9/23- Pulmonary Vascular Diseases Flashcards Preview

MS2 Respiratory > 9/23- Pulmonary Vascular Diseases > Flashcards

Flashcards in 9/23- Pulmonary Vascular Diseases Deck (54):

What are the systolic/diastolic/mean BP for pulmonary arteries?

Characteristics of pulmonary circulation?

Pulmonary circulation is high flow, low pressure, highly compliant system (low resistance)

- Systolic: 30 mmHg

- Diastolic: 10 mmHg

- Mean: 15 mmHg


What regulates vascular tone in pulmonary circulature?

Vascular endothelium

- NO (dilator)

- Endothelin (constrictor)

Autonomic nervous system

- a1 adrenergic receps (constriction)

- B2 adrenergic receps (dilation)


What is the mechanism of NO dilation of vasculature?

- Secreted by endothelial cells

- Activates guanylate cyclase (GC) to increase cGMP levels

- Also activates Ca dependent K channels in vascular smooth muscle

- Dilates both venous > arterial

- NO is a gas, which can be inhaled to result in primary pulmonary vasodilation


What are the determinants of pulmonary artery pressure?

- Blood volume

- Rate of fluid flow through system (CO, viscosity, vessel size)

- Pressure inhibiting flow across cap bed (left atrial pressure)

- PAP = CO x (PVRa + PVRcaps + PVRv)


What are some pulmonary vascular disorders?

- Pulmonary hypertension

- Pulmonary embolism

- Pulmonary vasculitides

- Pulmonary arteriovenous malformation


What is the cutoff for pulmonary HTN?

Mean PA pressure > 25 mmHg

(recall, normal is 15 mmHg)


How is Pulmonary HTN classified?

1. Pulmonary arterial hypertension (PAH)

- Toxin/drug use


- Portal hypertension, liver cirrhosis

- Sickle Cell Disease

Group 1 disease have specific targeted treatments

2. Left heart disease

3. Lung diseases and/or hypoxia

- Obstructive

- Restrictive

- Chronic hypoxemia

4. Chronic thromboembolic pulmonary HTN (CTEPH)

- Persistent elevation of pulmonary P -> symptoms and heart failure

5. Unclear multifactorial mechanisms

- Sarcoidosis


What are the structural and functional changes in pulmonary HTN?

Increased PVR

- Sustained vasoconstriction (muscle layer hypertrophy and permeation into other layers)

- Vascular remodeling

- In-situ thrombosis

- Increased arterial wall stiffness


What is idiopathic Pulmonary Arterial HTN?

- Epidemiology

- Pathology


- Uncommon

- More in women

- Mean age = 50 yo


- Hypertrophy/fibrosis vascular bed

- In situ thrombosis 


What is the prognosis for idiopathic Pulmonary Arterial HTN?

- Variable

- Mean survival 2-3 yrs from time of diagnosis

- Depends on severity, cardiac function, exercise tolerance, response to vasodilators

  • Non-responders: 9-18 months
  • Responders w/ preserved function:- >50% for 5 yrs


What are the clinical features of PAH?

- Shortness of breath

- Atypical chest pain

- Palpitations

- Cough

- Syncope (if advanced; developing RHF)

- Hemoptysis

- Hypotension

- Tachycardia

- Atrial arrhythmias

- Loud P2

- Tricuspid regurgitation murmur


- Signs and symptoms of cor pulmonale (RHF)



- 45 yo female with worsening SOB

- Chest pain, orthopnea, PND What is seen on her CXR? 

- Don't see infiltrate, pneumonia, fibrosis

- Preserved lung structure/anatomy

Heart seems somewhat abnormal:

- Large pulmonary artery indicative of pulmonary HTN 


What is seen of echocardiogram of pulmonary HTN?

- Small LV cavity; normal LV ejection fraction

- Severe RV dilatation, severely reduced RV global systolic function

- PA systolic pressure estimate 105-110 mmHg

- No interatrial septal defect


What does the evaluation of suspected pulmonary HTN look like?

