Respiratory System II Flashcards
Epidemiology and pathogenisis of pulmonary thromboembolism
Third most common cardiovascular cause of death after acute MI and stroke
Source of Pulmonary thromboembolism
Majority (90%) originate from the deep veins of the lower extremities and pelvis
Risk factors for pulmonary thromboembolism
Stasis of blood flow (prolonged bed rest, plane rides)
hypercoagulable states
Size of embolus in pulmonary thromboembolism
Determines the pulmonary vessel that is occluded
Large embolis in pulmonary thromboembolism
Occlude the main pulmonary arteries (saddle embolus)
Small emboli in pulmonary thromboembolism
Occlude medium sized and small pulmonary arteries
Consequences of pulmonary thromboembolism
- increase in pulmonary artery pressure
- decreased blood flow to pulmonary parenchyma
- may cause hemorrhagic infarction
- red-blue raised, wedge-shaped area that extends to the pleural surface
- hemorrhagic pleural effusion May also occur
- majority in lower lobes
- perfusion is greater than ventilation in the lower lobes
Clinical findings in pulmonary thromboembolism
- saddle embolus
- sudden onset of dyspnea and tachypenia
- pleuritis chest pain, friction rub
- fever
- experitory wheezing
Saddle embolus in pulmonary thromboembolism
Sudden death
Formed elsewhere that detaches and travels throughout the vasculatiure
Thrombus
DX for pulmonary thromboembolism
- CT scan
- X ray
- Abnormal perfusion radionuclide scan
- Ventilation scan is normal, but the perfusion scan is abnormal
- positive D-dimers-non-specific
Smokers and high dose contraceptives can cause
Pulmonary thromboembolism
Mean pulmonary artery pressure >25mmHg at rest and mean pulmonary artery pressure >30mmHg with exercise
Pulmonary HTN
Primary PH
More common in women, genetic predisposition
-vascular hyperreactivity with proliferation of smooth muscle
Secondary PH
- endothelial cell dysfunction, loss of vasodilator (NO), increas in vasoconstrictors
- hypoxemia and respiratory acidosis stimulate vasoconstriction of pulmonary arteries, causes smooth muscle hyperplasia and hypertrophy
Hypoxia and respiratory acidosis in PH
Stimulate vasoconstriction of pulmonary arteries
Mechanism secondary PH
Respiratory acidosis/hypoxemia, vasoconstriction
TX for PH
Cialis, lol
Combination of PH and RVH leading to right sided heart failure
Cor pulmonae
Causes of cor pulmonae
-chronic hypoxemia, chronic lung disease, living at high altitude
-chronic respiratory acidosis
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Pathological findings of cor pulmonae
Enlarged right side of heart
Condition caused by excess fluid in the lungs, this fluid collects in the numerous air sacs in the lungs, making it difficult to breathe, in most cases, heart problems causes it
Pulmonary edema
Increases hydrostatic pressure in lung capillaries in PE
Left sided heart failure, volume overload, mitral stenosis
Decrease oncotic pressure in PE
Nephrotic syndrome and cirrhosis
PE due to microvascular or alveolar injury (exudate)
- Infections-sepsis, pneumonia
- aspiration-drowning and gastric contents
- drugs (heroin)
- high altitude
Fibrosis disorders, granulomatous disease
Chronic intestinal lung disease
Pathogenisis of interstitial fibrosis
Earliest manifestation is alveolitis
Leukocytes release cytokines, which stimulate fibrosis
Effects of interstitial fibrosis
- decreases lung compliance (capacity to expand), decreased expansion of the lung parenchyma during inspiration, functional loss of alveolar capillary units
- increases lung elasticity (stiffness)
Clinical findings of interstitial lung disease
Dry cough and exertion all dyspnea
Potential for cor pulmonae
Ability of lungs to expand
Compliance