[The association between thenar eminence and I-gel™ dimensions in paediatric patients]

A practical anatomic landmark may be helpful to perform the appropriate size of the airway devices easily in paediatric patients. The aim of this study was to investigate the association between thenar eminence and I-gel dimensions in children.

After Institutional Ethics Committee approval, two hundred and seventy ASA Class I-II patients between 0 and 12 years old, who were scheduled for elective procedures under general anaesthesia not requiring tracheal intubation, were recruited to the study. The size of the I-gel selected was based on the patient's body weight according to the manufacturer's recommendation. After successful insertion of the I-gel, thenar eminence dimensions were determined. Long-axis (Th-l) was measured from junction point of the thumb to wrist curl and short-axis (Th-w) constitutes the largest portion of the thenar eminence from lateral end of the thumb to the first hand line. The manufacturer's dimensions of the I-gel which was inserted into the patients were compared with the measurements obtained from thenar eminence.

The mean (SD) values for (Ig-w) and (Ig-l) were 2.98cm (0.53) and 4.54cm (0.82), and the mean (SD) values for (Th-w) and (Th-l) were 2.99cm (0.60) and 3.88cm (0.93), respectively. There was a statistically significant correlation between Th-w and Ig-w (r=0.794, p<0.001), and between Th-l and Ig-l (r=0.820, p<0.001).

The dimensions of thenar eminence were fitted to that of the weight based size of I-gel and this anatomic landmark may be a practical tool to assess appropriate size for paediatric patients.