- ECHO to screen for PH and r/o primary cardiac disease

- PFT to r/o primary lung disease (esp. COPD) and restrictive lung disease

- Spiral CT (possible angiogram) to r/o pulmonary vascular disease (thromboembolic disease, vasculitis)

- Right heart cath: Pulmonary artery pressure, PCWP, hemodynamics


What is the treatment for PAH (pulmonary HTN in general?) ?

- Optimize therapy for related diseases

- Supportive (O2, anticoagulation, diuretics, digoxin)

- Targeted therapy - Surgical


What are targeted therapies for PAH?

- Prostacyclins

- Endothelin receptor antagonist

- NO pathway drugs

- Soluble guanylate cyclase stimulators


What are characteristics of prostacyclins for PAH treatment?

Examples (probably don't need to name)?

Vasodilatory, antiplatelet, antiproliferative

- Berapost (PO)

- Epoprostenol (IV)

- Iloprost (inhaled)

- Treprostinil (SQ, IV, inhaled, PO)


What are characteristics of endothelin receptor antagonists for PAH treatment?

Examples (probably don't need to name)?

Blocks receptor for ET-1, a potent vasoconstrictor and mitogen

- Bosentan (PO)

- Ambrisentan (PO)

- Sitaxsentan


What are examples of NOs for PAH treatment (probably don't need to name)?

- Phosphodiesterase inhibitors: Sildenafil/Tadalafil

- Inhaled NO

- Dipyridamole


Name soluble guanylate cyclase stimulators (probably don't need to name)?



What are surgical therapies for PAH?

Lung transplantation

- Double lung transplantation typically

- Heart-lung if PAH secondary to congenital heart disorders

Atrial septostomy

- Reduces RVEDP, improves cardiac index at expense of decreased PaO2

- Bridge to transplantation

Pulmonary endarterectomy for CTEPH


What is cor pulmonale?

- Cause

- Signs

- RV hypertrophy (and ultimately resulting in right heart failure) 2ndary to increased PVR

- Most commonly results from chronic pulmonary diseases (esp. COPD) that affect pulmonary vasculature.

- Signs:

  • Hepatojugular reflux
  • Lower extremity edema
  • Pulsatile liver
  • Tricuspid regurgitation
  • Ascites


What is the treatment for cor pulmonale?

- Treat underlying cause(COPD, etc.)

- Minimize vasoconstriction, vasodilate (O2),

- Improve cardiac output w/rhythm control and contraction


Epidemiology of PE/DVT?

- Venous thromboembolism is a major medical problem

- > 5 million DVT cases annually

- Of these, 650,000 develop pulmonary embolism (PE)

- Of pts with PE, 100,000 die annually

- Not uncommon cause of death in acute care hospital setting

- > 70% of pts that die of PE are not suspected before death; maintain a high index of suspicion and pursue the diagnosis when warranted


What are causes of pulmonary embolism?

- Thrombus

- Fat (occurs in long bone fractures)

- Tumors

- Trophoblast

- Air (catheter placement, scuba diving)

- Amniotic fluid


What is VIrchow's triad?

1. Venous stasis

2. Intimal injury

3. Altered coagulation


What are the risk factors for thrombosis?

- Age > 70 yo

- Obesity

- Sedentary/Bed rest

- Trauma

- Chronically ill

- Pelvic surgery/trauma

- Prolonged anesthesia (>1 hour)

- Surgery of lower extremities

- Hip fracture/replacement

- Pregnancy/postpartum

- Right ventricular failure

- Oral contraceptives (5-10 fold increase)

- Underlying malignancy (Trousseau’s syndrome)

- Inherited/acquired deficiency of naturally

  • occurring anticoagulants:resistance to activated protein C (Factor V Leiden)
  • Prothrombin gene mutation
  • protein C deficiency
  • protein S deficiency
  • Antiphospholipid antibody syndrome
  • Anti-thrombin III deficiency
  • Hyperhomocysteinemia


What are symptoms of DVT?

