A randomised comparison of three laryngoscopes with the Macintosh

The Macintosh laryngoscope blade was compared with three modified blades--the Bizzarri-Giuffrida, the 'Improved Vision' Macintosh, and the Wiemers blade. Before and after a training session 24 participants intubated a Laerdal Airway Management Trainer with the four blades in random order. Intubation time was measured, oesophageal malpositions and 'clicks' indicating possible teeth damage, were counted. Each participant scored the handling of each blade on a 6-point scale (1 = very good, 6 = very poor). Intubation times before training were 10.6 +/- 5.3 s for the Macintosh, 16.7 +/- 9.2 s for the Bizzarri-Giuffrida, 13.3 +/- 9.0 s for the 'Improved Vision' Macintosh and 11.7 +/- 6.1 s for the Wiemers. Intubation times after training were 7.1 +/- 2.5 s for the Macintosh, 10.6 +/- 5.4 s for the Bizzarri-Giuffrida, 8.1 +/- 3.4 s for the 'Improved Vision' Macintosh and 7.6 +/- 2.5 s for the Wiemers. The handling scores were: 2.0 +/- 0.8 for the Macintosh, 3.9 +/- 1.2 for the Bizzarri-Giuffrida, 2.1 +/- 0.8 for the 'Improved Vision' and 2.3 +/- 0.8 for the Wiemers. In regard to the intubation time before training (P < 0.02), the intubation time after training (P < 0.003), and handling (P < 0.0005), the Bizzarri-Giuffrida was significantly inferior to the Macintosh. The 'Improved Vision' Macintosh and the Wiemers were not significantly different to the Macintosh. No significant difference was seen for oesophageal malpositioning and 'clicks' between any of the blades.