Mortality due to anaesthesia

The UK is probably comparable to other developed countries where the mortality has been found to be approximately 1:10,000. UK anaesthetists will administer approximately 18,000–30,000 anaesthetics in their careers, so the chances of being involved in a tragedy are not negligible.

Causes of anaesthetic mortality

Mistakes or complications associated with drug administration cause the majority of deaths (approximately 40%). Deaths due to airway management have declined and in the last reported study from the USA, problems with airway management caused the same number of fatalities as central venous line insertion (20%).

Causes of airway mortality

The causes continue to be loss of airway during attempts at intubation, perforation of the pharynx, oesophagus or trachea, and oesophageal intubation. Rarer causes are aspiration of stomach contents, laryngospasm and bronchospasm.

Loss of airway at intubation

The mechanism is unclear but the scenario is well recognized –a patient, who was initially possible to ventilate with a mask, becomes impossible to ventilate after repeated attempts to intubate. Possible causes are swelling of tissues due to trauma, laryngospasm, operator fatigue and panic. The message is clear – do not make repeated fruitless attempts to intubate. Aim to make one ‘optimal best attempt’ with all factors properly arranged.

Perforation of pharynx/oesophagus or trachea

The cause of death is usually sepsis following the development of mediastinitis or cervical abscess. The mortality rate from mediastinitis is about 20%. Acute airway obstruction or respiratory failure can result from surgical oedema or pneumothorax. Only half of the perforations are recognized (pneumothorax or subcutaneous air) at the time. Perforation can occur during easy intubation, but is strongly associated with difficult intubation.