Lecture 9: Pulmonary Circulation Disorders Flashcards
What # cause of death is PE for hospitalized patients and for cardiac deaths?
3rd in both.
When does a fat embolus tend to cause PE?
Long bone fx (usually femur)
What demographic tends to have foreign body emboli for PE?
- IVDU (talc)
- Joint replacements (cement)
What is the pathophysiology of impaired gas exchange in PE?
- Altered V/Q ratio
- Inflammation => surfactant dysfunction => atelectasis => functional intrapulmonary shunting
- Stimulation of the respiratory drive => hypocapnia and respiratory alkalosis
What happens to the heart as a PE progresses?
- Increased pulmonary pressure => R sided heart strain => reduced preload => reduced CO => hypotension
Ultimately, this kills a patient.
What is Virchow’s triad?
- Venous stasis
- Hypercoagulable state
- Injury to the vessel wall
What is the MC inherited gene defect that results in hypercoagulability?
Factor V Leiden
What two medications are commonly known to cause hypercoagulable states?
- OCPs
- Hormonal Replacement Therapy
What kind of malignancy puts someone in a hypercoagulable state?
Active malignancy being treated.
What are the usual PE S/S?
- Sudden onset dyspnea
- Pleuritic chest pain
- Cough
- Tachypnea (Most reliable exam finding)
DVT may precede a PE:
- Lower leg pain
- Unilateral swelling/warmth/erythema of calves.
Pleuritic chest pain is most associated with small PE’s causing infarction.
What is considered high risk and mod risk Well’s criteria?
- High-risk: > 6 pts
- Mod-risk: 2-6 pts
What are the Well’s Criteria for PE and the point values?
- Suspected DVT: 3
- PE is most likely: 3
- Tachycardia: 1.5
- Prior VTE: 1.5
- Immobilization of >=3 days or sx in past 4 weeks: 1.5
- Tx for malignancy within 6 months or palliative: 1
- Hemoptysis: 1
When is PERC Rules used?
Low-risk Well’s score
What are the PERC Rules?
- Hormones
- Age > 50
- DVT/PE History
- Coughing blood
- Leg Swelling
- O2 < 95%
- Tachycardia
- Surgery/trauma in past 4 weeks.
HAD CLOTS
If any of these are positive, advised to get a D-Dimer.
How do we order testing and diagnostics based on Well’s and PERC Rules?
- High-risk Well’s = imaging
- Low-risk with 1 positive PERC or mod-risk = high sens D-dimer
- Low-risk + no PERC Rules = no d-dimer.
As we get older, what happens to the d-dimer range?
Threshold is lower to be positive for an abnormal d-dimer.
What is the first-line imaging modality for most suspected PE patients?
CTA
Requires contrast, and pre-testing BUN/Cr
It will show filling defect.
Be careful of metformin use! Contrast is nephrotoxic, so hold metformin for the next 2 days.
What can cause a falsely-elevated d-dimer?
- Age > 50
- Recent surgery or trauma
- Acute illness
- Pregnancy/postpartum
- Rheumatologic disease
- Renal dysfunction
- SCD
When do we use V/Q scans?
- Pregnancy
- Renal insufficiency
- Prior reaction to contrast
What kind of V/Q scan is most suggestive for a PE?
Abnormal perfusion with normal ventilation.
What is the GOLD STANDARD for diagnosing PE?
Pulmonary angiography.
Only use if CTA was inconclusive.
What causes leukocytosis in PE?
Marginal pool of WBCs shifts into circulation.
Usually above 20k
What ABG findings are typical of a PE?
- Low pO2
- Respiratory alkalosis with hypocapnia
Can appear in other conditions besides PE.
What are the probable findings on EKG for a PE?
- Sinus tach
- S1Q3T3 pattern (boards)
- new incomplete RBB
Generally non-specific. More used to r/o STEMI.
