Emergency front of neck access in children: a new learning approach in a rabbit model.
What we already know:
Emergency front of neck access (eFONA) is uncommon in infants and small children (<8 years) and there is a lack of consensus on the appropriate strategy. These situations are linked to poor survival. The Association of Paediatric Anaesthetists of Great Britain and Ireland’s guidelines for 1-8 year olds recommends percutaneous cricothyroidotomy when a trained surgeon is not available. Surgical cricothyroidotomy is discouraged due to the risk of damaging the laryngeal cartilages when passing the tube between the relatively small cricothyroid space. Nonetheless, needle cricothyroidotomy also has potential for significant airway trauma, with a paediatric scale animal study demonstrating laryngeal cartilage fractures and posterior wall injury in 20% and 13% of attempts respectively. Emergency surgical tracheostomies in paediatric patients have not been well studied and data from actual cases is lacking. The authors propose that this learning technique may offer a viable alternative.
What this study examined:
50 physicians from 5 different paediatric specialties (10 intensivists, 10 emergency physicians, 10 surgeons, 10 anaesthesiologists and 10 emergency response physicians) watched an instructional video and subsequently performed 10 consecutive emergency tracheostomies on rabbit cadavers. No participants had prior experience with the procedure and the learning curves were examined for success, time and concurring injuries.
What was learnt:
Success: Overall success was 94%, which remained stable throughout attempts.
Time: Performance time improved over 10 attempts from 107(±45) seconds to 55(±17) seconds. The learning curve was steep between the 1st and 4th attempts, and relatively flatter thereafter. Men performed their 1st attempt faster, but by the 4th attempt there was no difference between genders. Higher participant age and years of clinical experience was associated with a flatter learning curve (i.e. less improvement). Medical specialty and prior adult eFONA experience (clinical or simulated) did not affect the learning curve.
Injuries: Severe injuries occurred in 16% of all attempts. This was much more likely to occur during the 1st attempt (58%, 95% CI 44-72%) but decreased significantly by the 2nd attempt (14%, 95% CI 8-20%). Overall, minor injuries occurred in 15% and this was stable throughout attempts. Men were more likely to cause minor injury, but no participant factors showed significant association to injuries. Of note, the complication rate appears to be less compared with paediatric studies examining other eFONA techniques.
There are obvious limitations to studying a simulated animal-based model. There was also an absence of a clear hypothesis and power calculation.
Take home message:
Surgical tracheostomy in paediatric sized animal models can be executed by doctors from a variety of backgrounds and experience levels with a high success rate (94%) after only brief training and repetition. It is difficult to make recommendations based on this study. Airway injury is still a major concern, and despite a reduction in major injuries with subsequent attempts, the retention of this skillset in the longer term is unclear. In practical terms, surgical tracheostomy sets are not currently readily available in most hospital settings.
Reviewed by Dr. Adam Kay