Exam 1 Part 1 Flashcards
what 3 factors are involved in maintaining adequate respiration?
- adequate intake of air
- rapid diffusion
- adequate perfusion
where is the blood air interface?
between type I pneumocytes & endothelium
what are the 4 classical classifications of pulmonary pathology?
- degenerative
- inflammatory
- pleural
- neoplasm
what are congenital pulmonary abnormalities? what can they cause?
- agenesis
- hypoplasia
- tracheal/bronchial anomalies
- all can cause NRDS
what is pulmonary hypoplasia often secondary to?
- IUGR
- congenital diaphragmatic hernia
what TE fistula is the most common?
esophageal atresia + distal TE fistula
what causes NRDS? what is it also known as?
- lack of surfactant
- born <28 wks
- hyaline membrane disease (membranes form as result of loss of surfactant)
what are some other causes of NRDS (besides congenital)?
- over sedation of mom
- head trauma during birth
- aspiration of blood or amniotic fluid
- intra-uterine hypoxemia
is atelectasis a disease itself?
NO it is an anatomic/physiologic/geometric CONCEPT seen in many disease states
what are the 3 forms of atelectasis?
- resorption, tumor
- compression, pleural effusion
- contraction, diffuse lung fibrotic process
what is PEd? what are causes of PEd?
- accumulation of fluid in lungs= impaired gas exchange= possible respiratory failure
1. failure of heart to remove fluid from lung circ
2. direct injury to parenchyma
3. fluid overload
4. hypoalbuminemia
5. lymphatic obstruction
6. “strange things”
7. infection
8. liquid or gas or chemical aspiration
9. chemotherapeutic agents
10. high altitude sickness
what are the 4 main pathologic mechanisms which lead to PEd?
- increased venous pressure
- increased oncotic pressure
- lymphatic obstruction
- alveolar injury
how does acute PEd present? chronic PEd?
ACUTE: rapid, pain, potentially life threatening, usu due to left ventricular failure
CHRONIC: pain or maybe not
what are sxs of acute PEd?
- tachypnea
- extreme dyspnea (SOB)
- restlessness & anxiety (sense of suffocation)
- marked bronchospasm & wheezing (cardiac asthma)
what can alveolar fluid act as in chronic PEd? how are the alveolar walls? what else appears in the alveoli?
- culture medium for bac
- walls become fibrotic
- micro-hemorrhages phagocytized by MOs= heart failure cells
is ARDS NCPE or CPE? what does this lead to accumulating in the alveoli?
- ARDS is NCPE
- leads to exudate (proteins) in the alveoli
what does ARDS lead to?
- low blood O2
- increased permeability of pulmonary bvs
- fluid accumulation in lungs
- death of lung cells
what is ARDS commonly due to? what if it is idiopathic?
- sepsis
- widespread lung infections
- gastric aspiration
- mechanical trauma
- multi-organ failure
- burns, inhaled gases & chemicals
- about 20% no identified risk factor= INTERSTITIAL PNEUMONIA
what is damaged in ARDS? what does this lead to?
- endo and/or type 1 epithelial cells, possibly type 2 epis
- damage to endo & type 1 leads to increased permeability of capillaries, flooding of fluid, loss of gas exchange
- damage to type 2 leads to less surfactant
- form microscopic clots= decreased blood flow & O2
- hyaline membranes (protein-rich fluid & dead alveolar epithelial cells)
what immune cell causes the most damage in ARDS and how?
- neutrophils
- produce oxidants, proteases, PAF, leukotrienes
- normally balanced by antioxidants, anti-proteases, anti-inflammatory cytokines
SSxs of ARDS?
- tachypnea
- dyspnea
- cyanosis
- respiratory failure & possible acidosis
- bilateral fluid seen on CXRs
what is the prognosis of ARDS? what does it often progress to? how does resolution happen?
- prognosis: 30-70% mortality rate, increases with age, usu due to sepsis
- often progresses to multi-system organ failure and death
- resolution includes resorption of fluids & debris, replacing epi & endothelial cells
what are the characteristics of obstructive lung diseases?
- small airway expiratory disease
- hyperexpansion on CXR