cvpr physiology 3 Flashcards
Pulmonary embolism features on ECG
May have S1Q3T3 abnormality on ECG
PE diagrams
pg 654
Flow-volume loops
Pg 655
RV in obstructive lung disease
↑
RV in restrictive lung disease
↓
FRC in obstructive lung disease
↑
FRC in restrictive lung disease
↓
TLC in obstructive lung disease
↑
TLC in restrictive lung disease
↓
FEV1 in obstructive lung disease
↓↓
FEV1 in restrictive lung disease
↓
FVC in obstructive lung disease
↓
FVC in restrictive lung disease
↓
FEV1/FVC in obstructive lung disease
↓
FEV1/FVC in restrictive lung disease
Normal or ↑ FEV1 decreased proportionately to FVC
Flow volume loops pg
655
Blue bloater disease
Chronic bronchitis
Pink puffer disease
Emphysema
Chronic bronchitis presentation
- Wheezing
- Crackles
- Cyanosis (hypoxemia due to shunting)
- Dyspnea
- CO2 retention (respiratory acidosis)
- 2° polycythemia
Pathology of chronic bronchitis
Hypertrophy and hyperplasia of mucus-secreting glands in bronchi → Reid index (thickness of mucosal gland layer to thickness of wall between epithelium and cartilage) > 50%
DLCO is usually normal
Diagnostic criteria of chronic bronchitis
Productive cough for > 3 months in a year for > 2 consecutive years
Emphysema presentation
Barrel-shaped chest
Exhalation through pursed lips (increases airway pressure and prevents airway collapse)
Pathology of emphysema
- Centriacinar - associated with smoking Frequently in upper lobes (smoke rises up)
- Panacinar - associated with α1-antitrypsin deficiency, frequently in the lower lobes
- Enlargement of air spaces ↓ recoil, ↑ compliance, ↓ DLCO from the destruction of alveolar walls
- Imbalance of proteases and antiproteases → ↑ elastase activity → ↑ loss of elastic fibers → ↑ lung compliance
Imaging of emphysema
CXR: ↑ AP diameter, flattened diaphragm, ↑ lung field lucency
Presentation of asthma
- Cough
- Wheezing
- Tachypnea
- Dyspnea
- Hypoxemia
- ↓ inspiratory/expiratory time ratio (expiratory time is increased)
- Pulsus paradoxus
- Mucous plugging
What is pulsus paradoxus
Pulsus paradoxus, also paradoxic pulse or paradoxical pulse, is an abnormally large decrease in stroke volume, systolic blood pressure and pulse wave amplitude during inspiration. The normal fall in pressure is less than 10 mmHg. When the drop is more than 10 mmHg, it is referred to as pulsus paradoxus.
Asthma triggers
- Viral
- URIs
- Allergens
- Stress
Dx of asthma
- Spirometry
- Methacholine challenge
Histology of asthma
- Hyperresponsive bronchi → reversible bronchoconstriction
- Smooth muscle hypertrophy and hyperplasia
- Crurschman spirals (shed epithelium forms whorled mucous plugs)
- Charcot-Lyden crystals (eosinophilic hexagonal, double-pointed crystals formed from breakdown of eosinophils in sputum
Asthma type of reaction
Type I hypersensitivity reaction
What is aspirin-induced asthma
Aspirin-induced asthma is a combination of:
- COX inhibition (leukotriene overproduction → airway constriction)
- Chronic sinusitis
- Nasal polyps
- Asthma symptoms
List of Obstructive lung diseases
Bronchiectasis
Chronic bronchitis
Emphysema
Asthma
List of restrictive lung diseases
Sarcoidosis
Inhalation injury and sequelae pneumoconiosis
Pulmonary fibrosis
Presentation of bronchiectasis
- Purulent sputum
- Recurrent infections
- Hemoptysis
- Digital clubbing
Pathology of bronchiectasis
Chronic necrotizing infection of bronchi or obstruction → permanently dilated airways
Bronchiectasis associated risks
- Bronchial obstruction
- poor ciliary motility (eg smoking, Kartagener syndrome)
- Cystic fibrosis
- Allergic bronchopulmonary aspergillosis
PFTs of restrictive lung diseases
↑ FEV1/FVC ratio Restricted lung expansion causes ↓ lung volumes (↓ FVC and TLC)
