2-agonist first line (MDI route and spacer device recommended)
- systemic steroids (PO or IV if severe)
- if severe add anticholinergic therapy ± magnesium sulfate
- rapid sequence intubation in life-threatening cases (plus 100% O2, monitors, IV access)
- SC/IV adrenaline if caused by anaphylaxis, IV salbutamol if unresponsive
- corticosteroid therapy at discharge
What asthma medication is good to try if the patient is having night time symptoms
LABA
Use of LTRA in acute asthma
Currently, there is no evidence to support routine use of LTRAs in acute asthma.
Asthma pyramid guidelines
Confirm diagnosis
Environmental control, education, written action plan
SABA or ICS/LABA on demand
ICS
2nd line: LTRA
12+ years: add LABA
6-11 years: increase ICS
12+ years: add LTRA (apparently LTRA doesn’t actually work, should use LAMA/LAAC before this to achieve triple therapy with ICS, LABA, LAAC (same as COPD triple therapy))
6-11 years: increase LABA or LTRA
Anti IgE
Prednisone
What is the natural progression of COPD
40s - Chronic productive cough, wheezing occasionally
50s - 1st acute chest illness
60s - Dyspnea on exertion, increasing sputum, more frequent exacerbations
Late Stage- Hypoxemia with cyanosis, polycythemia, hypercapnia (morning headache), cor pulmonale, weight loss
COPD definition
- progressive and irreversible condition of the lung characterized by chronic obstruction to airflow with many patients having periodic exacerbations, gas trapping, lung hyperinflation, and weight loss
- 2 subtypes: chronic bronchitis and emphysema (usually coexist to variable degrees)
- gradual decrease in FEV1 over time with episodes of acute exacerbations
What are some potential complications of COPD
- Polycythemia 2° to hypoxemia
- Chronic hypoxemia
- Pulmonary HTN from vasoconstriction
- Cor pulmonale
- Pneumothorax due to rupture of emphysematous bullae
- Depression
- Bacterial infections
What are the clinical features of chronic bronchitis
Defined clinically
Productive cough on most days for at least 3 consecutive months in 2 successive years
Obstruction is due to narrowing of the airway lumen by mucosal thickening and excess mucous
What are the pathological features of emphysema
Defined pathologically
Dilation and destruction of air spaces distal to the terminal bronchiole without obvious fibrosis
Decreased elastic recoil of lung parenchyma causes decreased expiratory driving pressure, airway collapse and air trapping
What are 2 types of emphysema
1) Centriacinar (respiratory bronchiole) - typical form seen in smokers, primarily affects upper lung zones
2) Panacinar (all parts of acinus) - accounts for about 1% of emphysema cases, alpha 1 - antitrypsin deficiency, primarily affects lower lobes
What should be a target O2 sat for CO2 retainers
On ABG, retainers have chronically elevated CO2 levels with a normal pH. Maintain O2 Sat between 88-92% to prevent Haldane effect, worsening V/Q mismatch, and decreased respiratory drive
What is first line therapy for COPD
SMOKING CESSATION
What is alpha 1 Antitrypsin deficiency
Inherited disorder of defective production of α1antitrypsin, a protein produced by hepatocytes.
