Distal oesophageal pH measurement in children during general anaesthesia using the laryngeal mask airway, tracheal tube and face mask.

BACKGROUND

Distal oesophageal pH was measured during controlled ventilation in children with the laryngeal mask airway (LMATM), tracheal tube (TT) and face mask (FM).

METHODS

Fifty-six children scheduled for inguinal surgery with a standardized general anaesthetic technique were randomly allocated to receive LMA (n=21), TT (n=18) or FM (n=19). A 14 Fr pH probe was placed into the distal oesophagus and pH values were measured over 1 min at 2-min intervals during the first 20 min of anaesthesia.

RESULTS

The median values of pH were 4.4 (3.5-5.5), 4.2 (3.3-4.9), 4.1 (3.2-5.1), 4.1 (3.3-5.0), 4.0 (3.3-4.9), 4.0 (3.4-5.1); 4.2 (3.3-5.1), 4.2 (3.6-5.0), 4.2 (3.5-5.0), 4.2 (3.5-5.2), 4.2 (3.5-5.0), 4.1 (3.5-5.0) and 4.2 (3.6-5.0), 4.2 (3.8-5.8), 4.1 (2.8-5.2), 4.2 (3.3-5.1), 4.2 (3.4-5.1), 4.3 (3.4-5.1) for LMA, TT and FM groups, respectively.

CONCLUSION

There was no difference in the median pH values, within and between the groups (P > 0.05). We conclude that there is no difference in gastro-oesophageal reflux, when using a LMA, TT or FM during controlled ventilation in anaesthetized children.