| What is smoking induced lung disease RBILD? | Respiratory bronchiolitis interstitial lung diseae, Smoking related pneumonia, Idiopathic interstitial pneumonia (IIP)
It is a pathological lesion found in cigarette smokers lungs not associated with symptoms.
Histologic features: tan-pigmented macrophages, patchy submucosal and peribronchiolar infiltrates (lymphocytes), peribronchiolar fibrosis contiguous to alveolar walls
Could be a part of a spectrum of lung disease. |
| How is epidemiology of RBILD? | RB is Common found in smokers (89% found in biopsies)
RB-ILD is uncommon (0.04/10,000 in greece) |
| How is pathogenesis of RBILD? | Unknown, all are current or former smokers, and disease improves after cessation |
| What are clinical features of RBILD? | pt in 30-50 with subacute dyspnea (94%), wheeze (70%), cough (65%) and sputum production (50%)
Fine bibasilar crackles are common findings on chest exam, throughout inspiration sometimes continue till expiration |
| How is diagnostic evaluation of RBILD? | When pt with non-specific symptoms comes that is a smoker: typical for RB
Most imp dx and tx is cessation of cigarettes and exposure to it
Labs: typical non-specific ones, may make a1antitrypsin to exclude AAT deficiency
PFTs: mixed obstructive-restrictive pattern mild to moderate reduction in DLCO
(airway inflammation: obstructive pattern, interstitial disease causes restrictive pattern) |
| What are image findings in RBILD? | CXR: Diffuse, fine reticular/nodular opacities, or normal in 28% of pt.
Bronchial wall thickening, peribronchovascular markings, opacities are seen
HRCT: patchy ground-glass opacities air trapping.
Central bronchial wall thickening (90%), peripheral wall thickening (86%), centrilobular nodules (71%), ground glass opacitiy (67%) and centrilobular emphysema (50%) |
| What is indication of bronchoscopy in RBILD? | bronchoscopy with BAL is reserved for pt with uncertain dx with moderate-severe case (not mild - can wait)
Used to exclude other causes, RBILD non-specific BAL findings.
Increased macrophages with golden pigmented inclusoons and lower other cellular constituents. |
| What is therapy for RBILD? | Smoking cessation, supportive therapy, glucocorticoids, second-line immunosupressive agents |
| What are inhalation injuries from heat, smoke or chemical agents? | Damage to respiratory tract from chemical/heat irritants inspired with air.
Synonym of inhalation injury, one resulting from fire is one of the leading causes of death |
| How is pathophysiology of inhalation injuries? | Airways only, or systemic toxicity.
Location and severity depends on ignition source, size and diameter of particles entering, duration of exposure and solubility of the gases inhaled.
Direct damage by low molecular weight constituents of smoke due to their pH, free radical formation and reach (to alveoli and distal airways)
We have 3 classes of injuries based on where they injure: upper airway, tracheobronchial, and lung parenchyma. |
| What is upper airway inhalation injury? | leading one is heat injury (in oro-nasopharynx), result in erythema, ulceration and edema.
If combined burn and inhalation injury, aggressive fluid admin will promote edema formation.
Burns to face and neck can also cause anatomic distortion or external compression of upper airway complicating airway management.
Damage to ciliary function can also be a cause of increased risk of infection for several weeks, and increased thick secretion can lead to distal wall obstruction, atelectasis and impaired gas exchange |
| What are tracheobronchial injuries? | Usually caused by chemicals of smoke, toxic inhalations, liquids, or direct airway fire.
Symptoms include persistent cough, wheeze, soot-containing secretions (melanoptysis), increased work of breath, erythema, hyperemia, increased pulmonary shunt from atelectasis.
Smoke promotes neuropeptide formation, inducing bronchoconstriction and formation of ROS, to potentiate local cellular damage and loss of hypoxemic pulmonary vasoconstriction.
Increased blood flow increases PMNs and increase inflammatory response, we get an exudate in airways and possibly airway collapse |
| What is inhaled smoke parenchymal injury? | Delayed usually, time difference from initial injury to decrease in arterial oxygen correlates the severity of the injury, faster = more severe.
Characterized by atelectasis and alveolar collapse, increased transvascular fluid flux, decrease surfactant, loss of hypoxic vasoconstriction and then impaired oxygen.
We also get decreased fibrinolytic activity thus massive fibrin deposits causing ventilation-perfusion mismatch.