Acts in the alveolar tissue by inhibiting the action of proteases from destroying alveolar tissue. When deficient, proteases can destroy lung alveoli resulting in emphysema
COPD risk factors
• smoking is #1 risk factor
• others
■ environmental: air pollution, occupational exposure, exposure to wood smoke or other biomass fuel for cooking
■ treatable factors: α1-antitrypsin deficiency, bronchial hyperactivity
■ demographic factors: age, family history of atopy, male sex, history of childhood respiratory infections, low socioeconomic status
GOLD classification of severity of COPD
GOLD 1 Mild FEV1 ≥80% of predicted
GOLD 2 Moderate 50% ≤FEV1 <80% of predicted
GOLD 3 Severe 30% ≤ FEV1 <50% of predicted
GOLD 4 Very Severe FEV1 <30% of predicted
Symptoms and signs of “blue bloater” bronchitis
Chronic productive cough
Purulent sputum
Hemoptysis
Cyanosis (2º to hypoxemia and hypercapnia)
Peripheral edema from RVF (cor pulmonale)
Crackles, wheezes
Prolonged expiration if obstructive
Frequently obese
Bronchitis investigations
PFT: Decreased FEV1 Decreased FEV1/FVC Normal TLC Decreased or Normal DLCO
CXR:
AP diameter normal
Increased bronchovascular markings
Enlarged heart with cor pulmonale
Signs and symptoms of “pink puffer” emphysema
Dyspnea (± exertion)
Minimal cough
Tachypnea
Decreased exercise tolerance
Pink skin
Pursed-lip breathing
Accessory muscle use
Cachectic appearance due to anorexia and increased work of breathing
Hyperinflation/barrel chest, hyperresonant percussion
Decreased breath sounds
Decreased diaphragmatic excursion
Emphysema investigations
PFT: Decreased FEV1, Decreased FEV1/FVC Increased TLC (hyperinflation) Increased RV (gas trapping) Increased DLCO
CXR: Increased AP diameter Flat hemidiaphragm (on lateral CXR) Decreased heart shadow Increased retrosternal space Bullae Decreased peripheral vascular markings
Systemic corticosteroids for acute COPD exacerbations
There is high-quality evidence to support treatment of exacerbaions of COPD with systemic corticosteroid by the oral or parenteral route in reducing the likelihood of treatment failure and relapse by 1 mo, shortening length of stay in hospital inpatients not requiring assisted ventilation in ICU and giving earlier improvement in lung function and symptoms. There is no evidence of benefit for parenteral treatment compared with oral treatment with corticosteroid on treatment failure, relapse or mortality. There is an increase in adverse drug effects with corticosteroid treatment, which is greater with parenteral administration compared with oral treatment.
What are COPD treatments that prolong survival
PROLONG SURVIVAL
Smoking Cessation - Nicotine replacement, bupropion, varenicline
Vaccination - Influenza, pneumococcal vaccine
Home Oxygen -
Prevents cor pulmonale and decreases mortality if used >15h/d
Indicated if
(1) PaO2 <55 mmHg or
(2) PaO2 <60 mmHg with cor pulmonale or polycythemia
What are COPD treatments that provide symptomatic relief with no mortality benefit
SYMPTOMATIC RELIEF (no mortality benefit)
- Bronchodilators (mainstay of current drug therapy, used in combination)
• Short-acting antcholinergics (e.g. ipratropium bromide) and short-acting β2-agonists (e.g. salbutamol, terbutaline)
SABAs: rapid onset but significant side effects at high doses (e.g. hypokalemia)
Short-acting anticholinergics more effective than SABAs with fewer side effects but slower onset; take regularly rather than PRN
• LABAs (e.g. salmeterol, formoterol, indacaterol) and long acting anticholinergics (e.g. tiotropium bromide, glycopyrronium bromide)
• More sustained effects for moderate to severe COPD
• Inhaled corticosteroid (ICS) + LABA combination (e.g. Advair®: fluticasone + salmeterol, Symbicort®: budesonide + formoterol)
• ICS/LABA increases effectiveness vs LABA alone
• Theophylline: weak bronchodilator; limited evidence to suggest combination with bronchodilator
• Side effects: nervous tremor, nausea/vomiting/diarrhea, tachycardia, arrhythmias, sleep changes
• PDE4 inhibitor: roflumilast (Daxas®) anti-inflammatory medication useful in COPD with chronic bronchitis, severe airflow obstruction, frequent exacerbations - Corticosteroids
• ICS monotherapy has been shown to increase the incidence of pneumonia in COPD; ICS should only be used with a LABA in combination in patients with a history of exacerbations
• Oral steroids are important when treating exacerbations; chronic systemic glucocorticoids are generally not recommended due to unfavourable benefit to risk ratio - Surgical
• Lung volume reduction surgery (resection of emphysematous parts of lung, associated with higher mortality if FEV1 <20%)
• lung transplant - Other
• Patient education, eliminate respiratory irritants/allergens (occupational/environmental), exercise rehabilitation to improve physical endurance
Workup for patients with unexplained COPD exacerbation
Prevalence of PE in patients hospitalized for COPD exacerbation of unknown origin is 25%. Therefore, all patients presenting to hospital with COPD exacerbation without obvious cause require PE workup (leg dopplers or CTA – decision of which to use depends on pre-test probability of the patient).
