B4.067 Pulmonary Vascular Disease

Question 1

3 major diseases of the pulmonary vessels

Answer 1

pulmonary embolism
pulmonary hypertension
pulmonary edema

Question 2

normal RA pressure

Answer 2

0-8 mmHg

Question 3

normal RV pressure

Answer 3

20-30/0-8 mmHg

Question 4

normal pulm artery pressure

Answer 4

20-30/8-15 mmHg

Question 5

normal pulmonary artery wedge pressure

Answer 5

8-12 mmHg

Question 6

how do you get a wedge pressure?

Answer 6

extend catheter through pulm artery until it completely occludes a vessel and the only pressure is the backpressure

Question 7

how do you calculate pulmonary vascular resistance?

Answer 7

(mean pulm artery pressure - LA pressure) / pulm blood flow

Question 8

what are the 5 primary classes of pulmonary hypertension

Answer 8

1. pulmonary artery hypertension
2. left heart disease
3. PH with respiratory disease or hypoxia
4. chronic thromboembolic disease
5. unclear/multifactorial

Question 9

what does the new classification system emphasize?

Answer 9

similar pathologic findings, similar hemodynamic characteristics, and similar management

Question 10

what is pulmonary arterial hypertension (PAH)?

Answer 10

sustained elevation of mean pulm arterial pressure of > 25 mmHg
mean pulmonary capillary wedge pressure and/or mean LV end diastolic pressure <15 mmHg

Question 11

what is the multiple hit hypothesis of the pathogenesis of PAH

Answer 11

primary genetic background + modifier genes + environmental trigger = PAH

Question 12

what are some examples of environmental triggers of PAH

Answer 12

meth

scleroderma

Question 13

discuss the pathology of PAH

Answer 13

pulm artery remodeling:

• intimal fibrosis
• medial hypertrophy
• adventitial proliferation
• luminal obliteration

Question 14

what are some effects of PAH

Answer 14

RV hypertrophy
increased central venous pressure
peripheral edema
JVD
SOB

Question 15

what 3 pathways may target PAH

Answer 15

endothelin
NO
prostacyclin

Question 16

discuss prostacyclin

Answer 16

activity through cAMP
vasodilator
inhibits proliferation of vascular smooth muscle
decreases platelet aggregation
decreased prostacyclin synthase in PAH

Question 17

discuss endothelin 1

Answer 17

increases intravascular volume and CO by being a potent vasoconstrictor
inhibiting this may help with PAH

Question 18

what are goals of PAH therapy

Answer 18

dilate blood vessels
help heart
prevent blood clots
decrease scarring/blocked vessels

Question 19

what are some options for PAH supportive therapy

Answer 19

oxygen
Coumadin
diuretics
treatment of underlying/ co-existing disease

Question 20

spectrum of treatment options for PAH from least to most intensive

Answer 20

nothing
oral meds
nebulized meds
continuously infused meds
gene therapy
lung transplant

Question 21

classes of drugs that help with PAH

Answer 21

prostacyclin
prostacyclin analogues
phosphodiesterase inhibitors (increases NO concentration)
endothelin-receptor antagonists

Question 22

how do thrombi form?

Answer 22

blood stasis
hyper-coagulable states
vessel wall abnormalities

Question 23

where do pulmonary emboli originate?

Answer 23

deep veins of the lower extremities or pelvis
upper extremity veins (catheters)
right heart chamber (a fib)
superior vena cava

Question 24

what is the effect of a pulmonary embolus?

Answer 24

decreases or total cessation of pulm blood flow to the affected distal zone
increased PVR (50% occlusion necessary)

Question 25

what happens when pulm blood flow decreases?

Answer 25

physiologic dead space increased bronchoconstriction surfactant production decreases-resulting in atelectasis arterial hypoxemia

Question 26

what happens when PVR increases after 50% occlusion occurs?

Answer 26

when mean PAP reaches > 40 mmHg, RV will fail and collapse occurs

Question 27

what causes death from PE?

Answer 27

cardio collapse, not resp failure

Question 28

characterize resolution of PEs

Answer 28

resolution occurs rapidly with only a small percentage suffering permanent perfusion defects

Question 29

what are clinical signs of PE

Answer 29

``` pain/swelling of extremities (DVT) dyspnea (sudden onset) pleuritic chest pain cough apprehension hemoptysis tachycardia, tachypnea, hypoxia ```

Question 30

how do you diagnose DVT

Answer 30

ultrasound

Question 31

how do you diagnose PE

Answer 31

CT chest

Question 32

how do you prevent PE

Answer 32

most immobilized hospitalized patients need prophylaxis for DVT - pharmacological anticoagulants - mechanical: pneumatic calf compression

Question 33

how do you treat an acute DVT or PE?

Answer 33

anticoagulation | heparin/warfarin/NOACS

Question 34

what are supportive therapies for PE?

Answer 34

oxygen to treat hypoxemia fluid and vasopressors for hypotension and shock thrombolytics only when shock/cardiac arrest embolectomy

Question 35

what are 2 types of pulm edema

Answer 35

cardiogenic | non-cardiogenic

Question 36

what is the cause of cardiogenic pulm edema

Answer 36

pressure related phenomenon | LV problems, left sided valve problems, pulm vein obstructions

Question 37

what is the cause of noncaridogenic pulm edema

Answer 37

leaky capillaries | ARDS, HAPE, neurogenic, opiate overdose

Question 38

how do lungs typically protect themselves from excessive accumulation of fluid into interstitial spaces?

Answer 38

lymphatic drainage into SVC aided by changes in intrathoracic pressure with normal respiration loose connective tissue located along peribronchovascular space and extending to the level of the bronchiole is capable of storing 2x the normal fluid content of the lungs gel like matrix of the lung is capable of absorbing additional fluid without affecting interstitial pressures

Question 39

pathophysiology of pulm edema

Answer 39

``` decreased lung compliance decreased lung volumes increased airway resistance increased work of breathing V/Q mismatch increased (A-a)O2 gradient hypoxemia ```

Question 40

clinical findings of mild pulm edema

Answer 40

dyspnea on exertion orthopnea few rales in bases variable peripheral edema

Question 41

clinical findings of acute/severe pulm edema

Answer 41

``` productive cough of frothy blood tinged sputum tachypnea apprehensive peripheral extremities cool, clammy, cyanotic rales, wheezing throughout engorged neck veins tachycardia cardiac enlargement ```

Question 42

how to manage cardiogenic edema

Answer 42

improve cardiac function (afterload reduction, inotropes) eliminate excess fluid oxygen/ventilator support advanced therapies : ECMO, LVAD

Question 43

how to manage non-cardiogenic edema

Answer 43

oxygen/respiratory support ICU care advanced support treat underlying disease