Increase risk of pneumonia (impaired macrophages, PMNs, and mucociliary mechanisms |
| What is systemic toxicity caused by smoke inhalation? | Breathing toxic substances formed via combustion/pyrolysis, two most relevant gases are CO and hydrogen cyanide |
| What is CO poisoning? | One of the most frequent causes of death (immediate), colorless, odorless, with 200 x O2 affinity to Hb, shifts curve to left causing hypoxia
Screened by aretrial or venous blood measure (CO-oxumetry) but not pulse oximetry (cannot diff O2 from CO)
Tx: Incubate, high flow O2, hyperbaric O2 for CO>25%, loss of conscious, severe metabolic acidosis, and concern of organ ischemia
Each level of CO in blood increases symptoms and death occurs from 60-100% CO |
| What is hydrogen cyanide poisoning? | CN , colorless gas with almond bitter odor.
difficult to confirm post-burn since non-specific and can't be measured timely, tx is considered for every pt with smoke inhalation, risk of loss of conscious, cardiac arrest, decompensation.
Tx: secure airway, no mouth to mouth resusication, single dose of activated charcoal (50g adults, 1g/kg child), treat symptoms, antidote (hydroxycobalamine (70mg/kg) if not available give nitrite |
| What are clinical features of smoke inhalation? | Hx of exposure, loss of conscious, dizziness, nausea, vomit, difficulty breathing, SoB, cough, burn to face, singed nasal vibrissae, nasal passages, carbonaceous sputum, hoarseness, increase work of breath, tachypnea, decreased breath sounds, wheezing, use of accessory muscles. |
| What are lab findings of smoke inhalation? | ABG sent for CO oximetry, other normal labs done |
| What are image findings in smoke inhalation? | Normal CXR at begning, and underestimated injury if seen.
pulmonary opacities -> severe injury and poor prognosis. |
| How is direct airway exam of smoke inhalation? | We should inspect it, direct laryngoscopy (for UA for smoke inhalation signs), fiberoptic bronchoscopy (of oropharynx to lobar bronchi (confirms dx), we see mucosal erythema, edema, blistering, ulceration, bronchorrhea |
| How is management of smoke inhalation pt? | Rescue pt, asess airway, breathing, monitor for 4-6 hours if normal, if had syncope/carbon sputum... should be hospitalized, intubated with O2 100% mask, bronchodilators, mucolytic agents, supportive tx |
| What are drowning injuries? | Process resulting in primary respiratory impairment from submersion or immersion in liquid.
Common cause of accidental death and childhood fatalities worldwide.
Age is bimodal (children less than 5 (7% of abuse and neglect), between 15-25 years (at rivers, lakes and beaches))
Risk factors include (inadequate supervision, risk taking behavior, alcohol, hypothermia (rapid exhaustion and arrythmia) trauma, stroke or MI, seizures, undetected arrhythmia, hyperventilation (shallow dive) |
| What is pathophysio of submersion injuries? | Begins with panic, loss of normal breathing, breath holding, air hunger, struggle to stay above water.
Aspiration and reflex laryngospasm occurs for inspiratory efforts.
Hypoxemia -> multiorgan failure
Distinct salt and fresh water, aspirate 11ml/kg body weight for volume change and 22 for electrolyte change (but no longer important to distinguish the two)
Cause decreased lung compliance, vent-perfusion mismatch ,intrapulmonary shunt, hypoxemia |
| What are end-organ effects of submersion injuries? | Pulmonary (Noncardiogenic edema and ARDS)
Neuro (cerebral edema, high intracranial pressure)
Cardiovascular (arrhythmia secondary to hypothermia and hypoxemia (sinus tachycardia, bradycardia and a.fib, takotsubo cardiomyopathy, CAD (spasm))
Renal (failure, tubular necrosis)
Coagulation (hemolysis and coagulopathy)
Acid-base (metabolic/respiratory acidosis) |
| How is management of submersion injuries? | Prehospital care (CPR, ventilation, chest compressions)
ER care (intubation (if neuro signs, PaO2<60, PaCO2>50), oxygen support (SpO2>94%) |
| What are drug induced pulmonary disorders? | Non-specific spectrum of symptoms, exclusion dx.
Lung is the only organ to recieve the whole circulation, so all drugs affect it.