COPD pharmacological management pyramid
Educations/Self-Management
PRN short acting bronchodilators
Long acting bronchodilators
Rehabilitation
ICS/LABA
O2
Surgery
NIPPV for treatment of respiratory failure due to COPD exacerbations
For patients in respiratory failure due to a COPD exacerbation, NPPV is effective in reducing treatment failure, mortality, and need for intubation when used as a first line treatment adjunct to UMC.
Acute exacerbations of COPD definition
■ sustained (>48 h) worsening of dyspnea, cough, or sputum production leading to an increased use of medications
■ in addition, defined as either purulent or non-purulent (to predict need for antibiotic therapy)
Acute exacerbations of COPD etiology
viral URTI, bacteria air pollution, CHF, PE, MI must be considered
COPD exacerbation management
■ ABCs, consider assisted ventilation if decreasing LOC or poor ABGs
■ O2: target 88-92% SaO2 for CO2 retainers
■ bronchodilators by MDI with spacer or nebulizer
◆ SABA + anticholinergic, e.g. salbutamol and ipratropium bromide via nebulizers × 3 back-toback q15min
■ systemic corticosteroids: IV solumedrol or oral prednisone
■ antibiotics for exacerbations with increased sputum production and at least one of the following:
◆ increased dyspnea or sputum purulence
◆ simple exacerbation (no risk factors): amoxicillin, 2nd or 3rd generation cephalosporin, macrolide, or TMP/SMX ◆ complicated exacerbation (one of: FEV1 ≤50% predicted, ≥4 exacerbations per year ischemic heart disease, home O2 use, chronic oral steroid use): fluoroquinolone or β-lactam + β-lactamase inhibitor (amoxicillin/clavulanate)
■ post exacerbation: rehabilitation with general conditioning to improve exercise tolerance
• ICU admission
■ for life-threatening exacerbations
■ ventilatory support
◆ non-invasive: NIPPV, BiPAP
◆ conventional mechanical ventilation
Duration of corticosteroid therapy for COPD exacerbation
5 d of oral corticosteroids is likely to be sufficient for treatment of adults with acute exacerbations of COPD, and this review suggests that the likelihood is low that shorter courses of systemic corticosteroids (of around five days) lead to worse outcomes than are seen with longer (10 to 14 d) courses.
COPD prognosis
• prognostic factors
■ level of dyspnea is the single best predictor
■ development of complications, e.g. hypoxemia or cor pulmonale
• 5 yr survival
■ FEV1 <1 L = 50%
■ FEV1 <0.75 L = 33%
• BODE index for risk of death in COPD
■ greater score = higher probability the patient will die from COPD; score can also be used to predict hospitalization
■ 10 point index consisting of four factors:
◆ Body mass index (BMI): <21 (+1 point)
◆ Obstruction (FEV1): 50-64% (+1), 36-49% (+2), <35% (+3)
◆ Dyspnea (MRC scale): walks slower than people of same age on level surface, stops occasionally (+1), stops at 100 yards or a few minutes on the level (+2), too breathless to leave house or breathless when dressing/undressing (+3)
◆ Exercise capacity (6 minute walk distance): 250-349 m (+1), 150-249 m (+2), <149 m (+3)
Bronchiectasis definition and common pathogens
- irreversible dilatation of airways due to inflammatory destruction of airway walls resulting from persistently infected mucus usually affects medium sized airways
- P. aeruginosa is the most common pathogen; S aureus, H. influenzae, and nontuberculous mycobacteria also common
What is Kartegener’s syndrome
bronchiectasis, sinusitis, situs inversus
What types of obstructions can lead to bronchiectasis
Tumour
Foreign body
What types of infections can lead to post- infectious bronchiectasis (results in dilatation of bronchial walls)
Pneumonia TB Measles Pertussis Allergic bronchopulmonary aspergillosis Non tuberculous mycobacterium (NTM)
What kinds of Impaired Defenses (leads to interference of drainage, chronic infections, and inflammation) can lead to bronchiectasis
Hypogammaglobinemia CF Defective leukocyte function Ciliary dysfunction Kartagener's syndrome
