Pulm Vascular Disorder: Acute Respiratory Distress Syndrome Flashcards
What is Acute Respiratory Distress Syndrome (ARDS)?
severe, progressive alveolar and capillary damage
ARDS is associated with ____ lungs or _____- _______ lungs
wet
post-traumatic
What is the onset? Happens ______ without much _______.
acute
quickly
warning
What is the prognosis like?
High loss of life
What is the mortality rate?
35-60%
Etiology of ARDS (4)
- Aspiration: anything but air in lungs eg water, smoke fire, gastric content etc
- Near of drowning: inhaling H20
- increase smoke inhalation
- severe burns: not direct link
Chart 29.2 Conditions which ARDS develop
ASPIRATION:
- near drowning
- aspiration gastric content
DRUGS, TOXIN, THERAPEUTIC AGENTS:
- free base cocaine smoke
- heroin
- inhaled gases
- breathing high concentration of O2
- radiation
INFECTIONS:
1. septicemia
TRAUMA AND SHOCK:
- burns
- fat embolism
- chest trauma
DISSEMINATED INTRAVASCUALR COAGULATION
MULTIPLE BLOOD TRANSFUSION
Lungs in ARDS are ____ and _______
firm and rubbery
Patho: How does lung trauma lead to impaired GE?
lung trauma–> inflm cell reflux–> release of free radicals and proteases–> damage to alveoli and capillaries–> increase perm–> proteins, cells, and fluid enter IS and alveoli—> edema –> l/o compliance –> impaired GE
Exudate accumulating in alveolus and IS leads to pulm ____ —> increase ______ ____ —> impact GE
edema
diffusion distance
Person may end up in ____-____ failure
multi-organ
PAtho: What is diffusion consolidation? What appearance does it give?
solidification of fluid, debris, and cells –> become non-functional
if diffuse enough most of lungs do not work
rubbery
Patho: How does l/o surfactant lead to atelectasis
w/ increase permeability–> protein enter the alveolus–> protein interact with surfactant and change the properties of surfactant—> surfactant become inactive or inadequate–> atelectasis
What is surfactant? What secrete surfactant? Fxn?
A mixture of lipids and proteins secreted by type II alveolar cells
Surfactant decrease surface tension between alveolar cells
Patho: What is the impervious hyaline membrane? Is it cartilage and a membrane? Why is it called a membrane?
Protein rich thick exudate and cellular debris forms a band that lines the alveoli
Not an anatomical membrane or cartilage
It is called a membrane b/c it forms a band
What is the appearance of the hyaline membrane?
glossy and hard
What does impervious mean? What does it result in?
nothing can move across –> no GE –> hypoxia
In hyaline membrane, if gases can move across, the ____ ______ is too large for GE
diffusion distance
Damaged cell release free radicals and proteases. How does it contribute to damage?
- oxidative damage
2. break down structure protein of alveoli and capillaries
Patho: what does profound hypoxia lead to?
vital organ suffers and leads to death
What occurs when injurious agent enter the lungs? (2)
vasodialtion and hyperemia
Manifestations of ARDS (8)
- severe acute respiratory distress
- tachypnea (comp mech to hypoxia)
- dyspnea (associated wirh hypoxia)
- increase hypoxemia (profound hypoxia)
- pulm HTN (hypoxia in lungs lead to comp vasoconstriction)
- early respiratory alkalosis
- late metb acidosis
- multi-organ failure
Explain early respiratory alkalosis. What is carbonic acid?
tachypnea–> exhaling lots of CO2–> CO2 is removed –> less carbonic acid is made–> increase pH–> early respiratory alkalosis
Volatile acid
Explain late metb acidosis
tachypnea–> increase workload of breathing–> the person utilizing more muscles for breathing (both accessory and normal muscles)–> increase ATP demand for energy which req more O2 –> not enough O2 for the energy demand–> cells move into glycolysis for energy –> lactic acid is a by-product –> metb acidosis
What do fixed acid indicate?
metb acidosis eg lactic acid
complications of ARDS (4)
- pulm HTN
- early resp alkalosis
- late metb acidosis
- multi-organ failure
Treatment of ARDS
- stat detection and intervention–> good prognosis
- respiratory support —>eg indirectly supporting organ, O2 supplement, and mech ventilation
- address underlying cause eg remove from fire or save from drowning
- eliminate complications
