Even with a clear airway, ventilation (breathing) may be inadequate because of:

  • Central depression of respiratory drive as a result of IV/inhalational anaesthetics, opioids or benzodiazepines
  • Peripheral impairment of respiratory mechanics from residual neuromuscular blockade, diaphragmatic splinting (obesity, abdominal distension) or pain (thoracic or abdominal surgery)

Question: What factors are associated with prolonged neuromuscular blockade?

Click here for the answer.

Fig 1 Spirometry

Even with a clear airway, ventilation (breathing) may be inadequate because of:

  • Central depression of respiratory drive as a result of IV/inhalational anaesthetics, opioids or benzodiazepines
  • Peripheral impairment of respiratory mechanics from residual neuromuscular blockade, diaphragmatic splinting (obesity, abdominal distension) or pain (thoracic or abdominal surgery)

Question: What factors are associated with prolonged neuromuscular blockade?

Answer: Factors associated with prolonged neuromuscular blockade include:

  • Hypothermia
  • Respiratory acidosis
  • Electrolyte abnormalities: hypokalaemia, hypocalcaemia, hyponatraemia, hypermagnesaemia
  • Drug interactions: volatile agents, calcium channel blockers, aminoglycosides, diuretics
  • Decreased excretion: renal failure, liver failure

Click here to see: Other causes of hypoxaemia.

Fig 1 Spirometry

Even with a clear airway, ventilation (breathing) may be inadequate because of:

  • Central depression of respiratory drive as a result of IV/inhalational anaesthetics, opioids or benzodiazepines
  • Peripheral impairment of respiratory mechanics from residual neuromuscular blockade, diaphragmatic splinting (obesity, abdominal distension) or pain (thoracic or abdominal surgery)

Question: What factors are associated with prolonged neuromuscular blockade?

Answer: Factors associated with prolonged neuromuscular blockade include:

  • Hypothermia
  • Respiratory acidosis
  • Electrolyte abnormalities: hypokalaemia, hypocalcaemia, hyponatraemia, hypermagnesaemia
  • Drug interactions: volatile agents, calcium channel blockers, aminoglycosides, diuretics
  • Decreased excretion: renal failure, liver failure

Other causes of hypoxaemia include:

  • Pulmonary complication - atelectasis, aspiration, pulmonary oedema, pneumothorax
  • Diffusion hypoxia (from nitrous oxide use)
  • Increased oxygen utilization – shivering, pyrexia, sepsis
  • Low cardiac output states