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Capnography: the lesson of the NAP4 audit

What the UK Fourth National Audit Project found in ICU and emergency departments
November 2, 2026 by
Intubation simulation in the Airway Zen program.
Intubation simulation in the Airway Zen program.

NAP4 was a national audit by the Royal College of Anaesthetists and the Difficult Airway Society that gathered the major complications of airway management in the UK. Its second part (Cook et al., British Journal of Anaesthesia 2011) analyzed what happened in intensive care and emergency departments.

What it found

NAP4 findings in ICU and emergency departments
FindingData
Capnography and serious outcomeIts absence contributed to 74% of cases of death or persistent neurological injury in ICU and emergency departments
Where events happenAt least 1 in 4 major in-hospital airway events occurs in ICU or the emergency department
PreventionMost emergency department events could have been prevented with better systems, preparation and communication

Core idea: the problem was not only technique but recognizing a displaced or misplaced tube in time. The capnography waveform shows it continuously.

Follow-up

A later audit in the ICU of a district general hospital found that only 27% of intubated patients had continuous capnography, and noted that NAP4 recommends it for all intubations and for ventilated patients with a tracheal tube or tracheostomy in ICU.

Sources

Image: Airway Zen program simulation.

Educational content; it does not replace clinical judgment or your institution's guidelines.

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