Comparison of Macintosh and AirtraqTM laryngoscopes in obese patients placed in the ramped position

Airway management in bariatric surgery is a major challenge for anaesthesiologists. Thus, the aim of this study was to investigate the time required for tracheal intubation, the number of attempts to intubate, larynx visualization and the need for manoeuvres to optimize the glottis view of obese patients in ramped position by comparing the AirtraqTM and Macintosh laryngoscopes. Likewise, the influence of anatomical variables on intubation time was investigated. From 132 bariatric surgery patients with body mass index ≥35 kg.m-2 and aged 18 to 60 years, cervical perimeter, sternomental distance, interincisor distance, and Mallampati score were recorded. Patients were randomised into two groups according to whether a Macintosh (n = 64) or an AirtraqTM (n = 68) laryngoscope was used for tracheal intubation. Cormack & Lehane score, time required for intubation, pulse oximetry (SpO2), mean arterial pressure (MAP), and heart rate were assessed. Characteristics and consequences of airway management were evaluated. Intubation failed in two patients in the Macintosh laryngoscope group, and these patients were considered as worst case scenario (intention to treat analysis). The intubation times were 13.7 ± 3.1 seconds and 36.9 ± 22.8 seconds for AirtraqTM and Macintosh laryngoscope groups (P<0.01), respectively. The SpO2 values did not exhibit clinically relevant variation, and MAP was significantly lower in the AirtraqTM group three minutes after tracheal intubation. Cormack-Lehane scores were also lower for the AirtraqTM group. One patient in the Macintosh group with intubation failure was quickly intubated with the AirtraqTM. Cervical circumference (P<0.01) and interincisor distance (P<0.05) influenced the time required for intubation in the Macintosh group but not in the AirtraqTM group. For obese patients in the ramped position, the AirtraqTM laryngoscope affords faster tracheal intubation than does the Macintosh laryngoscope, and it may serve as an alternative when conventional laryngoscope fails.