Pulmonary Circulation Disorders Flashcards
What is the MC PE? What are some other causes?
Thrombus that starts in the venous system, gets lodged into the pulmonary system
Air embolus
Amniotic fluid (during delivery, travels through the placenta, into the circulation of the female)
Fat
Foreign bodies (talc in injection from IV users, cemement from surgery)
Parasite eggs (schistosomiasis, not in the US)
Septic emboli (IV drug users w/ infective endocarditis)
Tumor cells (kidney specifically)
How does fat lead to PE?
long bone fractures (disruption in vascular supply, and fat inside the fat that gets sucked up into the system)
What is the overview of the pathophys of PE?
- Infarction (Most often occurs when small emboli lodge distally where there is little collateral blood flow)
- Impaired gas exchange
- Cardiovascular compromise
What does surfactant do?
Dawn dish soap (allows alveoli to open and close easily)
Explain how PE leads to impaired gas exchange
Altered ventilation to perfusion ratio
Inflammation → Surfactant dysfunction → Atelectasis → Functional intrapulmonary shunting
Stimulation of the respiratory drive → hypocapnia and respiratory alkalosis
all because of lack of CO2 O2 exchange
Explain the cardiovascular compromise of PE
Obstruction of the vascular bed → Increased pulmonary vascular resistance → Right heart and intraventricular septal strain
Less blood returning to the left ventricle → Reduced cardiac output → Hypotension
this is what kills them
What is virchow’s triad?
Venous stasis
Injury to vessel
hyper-coagulability
risk factors for PE
What are the risk factors for Venous Stasis?
Immobility
obesity, stroke, bed rest, post-op
Hyperviscosity (polycythemia, increased in RBC makes it thicker)
Increased central venous pressures
low cardiac output states, pregnancy
What does pregnancy lead to venous stasis?
Baby get big and then when you sit flat, it pushes pressure in the IVC and then this coagulates to the lower extremity
What can cause injury to vessel wall?
Prior episodes of thrombosis (makes it more likely to clot), orthopedic surgery, or trauma
anything that disrupts normal blood vessel anatomy
What medications can lead to hypercoagubility?
Oral contraceptives, estrogen and testosterone
What disease makes someone more likely to have a blood clot?
malignancy, surgery
What is the MC gene defect that causes hypercoagubility?
Factor V Leiden
can also be other problems
What are the MC symptoms of PE
Tachypnea (increased RR) is most reliable exam finding (70%), Pleuritic Chest pain (hurts more when you take a breath), dyspnea, cough
tachpnea, crackles, and tachycardia are most important physical exam finding
often preceded by a DVT
What is the wells criteria for PE and if it does not meet it, what do you use?
If greater then 6, straight to D dimer
PERC, if they have ANY then you do a d-dimer
What is a d-dimer and what is normal?
a protein fragment from a broken down blood clot
<50 is normal
if >50 years old, then
10 x their age (70 yo x 10 = 700)
what are the false positives of d-dimer?
age >50 years (should adjust by calculating 50x10), recent surgery or trauma, acute illness, pregnancy or postpartum state, rheumatologic disease, renal dysfunction and sickle cell disease
What is the first-line imaging modality?
CTA
CT angiography which only show pulmonary vessels and you see filling defect (you see it turn from white to grey = grey spot is filling defect)
What are the caution of CTA for PE
Pregnancy
Metformin (med is hard on the kidneys and the contrast is also hard on kidneys. Should withhold use for 48 hours).
Allergy to contrast dye (promedicate with methyoprolcin)
What do you see in V/Q scan of PE?
Good ventilation and poor profusion
indicated for those who are CI for CTA
Good profusion rules it out
What is the gold standard of PE?
Pulmonary angiography, but not first line because it is invasive
Indicated when there is high pre-test probability and inconclusive CTA results
What do you see in CBC of PE and why?
CBC: shows leukocytosis (because the marginal pool WBCs detach thinking they can help)
What does ABG show for PE?
Normal or low
respiratory alkalosis with hypocapnia (results from hyperventilation)
What does troponin and BNP show in PE?
elevated in up to 25-50% of patients
related to size of PE causing acute right ventricular myocardial stretch
What EKG finding is classic of PE?
S1Q3T3 specifically
S wave on lead 1
Q wave and inverted T waves in lead 3
New RBBB
What does the CXR show in PE?
Normal typically, but can also see
Westermark’s sign (an area of lung oligemia - usually from complete lobar artery obstruction)
Hampton’s hump (dome-shaped dense opacification in the periphery of the lung - indicative of pulmonary infarction)
When do you order a venous doppler of lower extremity for sus PE?
