ARDS Flashcards
Define ARDs
Life-threatening lung condition that prevents enough oxygen from getting to the lungs and into the blood
What general class of pulmonary dysfunction does ARD fall under?
Form of pulmonary edema that can quickly lead to acute respiratory failure
What can ARDs follow?
May follow direct or indirect injury to lungs
What can happen if ARDs isn’t promptly diagnosed and treated?
Death can occur within 48 hours of onset if ARDS isn’t promptly diagnosed and treated
What is the number 1 cause of Ards? What are number 2 and 3?
1. Sepsis # 1 cause 2. Severe multiple trauma A. Fat emboli B. Pulmonary contusion 3. Aspiration pneumonia (gastric contents)
What percentage of ARDs cases are due to the top 3 causes?
75%
What are the less common causes of ARDs?
- Shock
- Toxic inhalation
A. Ammonia
B. Chlorine - Near drowning
- Multiple transfusions
What is the pathophys of ARDs?
Injury involves both pulmonary capillary epithelium and alveolar epithelium
What is direct damage that can cause ARDs?
Direct – aspiration of gastric contents or noxious fumes
What is the indirect damage that can cause ARDs?
Indirect – chemical mediators released in response to systemic disease
How does pulmonary edema develop in ARDs?
↑ permeability of alveolar capillary membrane which leads to development of protein rich pulmonary edema
What is the cascade of biochemical and cellular changes seen in ARDs?
- Injury reduces normal blood flow to lungs
- Platelets aggregate & release histamine, serotonin, and bradykinins
- → inflame & damage alveolar capillary membrane
- ↑ capillary permeability
- Proteins & fluid leak out increasing interstitial osmotic pressure pulmonary edema
- Fluid in alveoli alveoli collapse
- ↓ gas exchange
What are the symptoms of ARDs?
- Restlessness, apprehension, mental sluggishness
2. Frothy pink sputum
What are the signs of ARDs?
Tachypnea
Shallow breathing
Diffuse rales
What are the CXR results seen in ARDs?
- May be normal in early stages, w/ ↑ abnormal findings as progresses
A. Peripheral infiltrates, sparing costophrenic angles
B. Air bronchograms in 80% patients
-Air-filled bronchi (dark) being made visible by the opacification of surrounding alveoli - In later stages, lung fields with “white outs” of both lung fields
What are the initial results of ABG dx studies in ARDs?
- Dec pO2 (< 60 mm Hg)
- Decreased pCO2 (< 35 mm Hg)
- pH = ↑ (respiratory alkalosis)
What are the results of ABG dx studies in ARDs if the pt is septic?
Metabolic acidosis → +/- resp compensation
What is the hallmark of ARDs?
Hypoxemia despite increased supplemental oxygen
What are the later stage results of ABG dx studies in ARDs?
1. As ARDS worsens: A. ↑ pCO2 (> 45 mmHg) B. → resp acidosis C. ↓ HCO3 level (< 22 meq/l) D. ↓ pO2 -Despite oxygen therapy
What test results indicate multi-organ failure?
A. ↑ BUN/Cr
B. ↑ LFT’s
C. ↑ coagulation parameters
What is the supportive care treatment for ARDs?
- Supportive care for severe resp dysfunction
A. Oxygen via ET intubation with positive pressure ventilation
B. Hypoxia often resistant to oxygen
What is the treatment for ARDs?
- Antibiotics
- Respiratory support: ventilator
- Diuretics
- Situate patient in semi-prone position
What is the prognosis for ARDs?
- High mortality rate
- 33% of deaths occur within 3 days of onset of sx’s
- Remaining deaths occur within 2 weeks of Dx
A. Caused by multi-organ failure or infection
