In June this year, an interesting discussion article was published in Resuscitation by Schmölzer et al, entitled, ‘Supraglottic airway devices during neonatal resuscitation: An historical perspective, systematic review and meta-analysis of available clinical trials’.
This is a welcome review. Whilst The World Health Organisation (WHO) report that neonatal mortality rates have declined from 32 per 1,000 births in 1990 to 22 per 1,000 births in 2011, a reduction of over 30%, the proportion of child deaths which occur in the neonatal period has increased in all WHO regions over the last 20 years. In an analysis of neonatal mortality – situation and trends, WHO state that prematurity is the leading cause of newborn deaths and that up to two thirds of newborn deaths could be prevented if skilled health care workers perform effective health measures at birth and during the first week of life.
The WHO Guidelines on Basic Newborn Resuscitation 2012 confirm that globally, approximately a quarter of neonatal deaths are caused by birth asphyxia, defining birth asphyxia as the failure to initiate and sustain breathing at birth. The guidelines go on to state that ‘effective resuscitation at birth can prevent a large proportion of these deaths’.
Schmölzer et al state that the International Liaison Committee on Resuscitation (ILCOR) and various national guidelines all agree that, ‘mask ventilation is the cornerstone of respiratory support immediately after birth.’ However, delivery room studies have shown that mask ventilation is difficult and mask leak and airway obstruction are common. In light of this, it is interesting to consider, as Schmölzer et al have done, what role supraglottic airways might have in neonatal resuscitation and examine the current evidence base for their use.
Current neonatal guidelines, such as those issued by the American Heart Association (AHA), state that Laryngeal Mask Airways (LMs) have been shown to be effective for ventilating newborns weighing more than 2kg or delivered ≥ 34 weeks gestation, and that there are limited data on the use of these devices in small preterm infants <2kg or <34 weeks gestation. The AHA guidelines also confirm that, ‘A laryngeal mask should be considered if facemask ventilation is unsuccessful and tracheal intubation is unsuccessful or not feasible. The laryngeal mask has not been evaluated in cases of meconium-stained fluid, during chest compressions, or for administration of emergency intratracheal medications.’
Perhaps unsurprisingly, Trevisanuto et al reported that although 35% of Italian anaesthetists and 23% of paediatricians have experience with LMs for airway management in newborn infants, anaesthetists were more enthusiastic about the LM than paediatricians. Schmölzer et al confirmed that although there are various studies comparing LMs, randomised trials comparing the performance of each LM are warranted.
There is a meta-analysis of randomised trials (RCT) in the Schmölzer et al review, which concludes that, ‘Overall, RCTs have shown that initial respiratory support with a LM is feasible and safe. However, there is not enough evidence to recommend LM instead of mask ventilation for initial respiratory support in the delivery room and large randomised trials are warranted before the technique is widely applied.’
The review also discusses the potential of supraglottic airways as a conduit for the administration of surfactant. An important subject, particularly given that surfactant administration via an ET tube has been associated with a series of adverse events. The review notes that, ‘although pilot data are promising, the current available evidence suggests that surfactant administration via laryngeal mask should be limited to clinical trials.’
At the 54th Annual Meeting of the European Society for Paediatric Research in Porto in October this year, three posters are being presented regarding the use of supraglottic airways in neonatal resuscitation. The first is entitled, ‘The relationship between successful insertion of a neonatal sized i-gel and a health care provider’s profession or experience’, by Sugiura et al from Shizuoka, in Japan. The second, from the same group of investigators, is entitled, ‘Randomised controlled study comparing a neonatal sized i-gel and the Laryngeal Mask Airway in a neonatal resuscitation mannequin.’ The third is entitled, ‘Higher success rate and operator satisfaction with i-gel laryngeal mask airway compared to face mask: A mannequin study of neonatal resuscitation in Uganda’, by Pejovic et al, from Stockholm in Sweden, Padua in Italy, Kampala in Uganda and Bergen in Norway.
It will not be possible to draw any conclusions from these posters, so the authors will no doubt conclude that further research is required. Of significance is the potential benefits of using supraglottic airways during neonatal resuscitation compared to a BVM or ET tube being discussed and studied, and the recognition that all supraglottic airways are not the same.
The latter point is important. Evidence for one supraglottic airway should not be extrapolated to another device with different design characteristics.
Further data regarding the potential use of supraglottic airways in neonatal resuscitation is awaited with great interest.