Difficult or impossible facemask ventilation in children with difficult tracheal intubation
A retrospective analysis of the PeDI registry
British Journal of Anaesthesia
September 2023 by Dr Rory Walsh
The Pediatric Difficult Intubation (PeDI) Registry is a large, multicentre international registry that collects data on paediatric patients where difficult intubation is identified. The authors performed a retrospective, observational cohort analysis of the registry with the following aims:
Identify the physical characteristics and anaesthetic factors associated with difficult or impossible mask ventilation (MV).
i) Compare the incidence of complications between patients with difficult intubation AND difficult or impossible MV vs those with difficult intubation alone.
ii) Determine whether difficult MV was worsened or improved after neuromuscular blocking agents.
iii) Determine the efficacy of supraglottic airway devices as a rescue ventilation technique.
The analysis included cases between 2011 to 2021 across 36 institutions in seven countries. 5453 difficult intubation cases were ultimately included.
Given that the combination of both difficult intubation AND difficult MV is a potential crisis situation, identifying factors associated with difficult MV may help clinicians avoid ‘can’t intubate, can’t oxygenate’ scenarios. Similarly investigating the effectiveness of supraglottic airways and neuromuscular blocking agents in the context of difficult MV is also important.
While predictors of difficult MV and the effects of neuromuscular blocking agents on ventilation have been well studied in adults, there is a relative lack of paediatric-specific studies in these areas.
The incidence of difficult or impossible MV in children with difficult intubation was 9% (difficult 8%, impossible 1%). As a comparison previously published data suggests that difficult MV occurs in up to 6% of children in the general population.
Patient factors associated with difficult/impossible MV:
• Age <1y
• Increased weight
• Low weight (<5th percentile for age)
• Treacher Collins Syndrome
• Limited mouth opening
Anaesthetic factors associated with increased risk of difficult or impossible MV:
• Intravenous induction
• Tracheal intubation attempt in ICU
Anaesthetic factors associated with decreased risk of difficult impossible MV:
• Inhalational induction
• Opioid administration
The incidence of complications (including hypoxaemia, major airway trauma & cardiac arrest) was higher in patients with difficult or impossible MV than those with easy MV.
Supraglottic airway placement improved ventilation in 71% of patients with difficult MV, and 48% with impossible MV.
In patients with difficult or impossible MV, the use of neuromuscular blocking agents was more frequently associated with improvement or no change in ventilation (90%), than worsening (10%).
The main strength of this study is that it utilises a very large international, multicentre registry across a ten-year time frame. The main limitation of the study, as acknowledged by the authors, is that the analysis was limited to MV in patients with difficult intubation only. The findings cannot be generalised to patients who are not difficult to intubate.
The PeDI registry is large. This study analysed data from over 5000 difficult intubations collected from 36 institutions across seven countries (including the USA, Canada, and Australia). It can be reasonably inferred that the findings from such a large analysis are applicable to Australian and New Zealand paediatric practice.
Take Home Message/Commentary
Unsurprisingly the combination of difficult or impossible MV AND difficult intubation puts children at greater risk of complications.
In children that are difficult to intubate there are certain patient and anaesthetic factors that are associated with difficult or impossible MV. These factors should be considered when planning the airway management of children with known or suspected difficult intubation.
Supraglottic airways frequently improve ventilation when MV is difficult or impossible. A supraglottic airway should always be considered for rescue ventilation.
In some cases the administration of neuromuscular blocking agents will worsen MV. However, this analysis suggests that the use of these agents more often either improve or have no effect on MV.