01a: Dyspnea, Obstructive Diseases Flashcards
Hearing “velcro” on lung sounds; formally called (X).
X = crackles
(X) breath sound is normal if heard over trachea, but abnormal if heard over lungs.
X = bronchial
Obstruction of airflow in bronchial tree will present as (X) breath sounds. If obstruction is in upper airway, (Y) breath sounds heard.
X = wheezing Y = stridor
T/F: PaO2 is more tightly regulated by CNS than PaCO2.
False - PO2 detected by peripheral chemoreceptors, while PCO2 tightly regulated by CNS
PaO2 is determined by which three factors?
- PAO2 (in alveolus)
- Ability of O2 to diffuse into blood of lung cap
- Ability of lung to match ventilation and perfusion (V/Q ratio)
Write out Alveolar Gas Equation. Which factor(s) is/are measured?
PAO2 = FO2(PB-PH2O) - (PaCO2/R)
PaCO2 is measured
Respiratory quotient (R) represents (X). What’s the normal value?
X = CO2 produced/O2 consumed
0.8
The ABG provides (X) value(s) to allow clinician to calculate A-a gradient.
- PaCO2 (to calculate PAO2)
2. PaO2
Reduced PaO2 with normal A-a gradient are due to which potential causes? How can the clinician differentiate between these?
- Hypoventilation (will produce hypercarbia)
2. Low FIO2 (high altitude)
Shunt: you would expect SvO2 to be (increased/decreased).
Increased
Four main causes of low SvO2:
- Anemia
- Low CO (delivery)
- High VO2 (tissue consumption)
- Arterial desaturation
Hypoxemia is present if (X) value is (over/under) (Y).
- X = PaO2 under Y = 60mmHg
2. X = oxygen sat under Y = 90%
List the mechanistic causes of hypoxemia. Star the most common cause.
- V/Q Mismatch*
- Shunt
- Hypoventilation
- Diffusion abnormality
At (X) landmark, V/Q ratio equals 1.
X = rib 3
Which shunt(s) may exist in normal, healthy individual?
- Thebesian veins (heart)
2. Bronchial to pulm venous anastamoses
V/Q ratio equals zero in which disease state?
Shunt (V equals 0)
V/Q ratio equals infinity in which disease state?
Pulmonary embolism (Q equals 0)
Patient is hypoxemic and treatment with 100% O2 does not cause PO2 levels to rise as expected. What do you suspect is the cause of his hypoxemia?
R to L shunt
Patient has thickened blood-gas barrier. Will exercise help raise his PO2?
No - increase in blood flow will shorten time that RBC has in pulmonary capillary, so won’t reach full O2 saturation
Bronchial mucosa has (X) epithelium and which other cells/structures?
X = pseudostratified ciliated
Goblet cells, cartilage, submucosal (mucus) glands
(X), fundamental unit of lung, consists of which structures?
X = acinus
- Resp bronchiole
- Alveolar duct
- Alveolus
Alveolar wall: (X) lined by endothelium rests on BM in contact with (Y), which is in contact with BM of (Z).
X = capillary Y = interstitium (collagen, elastic fibers) Z = alveolar epithelium (Type I and II pneumocytes)
95% of alveolar surface is covered by (X) cells.
X = Type I pneumocytes (flattened)
Function(s) of Type II pneumocytes.
- Stem cells (replace Type I pneumocyte)
2. Surfactant production
(X) structures in (bronchi/bronchioles/alveoli) walls allow communication.
X = pores of Kahn
Alveoli
Most, (X)% of emphysema, is (pan/centri)-acinar emphysema and affects (Y) portion of acinus.
X = 95
Centriacinar;
Y = respiratory bronchiole
(Centri/pan)-acinar emphysema occurs in heavy smokers (often with COPD) and is more severe in (upper/lower) lobes.
Centriacinar;
Upper
(Centri/pan)-acinar emphysema associated with (X) deficiency and is more common in (upper/lower) lobes.
Panacinar;
X = alpha-1 antitrypsin
Lower
Pathogenesis of emphysema is primarily based on (X) phenomena.