- Pain

- Tenderness

- Swelling

- (+) Homan's sign: dorsiflexion of foot/ankle -> pain


What are the symptoms and findings of pulmonary embolism?


- Dyspnea

- Impending doom

- Palpitations (tachycardia)

- Hemoptysis and pleuritic chest pain are signs of infarction (uncommon, 20% of patients with significant cardiopulmonary disease)


- Tachypnea

- Tachycardia

- Low grade fever

- With massive embolism

- fixed split of S2, and S3 or S4, dilated neck veins, and cyanosis, hypotension


What is the diagnostic process of DVT?

- Contrast venography: Gold standard, only accurate method in asymptomatic individuals.

- IPG: Serial negative IPG or US is comparable in accuracy to negative venography in patients with suspected DVT

- Compression ultrasonagraphy*: Often the diagnostic modality of choice. The sensitivity and specificity approach 97%-98% for symptomatic patients.

- MRI: High sensitivity and specificity, expensive

- D-dimer: Low levels of plasma D-dimer (under 500 ng/mL) by ELISA technique may have a high negative predictive value


T/F: You can get DVT in upper extremity veins?



What is seen on CXR for someone with DVT?

- Localized oligemia -> Westermark sign:

- Hampton's hump

- Consolidation (infarct)

- Usual report is "normal"


What is seen on EKG for someone with DVT?

- Tachycardia

- Right axis deviation (right sided strain)

- New onset atrial fib


What is S1Q3T3?

The classic finding; "not common, but always talked about"


What are the diagnostic tests on PE of someone with DVT?

ABG’s: increased A-a difference;

Pa02 may be above 80;

C02 usually decreased

Remember to calculate the A-a diff

- A-a difference is usually increased

- Alveolar gas equation

- [FIO2(PB-PH20) – PaC02/R] – Pa02

- [150-PaC02/0.8] - Pa02


What is the Wells Diagnostic Scoring? Considerations?

Predicts clinical likelihood of PE

- Signs/symptoms of DVT (3)

- Another diagnosis less likely than DVT (3)

- HR > 100 (1.5)

- Immobilization/surgery within 4 wks (1.5)

- Previous DVT/PE (1.5)

- Hemotpysis (1)

- Malignancy (active or treated within 6 mo) (1)

Pre test probability: ≤ 2 low; 2-6 Moderate; >6 High


What is the diagnostic approach?

- Chest CT with contrast, PE protocol

- Less commonly VQ scan

- Rarely, pulmonary angiogram

- If negative or inconclusive and clinical suspicion present….

-->further diagnostic testing

- Evaluate for DVT or perform other diagnostic test.


Pros/cons of diagnosing PE with helical/spiral CT?

Helical/spiral CT:


- Specificity

- Availability

- Safety

- Relatively rapid

- Other diagnosis

- Advancing technology


- Expense

- Not portable

- Need contrast

- Poor visualization in some areas

- Contraindication: renal insufficiency/allergy

- Reader expertise 


What is a ventilation perfusion scan (VQ scan)?

- Nuclear medicine test to evaluate ventilation (V) and perfusion (Q)

- “Matched” defects

- non-diagnostic, compare to x-ray

- “Unmatched” defects

- suggestive of perfusion abnormality


Describe Pulmonary Angiogram

- Process

- Purpose

- Commonality

- Intra-arterial dye

- Directly assesses vasculature

- Rarely used now


What do each of these gross pictures show? 

1- Embolus with infarct

2- Saddle embolus

3- Infarct


How can DVT be prevented?

Based on level of risk and risk of bleeding

- Low: (under 10% VTE without prophylaxis) early ambulation only

- Moderate: (risk of VTE 40%): most general surgical pts or med pts at bedrest; give LMWH, LDUH, fondaparinux or mechanical if bleeding risk high

- High: orthopedic, major trauma, spinal cord injury; give LMWH, fondaparinux, rivoroxaban, Vit K antagonist; mechanical if bleeding risk high


How to treat PE?