Rxns can affect pleura, airways, vessels, muscles
Theories (cytotoxic effect on endothelia, direct oxidative injury, deposit of phospholipid particularity in macrophage, immune-mediated injury (SLE, hypersensitivity)
Injuries include (pneumonia, fibrosis, hypersensitivity, edema, bronchospasm, pulmonary HTN |
| How are drug-induced pneumonia and fibrosis? | Symptoms of dyspnea, cough weeks to months.
By amiodarone, beta blockers, cipro, ...many are dose dependent with symptoms.
long-term nitrofurantonin for UTI classic cause of pulmonary fibrosis |
| What is hypersensitivity lung disease? | Quicker onset, days-weeks, fever, rash myalgias, responds to corticosteroids usually |
| What is non-cardiogenic edema drug induced? | Develops within hours after exposure, usually by sympathomimetics, narcotics and salicylates. |
| What are drug-induced bronchospasms? | By NSAIDs, aspirin and beta blockers, for pt with asthma and COPD (20% of asthma cannot take aspirin and NSAIDs)
Also caused by ACE inhibitors. |
| What is bronchiolitis obliterans? | Small airway inflammation, granulation tissue formation, secondary airway obstruction.
(drugs causing it are sulfasalazine and penicillamine) |
| What is drug-induced alveolar hemorrhage? | By anticoagulants, cyclosporin,epoprostenol...
Geftinib (chemotherapy, antitumor against EGFR |
| What is drug-induced hypoventilation? | Can either cause depression of respiratory drive, peripheral neuropathies, Guillain Barre like, myopathy, neuromuscular blockade.
Usually alcohol, sedative, narcotics, hypnotics
Glucocorticoids, Ca blockers, Abx (aminoglycosides) can cause blockade |
| What are drug-induced pulmonary renal syndrome? | Penicillamine therapy (dyspnea, hematuria, hemoptysis, pleuritic pain)
Onset maybe delayed (2 years of penicillamine therapy)
resembles Goodpasture's syndrome (distinguished by antiglomerular Ab not present in drug induced) |
| What are the consequences of illicit drug use? | Vascular congestion/pulmonary edema (w/in 3 hours of overdose)
Lobar pneumonia (more than 12 hours after overdose)
Heroin overdose: hypoxic failure and pulmonary edema
Talc /magnesium used to cut drugs can lead to foreign body entering, granulomatousis, fibrosis, pulmonary HTN.
Crack cocaine lung disease (pleurisy, cough, wheeze, dyspnea, hemoptysis, upper airway burns, increased ferritin and iron ->chronic lung disease) |
| What are primary pneumoconioses? | Asbestos-related diseases, silicosis, coal workers pneumoconiosis (black lung) |
| What are asbestos-related pleuropulmonary disease? | Asbestosis, pleural diseases (benign effusion, focal and diffuse pleural plaques), malignancies (NSCLC, SCLC, malignant mesothelioma) |
| What is asbestosis? | Slow progressive diffuse pulmonary fibrosis, small, stiff lungs with fibrosis in subpleural regions of lower lobes (visceral pleura may also be fibrotic and associated with parietal pleura plaques while central lung portions are spared
Presence of uncoated or coated asbestos fibers, in association with interstitial pulmonary fibrosis similar to usual interstitial pneumonia (UIP) |
| How is pathogenesis of asbestosis? | Direct toxic effect of fibers on parenchyma and release of various mediators by inflammatory cells.
ROS species may be formed by iron reacting with asbestos or activation of inflammatory cells (they can damage cellular macromolecules and disrupt DNA to become malignant.) |
| What are clinical findings of asbestosis? | Most pt are asymptomatic for 20-30 years after initial exposure, latency is inversely proportional with intensity of exposure.
Earliest symptom usually is insidious dyspnea, then progresses even with no further exposure.
Cough, sputum production, wheezing are unusual
On PE: bibasilar fine end-inspiratory crackles and clubbing, cor pulmonale as well in advanced cases. |
| How is the evaluation of asbestosis? | Depends on hx of exposure, includes pulmonary function, imaging, BAL (limited role).