X = protease-antiprotease and oxidant-antioxidant imbalances
Emphysema: loss of (X) of lung parenchyma results in collapse of (Y) structures. Hence, “obstructive” disease.
X = elastic recoil Y = respiratory bronchioles
Chronic bronchitis is defined clinically with which symptoms?
Persistent cough with sputum production (for at least 3 months in at least 2 consecutive years)
Chronic bronchitis: which histological/structural changes would you expect to find?
- Hypertrophy of submucosal glands (Reid index)
- Goblet cell metaplasia
- Mucus plugging
- Fibrosis
Reid index is the ratio of (X) to (Y). What’s a normal value?
X = thickness of bronchial submucosal glands Y = thickeness of wall between epithelium and cartilage
0.4
Bronchiectasis: (reversible/irreversible) dilation of (X) structures due to (Y).
Irreversible;
X = bronchi/bronchioles
Y = destruction of wall by necrotizing infections/pneumonia
Congenital bronchiectasis is associated with (X) disease.
X = CF
Bronchiectasis typically affects (upper/lower) lobes, (uni/bi)-laterally.
Lower;
bilaterally
Bacterial pneumonia presents as which patterns/distributions?
- Lobar (consolidation)
2. Bronchopneumo (patchy)
Stages of lung inflammation in pneumonia:
- Congestion
- Red hepatization
- Grey hepatization
- Resolution
In (X) stage of pneumonia inflammation, there’s massive confluent exudation of RBCs, neutrophils, and fibrin in (interstitium/alveoli). Lung is red, firm, airless.
X = Red hepatization
Alveolar spaces
Location of inflammation in viral/mycoplasma pneumonia is:
confined to alveolar septa and interstitium
T/F: Pleuritis is more frequent in viral pneumonia than in bacterial pneumonia.
False
Viral pneumonia: alveolar spaces typically contain (X).
X = nothing (inflammation confined to interstitium/septa)
OR may have cell exudate/fibrin due to alveolar damage
(X) pneumonia usually occurs in markedly debilitated patients. The infectious agents originate from (Y).
X = aspiration Y = oral flora (bacteria)
Methacholine challenge: Increasing dose of methacholine is expected to (increase/decrease) (X) in (Y) patients. Why?
Decrease;
X = %FEV1 (when compared to their original value)
Y = asthmatic/hyperactive airway patients
Methacholine increases twitchiness/bronchoconstriction of airway and asthmatics will react to lower doses of this drug
Early phase response to inhaled allergen involves (sudden/gradual) decrease and then increase in (X) value. This is due to (Y) phenomenon.
Sudden;
X = FEV1
Y = bronchoconstriction
Late phase response to inhaled allergen involves (sudden/gradual) decrease and then increase in (X) value. This is due to (Y) phenomenon.
Gradual
X = FEV1
Y = edema, secretions, inflammation
Asthma histology: goblet cell (hypo/hyper)-plasia, (X) changes in BM, and submucosal (Y) deposition.
Hyperplasia;
X = thickening
Y = collagen
Asthma histology: smooth muscle (hypo/hyper)-plasia and vascular (constriction/dilation).
Hyperplasia;
Dilation
List the causes of airway obstruction in asthma.
- Bronchial/bronchiolar mucosal inflammation and edema
- Smooth muscle hypertrophy/constriction
- Excess mucous in lumen
Early day care exposure and older siblings are factors that favor Th(1/2) phenotype, aka (X).
Th1;
X = protective immunity
Widespread use of antibiotics and urban environments are factors that favor Th(1/2) phenotype, aka (X).
Th2;
X = allergic diseases (i.e. asthma)
Asthma: (increase/decrease) in AP diameter and (increase/decrease) in accessory muscle use.
Increase both
Which skin findings might you look for when suspecting asthma in patient?
Eczema
Which upper airway findings would you look for when suspecting asthma in patient?
- Sinusitis
- Rhinitis
- Nasal polyps
T/F: In most cases of asthma, chest X-ray is normal.
True
List the primarily therapies for acute asthma exacerbation.
- Beta-2 agonist administration (repetitive, rapid-acting)
- Glucocorticosteroids (systemic)
- Oxygen supplementation
