Sniffing position combined with mouth opening improves facemask ventilation in children with adenotonsillar hypertrophy

Background This study evaluates the influence of sniffing position combined with mouth opening on the effectiveness of facemask ventilation in paralyzed pediatric patients undergoing adenotonsillectomy during sevoflurane-N2O anesthesia. Methods After Institutional Ethics Committee approval, 40 children 5-11 years of age who were scheduled for an elective adenotonsillectomy operation were enrolled in this prospective randomized study. After routine monitoring and pre-oxygenation, anesthesia was induced with sevoflurane 8% in a mixture of 50% N2O-O-2. Three minutes after the administration of vecuronium, the sequence of the positions was randomized. Three positions were applied during facemask ventilation: Position CN (closed mouth - neutral head and neck position), position CS (closed mouth-sniffing position) and position OS (opened mouth-sniffing position). Volume-controlled ventilation was started. Peak inspiratory pressure (PIP), tidal volume (V-T), expired tidal volume (V-Texp) and end-tidal CO2 pressure were recorded. The percent of leakage was calculated. The primary endpoint of this study was the expired tidal volume (V-Texp). Results There was a statistically significant difference among the three positions for V-Texp and PIP values. The OS resulted in higher V-Texp values when compared with CN (P=0.022). The OS was significantly better than the other two positions, resulting in lower PIP values (P < 0.001 and P=0.004, for CN and CS, respectively). The OS also resulted in less leakage during facemask ventilation when compared with CN and CS. Conclusions Sniffing position combined with mouth opening improves V-Texp and PIP values during facemask ventilation during sevoflurane-N2O anesthesia in paralyzed pediatric patients with adenotonsillar hypertrophy.