- Acute

  • Weight-adjusted heparin IV
  • LMWH

- Long term

  • Warfarin
  • Oral factor XA inhibitors
  • LMWH Thrombolysis


IVC Filter


What is HIT?

- Mechanism

- Labs

Heparin Induced Thrombocytopenia

- Immune-mediated drug reaction

- Results in platelet removal -> thrombocytopenia (most common, 90%)

- Results in platelet aggregation and release of procoagulant microparticles (thrombosis)

- Defined by presence of heparin-reactive antibodies to platelet factor 4 (HIT Abs)


What are complications of HIT?

- Deep vein thrombosis

- Pulmonary embolism

- Myocardial infarction

- Occlusion of limb arteries (possibly resulting in amputation)

- Cerebrovascular accidents (stroke, TIA)

- Skin necrosis

- End-organ damage (e.g., adrenal, bowel, spleen, gallbladder or hepatic infarction; renal failure)

- Death


What is Warfarin?

- Mechanism

- Dynamics/activity

- Metabolism

- ASEs

- Management

- Reversal

- Antagonizes Vitamin K dependent factors (Factors 2, 7, 9, and 10 as well as protein C and protein S)

- Delayed effect based on the shortest 1/2 life (Factor 7: 6 hrs); 18-24 hrs

- Crosses placenta; CONTRAINDICATED in pregnancy

- Numerous drug-drug, drug-disease (liver), and drug-food (Vit K) interactions

- Careful monitoring of INR (standardized msmt of PT); usual targeted range is 2-3

- Reversal with Vitamin K (mild) or FFP


What things diminish Warfarin effect? INR level?

INR level will be low

- Inhibits drug absorption: Cholestyramine

- Increases metabolism (enhance p450): Barbiturates, Carbamazepine, Phenytoin, Rifampin

- Vitamin K: foods, esp leafy greens


What things enhance Warfarin effect? INR level?

INR will be high

- Displaces from albumin: choral hydrate

- Decreased metabolism (inhibits p450): Amiodarone, clopidogrel, ethanol, fluconazole, fluoxetine, metronidazole, sulfamethoxazole

- Eliminate gut bacteria and decrease K: Broad-spectrum antibiotics


What should the duration of therapy be for ?? (HIT?) (PE?)

- 3 months in patients with transient risk factors

- May be life long in patients with recurrent thrombosis or continued risk factors (e.g. malignancy, hypercoagulable state)


What is an IVC filter? What is it used to treat?

IVC filter: treatment of PE

- Patients with massive PE who could not tolerate a recurrence

- Patients with contraindications to anticoagulation

- Recommended for repeat PE despite anticoagulation or when anticoagulation is contraindicated

- Filter is a wire apparatus inserted through a catheter in the inferior vena cava to prevent PE

- Filter may be removed


What are other therapies for PE?

- Thrombolytic: reserved for patients with massive PE (clinically severe, severe cardio pulmonary compromise, i.e. hemodynamic instability, hypoxemia, RV dysfunction despite resuscitative efforts).

- Embolectomy


Summary of Pulmonary HTN

- Various causes and important to classify based on WHO grouping

- Treatment will be guided by etiology

- Progressive shortness of breath, loud P2

- Idiopathic Pulmonary Arterial HTN pathology is medial hypertrophy and intimal fibrosis

- Treatment with pulmonary vasodilators and lung transplant


Summary of DVT/PE

- Risk factors of prolonged immobility, hypercoagulable states etc.

- Symptoms of leg swelling, pain in DVT

- Sudden onset SOB+- pleuritic chest pain with hypoxemia in PE

- DVT diagnosed with venous compression ultrasonography

- PE diagnosed by spiral CT or V/Q scan


Summary of Pulmonary Vascular Disorders

- Treatment with anticoagulation (UFH, LMWH or Warfarin); Less commonly IVC filter, thrombolysis, embolectomy

- Major complications of heparin is Heparin induced thrombocytopenia

- Major complication of Warfarin is drug-drug interactions