S wave in lead I
Q wave in lead III
T-wave inversion in lead III
What are the two possible findings suggestive of PE on a CXR?
- Westermark’s sign: lung oligemia 2/2 complete lobar artery obstruction
- Hampton’s hump: dome-shaped dense opacification in lung periphery.
Westermark makes one lung look much blacker.
Hampton’s hump presents as consolidation.
When is a venous doppler of the LE recommended?
Positive PE so we can look for evidence of a DVT.
Determining PE etiology.
What are the 3 levels of risk stratification for PE?
- High-risk = hemodynamic instability
- Mod-risk = hemodynamic stability with signs of R-sided heart strain.
- Low-risk = normotensive with no signs of right ventricle dysfunction.
What are the 3 primary forms of therapy for all PE patients?
- Anticoagulation
- Fibrinolysis
- Thrombectomy
When is unfractionated heparin recommended for anticoagulation for PE? Dosing and goal?
- Unstable patients
- Severe renal insufficiency.
- 80 units/kg/dose, followed by 18 units/kg/hr.
- Aim for aPTT of 60-80s
Normal PTT is 20-30.
What is used to reverse heparin?
Protamine sulfate.
When is LMWH used?
Preferred version of heparin.
Careful in obesity or renal impairment.
What drug class are xarelto and eliquis and what are the benefits?
- Both are DOACs, specifically 10a inhibitors.
- Requires NO BRIDGING therapy
- Xarelto is QD, eliquis is BID.
Reversed with AndexXa
What drug class is dabigatran and what must be done prior?
- Direct thrombin inhibitor
- Requires bridging therapy
- Reversed with Praxbind
Brand name is Pradaxa.
When is arixtra usually used for PE?
Hx of HIT.
Heparin is still preferred.
Why does warfarin suck?
- Bridging with lovenox first to INR of 2-3.
- Monitoring required
- Many, many, many DDIs and food interactions
Vit K antagonist.
When is tPA indicated for PE pts?
- High risk PE patients
- Intermediate risk PE with elevated trop or BNP, or persistent hypoxemia with distress.
When is tPA contraindicated?
- Intracranial disease
- Uncontrolled HTN (>220/110)
- Recent surgery/trauma in 3 weeks
- Ischemic CVA in past 3 months
- Metastatic cancer
What should be given first; tPA or anticoagulation?
tPA is given first, then anticoagulation.
When is embolectomy indicated?
Hemodynamically unstable patient with a CI or failure to tPA.
Involves direct and local injecton of tPA.
When is IVC filter indicated?
- Active bleeding contraindicated anticoag
- Recurrent VTE despite adequate anticoag
What are the risk factors that prompt admission of PE?
- Age > 80
- Hx of CA
- Hx of chronic cardiopulm dz
- HR >= 110
- SBP < 110
- O2 sat < 90%
What indicates general IP tx of PE?
- Severe illness or presence of comorbidities
- Associated DVT
- Educational needs
- Problematic social situations
How long should PE anticoag be post discharge?
3-6 months at minimum.
Whether it is provoked or unprovoked.
Keep on longer if unable to modify any risk factors.
Unprovoked should be kept on lifelong probably.
What is normal mean pulmonary arterial pressure?
10-18 mm Hg
What 3 things tend to cause increases in pulmonary vascular resistance? What is the ultimate result?
- Vasoconstriction
- Remodeling
- Thrombosis
All of which leads to hyperplasia and hypertrophy of the vessels.
Formally, pulmonary HTN is a mPAP > 20mm Hg
What falls under group 1 for WHO PH?
- Idiopathic PAH
- Hereditary PAH
- Drug induced PAH
- HIV
- Congenital PAH
AKA primary causes and HIV.
What falls under group 2 for WHO PH?
Left sided heart disease.
AKA heart
What falls under group 3 for WHO PH?
Lung disease or hypoxia
AKA lung
What falls under group 4 for WHO PH?
