A cadaver study comparing three fibreoptic‐assisted techniques for converting a supraglottic airway to a cuffed tracheal tube

Abstract

After rescuing an airway with a supraglottic airway device, a method to convert it to a cuffed tracheal tube is often needed. The best method to do this has never been directly studied. We compared three techniques for conversion of a standard LMA Unique airway to a cuffed endotracheal tube using a fibrescope. The primary endpoint was time to intubation, with secondary endpoints of success rate, perceived difficulty and preferred technique. We also investigated the relationship between level of training and prior training and experience with the techniques on the primary outcome. The mean (95% CI) time to intubation using a direct tracheal tube technique of 37 (31-42) s was significantly shorter than either the Aintree intubation catheter technique at 70 (60-80) s, or a guidewire technique at 126 (110-141) s (p < 0.001). Most (13/24) participants rated the tracheal tube as their preferred technique, while 11/24 preferred the Aintree technique. In terms of perceived difficulty, 23/24, 21/24 and 9/24 participants rated the tracheal tube technique, Aintree technique and guidewire technique, respectively, as either very easy or easy. There was no relationship between prior training, prior experience or level of training on time to completion of any of the techniques. We conclude the tracheal tube and Aintree techniques both provide a rapid and easy method for conversion of a supraglottic airway device to a cuffed tracheal tube. The guidewire technique cannot be recommended.

Direct and indirect low skill fibre-optic intubation: A randomised crossover manikin study of six supraglottic airway devices

“…Shorter intubation times can be expected with the direct method as it has fewer steps and is confirmed in other manikin and cadaver studies. [ 5 19 ] Possible explanations why direct FOI times may be longer for the classic LMA are the cross-bars may make railroading difficult; railroading a tracheal tube over the FOB may take more time compared with the AIC due to inadvertent withdrawal of the FOB with subsequent oesophageal intubation;[ 5 ] looping of the FOB and impingement during railroading. Looping of the FOB occurs as it is more pliable than the AIC.…”

“…The direct method has advantages over the indirect method: there are fewer steps; the AIC is not used, thus avoiding its associated problems (below) and the SAD does not have to be removed, thus maintaining the airway and minimising interruptions in ventilation. [ 19 ] The main disadvantage is that the SAD dictates what type of tracheal tube can be used. For example, the Proseal and Supreme LMAs fit a smaller endotracheal tube than other SADs [ Table 1 ].…”

“…Advantages of the indirect method include the following:[ 19 22 ] first, the narrow AIC can be inserted into adult sizes of SAD1 and SAD2. Second, the FOB/AIC unit can be inserted through a self-sealing bronchoscopy catheter mount, allowing continued ventilation during the intubation process.…”

Human cadavers preserved using Thiel's method for the teaching of fibreoptically‐guided intubation of the trachea: a laboratory investigation

“…Simulation in different human cadaver models has been attempted with success [7,10,12,18]. Although there is evidence to support the use of embalmed cadavers for the teaching of fibreoptic intubation alone or with other devices, Thiel's model has not been studied for this purpose [7,21].…”

Assessment of flexible bronchoscopic intubation through the AuraGain™ laryngeal mask versus a slit Guedel tube

“…Finally, we were interested in knowing why a Unoflex TM reinforced tracheal tube (ConvaTec Ltd, Flintshire, UK) was used for FBI in the AuraGain laryngeal mask group even though it has a fixed connector that could prevent removal of the AuraGain laryngeal mask after successful intubation. 4 Competing interests None declared.…”