ARDS Flashcards
ARDS
a condition of severe acute inflammation and pulmonary edema without evidence of fluid overload or impaired cardiac function
is ARDS a progressive disorder?
yes
phases of ARDS
- injury reduced blood flow to lungs, platelets aggregate and release histamines, serotonin, & bradykinin
2.Histamines inflame & damage the aveolocapillary membrane, increasing capillary permeability, fluids then shift into the interstitial space
- As capillary permeability increases, protein & fluids lead out, increasing interstitial osmotic pressure causing pulmonary edema
- decrease blood flow and fluids in the alveoli damage surfactant and impair cell’s ability to produce more, impedes gas exchange
- sufficient oxygen can’t cross membrane
- pulmonary edema worsens
ARDS mnemonic
Assault to the pulmonary system
Respiratory distress
Decreased lung compliance
Severe respiratory failure
Risk Factors for ARDS
-aspiration (gastric secretions, drowning)
-COVID-19 pneumonia
-drug ingestion & overdose
-hematologic disorders (DIC, massive transfusions, cardiopulmonary bypass)
-prolonged inhalation of high concentrations of oxygen, smoke, or corrosive substances
-localized infection (bacterial, fungal, or viral pneumonia)
-metabolic disorders (pancreatitis, uremia)
-shock (any cause)
-trauma (pulmonary contusion, multiple fractures, head injury)
-major surgery
-fat or air embolism
-sepsis
Clinical manifestations (acute phase)
-rapid onset of severe dyspnea (early sign)
-occurs <72 hours after injury
-arterial hypoxemia that does not respond to supplemental oxygen
ABG results
-initially decreased PaO2 despite supplemental O2
-PaCO2 increases and pH decreases
-acidosis worsened by metabolic acidosis from anaerobic metabolism
chest x-ray results
after 24 hours basilar infiltrates; later stages, ground glass appearance & white patches
PA catheterization results
PAWP of 19 mmHg or lower with ARDS
BNP
normal range <125, rules out cardiac cause
diagnostic tests/findings to determine ARDS
-ABG analysis
-chest x-ray
-PA catheterization
-BNP
-differential diagnosis (sputum analysis, blood cultures, toxicology tests, serum amylase to rule out pancreatitis)
clinical manifestations
-intercostal retractions & crackles with auscultation
-persisten, severe hypoxia
-tachypnea and use of accessory muscles
-“stiff lungs” that are difficult to ventilate
-systemic hypotension
-restlessness –> extreme anxiety & agitation
-skin cool, clammy –> pale & cyanotic (later manifestations)
-tachycardia with dysrhythmias (PVCs)
Medical Management of ARDS
-primary focus: identification and treatment of the underlying condition
-provide enough O2 to allow for normal body processes to continue until the lungs heal (almost always includes ET intubation and mechanical ventilation as hypoxemia progresses)
-PEEP -> positive end expiratory pressure - critical part of ARDS treatment
PEEP (positive end expiratory pressure)
-most effective treatment for the management of hypoxemia
-reverses alveolar collapse
-improves PaO2/FIO2 (indication of alveolar function)
what should the PaO2/FIO2 value be?
above 300?
