Respiratory Failure Flashcards
Define respiratory failure
A syndrome of inadequate gas exchange due to dysfunction of one or more components of the respiratory system
What is the main clinical feature of respiratory failure
Shortness of breath
What are the 3 main systems affected in respiratory failure?
Respiratory
Nervous
Pulmonary
Where in the world is respiratory failure most common
North America and north Europe
How does the epidemiology of respiratory failure differ between men and women?
Biggest risk factor for men is smoking
Biggest risk factor for women is household air pollution
What is the acute outcome of respiratory failure?
Respiratory distress syndrome
What causes increased risk of mortality in ARDS?
With age and severity
What are some causes of acute respiratory distress?
Pulmonary causes eg infection, graft dysfunction, aspiration
What are some causes of chronic respiratory distress?
Pulmonary causes eg COPD, lung fibrosis, lobectomy
Musculoskeletal causes eg muscular dystrophy
What are some causes of acute on chronic respiratory distress?
Infective exacerbation eg in COPD and CF
Myasthenic crisis
Post operative
What is type 1 respiratory failure known as
Hypoxemic respiratory failure
What are some common causes of type 1 respiratory failure?
Collapse, aspiration, pulmonary oedema, fibrosis, pulmonary embolism, pulmonary hypertension
What is pO2 in type 1 respiratory failure?
< 60
What is type 2 respiratory failure known as?
Hypercapnic respiratory failure
What are some causes of type 2 respiratory failure?
Neuromuscular disorders, nervous system disorders, airway obstruction, chest wall deformity
What is pCO2 in type 2 respiratory failure?
> 45
What is the issue in type 2 respiratory failure?
Failure to exchange or remove carbon dioxide
What is the issue in type 1 respiratory failure?
Failure of oxygen exchange
What is type 3 respiratory failure known as?
Perioperative respiratory failure
What is the issue in type 3 respiratory failure?
Hypoxemia or hypercapnia
What causes type 3 respiratory failure?
Low functional residual capacity and abnormal wall mechanics
How is type 3 respiratory failure prevented?
Anaesthesia, analgesics, correct posture during surgery, attempts at lowering intra abdominal pressure
What is type 4 respiratory failure known as?
Shock
What are some types of shock?
Neurologic, cardiogenic, spetic
How does positive pressure ventilation affect the left ventricle?
In a good way as there is reduced afterload
How does positive pressure ventilation affect the right ventricle?
In a bad way as there is increased preload
What are some risk factors for chronic respiratory failure?
COPD Pollution Recurrent pneumonia CF Pulmonary fibrosis Neuromuscular disease
What are some risk factors for acute respiratory failure?
Infection Aspiration Trauma Pancreatitis Transfusion
Describe how acute lung injury occurs in ARDS and how it leads to inefficient gas exchange
Injury causes damage to the interstitium
Alveolar macrophages are activated
Cytokines are released eg IL6, IL8, TNF alpha
Alveolar fluid builds up=oedema
Lung is less efficient at expanding
Damage to the vessels means neutrophils etc leak out into the intertsitium
There is an increased gap between the vessel and alveoli leading to reduced gas exchange
