What may a decreased chest wall expansion be caused by?
- post operative pain
- rib fractures
- Pneumothorax
What may increase airway resistance?
- asthma
- COPD
What may cause a decrease in respiratory muscle strength?
- Gillian-Barre syndrome
- poliomyelitis
- Myasthenia graves
- spinal cord injury
What may cause a decreased respiratory drive?
- brain trauma
- drug overdose
- anaesthesia/sedation
Decreased capacity for gas exchange may be caused by?
- impairment of ventilation (pulmonary oedema, pneumonia, COPD, ALI)
- impairment in pulmonary perfusion (pulmonary embolism)
- combination of both
List the 3 largest groups of presentations that require hospital admission?
- influenza
- pneumonia
- COPD / asthma
When does respiratory failure occur?
When the respiratory system fails to achieve one or both of its essential gas exchange functions. (Oxygenation or elimination of carbon dioxide)
What is Type 1 respiratory failure?
Failure to oxygenate or “hypoxaemia” presents with a low partial pressure of oxygen (PaO2) and a normal or low partial pressure of carbon dioxide (PaCO2).
What might cause hypoxaemic respiratory failure?
Hypoxaemic respiratory failure may occur due to:
- extreme altitude
- hypoventilation
- impaired diffusion
- ventilation-perfusion mismatch
What is Intrapulmonary shunting?
It is a severe form of ventilation perfusion mismatch
-occurs when adequate perfusion exists but there are sections of lung tissue that are not ventilated.
What is dead space ventilation?
It is when the lungs continue to be ventilated but there is limited or no perfusion and therefore no gas exchange.
What is Type II respiratory failure?
- failure to ventilate
- Pt presents with a high PaCO2 and low PaO2
What may cause type II respiratory failure?
Conditions that affect the respiratory drive
- neuromuscular diseases
- chest wall abnormalities
- severe airway disease (COPD, asthma)
What is the most common symptom associated with acute respiratory failure?
-Dyspnoea
This is generally accompanied by increased rate and depth of breathing and the use of accessory muscles.
What clinical assessments may be performed on a pt with acute respiratory failure?
-assess the cause of respiratory failure to work out how to proceed
-continuous monitoring of oxygen saturation
- may monitor pt response to O2 supplements if implemented
- arterial blood analysis
-CXR
-CT of the chest may be used
-microbial cultures may be taken in special circumstances
-
What management might be performed on a pt presenting with acute respiratory failure?
-primary survey (A,B,C’s)
-frequent assessment and monitoring of respiratory assessment including pt response to O2 supplement or ventilator support
-pt comfort and compliance with ventilator mode
-ABG analysis and O2 says
The key goals of management are to treat primary cause of respiratory failure, maintain adequate gas exchange and prevent or minimise the potential for complications of positive pressure mechanical ventilation
List at least 3 commonly prescribed medications for respiratory failure.
- inhalation/intravenous steroids
- bronchodilators
- antibiotic therapy
- analgesia and sedation (to maintain pt-ventilator synchrony)
List at least 4 causes that result in direct lung injury.
- pneumonia
- aspiration of gastric contents
- pulmonary contusion
- near drowning
- inhalation injury (smoke/chemical)
- repercussion pulmonary oedema
List at least 4 causes that result in indirect lung injury.
- sepsis
- multiple trauma
- cardiopulmonary bypass
- drug overdoes
- acute pancreatitis
- transfusion of blood products
List at least 4 indications for intubation or mechanical ventilation.
- apnoea
- Inability to protect airways (decreased LOC)
- clinical signs of respiratory distress
- inability to sustain adequate oxygenation for metabolic demands
- respiratory acidosis
- shock
- respiratory failure
List 4 indications for NIV (non-invasive ventilation).
- asthma
- pulmonary infiltrates in immunocompromised pt’s
- neuromuscular disorders
- fractured ribs
- Obesity and central hypoventilation syndromes
- palliative
Pneumonia can be classified into 2 types, what are they?
- Community-acquired pneumonia (CAP)
2. Ventilator-associated pneumonia (VAP)
Currently lung transplantation take 2 main forms, what are they?
- Bilateral sequential lung transplantation (BSLTx)
2. single-lung transplantation (SLTx)
High oxygen concentrations may lead to oxygen toxicity. List (3 of each) signs and symptoms that may occur in the CNS and pulmonary.
CNS: -nausea and vomiting -anxiety -visual changes -hallucinations -tinnitus -vertigo -hiccups -seizures Pulmonary -cry cough -sub sternal chest pain -pulmonary oedema -pulmonary fibrosis
