Unrecognised oesophageal intubation: checklist for capnography and two-person verbal check of sustained exhaled carbon dioxide. Comment on Br J Anaesth 2025; 134: 1223–4

Editor

In response to the recent correspondence by Whitaker and O'Sullivan,¹ we support the continued efforts to raise awareness of the ongoing issue of unrecognised oesophageal intubation and to drive change. Despite widely publicised educational campaigns² emphasising the importance of sustained exhaled CO₂, which followed publication of the PUMA guidelines³ in 2022, deaths relating to unrecognised oesophageal intubation continue to occur within the UK.⁴

Whitaker and O'Sullivan mention the importance of human factors in understanding why unrecognised oesophageal intubations continue to occur. Anchoring bias, a powerful cognitive bias, describes how the first piece of information we receive greatly influences⁵ how any subsequent information is perceived and processed, and has been shown to affect physician decision making. There is still frequent use amongst anaesthetists of unreliable clinical signs such as misting of the tracheal tube and observation of chest rise as initial indicators of successful tracheal intubation. Using these signs, however well intentioned, makes it more likely that even the most skilled clinicians would seek alternative explanations (other than oesophageal intubation) for an unusual capnography trace after placing a tube. The authors’ suggestion for redesigning tracheal tube packaging with a simple pictorial checklist makes sense from a human factors perspective as it would be available at point of care and has a developing evidence base to support its use.

Manufacturers of tracheal tubes already provide instructions for use⁶ that detail recommendations for the proper care, storage, and directions for use. These instructions are not usually available, and are not appropriate at point of care during intubation. A recent study⁷ showed that a two-person verbal check of sustained CO₂ to confirm tracheal intubation represented a quick and effective human factors-influenced method to improve communication and patient safety. The majority of intubators and assistants who participated in the study planned to continue using the two-person check. Importantly, intubators’ assistants reported feeling empowered to voice concerns, potentially aiding in identifying oesophageal intubation which had been ‘unrecognised’ by the intubator.

Declaration of interest

The authors declare no conflict of interest.

Handling Editor: Hugh C Hemmings Jr