Cuffed versus uncuffed endotracheal tubes in pediatric anesthesia: the debate should finally end.

500 March 2013 I this issue of Anesthesiology, sathyamoorthy et al.1 describe three cases of postextubation airway swelling in young infants. The cases are noteworthy because the endotracheal tube used in all three infants was a recently developed cuffed endotracheal tube called the Microcuff® (Kimberly-Clark, Roswell, gA), which has been specifically designed for use in pediatric anesthesia. it differs from a traditional cuffed endotracheal tube in two major modifications: first, the cuff is made of ultrathin (10 microns) polyurethane, which allows a more effective tracheal seal at pressures below those known to cause tracheal mucosa pressure necrosis; and second, the cuff is physically located more distally on the endotracheal tube shaft, facilitated by the omission of the Murphy eye. This latter feature more reliably places the cuff below the nondistensible cricoid ring and theoretically reduces the chance of an accidental main bronchus intubation. As sathyamoorthy et al. demonstrate,1 these innovations do not guarantee that tracheal injury will not occur. in fact, the report is important because it reminds us that postextubation stridor (i.e., airway injury and swelling) can occur after tracheal intubation with any type of endotracheal tube; however, it does not implicate the Microcuff® as a unique offender. The infants in cases 1 and 2, who were born preterm and weighed less than 3 kg, were intubated with a size 3.0 Microcuff® tube, but the manufacturer recommends this size only for full-term infants weighing more than 3 kg. The 3-week-old infant presented in case 3 was born at term and weighed 4 kg at the time of intubation with a size 3.5 Microcuff® tube, but the manufacturer recommends this size tube only for infants from 8 months to less than 2 yr of age.* in the three described infants, the use of Microcuff® tube sizes greater than that recommended by the manufacturer was likely more responsible for the airway swelling than the tube and cuff design. Careful examination of the literature leads us to believe that the most important cause of endotracheal tube related airway damage is actually the lack of a cuff. in the 1960s, when neonatal care was improving at an exponential pace, oral or nasal tracheal intubation began to replace tracheostomy.2,3 Uncuffed endotracheal tubes were preferred because the absence of a cuff allowed for a relatively larger internal diameter endotracheal tube. This allowed easier suctioning of secretions and a lower resistance to spontaneous ventilation. since that time, many authors have promulgated, without evidence, the notion that uncuffed tubes are required until the pediatric larynx goes through a transformation from cone-shaped to cylindrical at 8 yr of age. to this day, authoritative textbooks on pediatric anesthesia still claim that this occurs at or around the age of 8 yr and is responsible for the ability of the pediatric larynx to safely accommodate a cuffed endotracheal tube. even if this were true (it is not),4 it simply does not matter. to be clear, we need to distinguish between two distinct populations under consideration. The largest population of children that requires tracheal intubation most often comprises those children of any age who undergo general anesthesia for medical or surgical procedures. The use of an uncuffed tube is generally safe, and associated with a low incidence of postextubation stridor, but there are drawbacks to having a ventilation leak around the tube. These include an inaccurate capnographic tracing,5 inaccurate spirometric tidal volume measurement, inaccurate end-tidal anesthetic level measurement, waste and increased cost of inhaled Cuffed versus Uncuffed Endotracheal Tubes in Pediatric Anesthesia