Disposable laryngoscope blades

Further to recent correspondence [1–4] on the hazards of prion-related diseases and the hazards encountered when using new disposable surgical equipment [1], we would like to report our experience with the use of new disposable anaesthetic equipment. Recent concerns regarding the possibility of transmission of prion-related diseases following the use of re-usable laryngoscopes [2, 3] have stimulated the trial of various single use laryngoscope blades or blade covers. Recently, we were asked to use two such blades from one supplier (Lite-BladeTM II blades 1 and 2, Truphatek International Ltd) during the course of our anaesthetic list. We found that the curved infant blade (blade 2) offered little or no view of the larynx and very little room for manoeuvre in the mouth. When a re-usable Macintosh infant blade was used, laryngoscopy was performed without difficulty. The blade was compared with our standard equipment (also made by Truphatek); it could be seen that cross sections of the blades were very different in shape (Fig. 1), the disposable blade having no oblique profile where it would have been in contact with the tongue. In addition, the portion of the blade which would have been in the mouth during laryngoscopy was much larger (Fig. 2). The result was that the blade did not curve around the tongue. This significantly reduced the unoccupied area of the mouth and pharynx when the blade was inserted compared with the similar re-usable blade. In the small infant's mouth this reduction in area prevented a good view of the larynx. We were therefore not satisfied with the performance of the disposable curved infant blade. Later, on a different patient, we tried to use a disposable straight infant blade from the same supplier (blade 1). During laryngoscopy a small piece of green material, looking very similar to the material of which the laryngoscope blade was manufactured, was seen in the vallecula. This was removed using a yankauer sucker (Fig. 3), prior to intubation. We can only assume that a fragment of the larngoscope blade had fallen off. On re-examination of the blade, a piece was missing where the blade joined the laryngoscope handle (Fig. 4), although the material removed from the airway did not appear to be the appropriate size or shape. It may have been that the moulding process had left a small tag attached to the blade near the light bulb (Fig. 5). If so, this was not noticed during routine inspection. Had the fragment been inhaled we do not know whether it would have produced a significant inflammatory response or whether it would have been clinically or radiologically detectable. We do believe that if detection and removal of the fragment bronchoscopically had been necessary it would have been very difficult. Our experience re-emphasises the importance of quality control, the checking of equipment, and the potential dangers of converting to new equipment in the light of concerns over repeated use equipment. Like those incidents already reported [1, 5], there have also been several problems with the disposable ENT surgical equipment in our trust. We agree with some of the comments made in Anaesthesia News[4,␣5] cautioning against the hasty change to disposable equipment. We recognise that this change has been made in an attempt to reduce a risk, which may be significant but is not yet fully quantified. The change has already led to critical incidents which, if repeated could lead to morbidity or mortality.