Breathing in restrictive lung diseases
Patients present with short shallow breaths
Categorical etiology of restrictive lung diseases
- Poor breathing mechanics
- Interstitial lung diseases
Restrictive lung diseases w/ a muscular etiology
Polio
Myasthenia gravis
Guillain-Barre syndrome
Restrictive lung diseases w/ poor structural apparatus
Scoliosis
Morbid obesity
List of restrictive lung diseases
- Pneumoconioses
- Sarcoidosis
- Idiopathic pulmonary fibrosis
- Good pasture syndrome
- Granulomatosis with polyangiitis
- Pulmonary langerhans cell histiocytosis
- Hypersensitivty pneumonitis Drug toxicity
What is hypersensitivity pneumonitis
Mixed type III/IV hypersensitivity reaction to environmental antigen
Symptoms of hypersensitivity pneumonitis
4 listed
- Dyspnea
- Cough
- Chest tightness
- Headache
hypersensitivity pneumonitis most commonly occurs in?
Often seen in farmers and those exposed to birds
Reversibility of hypersensitivity pneumonitis
Reversible in early stages if stimulus is avoided
Histological and lab test features of sarcoidosis
- Characterized by immune-mediated, wide-spread noncaseating granulomas
- Elevated serum ACE levels
- elevated CD4/CD8 ratio in bronchoalveolar lavage fluid
Sarcoidosis most commonly occurs in?
African-American females
Symptoms of sarcoidosis
Often asymptomatic except for enlarged lymph nodes
Imaging of sarcoidosis
- CXR of bilateral hilar adenopathy and coarse reticular opacities
- CT of chest better demonstrates the extensive hilar and mediastinal adenopathy
Sarcoidosis associations
- A facial droop is UGLIER
- Bell palsy
- Uveitis
- Granulomas (epithelioid, containing microscopic Schaumann and asteroid bodies)
- Lupus pernio (skin lesions on face resembling lupus)
- Interstitial fibrosis (restrictive lung disease)
- Erythema nodosum
- Rheumatoid arthritis-like arthropathy
- Hypercalcemia (due to ↑ 1α-hydroxylase-mediated vitamin D activation in macrophages)
Describe granulomas in sarcoidosis
(epithelioid, containing microscopic Schaumann and asteroid bodies)
Describe lupus pernio
(skin lesions on face resembling lupus)
What is Erythema nodosum?
- Is a type of skin inflammation that is located in a part of the fatty layer of skin
- Erythema nodosum results in reddish, painful, tender lumps most commonly located in the front of the legs below the knees.
- The tender lumps, or nodules, of erythema nodosum range in size from a dime to a quarter.
- Associated with sarcoidosis
Treatment of sarcoidosis
Steroids (if symptomatic)
What is inhalation injury and sequelae
Complication of smoke inhalation from fires or other noxious substances
Common causes of inhalation injury and sequelae
Caused by heat particulates (< 1µm diameter) or irritants (eg NH3) → chemical tracheobronchitis, edema, pneumonia, ARDS
Associations of inhalation injury and sequelae
Many patients present 2° to burns and also
- CO inhalation
- Cyanide poisoning
- Arsenic poisoning
Common physical exam finding in inhalation injury and sequelae
Singed nasal hairs common on exam
Bronchoscopy in inhalation injury and sequelae
Shows severe
- Edema
- Congestion of bronchus
- Soot deposition
Pictures of inhalation injury and sequelae
658
Pneumoconiosis Mnemonic
Asbestos is from the roof, (was common in insulation), but affects the base (lower lobes) Silica and coal are from the base (earth), but affect the roof (upper lobes)
Asbestosis is associated with
Shipbuilding Roofing Plumbing
Histological features of asbestosis
Ivory white calcified supradiaphragmatic and pleural plaques are pathognomonic of asbestosis
Risks associated with asbestos
Bronchogenic carcinoma > risk of mesothelioma
↑ risk of pleural effusions
In what part of the lung does asbestosis occur?
