ARDS Flashcards
What is ARDS?
syndrome of acute + persistent lung inflammation with increased vascular permeability.
What 4 features characterise ARDS?
Acute onset < 1 week
Bilateral infiltrates consistent with pulmonary oedema “White out”
Hypoxaemia (PF ratio <300)
Not caused by heart failure (Normal pulmonary capillary wedge pressure)
ARDS is at the severe end of what spectrum?
Spectrum of acute lung injury
Describe the pathophysiology of ARDS
Severe insults to lungs + other organs leads to release of inflammatory mediators
These lead to increased capillary permeability, pulmonary oedema, impaired gas exchange + reduced lung compliance
List 8 causes of ARDS
Sepsis Aspiration Pneumonia Pancreatitis Trauma/ burns Transfusion Transplantation (bone marrow + lung) Drug OD/reaction
Describe the epidemiology of ARDS
Annual UK incidence: 1/6000
What are the 3 pathological stages of ARDS?
Exudative
Proliferative
Fibrotic
List 4 symptoms of ARDS
Dyspnoea
Respiratory distress
Cough
Symptoms of CAUSE
List 5 signs of ARDS
Cyanosis Tachypnoea Tachycardia Widespread inspiratory crepitations Hypoxia refractory to oxygen tx
What is seen on CXR in ARDS?
bilateral alveolar infiltrates + interstitial shadowing
“White out”
Why are bloods taken in ARDS? Which ones?
to determine cause FBC U+Es LFT ESR/CRP (sepsis) Amylase (pancreatitis)
List 8 investigations that may be used in ARDS
CXR Bloods ABG (low PaO2) Blood culture (infection) Sputum culture (infection) Echocardiography (exclude HF) Pulmonary Artery Catheterisation: Check pulmonary capillary wedge pressure Bronchoscopy
Name 2 measurements that indicate ARDS rather than heart failure
plasma BNP < 100 pg/mL
Normal PCWP
Why perform an echocardiogram in ARDS?
Check for severe aortic or mitral valve dysfunction
Low left ventricular ejection fractions = haemodynamic oedema rather than ARDS
Why perform bronchoscopy in ARDS?
If infectious cause can’t be determined from hx