Bronchiectasis signs and symptoms
- chronic cough, purulent sputum (but 10-20% have dry cough), hemoptysis (can be massive), recurrent pneumonia, local crackles (inspiratory and expiratory), wheezes
- clubbing
- may be difficult to differentiate from chronic bronchitis
Bronchiectasis investigations
• PFTs: often demonstrate obstructive pattern but may be normal
• CXR
■ nonspecific: increased markings, linear atelectasis, loss of volume in affected areas
■ specific: “tram tracking” – parallel narrow lines radiating from hilum, cystic spaces, honeycomb like structures
• high-resolution thoracic CT (diagnostic, gold standard)
■ 87-97% sensitivity, 93-100% specificity
■ “signet ring”: dilated bronchi with thickened walls where diameter bronchus > diameter of accompanying artery
- sputum cultures (routine + AFB)
- serum Ig levels
- sweat chloride if cystic fibrosis suspected (upper zone predominant)
Bronchiectasis treatment
- vaccination: influenza and pneumococcal vaccination
- chest physiotherapy, breathing exercises, physical exercise
- antibiotics (oral, IV, inhaled): routinely used for mild exacerbations, driven by sputum sensitivity; macrolides may be used chronically for an anti-inflammatory effect
- inhaled antibiotics (tobramycin) used chronically to suppress Pseudomonas and reduce exacerbations
- mucolytics (e.g. hypertonic saline, N.B. DNAse only in CF)
- inhaled corticosteroids: decrease inflammation and improve FEV1; however, may increase risk of exacerbations
- oral corticosteroids for acute, major exacerbations
- pulmonary resection: in selected cases with focal bronchiectasis
Cystic fibrosis usual first presentation
Usually presents in childhood as recurrent lung infections that become persistent and chronic
Cystic fibrosis pathophysiology
• chloride transport dysfunction: thick secretions from exocrine glands (lung, pancreas, skin, reproductive organs) and blockage of secretory ducts
Cystic fibrosis clinical features
- results in severe lung disease, pancreatic insufficiency, diabetes, and azoospermia
- other manifestations: meconium ileus in infancy, distal ileal obstruction in adults, sinusitis, liver disease
• chronic lung infections ■ S. aureus: early ■ P. aeruginosa: most common ■ B. cepacia: worse prognosis but less common ■ Aspergillus fumigatus
Cystic fibrosis investigations
• Sweat chloride test
■ increased concentrations of NaCl and K+ ([Cl–] >60 mmol/L suggests diagnosis in children)
■ heterozygotes have normal sweat tests (and no symptoms)
• PFTs
■ early: airflow limitation in small airways
■ late: severe airflow obstruction, hyperinflation, gas trapping, decreased DLCO (very late)
• ABGs
■ hypoxemia, hypercapnia later in disease with eventual respiratory failure and cor pulmonale
• CXR
■ hyperinflation, increased pulmonary markings (especially upper lobes)
Cystic fibrosis treatment
- chest physiotherapy and postural drainage
- pancreatic enzyme replacements, high calorie diet
- bronchodilators (salbutamol ± ipratropium bromide)
- inhaled mucolytic (reduces mucus viscosity), hypertonic saline DNase
- inhaled antibiotics (tobramycin, colistin, aztreonam)
- antibiotics (eg ciprofloxacin)
- CFTR potentiators (e.g Ivacaftor)
- lung transplant
Cystic fibrosis prognosis
- depends on: infections (cepacia colonization), FEV1, acute pulmonary exacerbations, lung transplant vs. non-lung transplant
- female gender and low socioeconomic class have greater risk of early death
ILD upper lung disease differential
FASSTEN
Farmer’s lung (hypersensitivity pneumonitis)
Ankylosing spondylitis
Sarcoidosis
Silicosis
TB
Eosinophilic granuloma (Langerhans-cell histiocytosis)
Neurofibromatosis
ILD lower lung disease differential
BAD RASH
Bronchiolitis obliterans with organizing pneumonia (BOOP)
Asbestosis
Drugs (nitrofurantoin, hydralazine, INH, amiodarone, many chemo drugs)
Rheumatologic disease
Aspiration
Scleroderma
