Pulmonary Embolism Flashcards
pulmonary embolism
thrombus in a pulmonary vessel (within pulmonary circuit)
embolism
blood clot (thrombus) or air/other things obstructing blood flow that mobilizes within vessels
low or high rate of recurrence
high
etiology
- majority d/t DVT
- fat embolism
- air embolism
- amniotic fluid
how does DVT cause pulmonary embolism
- thrombus within iliac, femoral, popliteal and great saphenous veins of the legs that embolizes & reaches the vessels in the pulmonary circuit
how does fat embolism cause pulmonary embolism
fatty bone marrow released during orthopedic Sx or if a bone fractured in trauma –> fat enters circulation & moves as an emboli –> reaches pulmonary circuit
how does air embolism cause pulmonary embolism
from air bubble in syringe or tubing, less common w/ smart pumps
how does amniotic fluid cause pulmonary embolism
enters circulation during trauma or delivery through severed blood vessels
patho
- 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
how does platelet degranulation contribute to pulmonary embolism
- release mediators that attract more platelets
- degranulation causes bronchial & pulmonary artery constriction
how does hemodynamic instability contribute to pulmonary embolism
causes inadequate perf d/t obstr & further constriction of vessel
nervous system reflexively causes what
bronchoconstriction
ventilation:perfusion imbalance causes what
hypoxemia & systemic hypoxia
why does dec CO occur in pulmonary embolism
obstr in lungs dec blood flow to L-side of heart –> less blood pump out into systemic circuit
dec surfactant results in what
atelectasis d/t walls sticking tgt
normal surfactant Fx
dec adhesion forces & prevents walls of alveoli from sticking tgt on exhalation
what is surfactant composed of
phospholipids, cholesterol, proteins & fluid
what results in the heart from pulmonary embolism
R-sided HF
why does R-sided HF result
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
mnfts
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
which mnfts result from hypoxemia & hypoxia
- dyspnea
- tachypnea
- chest pain
which mnfts are compensatory
- dyspnea
- tachypnea
- tachycardia
Dx
- Hx, Px
- ABGs
- D-dimer
- LDH3
- lung scan (131I-HSA, IV)
- CT chest
- pulmonary angiogram
D-dimer
fibrin degradation product (breakdown of fibrin component of clot releases components, D-dimer being one of them)
- used to Dx DVT, DIC, PE
LDH3 (lactate dehydrogenase)
protein released when cells die
- if LDH3 high, it is b/c there is an inc in damaged lung cells
HSA
human serum albumin
131I
isotope of iodine
Tx
- stat Tx for better prognosis
- thrombolytic & anticoagulants
- maintain cardiopulmonary support
- DVT (address to dec recurrence)
