Acute Respiratory Distress Syndrome Flashcards
What is Acute Respiratory Distress Syndrome?
A syndrome of acute and persistent lung inflammation with increased vascular permeability
What is ARDS characterised by?
Acute Onset
Bilateral infiltrates consistent with pulmonary oedema
Hypoxaemia
No clinical evidence of increased left arterial pressure (pulmonary capillary wedge pressure)
ARDS is the severe end of the spectrum of acute long injury
How does ARDS develop?
Severe insults to the lungs and other organs leads to the release of inflammatory mediators
These lead to increased capillary permeability, pulmonary oedema, impaired gas exchange and reduced lung compliance
What are the causes of ARDS?
Sepsis
Aspiration
Pneumonia
Pancreatitis
Trauma/burns
Transfusion
Transplantation (bone marrow and lung)
Drug overdose/reaction
What are the three pathological stages of ARDS?
Exudative
Proliferative
Fibrotic
What is the epidemiology of ARDS?
Annual UK incidence: 1/6000
What are the presenting symptoms of ARDS?
Rapid deterioration of respiratory function
Dyspnoea
Respiratory Distress
Cough
Symptoms of CAUSE
What are the signs of ARDS on physical examination?
Cyanosis
Tachypnoea
Tachycardia
Widespread Inspiratory Crepitations
Hypoxia Refractory to Oxygen Treatment
Signs are usually bilateral but may be asymmetrical in early stages
What are the investigations for ARDS?
CXR
Bloods
Echocardiography
Pulmonary Artery Catheterisation
Bronchoscopy
What Chest X-Ray do you do ARDS?
Bilateral alveolar infiltrates and interstital shadowing
What bloods do you do ARDS?
To figure out the cause
FBC
U&Es
LFTs
ESR/CRP
Amylase
ABG
Blood Culture
Why would you use BNP for ARDS?
Plasma BNP < 100 pg/mL could distinguish ARDS from heart failure
Why would you use Echocardiography for ARDS?
Check for severe aortic or mitral valve dysfunction
Low left ventricular ejection fractions = haemodynamic oedema rather than ARDS
What would you use Pulmonary Artery Catheterisation for?
Check pulmonary capillary wedge pressure (PCWP)
Why would you use Bronchoscopy for ARDS?
If the cause can’t be determined from the history