Characteristics of PFT: reduced lung volume (DLCO, total lung capacity, decreased compliance, absence of airflow by spirometry (normal FEV1/FVC))
Earliest abnormalities are reduced DLCO and pulmonary compliance and presence of exertional hypoxemia |
| What are image findings of asbestosis? | Small bilateral parenchymal opacities with multinodular pattern or reticular pattern
15-20% normal chest, begins lower lung zone, bilateral plaques on parietal pleura
Combined interstitial and pleural involvement may cause hazy ground-glass appearance to the CXR blur heart making a shaggy heart sign.
Honeycombing may occur in advanced stages
HRCT: up to 30% pt get abnormal HRCT even with normal CXR, findings include: subpleural densities, basilar dorsal fibrosis, coarse parenchymal bands, honeycombing , pleural plaques |
| What are complications associated with asbestosis? | Respiratory failure (risk factors is cumulative exposure to asbestos, duration, symptoms of dyspnea, honeycombing, diffuse pleural thickening, cigartte smoke, fiber type)
Malignancy (risk include exposure to both smoke and asbestos (asbestos alone: 6 fold, cigarette smoking: 11 fold, both together: 59 folds malignancy) |
| What is benign asbestos pleural effusion? | Pleural involvement is hallmark of asbestos exposure (not seen in other ILD)
usually small unilateral effusions occur before onset of interstitial disease.
Duration is variable 5.5 years to 28 years (between exposure at onset of BAPE: 15 yrs - 46 yrs)
Earlier onset is correlated with high-moderate exposure.
May resolve spontaneously over weeks to months, can recur on same or opposite sides in 30% of individuals.
As it regresses, it may be seen in costophrenic angle with diffuse thickness of pleura.
No increased mesothelioma |
| What are asbestos pleural plaques and diffuse pleural thickening? | benign consequence of exposure, plaques in areas of thickening pleura, with linear, band like or nodular appearance
Composed of collagen deposits (parietal pleura), screened with low dose CT.
Involve parietal pleura close to ribs, intercostal space and rarely visceral pleura, mostly sixth-ninth ribs along diaphragm and typically bilateral |
| What are pleural diseases associated with asbestosis? | Calcifications (20% at CT scan)
Diffuse pleural thickening (>3mm, extends craniocaudad >8cm, axially>5cm)
Rounded atelectasis (without presence of BAPE) |
| What is malignant mesothelioma? | Highly associated with asbesotsis, neoplasm of pleural cavity, peritoneal cavity, pericardium and tunica vaginalis
MPM most common (malignant pleural mesothelioma), duration of exposure is 17 years, and latency is 24 years
Non specific symptoms, invasion of local structures also have additional symptoms. |
| What is silicosis? | Spectrum of diseases with free crystalline silica inhalation
acute silicosis, chronic silicosis (simple/ progressive massive fibrosis), accelerated silicosis. |
| What are occupations associated with silicosis? | Underground coal mining, steelwork (most common), glass manufacture, tunneling, sandblasting... |
| What is acute silicosis? | Acute silicoproteinosis (after exposure to high concentration of silica, symptoms within few weeks to years after initial exposure
symptoms include cough, weight loss, fatigue, pleuritic pain
bilateral alveolar filling pattern similar to proteinosis.
On imaging we see bilateral diffuse ground glass opacities, may be perihilar or basilar
CT: numerous centrilobular nodular opacities, focal ground glass opacities patchy areas of consolidations |
| What are is histologic findings in acute silicosis? | BAL: excludes infection, EP, alveolar hemorrhage. see thick opaque effluent similar to proteinosis.
Cytology see foamy macrophages bright positive image in PAS.
in acute one nodules are rarely seen and poorly developed, alveoli filled largely of phopholipids or surfactant
Thickened interstitium with inflammatory cells, minimal fibrosis, |
| How is dx of silicosis? | hx of exposure, image findings of consolidations, milky lipoproteinacious BAL, exclusion of other causes
Lung biopsy not necessary if definite exposure |
| What is chronic silicosis? | Simple (innumerable, sharply marginated, small rounded opacities composed of hyalinized, collagenous nodules, with a predilection for dorsal aspects of the upper lobes.)
Progressive massive (is characterized by nodular lung lesions 1 cm or greater in diameter that have radiating strands extending out from the nodule - may be calcified or air filled) |
| What is accelerated silicosis? | high level of exposure, within 10 years, more rapid than chronic
May be asymptomatic on CXR, symptoms include cough dyspnea (upon exertion) (PMF more severe)
Dx: 3 elements: hx of exposure, chest imaging with opacities, and absence of other dx |
