Pulm Vascular Disorders Flashcards
What is pulmonary congestion?
congestion within the blood VESSEL driving fluid out of vessels into interstitial spaces – is NOT BLOOD IN THE LUNGS!
•Not correct to say fluid in the lungs, because there is always fluid there (thin film essential for gas exchange)
What is pulmonary edema?
Accum of fluid INSIDE the alveoli
Et of pulmonary edema?
• Usually left sided heart failure • Non cardiogenic (not cardiac related causes): - IV Fluid overload - Smoke inhalation ( - Aspiration - IV drug abuse
How does smoke inhalation cause pulm edema?
not from smoking but rather from a fire…have toxic fumes in this smoke that will bring about inflm, alter permeability of vessels, which permits fluid to move into the alveoli)
How does IV drug abuse lead to pulm edema?
because inc permeability of vessels + depresses CNS (which controls resp and circ…impacting exchange of fluid between blood and instersitital spaces)
Patho of pulm edema?
`Fluid from blood to IS to alveoli → dec resp function (as longer diffusion distance)
• In order to move across for gas exchange, O2 and CO2 need to be able to dissolve into the fluid between the capillary and the alveoli…with PE, fluid is added into this space → expanded diffusion distance + also taking up space that air would otherwise occupy in alveoli
Manifestations of pulm edema?
- Cough – productive (frothy + blood tinged)
- Dyspnea
- Dec compliance (d/t presence of fluid)
- Crackles
Why is cough frothy + blood tinged with pulm edema?
frothy c/b mixing air and fluid
blood tinged if damage to blood vessels
Tx of pulm edema?
- Resp support (while find cause)
* Cause – eg: inc heart fx
What is pulm embolism?
How often does it reccur?
Is it serious?
- Thrombus in the pulmonary vessel (will be an ARTERY)
- Potentially lethal – if is one of larger arteries, will be about ~1/3 death rate
- MI is same thing in pulmonary circuit
- 10% recurrence rate (problem returns at later date)
Outline pulmonary circulation
right and left circuits, where is oxygenated, etc
R side heart Pulm arteries (deoxy) Pulm cap bed Pulm veins (oxy) L side heart Systemic circuit.
Et of pulm embolism?
- Usually from DVT (from iliac, popliteal, or femoral vein)
- Other emboli:
1) Fat
2) Air
3) Amniotic fluid
Where does a fat embolism come from?
could come from bone marrow if you have fracture (sever blood vessels which have marrow adjoining, fat enters circulation here)
Where would air embolism come from?
IV, injection
How does emboli occur from amniotic fluid?
during birthing process, these membranes rupture and release amniotic fluid….also during labour and birth, vessels are severed and burst…
• Here talking about the particulate matter in the fluid, not the fluid itself
What is a “saddle” embolus?
embolus settles in “saddle” formed by bifurcation of the pulmonary artery
Patho of pulm embolism
- DVT → embolus → thrombus in arterial bed → impaired perfusion
- Ventilation : perfusion imbalance → hypoxemia (this is small issue in comparison to thrombus)
- Platelets degranulate (mediators released) → bronchial and pulmonary artery constriction (which worsens problem) → hemodynamic instability
- Reflexive bronchoconstriction
- Dec in cardiac output
- L/o surfactant → atelectasis
- Right-sided heart failure possibly results
What is hemodynamic instability?
changes in blood volume, pressure, and flow
Why does reflexive bronchoconstriction occur with pulm embolism?
no benefit, is consequence of sympathetic response
Why dec CO with pulm embolism?
d/t thrombus occluding pulmonary artery so little blood returning to the left side of the heart