Pulmonary vascular disorders Flashcards
what is pulm edema
fluid accum in alveoli (theres always a small amount of fluid there)
et of pulm edema
usually left sided heart failure
- non cardiogenic
- IV fluid overload
- smoke inhalation
- aspiration
- IV drug abuse (recreational)
how does smoke inhalation affect pulm edema
toxic fumes such a from fire bring inflm which changes permb and leads to fluid int he alveoli
how does IV drug abuse contribute to pulm edema
there is inc permb and CNS depression of resp and circ fx
patho of pulm edema
Fluid from blood to IS to alveoli leads todec resp function
(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)
mnfts of pulm edema
- cough
- productive (frothy, blood tinged)
- dyspnea
- dec lung compliance (like inflating balloon in it)
- crackles
tx of pulm edema
- resp support
- cause eg inc heart fx
pulmonary embolism occurs where? what is it?
- 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)
which side of the pul circuit will the emboli come from
R side (from heart)
et of pulm embolus
•Usually from DVT (in veins
-Iliac, popliteal, or femoral V
•Other emboli:
o Fat – could come from bone marrow if you have fracture (sever blood vessels which have marrow adjoining, fat enters circulation here)
o Air (through IV, injection)
o 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)
• Saddle embolus = embolus settles in “saddle” formed by bifurcation of the pulmonary artery
patho of pulm embolus
- DVT –> embolus –> thrombus in arterial bed –> impaired perfusion
- Ventilation : perfusion imbalance –> hypoxemia
- Platelets degranulate(mediators released) –> bronchial and pulmonary artery constriction –>hemodynamic instability (= blood volume, pressure, and flow)
- Reflexive bronchoconstriction (SNS response)
- Dec in cardiac output (d/t thrombus occluding pulmonary artery so little blood returning to the left side of the heart)
- L/o surfactant–>atelectasis
- Right-sided heart failure possibly results
what is worse hypoxemia from pulm embolus of embolus itself
embolus
why does a loss of surfactant and atelectasis result from pulm embolus
1) Any secretion from a gland requires adequate perfusion;
2) Even if perfusion is partial or relatively adequate, whenever there is some impact in perfusion, you have ischemic damage to these cells
why can R side of heart fail with PE
what could result from this
heart is pumping against inc resistance which will cause hypertrophy and failure
LSHF could result but generaly there will be intervention before this stage
mnfts of PE
• Based on size and site
• Usually: chest pain, tachypnea, dyspnea(Ahmed says we will NOT be able to explain these!)
o Chest pain d/t Ischemia
o Tachypnea d/t resp system working in concert with cardio system…one is failing, the other is attempting to compensate. Also may have bronchoconstriction
• Tachycardia - compensatory response for dec’d CO
dx of pulmonary embolus
- Hx and px– could be MI for all we know.
- ABG
- LDH3
- Lung scan (131 I-HSA, IV)
- CT, Chest xray
- Pulmonary angiogram
what is LDH3
(Lactate Dehydrogenase, enzyme released when there is damage to the lung tissue (d/t infarction from ischemia) )
o #3 says is subset of other LDH…like subclasses of CKMB, BB, etc.
what is the lung scan and how does it relate to pulm embolus
what can it tell us
lung scan (131 I-HSA, IV) –( HAS is marked albumin (??Double check this???), protein is labeled with Iodine 131; a radio isotope used to tag compounds;
o Will show you if you have a larger obstruction
o Albumin marked with isotope injected
o This is non invasive procedure )
what is more definitive lung scan or pulmonary angiogram
pulm angiogram (camera on catheter threaded into pulmonary circuit; this is more definitive than HAS, but is invasive)
tx of pulm embolus
• STAT treatment improves prognosis
- Anticoagulants and thrombolytics
- Maintain cardio-pulmonary function (avoids shock)
• Treat DVT
what is pulm HTN
what is it similar to
- Sustained pressure inc in pulm circuit (>25 mmHg; normal ~15)
- Is like portal hypertension in that is confined to the pulmonary system
what is the pulm circuits P like
• Pulmonary circuit
o Is low pressure, low resistance circuit. ( has many paths as vessels disseminate, so as progress into capillary beds, pressure drops)
Analogy of cars leaving highway…if more streets to follow,
If cardiac output increases, will be slight increase in pressure of the circuit, but should not cause any significant inc in pressure (vessels should be able to handle that inc)
If traffic increases, and then you also have a bunch on construction, then going to be lots of backup of traffic
how does an inc in CO affect the pulm circuit
what affects the P in this circuit
o If CO inc -> minimal inc in pulmonary pressure
pulmonary vasoconstriction->inc P
et of pulm HTN
-occur secondary to crdiac and pulm problems
3 kinds
1) inc in pulm volume eg cardiac septal defects
2) hypoxemia
3) inc pulm venous P (eg left ventricular dysfx)
how is inc pulm volume (eg cardiac septal defects et factor for pulm HTN)
septal defects the fetal blood doesnt cycle through the lungs which is partially achieved by having opening of septum between RA and LA so blood is channeled through this and out through aorta
with a septal defect incomplete closure means more blood is being sent through the lungs
how is hypoxemia an et factor for pulm HTN
if tissues are deprived of O2 the vessels respond by dilating. In other tissues the oxygen comes from the lungs but with this hypoxemia in the lung tissue itself the lung vessels actually vasocontrict in an effort to localize the accum of CO2 instead of causing widespread hypoxemia