Hamman Rich (acute interstitial pneumonia) and IPF
Interstitial lung disease definition
• a group of disorders which cause progressive scarring of lung tissue and impair lung function and gas exchange
Interstitial lung disease pathophysiology
• inflammatory and/or fibrosing process in the alveolar walls → distortion and destruction of normal alveoli and microvasculature
• typically associated with
■ lung restriction (decrease in TLC and VC)
■ decreased lung compliance (increased or normal FEV1/FVC)
■ impaired diffusion (decreased DLCO)
■ hypoxemia due to V/Q mismatch (usually without hypercapnia until end stage)
■ pulmonary HTN and cor pulmonale occur with advanced disease secondary to hypoxemia and blood vessel destruction
Unknown etiologies of interstitial lung disease
- Idiopathic interstitial pneumonias
UIP (usual interstitial pneumonia)
NSIP (non-specific interstitial pneumonia)
LIP (lymphoctic interstitial pneumonia)
COP (cryptogenic organizing pneumonia ex BOOP)
DIP (desquamative interstitial pneumonia)
IPPFE (idiopathic pleuroparenchymal fibroelastosis)
AFOP (acute fibrinous and organizing penumonia) - Sarcoidosis
- Langerhans - cell histiocytosis (eosinophilic granuloma)
- Lymphangioleiomyomatosis
Known etiologies of interstitial lung disease
- ILD associated with systemic rheumatic disorders
- Scleroderma
- Rheumatoid arthritis
- SLE
- Polymyositis/dermatomyositis
- Anti-synthetase dynromes
- Mixed connective tissue disease - Environmental/occupation associated ILD
- Hypersensitivity pneumonitis (usually organic antigen)
Farmer’s lung, air conditioner/humidifier lung, bird breeder’s lung
- Pneumoconioses (inorganic dust)
Silicosis, asbestosis, coal worker’s pneumoconiosis, chronic beryllium disease
- Pneumonitis from gases/fumes/vapour - ILD associated with drugs or treatments
- Antibiotics (nitrofurantoin)
- Anti-inflammatory agents (methotrexate)
- Cardiovascular drugs (amiodarone)
- Antineoplastic agents (chemo)
- Illicit drugs (ex. crack lung, talc granulomatosis)
- Radiation - ILD associated with pulmonary vasculitis
- Granulomatosis with polyangiitis (GPA)
- Goodpasture’s syndrome
- Idiopathic pulmonary hemosiderosis - Inherited disorders
- Familial IPF
- Telomerase mutations
Neurofibromatosis, tuberous sclerosis, Gaucher’s disease
- Alveolar filling disorders
Chronic eosinophilic pneumonia, pulmonary alveolar proteinosis
ILD signs and symptoms
• dyspnea, especially on exertion
• nonproductive cough
• crackles (dry, fine, end-inspiratory)
• clubbing (especially in IPF and asbestosis)
• features of cor pulmonale
• note that signs and symptoms vary with underlying disease process
■ e.g. sarcoidosis is seldom associated with crackles and clubbing
ILD investigations
• CXR/high resolution CT
■ usually decreased lung volumes
■ reticular, nodular, or reticulonodular pattern (nodular <3 mm)
■ hilar/mediastinal adenopathy (bilateral especially in sarcoidosis)
The CXR can be normal in up to 15% of patients with interstitial lung disease
• PFTs
■ restrictive pattern: decreased lung volumes and compliance
■ normal or increased FEV1/FVC (>70-80%), e.g. flow rates are often normal or high when corrected for absolute lung volume
■ DLCO decreased due to V/Q mismatch (less surface area for gas exchange ± pulmonary vascular disease)
• ABGs
■ hypoxemia and respiratory alkalosis may be present with progression of disease
• other
■ bronchoscopy, bronchoalveolar lavage, lung biopsy
■ ESR, ANA (lupus), RF (RA), serum-precipitating antibodies to inhaled organic antigens (hypersensitivity pneumonitis), c-ANCA (GPA), anti-GBM (Goodpasture’s)
Idiopathic pulmonary fibrosis definition
- pulmonary fibrosis of unknown cause with usual interstitial pneumonia (UIP) histology (found on biopsy or inferred from CT)
- a progressive, irreversible condition
- DDx: NSIP, COP, desquamative interstitial pneumonitis (DIP), lymphocytic interstitial pneumonitis (LIP), Sjögren’s disease
IPF signs and symptoms
