Comparison of the Flexiblade levering laryngoscope with the English Macintosh laryngoscope in patients with a poor laryngoscopic view

The effectiveness of two laryngoscopes, the English Macintosh and the Flexiblade (a levering laryngoscope), were compared in a clinical setting. An investigation was carried out in 100 patients admitted for surgery under general anaesthesia, to compare intubation with the Flexiblade or the Macintosh laryngoscope. The patients had two anatomical characteristics that may predict difficult intubation - Mallampati score II and III, and a thyromental distance ≤ 6.5 cm. Patients were randomly allocated to receive intubation with one of the laryngoscopes. The laryngeal view obtained during laryngoscopy, the intubation time, and the need for optimization manoeuvres and assistance required were compared in the two groups. The correlation between intubation time and anatomical characteristics was determined. Only 49 patients had a poor laryngeal view during initial laryngoscopy and required additional facilitating manoeuvres. In these patients, successful intubation time (in seconds) using the Flexiblade was significantly shorter than using the Macintosh laryngoscope (median 14.3 s, IQR 6.3 vs. median 20.8 s, IQR 10.5) (p < 0.01). Assistance and additional manoeuvres were required significantly less frequently in the Flexiblade group (21%) compared to Macintosh group (67%) (p < 0.01). No correlation was found between intubation time, Mallampati scores, thyromental distance, or body weight. We concluded that in patients with an initial poor laryngoscopic view, the Flexiblade may enable faster and easier tracheal intubation.