Thoraco-abdominal asynchrony is frequently encountered during inhalation anaesthesia in children with adenotonsillar
hypertrophy causing an upper
airway obstruction. The study goal was to evaluate the impact of different airway opening manoeuvres on thoraco-abdominal asynchrony as a measure of
airway obstruction. Thirty anaesthetized children (aged 2-8 yrs;
sevoflurane 3% in 50%
oxygen/
nitrous oxide) were studied prior to elective adenotonsillectomy using respiratory inductance plethysmography to record ribeage and abdominal wave forms as a basis for calculation of the phase angle. Five airway situations were compared: 1) baseline (unsupported mandible); 2) chin lift; 3) chin lift combined with
continuous positive airway pressure of 10 cmH2O; 4) jaw thrust; and 5) jaw thrust combined with
continuous positive airway pressure of 10 cmH2O. Three children had complete upper
airway obstruction at baseline and were excluded from the study. With chin lift, thoraco-abdominal asynchrony improved in three patients, worsened in three patients and was unchanged in 21 patients. Additional
continuous positive airway pressure during chin lift did not markedly reduce thoraco-abdominal asynchrony (phase angle 89 +/- 43 , p = 0.33). Jaw thrust resulted in a significant decrease of the phase angle (from 106 +/- 53 at baseline to 65 +/- 49 , p < 0.01); when combined with
continuous positive airway pressure, no further effect on thoraco-abdominal asynchrony was found (72 +/- 44). In anaesthetized children with adenotonsillar
hypertrophy, airway opening manoeuvres have distinct effects on thoraco-abdominal asynchrony. Delivery of
continuous positive airway pressure and jaw thrust can be the first airway opening manoeuvres to improve breathing patterns. Chin lift without additional
continuous positive airway pressure should be used with caution in these patients because it may convert partial into almost complete
airway obstruction.