- commonly presents over age 50, incidence rises with age; males > females
- dyspnea on exertion, nonproductive cough, constitutional symptoms, late inspiratory fine crackles at lung bases, clubbing
IPF investigations
- labs (nonspecific, autoimmune serology usually negative)
- CXR: reticular or reticulonodular pattern with lower lung predominance; often see honeycombing in advanced disease
- high resolution CT: lower zone peripheral reticular markings, traction bronchiectasis, honeycombing; ground glass, consolidation, or nodules should not be prominent in IPF
- biopsy: rarely for UIP as honeycombing usually makes radiologic diagnosis possible
IPF treatment
- O2
- pirfenidone and nintedanib can slow disease progression
- lung transplantation for advanced disease
- mean survival of 3-5 yr after diagnosis
Sarcoidosis definition
- idiopathic non-infectious granulomatous multi-system disease with lung involvement in 90%
- characterized pathologically by non-caseating granulomas
- numerous HLA antigens have been shown to play a role and familial sarcoidosis is now recognized
Sarcoidosis epidemiology
- typically affects young and middle-aged patients
* higher incidence among people of African descent and from northern latitudes e.g. Scandinavia, Canada
Sarcoidosis signs and symptoms
- asymptomatic cough, dyspnea, fever, arthralgia, malaise, erythema nodosum, chest pain
- chest exam often normal
• common extrapulmonary manifestations
■ cardiac (arrhythmias, sudden death)
■ eye involvement (anterior or posterior uveitis)
■ skin involvement (skin papules, erythema nodosum, lupus pernio)
■ peripheral lymphadenopathy
■ arthralgia
■ hepatomegaly ± splenomegaly
• less common extra-pulmonary manifestations involve bone, CNS, kidney
• two acute sarcoid syndromes
■ Lofgren’s syndrome: fever, erythema nodosum, bilateral hilar lymphadenopathy, arthralgias
■ Heerfordt-Waldenstrom syndrome: fever, parotid enlargement, anterior uveitis, facial nerve palsy
What is the most common presentation of sarcoidosis
asymptomatic CXR finding
Sarcoidosis investigations
- CBC (cytopenias from spleen or marrow involvement)
- serum electrolytes, creatinine, liver enzymes, calcium (hypercalcemia/hypercalciuria due to vitamin D activation by granulomas)
- hypergammaglobulinemia, occasionally RF positive
- elevated serum ACE (non-specific and non-sensitive)
- CXR: predominantly nodular opacities especially in upper lung zones ± hilar adenopathy
- PFTs: normal, obstructive pattern, restrictive pattern with normal flow rates and decreased DLCO, or mixed obstructive/restrictive pattern
- ECG: to rule out conduction abnormalities
- slit-lamp eye exam: to rule out uveitis
Sarcoidosis diagnosis
• biopsy
■ transbronchial lung biopsy transbronchial lymph node aspiration, endobronchial ultrasound guided surgical (EBUS) biopsy, or mediastinoscopic lymph node biopsy for granulomas
■ in ~75% of cases, transbronchial biopsy shows granulomas in the parenchyma even if the CXR is normal
Hilar lymphadenopathy presentation and differential
Hilar adenopathy refers to enlargement of mediastinal lymph nodes which is most often seen by standard CXR as spherical/ellipsoidal and/or calcified nodes. If unilateral - think neoplasia, TB, or sarcoid. If bilateral - think sarcoid or lymphoma
Sarcoidosis staging
• radiographic, based on CXR
■ Stage 0: normal radiograph
■ Stage I: bilateral hilar lymphadenopathy ±paratracheal lymphadenopathy
■ Stage II: bilateral hilar lymphadenopathy with pulmonary infiltration
■ Stage III: pulmonary infiltration alone (reticulonodular pattern or nodular pattern) ■
Stage IV: pulmonary fibrosis (honeycombing)
Role for corticosteroids in pulmonary sarcoidosis
Oral steroids improve CXR findings and global scores of CXR, symptoms, and spirometry over 3-24 mo, but do not improve lung function or modify disease course. Oral steroids may be of benefit for patients with Stage 2 and 3 disease.
