Acute Respiratory Distress Syndrome (ARDS) Flashcards
1
Q
ARDS
A
- “wet lung” or “post traumatic lung”
- severe, acute onset and progressive alveolar + capillary damage
- 35-60% mortality
2
Q
etiology
A
near drowning aspiration gastric contents increased smoke inhalation radiation septicemia burns fat embolism drugs chest trauma
3
Q
patho
A
- trauma to lung tissue and cells that make up lung wall results in increased cap permb (inflmtn also increases cap permb)
- diffuse consolidation
- inactivation of surfactant -> atelectasis
- hyaline membrane forms d/t buildup of cellular debris and exudate that is rich in protein and thick
4
Q
describe the patho of trauma to lung tissue
A
- lung trauma -> influx of inflm cells, release of free radicals, phospholipids and proteases -> alveolar and capillary damage -> increased permb -> proteins, cells, and fluids enter IS and alveoli from capillaries
- pulm edema d/t compromised compliance and limited alveoli expansion, causing decreased gas exchange
- activated neutrophils release a variety of products that damage alveolar cells
5
Q
describe the patho of inactivation of surfactant
A
free radicals, increased movement of proteins into alveolus and proteases causes l/o surfactant
6
Q
hyaline membrane
A
hyaline refers to glossy hard appearance/structure (not an actual membrane)
- lining is impervious (: nothing can move across it) therefore gas exchange can’t occur -> profound hypoxemia
7
Q
manifestations
A
- appear abruptly
- acute resp distress
- tachypnea (compensatory response to hypoxia)
- dyspnea
- profound hypoxemia
8
Q
complications
A
- pulmonary HTN (compensatory vasoconstriction d/t hypoxemia)
- early resp alkalosis
- late metabolic acidosis
- multi-organ failure (kidneys, liver, brain, heart)
9
Q
why does early resp alkalosis occur?
A
- occurs with tachypnea as excess CO2 is exhaled
- decreased ability to form carbonic acid and increased pH (= respiratory)
- volatile acid, so its respiratory
10
Q
why does late metabolic acidosis occur?
A
- tachypnea causes increased workload of resp muscles, increasing demand for ATP
- w/ decreased gas exchange, O2 is in low supply to complete the ETC, so anaerobic metabolism occurs
- buildup of lactic acid = acidosis, fixed acid = metabolic
11
Q
diagnosis
A
CXR - shows lung consolidation
12
Q
treatment
A
- stat detection and intervention (if gas exchange is not completely impaired, admin O2)
- resp support
- address the cause
- deal w/ complx (ABGs for blood pH, treat w/ meds)