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Device stability and quality of ventilation of classic laryngeal mask airway versus air-Q and I-gel at different head and neck positions in anesthetized spontaneously breathing children.

BACKGROUND
Since its introduction into clinical practice, the use of laryngeal mask airway (LMA) has been dramatically increasing. We aimed to investigate the clinical performance of single use LMA classic, AIR-Q and I-gel at different head and neck positions and during the operative procedure in pediatric elective day case surgery.


METHODS
One hundred sixty-eight generally anesthetized spontaneously breathing children (2-9yr) were randomized to receive either LMA classic (n=56), I-gel (n=58) or AIR-Q (n=54). The oropharyngeal leak pressure (OLP), exhaled tidal volume (TV), peak inspiratory pressure (PIP), ventilation score and fiberoptic glottis view score were assessed at neutral position then at maximum flexion, extension and left rotation. Afterwards, the ventilation and fiberoptic view scores were assessed in neutral position at fixed time-points until end of surgery.


RESULTS
Compared to neutral position, maximum neck flexion increased OLP (P=0.000) and compromised the ventilation leading to increased PIP, decreased TV, worsening of ventilation score and fiberoptic glottis view. OLP mildly decreased with extension and left lateral rotation with mild effect on ventilation parameters (P<0.05). At all neck positions, the OLP was higher (P=0.000) and ventilation parameters were better with I-gel (P=0.000). Gradual worsening of ventilation score and fiberoptic view grade was recorded intraoperatively with the three devices, with the least deterioration observed in I-gel group (P=0.000).


CONCLUSIONS
Having the highest increase in OLP at neck flexion, the I-gel LMA exhibited the best ventilation parameters and fiberoptic view grade at different head and neck positions and throughout the intraoperative period.