Sarcoidosis treatment
- steroids for symptoms, declining lung function, hypercalcemia, or involvement of eye, CNS, kidney, or heart (not for abnormal CXR alone)
- methotrexate or other immunosuppressives occasionally used
Sarcoidosis prognosis
- 85% of stage I resolve spontaneously
- 50% of stage II resolve spontaneously
- approximately 10% mortality secondary to progressive fibrosis of lung parenchyma
Calcified diaphragmatic plaques are highly suggestive of what condition
asbestosis, especially if bilateral
Hypersensitivity pneumonitis pathophysiology
- also known as extrinsic allergic alveolitis
- non-IgE mediated inflammation of lung parenchyma (acute, subacute, and chronic forms) Type 4 hypersensitivity reaction
- caused by sensitization to inhaled agents, usually organic dust
- pathology: airway-centred, poorly formed granulomas and lymphocytic inflammation
• exposure usually related to occupation or hobby
■ Farmer’s Lung (Thermophilic actinomycetes)
■ Bird Breeder’s/Bird Fancier’s Lung (immune response to bird IgA)
■ Humidifier Lung (Aureobasidium pullulans)
■ Sauna Taker’s Lung (Aureobasidium spp.)
CXR fibrosis patterns for asbestos, silicosis and coal
- Asbestosis: lower > upper lobes
- Silicosis: upper > lower lobes
- Coal: upper > lower lobes
Hypersensitivity pneumonitis signs and symptoms
• acute presentation: (4-6 h after exposure)
■ dyspnea, cough, fever, chills, malaise (lasting 18-24 h)
■ CXR: diffuse infiltrates
■ type III (immune complex) reaction
• subacute presentation: more insidious onset than acute presentation
• chronic presentation
■ insidious onset
■ dyspnea, cough, malaise, anorexia, weight loss
■ PFTs: progressively restrictive
■ CXR: predominantly upper lobe reticulonodular pattern
• in both acute and chronic reactions, serum precipitins may be detectable (neither sensitive nor specific)
Hypersensitivity pneumonitis treatment
- early diagnosis: avoidance of further exposure is critical as chronic changes are irreversible
- systemic corticosteroids can relieve symptoms and speed resolution
Pneuomoconioses definition and treatment
- reaction to inhaled inorganic dusts 0.5-5 µm in size
- no effective treatment, therefore key is exposure prevention through the use of protective equipment
- smoking cessation, annual influenza and pneumococcal vaccination rehabilitation, lung transplant for endstage disease
Types of pneumoconioses
Asbestosis, silicosis, Coal Worker’s Pneumoconiosis (CWP)
Asbestosis etiology
Exposure risks: insulation, shipyard, construction, brake linings, pipe fitters plumbers Slowly progressive diffuse interstitial fibrosis induced by inhaled asbestos fibres Usually requires >10-20 yr of exposure Latency period: 20-30 yr
Asbestosis signs and symptoms
Insidious onset
Dyspnea
Cough: paroxysmal, non-productive
Clubbing (much more likely in asbestosis than silicosis or CWP)
Asbestosis investigations
CXR
Lower > upper lobe
Reticulonodular pattern, may develop IPF-like honeycombing
Asbestos exposure can also cause pleural and diaphragmatic plaques (± calcification), pleural effusion, round atelectasis
Microscopic examination reveals ferruginous bodies: yellow-brown rod-shaped structures which represent asbestos fibres coated in macrophages