Always even if no DVT s/s
What is intermediate risk PE (submassive)?
Hemodynamic stability with signs of R sided heart strain/dysfunction via CTA, echo, elevated troponin or BNP.
What is Low risk PE?
Normotension without signs of right ventricular dysfunction
What is high risk PE?
Hemodynamic instability
(any of the following)
hypotension (SBP < 90 mmHg for > 15 minutes)
drop in SBP > 40 mmHg below baseline
hypotension requiring vasopressors
causing a cardiac arrest
What is the initial management of PE?
supplemental oxygen
ventilatory support
hemodynamic support
avoid excessive IV fluids → increased risk of right sided heart failure
What are the 3 forms of therapy for PE?
Anticoagulation - mainstay
Fibrinolysis
Thrombectomy
Who gets unfractionated heparin?
unstable patients, severe renal insufficiency
What is the management of unfractionated heparin?
Binds to and accelerates the activity of antithrombin, preventing additional thrombus formation
80 units/kg/dose IV x 1 (or 5000 U) followed by 18 units/kg/hour (max 2000 u/hr)¹
Monitoring required: obtain aPTT every 6 hours during tx; goal of 60-80 seconds
In high risk patients, anticoagulation may be give before imaging confirms dx
Reserved for unstable patients, severe renal insufficiency
Risk of hemorrhage
What is protamine sulfate indiacted?
reverses effects of heparin
Indicated for life-threatening or intracranial hemorrhage
What is LMWH used for?
Preferred over other injectable agents in those who can not take oral anticoagulants
What are DOACs?
rivaroxaban
Xarelto
Eliquis
AndexXa is the reversal
What is tissue plasminogen activator (tPA) used for?
High risk PE patients used for fibronlyisis
it is used first for high risk PE patients or Intermediate risk PE with elevated troponin or BNP, or persistent hypoxemia with distress
What are the CI of fibronlysis?
intracranial disease (active tumor or hx of bleed), uncontrolled HTN (>220/110) at presentation, recent major surgery or trauma (past 3 weeks), ischemic CVA in last 3 months, and metastatic cancer
What is an embolectomy and when is it used for PE?
Manual removal of the emboli surgically or with a catheter
Indications
Hemodynamically unstable patients with a contraindication or failure to respond to tPA
Catheter-directed procedure offers the benefit of locally injecting tPA at a lower dose decreasing bleeding risk
When is an IVC filter considered?
recurrent VTE despite intensive anticoagulation
blood can get through because of the slats (looks like a head scratcher) but nothing large enough like a DVT
What are the indications for PE inpatient management?
Age > 80
Hx of CA
Hx of chronic cardiopulmonary dz
HR ≥ 110
SBP <110
O2 Sat <90%
Severe illness or presence of comorbidities
Associated DVT
Educational needs (eg, lack of knowledge about PE and its management)
Problematic social situations (eg, prior noncompliance with follow-up care)
How long is a patient on anticoagulants?
At least 3-6 months
Einstein choice study - longer you are on AC, the more likely you will not have embolus
consider the risk of the patient
provoked or unprovoked
presence of risk factors (eg, transient or persistent)
estimated risk of bleeding and recurrence
intensity and duration of the anticoagulation; concomitant administration of medications, such as aspirin, increased age, previous GI hemorrhage, and coexistent CKD
patient preferences and values (eg, occupation, life expectancy, burden of therapy)
After having a confirmed blood clot
Antithrombin III deficiency
Protein C and protein S deficiency
Lupus anticoagulant
Homocystinuria
Occult neoplasm
Connective tissue disorders
What is the pressure in the pulmonary circulation? What is the advantage of this?
VERY LOW
10-18 is normal - the pressure can go up much higher in the lungs during exercise
What is the physiology of pulmonary HTN?
Increase in pulmonary vascular resistance, typically due to vasoconstriction, remodeling, and thrombosis of the small pulmonary arteries and arterioles leading to hyperplasia and hypertrophy of the vessels.
What is the definition of pulmonary HTN?
By definition
(mPAP) >20 mmHg
What is group 1-5 cause of HTN?
- Idiopathic
- Left heart disease
- Lung disease
- Chronic thromboembolic
- Catch all
What is the clinical presentation of pulmonary HTN and the two MC symptoms?
Malaise/fatigue MC
dyspnea MD
Anginal pain
Nonproductive cough
Hemoptysis
Exertional syncope
What is the physical exam finding of PE?