Affects lower lobes
Histological features of asbestosis
Asbestos (ferruginous) bodies are golden-brown fusiform rods resembling dumbbells, found in alveolar sputum sample obtained by bronchoalveolar lavage
Asbestos stain
Prussian blue stain
Berylliosis associated with
Associated with exposure to beryllium in aerospace and manufacturing industries
Histological features of Berylliosis
Granulomatous (noncaseating) on histology and therefore occasionally responsive to steroids
Berylliosis associated risks
↑ risk of cancer and cor pulmonale
In what part of the lung does berylliosis occur?
Affects upper lobes
Common causes of coal workers pneumoconiosis
Prolonged coal dust exposure → macrophages laden with carbon → inflammation and fibrosis
Coal workers pneumoconiosis AKA
Black lung
coal workers pneumoconiosis associated risks
↑ risk for Caplan syndrome (rheumatoid arthritis and pneumoconioses with intrapulmonary nodules)
Location of the lung affected in coal workers pneumoconiosis
Affects upper lobes
Imaging of coal workers pneumoconiosis
Small, rounded nodular opacities seen on imaging
What is anthracosis?
asymptomatic condition found in many urban dwellers exposed to sooty air
Silicosis is commonly caused by?
Sandblasting Foundries Mines
Macrophages respond to silica and release fibrogenic factors leading to fibrosis
It is thought that silica may disrupt phagolysosomes and impair macrophages, increasing susceptibility to TB ↑ risk of cancer, cor pulmonale and Caplan syndrome
What part of the lung does silicosis affect?
Affects upper lobes
Imaging of silicosis
Eggshell calcification of hilar lymph nodes on CXR
Silicosis mnemonic
The silly egg sandwich I found is mine Histology: Eggshell calcification of hilar lymph nodes on CXR Causes: Sandblasting, Foundries, Mines
Pictures of pneumoconiosis
659
What is mesothelioma?
Malignancy of the pleura associated with asbestosis
Complications of mesothelioma
May result in:
hemorrhagic pleural effusion (exudative)
Pleural thickening
Histological features of mesothelioma
Psammoma bodies seen on histology
How to distinguish mesothelioma vs carcinoma
Calretinin (+) in almost all mesotheliomas, (-) in most carcinomas
Smoking in mesothelioma
Smoking is not a risk factor
ARDS AKA
Acute Respiratory Distress Syndrome
What is ARDS
Acute respiratory distress syndrome. Acute respiratory distress syndrome (ARDS) is a life-threatening lung condition that prevents enough oxygen from getting to the lungs and into the blood. Infants can also have respiratory distress syndrome.
Pathophysiology of acute respiratory distress syndrome
Alveolar insult → release of pro-inflammatory cytokines → neutrophil recruitment, activation and release of toxic mediators (eg, reactive oxygen species, proteases, etc) → capillary endothelial damage and ↑ vessel permeability → leakage of protein-rich fluid into alveoli → formation of intra-alveolar hyaline membranes and noncardiogenic pulmonary edema (normal PCWP)
PCWP in Acute Respiratory Distress Syndrome
Normal intra-alveolar hyaline membranes and noncardiogenic pulmonary edema (normal PCWP)
Most common cause of ARDS
Sepsis
Common causes of ARDS
Sepsis (most common)
Aspiration Pneumonia
Trauma
Pancreatitis
Dx of ARDS
A diagnosis of exclusion with the following criteria (ARDS)
Abnormal CXR (bilateral lung opacities)
Respiratory failure within 1 week of alveolar insult
Decreased PaO2/FiO2 (ratio < 300, hypoxemia due to ↑ intrapulmonary shunting and diffusion abnormalities)
Symptoms of respiratory failure are not due to HF/fluid overload
Consequences of ARDS
Impaired gas exchange
↓ lung compliance
Pulmonary HTN
Management of ARDS
Treat the underlying cause
Mechanical ventilation: ↓ Tidal Volumes, ↑PEEP
What is PEEP?
