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Flashcards in Pulmonary Embolism Deck (25):
1

What is the underlying cause of PE?

deep vein thrombosis

2

What two factors influence the morbidity and mortality of PE the most?

embolism size

cardiopulmonary status

3

Describe the main pathophysiology behind a pulmonary embolism.

increased pulmonary vascular resistance

right ventricle pressure and volume overload

decreased RV function and right coronary perfusion, RV wall ischemia

RV dilatation shifts the interventricular septum and decreases LV preload

decreased cardiac output and hypotension

4

What are some of the other pathophysiologic manifestations of PE outside of the main pathway.

hypoxemia and increased Aa O2 gradient caused by VQ mismatching from ventilation in poorly perfused capillaries and increased airway resistance

increased PVR and pulmonary hypertension due to vascular obstruction and vasoconstriction from vasoactive mediators

alveolar hyperventilation due to irritant receptor reflex stimulation and decreased O2 delivery

increased airway resitance due to bronchiolar constriction

decreased pulmonary compliance due to loss of surfactant, lung edema, or lung hemorrhage

5

Virchow's Triad

risk factors for pulmonary embolism

1) hypercoagulable

2) stasis

3) trauma

6

factors that can contribute to a hypercoagulable state

factor V mutation

prothrombin mutation

decreased antithrombine III, protein C, or protein S

cancer

antiphospholipid syndrome

hyperhomocysteinemia

hormonal Rx (BCP)

heparin-induced thrombocytopenia

7

factors that contribute to stasis

travel

immobility

pregnancy

morbid obesity

8

factors that suggest a genetic predisposition to PE

Family history of PE, DVT, or sudden death

Unrecognized PE/DVT risk factors in a patient with new DVT or PE

Recurrent PE/DVT

Young age

9

What are some of the common symptoms of PE?

chest pain

dyspnea

cough

hemoptysis

syncope

10

common signs of PE

RR > 16/min

loud P2

pulse > 100/min

T > 37.8 C

phlebitis / DVT

11

clinical syndromes commonly found with PE

pleuritic chest pain +/- hemoptysis

unexplained dyspnea

shock / loss of consciousness

12

ECG findings in PE

normal

sinus tachycardia

atrial arrhythmia

RV strain - RBBB, P pulmonale, S1Q3T3

13

S1Q3T3

a prominent finding in ECGs of some PE patients

includes a prominent S wave in lead 1, a prominent Q wave in lead 3, and inverted T waves in lead 3

14

common chest x-ray findings in PE

normal

small pleural effusions

atelectais/infiltrate

Westermark's Sign

15

Wstermark's sign

a prominent pulmonary artery with distal oligemia

specifictiy is 90%

16

What do arterial blood gases typically reveal in patients with PE

acute respiratory alkalosis and hypoxemia

increased AaO2 gradient due to V/Q mismatching

17

Wells Clinical Prediction Score

= 4 PE unlikely

> 4 PE likely

scoring system:

  • DVT signs/ symptoms - 3
  • HR > 100/min - 1.5
  • Hemoptysis - 1
  • Cancer - 1
  • PE >/= aternative Dx - 3
  • immobilization  - 1.5
  • previous DVT/PE - 1.5

18

D-Dimer test

D-dimers are elevated as a result of an activated fibrinolytic system

a low serum D-Dimer (<500ug/L by ELISA) has a negative predictive value of 97% in patients with low clinical suspicion

19

When is the D-Dimer test not useful?

when the patient has/had

cancer

recent surgery

liver disease

high clinical suspicion (Wells Score > 4)

20

ventilation perfusion scan

looks for VQ mismatch

less than 2% of patients with PE will have a normal VQ (%14)

21

diagnostic test for PE

D-Dimer

VQ scan

chest CT angiogra

Duplex ultrasound

22

management of PE/DVT

supportive therapy

anticoagulation

thrombolysis

23

supportive management for pulmonary embolism

pulmonary hypertension and hypotension - treat with fluids and rarely vasopressors

VQ mismatching - treat with supplemental O2, bronchodilators, and rarely mechanical ventilation

24

DVT/PD prophylaxis

moderate risk - heparin twice daily - LMWH, fondparinux, or pneumatic calf compression if needed

high risk - 10-14d LMWH, fondaparinux, apixiban, dabigatran, low-dose unfractionated heparin, warfarin, aspirin, or intermitten calf compression

25

advantages of thrombolysis for acute PE over heparin