Normal until progression, then
abnormal heart sounds
hepatomegaly
LE edema
Cyanosis if an open PFO leading to R–>L shunt (sending hypoxic blood into the left atria because it is lower pressure)
What are the extra heart sounds of pulmonary HTN
Accentuated P2 (louder dub)
S3 = compliant ventricle
Tricuspid regurg
What do you see in CXR of pulmonary HTN?
normal or
enlargement of the pulmonary arteries may be found incidentally
What is the EKG of pulmonary HTN?
Signs of RVH may be seen
What do you see in the TTE with doppler of pulmonary HTN?
Signs of PH
Elevated estimated pulmonary artery systolic pressure (ePASP)
Tricuspid regurgitation, RV enlargement, wall thickness or dysfunction may be seen
Normal echo doesn’t rule out PH
what is the gold standard of diagnosing plmonary HTN?
Right-sided heart catheterization (aka Swan-Ganz catheter)
What do we look for in Right-sided heart catheterization (aka Swan-Ganz catheter)?
mPAP ≥ 20 mmHg diagnostic for PH
then measure
Pulmonary capillary wedge pressure (PCWP) assesses left sided heart disease
≤15 mm Hg = no left sided heart (if elevated then there might be left-sided dysfunction)
After getting a Right-sided heart catheterization (aka Swan-Ganz catheter) what do you order?
Order a vasodilator response
After injection of a vasodilator, pressures are remeasured
Drop of mPAP of 10-40 mmHg indicative of positive acute vasodilator response
rare to respond
What is the management of pulmonary HTN?
left-sided r/o with 2D echo then
COPD (cxr and pft) and OSA (sleep study), ILD cxr,
What are the
CBC
CMP
Coags -pT, apTT
ABG
HIV testing
Hepatitis panel
Urine toxicology
Collagen-vascular disease screening
If you are diagnosed with pulmonary hypertension?
Exercise and pulmonary rehabilitation
Oxygen therapy
resting, exercise-induced, or nocturnal use
Age appropriate vaccinations
Smoking cessation (if applicable)
Maintain healthy body weight
Psychosocial support
Birth control (non-estrogen)
because pulmonary HTN is associated with increased maternal and fetal risks, including high risk of death.
Pulmonology or specialist in PH management
Cardiology if WHO II
What is the New York Heart Assocation Sused for and what are the stages?
Severity
NYHA I: No symptoms, no limitation of activity
NYHA II: Slight limitation of activity. Symptoms with ordinary activity
NYHA III: Marked limitation of activity. Symptoms with less than ordinary activity
NYHA IV: Unable to perform any activity without symptoms. Evidence of right heart failure. Dyspnea and fatigue at rest that worsens on exertion
What symptoms does the New York Heart association use?
NYHA Symptoms: dyspnea, fatigue, chest pain, or near syncope with exertion.
What are the steps of management for pulmonary HTN?
Step 1 : Treat any underlying condition
Step 2: Is there vasoreactive disease?
What are the endothelin receptor antagoists?
the entans
MOA: reduces endothelin release leading to vasodilation
Endothelin is produced in the cells that line the heart and lungs; when released results in vasoconstriction¹
What are the phosphodiesterase 5 inhibitors?
the -afil
MOA: inhibition of PDE5 leads to vasodilation
PDE5 is abundantly expressed in the lungs and causes vasoconstriction
they are also used for
What is soluble guanylate cyclase stimulators?
riociguat
Goal with this therapy is to improve exercise ability and NYHA functional class
MOA: stimulates the activity of guanylate cyclase
What are the prostanoid agents?
The prosts
epoprostenol (Flolan) - continuous IV pump
treprostinil - 3 delivery methods
iloprost
MOA: potent pulmonary vasodilation by acting on prostaglandin receptors with an additional benefit of inhibiting platelet aggregation
What are the prostacycin receptor agonists?
Selexipag
MOA: attaches to and activates prostacyclin receptors in the lung resulting in vasodilation
More selective for the prostacyclin receptor than the prostanoid agents.
only PO unless they cannot take oral
What nnon-vasoreactive drugs do you use based on your NYHA category?
NYHA I
Consider monotherapy
NYHA II/III
Combination therapy
Endothelin antagonists and PDE5 inhibitors is often used initially
Add on guanylate cyclase stimulators or oral prostacyclin receptor agonists if uncontrolled
NYHA IV
Add on parenteral prostanoid to oral combination therapy
