Pulmonary Embolism

Question 1

pulmonary embolism

Answer 1

thrombus in a pulmonary vessel (within pulmonary circuit)

Question 2

embolism

Answer 2

blood clot (thrombus) or air/other things obstructing blood flow that mobilizes within vessels

Question 3

low or high rate of recurrence

Answer 3

high

Question 4

etiology

Answer 4

• majority d/t DVT
• fat embolism
• air embolism
• amniotic fluid

Question 5

how does DVT cause pulmonary embolism

Answer 5

• thrombus within iliac, femoral, popliteal and great saphenous veins of the legs that embolizes & reaches the vessels in the pulmonary circuit

Question 6

how does fat embolism cause pulmonary embolism

Answer 6

fatty bone marrow released during orthopedic Sx or if a bone fractured in trauma –> fat enters circulation & moves as an emboli –> reaches pulmonary circuit

Question 7

how does air embolism cause pulmonary embolism

Answer 7

from air bubble in syringe or tubing, less common w/ smart pumps

Question 8

how does amniotic fluid cause pulmonary embolism

Answer 8

enters circulation during trauma or delivery through severed blood vessels

Question 9

patho

Answer 9

• DVT –> embolus in R-side of heart and into pulmonary circulation –> thrombus in arterial bed –> dec perf –> platelets attracted to site of thrombus d/t abnormality in vessel
• platelets degranulate
• hemodynamic instability
• ventilation:perfusion imbalance
• dec CO
• dec surfactant

Question 10

how does platelet degranulation contribute to pulmonary embolism

Answer 10

• release mediators that attract more platelets

- degranulation causes bronchial & pulmonary artery constriction

Question 11

how does hemodynamic instability contribute to pulmonary embolism

Answer 11

causes inadequate perf d/t obstr & further constriction of vessel

Question 12

nervous system reflexively causes what

Answer 12

bronchoconstriction

Question 13

ventilation:perfusion imbalance causes what

Answer 13

hypoxemia & systemic hypoxia

Question 14

why does dec CO occur in pulmonary embolism

Answer 14

obstr in lungs dec blood flow to L-side of heart –> less blood pump out into systemic circuit

Question 15

dec surfactant results in what

Answer 15

atelectasis d/t walls sticking tgt

Question 16

normal surfactant Fx

Answer 16

dec adhesion forces & prevents walls of alveoli from sticking tgt on exhalation

Question 17

what is surfactant composed of

Answer 17

phospholipids, cholesterol, proteins & fluid

Question 18

what results in the heart from pulmonary embolism

Answer 18

R-sided HF

Question 19

why does R-sided HF result

Answer 19

obstr in pulmonary circuit, which receives blood from R-side, so R ventricle is pumping against inc resistance –> inc workload on R-side of heart –> HF

Question 20

mnfts

Answer 20

depends on site obstr (aka size of vessel obstruced & severity)

• usually cardiac & resp symptoms
• dyspnea, tachypnea, chest pain
• tachycardia
• fever in the absence of infection

Question 21

which mnfts result from hypoxemia & hypoxia

Answer 21

• dyspnea
• tachypnea
• chest pain

Question 22

which mnfts are compensatory

Answer 22

• dyspnea
• tachypnea
• tachycardia

Question 23

Dx

Answer 23

• Hx, Px
• ABGs
• D-dimer
• LDH3
• lung scan (131I-HSA, IV)
• CT chest
• pulmonary angiogram

Question 24

D-dimer

Answer 24

fibrin degradation product (breakdown of fibrin component of clot releases components, D-dimer being one of them)
- used to Dx DVT, DIC, PE

Question 25

LDH3 (lactate dehydrogenase)

Answer 25

protein released when cells die

- if LDH3 high, it is b/c there is an inc in damaged lung cells

Question 26

HSA

Answer 26

human serum albumin

Question 27

131I

Answer 27

isotope of iodine

Question 28

Tx

Answer 28

• stat Tx for better prognosis
• thrombolytic & anticoagulants
• maintain cardiopulmonary support
• DVT (address to dec recurrence)