A new tracheal tube for difficult intubation

Abstract

We have compared a new Portex tracheal tube with the Oxford tube in performing simulated grade 3 difficult intubations. The Portex tube was modified so that the bevel faced backwards, as in the Oxford tube. A gum elastic introducer was used with both tubes. The time taken and number of attempts needed were recorded, with changes in arterial pressure, heart rate and incidence of sore throat. Both tubes were successful in avoiding the problem of obstruction at the cords, which occurs when a standard Magill tube is used with an introducer. Thus the new tube has the merits of the Oxford tube without the disadvantages of rubber. It is suitable for both easy and difficult intubations with advantages in safety, cost and convenience. An unexpected but important finding was a clear learning effect, despite both investigators being familiar with the technique at the outset. Over the course of the study, intubation time decreased progressively (P < 0.001). This provides new evidence of the need for trainees to practise the art of intubation when the cords are not visible. Our estimate of the learning "half-life" was 15 intubations; we conclude that 30 simulated grade 3 intubations would be a reasonable objective for trainees before handling high-risk cases.

Prehospital advanced airway management by ambulance technicians and paramedics: is clinical practice sufficient to maintain skills?

“…Competency in the anaesthetic room may not mean competency in the prehospital environment where airway management is generally more difficult. Three similar studies have found that novice anaesthetic trainees require 50–60 attempts at tracheal intubation to achieve a 90% success rate 4 5 6. Based on these exponential learning curves, completion of 25 tracheal tube insertions would produce a success rate of approximately 70%.…”

A critical reassessment of ambulance service airway management in prehospital care: Joint Royal Colleges Ambulance Liaison Committee Airway Working Group, June 2008

“…Similar results were reported in a study examining first-year anaesthetic residents in which it was found that 57 attempts at tracheal intubation were required to achieve a 90% success rate (figure 2). 19 35 More recently, an abstract detailing training requirements for tracheal intubation, reported that 32 intubations were necessary for a 75% success rate and 53 for a 90% success rate 36. These figures are similar to those reported in the two earlier studies 19 35…”

“…19 35 More recently, an abstract detailing training requirements for tracheal intubation, reported that 32 intubations were necessary for a 75% success rate and 53 for a 90% success rate 36. These figures are similar to those reported in the two earlier studies 19 35…”

“…○=Oxford tube, ●=Portex tube. Reproduced from West et al 35 by permission of Oxford University Press.…”

“…To reach a 90% success rate with the first intubation attempt, an average laryngoscopist needs at least 57 intubation attempts 19. By applying the results of the three studies19 35 36 to current paramedic training, we estimate that under ideal intubation conditions, the average paramedic is likely to achieve an intubation success rate of 70–75% at best; with little scope for further improvement in skills performance in practice after initial training.…”