Pulm Flashcards
How do panic attacks cause sx of anxiety, dizziness, blurred vision, weakness?
Hyperventilation! Decreased PCO2 - dec. cerebral perfusion. (CO2 is a cerebral vasodilator).
How does asbestosis present on imaging?
Calcified pleural plaques! esp in posterolateral lung zones
What is cheyne-stokes breathing?
Cyclic breathing: Apnea -> gradually increasing TV -> gradually decreasing TV -> apnea
Due to slow resp feedback loop and enhanced response to PaCO2 levels.
Seen in Cardiac (CHF) and Neuro (Stroke, Tumor, TBI) Patients!
What causes COPD?
- Chronic Bronchitis - anatomic narrowing bronchi
2. Emphysema - interalveolar destruction of walls
What happens in respiration when vagal nerve stimulated?
Bronchoconstriction & Increased mucus production
-> increased work of breathing.
What cell type generates elastase?
PMN!
In smoking induced emphysema, smoking activates PMNS and macrophages to release proteases (elastase) who then generate ROS species that inhibit alpha1antitrypsin. Imbalance of protease-antiproteases = emphysema.
Aspiration pneumonia ends up where supine vs. upright?
R > L bronchus
Supine: Posterior upper lobe, Superior lower lobe
Upright: Basilar lower lobe
Aspiration Pneumonia goes where when supine vs. upright?
supine - posterior upper lobe, superior lower lobe
upright - basilar lower lobe.
How are dust particles cleared from the lung?
Based on size:
< 2 microm = macrophages in alveoli
2.5-10 microm = mucociliary transport
10-15 microm = trapped in upper resp tract
Pneumoconiosis (interstitial fibrosis 2/2 inhalation of inorganic dust) arises bc after macrophages phagocytose the particle, they release cytokines that can induce injury and inflammation -> release of growth factors -> PDGF -> more inflam and fibrosis.
Function of CTFR on apical surface? Nasal Transepithelial potential difference shows?
Normal Function:
1. Secretes Cl- into the lumen
2. Causing inhibition of Na channel - decreasing Na absorption
=> Increased Cl, Na, water in the mucus
Nasal Transepithelial Potential Difference: difference btwn resp epithelial surface vs. interstitial fluid = (-) bc of increased Na absorption!
Surfactant acts to ?
Decrease surface tension in smaller alveoli as they decrease in size such that they don’t collapse during expiration.
Q477: Ex: P = 2T/r If surface tension is the same, alveoli with smaller radii have greater pressure and will therefore collapse as flow goes high to low pressure.
How to treat severe RSV bronchiolitis in children with immunodef, cardiopulm condition?
Warm humidified O2, IVF
Ribavarin - nucleoside analog inhibits synthesis of guanine nucleotides, active against RSV and Hep C
Lung Boundaries (midclav, midax, paravertebral)
Midclav: 5-7
Midax: 7-9
Paravertebral: 9-11
First # = lung border
Second # = pleural border
Thoracentesis should be done right above the second numbered rib.
Hypotension, Tachycardia in pt stabbed just above the clavicle?
Tension Pneumo!
At what lung volume is pulmonary vascular resistance the lowest?
Functional Residual Capacity
U-shaped curve: Q1620
- increased volume - stretch it so increased length and small diameter
- decreased volume - narrowed due to traction and compression by intrathoracic pressure from expiration
SVC syndrome vs. braciocephalic vein obstruction?
SVC: BILATERAL swelling of face, arms, neck, engorgement of collateral veins
Brachiocephalic: ONE SIDE - R or L
What is the difference btwn minute ventilation and alveolar ventilation?
Dead space.
Ve = Vt x RR Va = Vt-Vd x RR
Equilibration of O2 btwn tracheal pO2 and alveolar pO2 (ie diffusion from alveolar pO2 and arterial pO2) is limited how normally vs. in diseased states?
Perfusion Limited = Normal O2, CO2 - Reaches diffusion equilibrium before the end of the capillary.
- so if you see that tracheal pO2 and alveolar pO2 are not much different = Perfusion limitation = PE
Diffusion LImited = Emphysema, Pulm Fibrosis
Normal Tracheal pO2 150
Normal Alveolar pO2 104
Normal Alveolar pCO2 40
Q1522
How does V/Q change from apex to base?
High V/Q at apex – decreases – Low V/Q at base.
Although both V and Q are greater at the base, perfusion changes are relatively greater.
What disease is associated with calcified hilar nodes + birefringent particles surrounded by fibrosis?
Silicosis
Lab value changes at high altitude.
Hypoxemia = Low PO2 (~60)
Compensatory Hyperventilation -> Resp Alkalosis
Low PCO2, High pH
What should you add on to treat severe allergic asthma?
Omalizumab (anti-IgE antibody)
Where is airway resistance the lowest in the bronchial tree? highest?
Lowest = terminal bronchioles Highest = medium sized bronchioles
When hemoglobin picks up O2, what dose it release?
H+
Haldane effect Q1386