Chronic thromboembolic pulmonary hypertension (CTEPH)
AKA clots
What falls under group 5 for WHO PH?
Miscellaneous conditions that cause PH, like sarcoidosis.
AKA misc
WHO PH Mnemonic for classifications
- 1-A for primary arterial
- 2 heart for 2 people make a heart
- oxi = 3 letters (lungs)
- clot = 4 letters
- multi = 5 letters
What are the MC S/S of PH?
- Malaise and fatigue
- Dyspnea
- Anginal pain
- Non-productive cough
- Hemoptysis (rare)
In late stage PH, what other S/S tend to appear?
Right sided HF symptoms, such as S3.
Why can cyanosis occur in late stage PH?
If patient has a PFO, they will have a right to left shunt that mixes the deoxygenated blood with oxygenated blood before it leaves the left ventricle.
What can a 2D TTE with doppler tell us in regards to PH?
It can estimate the pulmonary artery systolic pressure (ePASP)
Normal echo does not r/o PH.
What is the gold standard for diagnosing PH?
Swan-Ganz catheter
What two things can a swan-ganz catheter measure?
- mPAP
- PCWP
Right-sided heart cath.
It can also be used to measure vasodilator response.
What PCWP is indicative of left-sided heart disease?
Greater than 15 mm Hg is highly suggestive of left-sided heart disease.
Indicates need to check via a left-sided heart cath.
If PCWP is not elevated, we can r/o group 2 of the WHO classifications.
What kind of birth control is recommended for patients with PH?
Non-estrogen, because it is associated with increased maternal and fetal risks, including high risk of death.
What are the 4 NYHA severity gradings?
- No symptoms, no limitation of activity.
- Symptomatic. Slight limitation of activity.
- Symptomatic with less than ordinary activity. Marked limitation of activity.
- Symptomatic with any activity. Evidence of RHF. Dyspnea and fatigue at rest that worsens with exertion.
Symptoms:
Dyspnea
Fatigue
Chest pain
Near syncope with exertion
What is step 1 to treating PH?
- Treat underlying condition
- WHO II = treat left sided HF
- WHO III = treat lung disease/hypoxia
For vasoreactive diseases, what is the main treatment?
High dose dilt or nifedipine
NYHA I-III
For nonvasoreactive diseases, what are the pharmacological options?
- Endothelin receptor antagonists (-entans)
- PDE-5 inhibitors (viagra)
- Soluble guanylate cyclase stimulators (riociguat)
- Prostanoid agents (-prost-)
- Prostacyclin receptor agonists (selexipag)
WHO I and IV only!!!!!!!
Endothelin release causes vasoconstriction.
PDE5 is in the lung and causes vasoconstriction.
Soluble guanylate cyclase stimulators reduce symptoms and should reduce the patient’s NYHA and improve their exercise tolerability. Vasodilator.
Prostanoids cause more release of prostanglandins and inhibition of platelet aggregation.
Prostacyclin receptor agonists are more selective for receptor than the prostanoid.
For non vasoreactive NYHA I, what is the recommended therapy?
Monotherapy
For non reactive NYHA II/III, what are the recommended options?
Start with BOTH endothelin antagonists and PDE5 inhibitors.
Add either guanylate cyclase stimulators or oral prostacyclin receptor agonists for uncontrolled.
For non vasoreactive NYHA IV, what is the recommended medical therapy to addon?
Add parenteral prostanoid to oral combo therapy.
If you are adding parenteral prostanoid, you must remove prostacyclin.
Which medication class for Pulmonary HTN can improve NYHA functional class?
Guanylate cyclase stimulators
How do you check if pulmonary HTN is vasoreactive?
- Injection of vasodilator
- Drop of mPAP of 10-40 mm Hg indicates positive response.
Vasoreactive is treated with CCBs.
What are the symptoms used in NYHA classification of PH?
- Dyspnea
- Fatigue
- Chest Pain
- Near syncope with exertion