positive end-expiratory pressure
Photos of ARDS
Pg 660
What is sleep apnea?
Repeated cessation of breathing > 10 seconds during sleep → disrupted sleep → daytime somnolence
Dx of sleep apnea
Sleep study Normal PaO2 during the day
Sleep Apnea complications
- Hypoxia → ↑ EPO release →↑erythropoiesis
- Nocturnal hypoxia → systemic/pulmonary hypertension, arrhythmias (atrial fibrillation/flutter),
- Sudden death
What is obstructive sleep apnea?
Respiratory effort against airway obstruction
obstructive sleep apnea common causes
Associated with obesity, loud snoring, daytime sleepiness
Caused by excess parapharyngeal tissue in adults, adenotonsillar hypertrophy in children
Treatment of obstructive sleep apnea
Weight loss CPAP Surgery
What is central sleep apnea
Impaired respiratory effort due to CNS injury/toxicity, HF, opioids
What causes central sleep apnea?
May be associated with Cheyne-Stokes respirations (oscillations between apnea and hypernea)
Treatment of central sleep apnea
Treat with positive airway pressure
What is obesity hypoventilation syndrome?
Obesity (BMI ≥30 Kg/m2) → hypoventilation → ↑ PaCO2 during waking hours (retention);↓ PaO2 and ↑PaCO2 during sleep
Pickwickian syndrome AKA
obesity hypoventilation syndrome
obesity hypoventilation syndrome AKA
Pickwickian syndrome
What is pulmonary hypertension
Pulmonary hypertension = ≥ 25 mmHg at rest
Consequences of pulmonary hypertension
- Arteriosclerosis
- Medial hypertrophy
- Intimal fibrosis of pulmonary arteries
- Plexiform lesions
Describe the course of pulmonary hypertension
Severe respiratory distress → cyanosis and RVH → death from decompensated cor pulmonale
Types of Pulmonary hypertension
- PAH
- LHD
- Lung disease or hypoxia
- Chronic thromboembolic
- Multifactorial
What is PAH
Type I pulmonary hypertension: pulmonary arterial hypertension
Most common causes of PAH
Often idiopathic
Heritable PAH can be due to an inactivating mutation in BMPR2 gene (normally inhibits vascular smooth muscle proliferation) = Poor prognosis
Other causes include:
drugs (amphetamines, cocaine)
Connective tissue disease
HIV
Portal hypertension
Congenital heart disease
Schistosomiasis
Mechanism of PAH
Pulmonary vasculature endothelial dysfunction results in ↑ vasoconstrictors (eg endothelin) and ↓ vasodilators (eg NO and prostacyclins)
Drugs that can cause PAH
(amphetamines, cocaine)
Type 2 pulmonary hypertension AKA
Left heart disease
Type 2 pulmonary hypertension causes
Systolic/diastolic dysfunction Valvular disease
Type 3 pulmonary hypertension AKA
Lung diseases or hypoxia
Causes of Type 3 pulmonary hypertension
Destruction of lung parenchyma (eg, COPD) Lung inflammation/fibrosis (eg, interstitial lung diseases) Hypoxemic vasoconstriction (eg, obstructive sleep apnea, living in high-altitude)
Type 4 pulmonary hypertension AKA
Chronic thromboembolic