Strength of disposable laryngoscope blades

Comparison of the strength of various disposable videolaryngoscope blades

PURPOSE

Breaking of disposable blades during emergency endotracheal intubation has been reported. Breakage can cause serious injury and foreign body ingestion. We aimed to measure and analyze the strength characteristics of different disposable videolaryngoscope blades with the application of an upward-lifting force.

METHODS

We measured the strength of four disposable videolaryngoscope blades (C-Mac® S Video laryngoscope MAC #3, Glidescope GVL® 3 stat, Pentax AWS® PBlade TL type, and King Vision® aBlade #3) using the fracture test. The strength of 12 samples of each type of disposable videolaryngoscope blade was measured using an Instron 5,966 tensile tester by applying an upward-lifting force.

RESULTS

After the fracture test using C-Mac, Glidescope GVL, Pentax AWS, and King Vision, the number of deformed blades were 0, 12, 3, and 7, respectively, and the number of broken blades were 12, 0, 9, and 5, respectively. The mean (standard deviation) maximum force strengths of Pentax AWS, C-Mac, King Vision, and Glidescope GVL blades were 408.4 (27.4) N, 325.8 (26.5) N, 291.8 (39.3) N, and 262.7 (3.8) N, respectively (P < 0.001).

CONCLUSION

Clinicians should be aware of the varied strength characteristics of the four types of disposable videolaryngoscope blades when they are used in endotracheal intubation.

Equipment to manage a difficult airway during anaesthesia

Airway complications are a leading cause of morbidity and mortality in anaesthesia. Effective management of a difficult airway requires the timely availability of suitable airway equipment. The Australian and New Zealand College of Anaesthetists has recently developed guidelines for the minimum set of equipment needed for the effective management of an unexpected difficult airway (TG4 [2010] www.anzca.edu.au/resources/professionaldocuments). TG4 [2010] is based on expert consensus, underpinned by wide consultation and an extensive review of the available evidence, which is summarised in a Background Paper (TG4 BP [2010] www.anzca.edu.au/ resources/professional-documents). TG4 [2010] will be reviewed at the end of one year and thereafter every five years or more frequently if necessary. The current paper is reproduced directly from the Background Paper (TG4 BP [2010]).

Flexibility and light emission of disposable paediatric Miller 1 laryngoscope blades*

With the emergence of Creutzfeldt-Jakob disease and the discovery of prions in tonsillar material, there has been an increase in the number of available disposable laryngoscope blades. This has led to non-conformity over many aspects of blade design. Miller 1 disposable blades have been produced in both metal and plastic and appear to have different properties of rigidity. We examined the rigidity of 11 disposable Miller 1 blades in three different axes of force. There was a significant difference in flexibility between metal and plastic blades in both primary and torsional axis (p = 0.006). We also studied the blades' light intensity and angle of light emission, finding up to an eightfold difference in the level of illumination provided at a distance of 10 mm from the tips of the blades. The area of maximal illumination varied, with some blades providing narrow beams of light, and others provided a more dispersed field of illumination. In addition, the angle of maximal illumination varied between the blade types from a central position to one directed to the right-hand side.