Respiratory failure Flashcards
What is respiratory failure?
Syndrome of inadequate gas exchange due to dysfunction of one or more components of the respiratory system
Which aspects of the nervous system is affected by respiratory failure?
CNS/Brainstem
Peripheral nervous system
Neuromuscular junctions (Myasthenia gravis)
Which respiratory muscles are affected by respiratory failure?
Diaphragm and thoracic muscles
Extra-thoracic muscles.
Which aspects of the pulmonary system are affected by respiratory failure?
Airway disease
Alveolar-capillary disease - a vascular disease or damage to the area due to fibrosis
Circulation (pulmonary hypertension can impair vascular supply)
Which parts of the world are predominantly affected by respiratory diseases?
North America and Europe
What is the largest risk factor for chronic respiratory failure in males?
Smoking
What is the largest risk factor for chronic respiratory failure in females?
Household air pollution from solid fuels.
Which two factors increase the mortality of acute respiratory distress syndrome?
Severity and advance age
What factors are considered in the definition and classification of acute respiratory distress syndrome?
Timing- Within 1 week of a known clinical insult or new or worsening respiratory syndrome.
Chest imaging - Bilateral opacities, not fully explained by effusions, lobar/Lung collapse or nodules.
Origin of oedema: Respiratory failure not fully explained by cardiac failure or fluid overload.
Oxygenation:
How does chest imaging reveal an individual with acute respiratory distress syndrome?
Bilateral opacities
What factors are classified as causes of acute respiratory failure?
Pulmonary: Infection, aspiration, primary graft dysfunction (Lung Tx)
Extra-pulmonary: Trauma, pancreatitis, sepsis.
Neuromuscular: Myasthenia/GBS
What factors are classified as causes of chronic respiratory failure?
Pulmonary/airways: COPD, lung fibrosis, CF, lobectomy.
Musculoskeletal: Muscular dystrophy
What factors are classified as causes of acute on chronic respiratory failure?
Infective exacerbation
COPD, CF
Myasthenia crises
Post-operative
What is type 1 respiratory failure?
Hypoxemic (PaO2 <60 at sea level)
-There is a failure of oxygen exchange.
Increased shunt faction (QS/QT)
Due to alveolar flooding
Hypoxemia refractory to supplemental oxygen
What type of respiratory failure is associated with a failure of oxygen exchange?
Type I
What are the six possible causes of hypoxemic respiratory failure?
Collapse Aspiration Pulmonary oedema Fibrosis Pulmonary Embolism Pulmonary hypertension
What type of respiratory failure is associated with a decreased alveolar minute ventilation?
Type II (Hypercapnic)
What is hypercapnic respiratory failure?
Type II respiratory failure, failure to exchange or remove carbon dioxide
What are the five psosible causes of hypercapnic respiratory failure?
Nervous system Muscle failure Airway obstruction Chest wall deformity Neuromuscular
What is type III respiratory failure associated with?
Perioperative respiratory failure, there is an increased atelectasis due to low functional residual capacity with abnormal abdominal wall mechanics.
Hypoxemia or hypercapnoea
How can type III respirator failure be prevented?
Anaesthetic, operative technique, posture, incentive spirometry, analgesia, attempts to lower intra-abdominal pressure
What is type IV respiratory failure associated with?
Type IV describes patients who are intubated and ventilated during shock (septic, cardiogenic, neurologic)
What treatment is available for type IV respiratory failure?
Optimise ventilation improve gas exchange and to unload the respiratory muscles, lowering their oxygen consumption.
Ventilatory effects on right and left heart (Reduced afterload on left ventricle) due to positive pressure.
What are the chronic risk factors for respiratory failure?
COPD Pollution Recurrent pneumonia Cystic fibrosis Pulmonary fibrosis Neuro-muscular diseases
What are the acute risk factors for respiratory failure?
Infection, viral, bacterial Aspiration - conscious level drops Trauma - induces inflammatory responses Pancreatitis Transfusion
What are the main causes of acute respiratory failure?
1) Lower respiratory tract infection (viral or bacterial)
2) Aspiration
3) Trauma - transfusion
4) Pulmonary vascular disease (embolus, haemopysis)
6) Extrapulmonary - pancreatitis, new medications