*7.3.6.3 Size selection, practical aspect, adjuncts*

Size selection is done on a weight basis (**Table 6**). However, individual anatomical variations should always be considered. Patients with cylindrical necks or wide thyroid/cricoid cartilages may require a larger size i-gel than would normally be recommended on a weight basis [81, 82].

The i-gel can be used in difficult or unanticipated difficult intubations. Owing to its ease of insertion, it can quickly establish and maintain a clear airway in a pre-hospital setting [83, 84]. In a study it was observed that hemodynamic parameters, ease of insertion and postoperative complications were comparable among the i-gel, pLMA and cLMA but airway sealing pressure was significantly higher with i-gel [85].

A modification of this device is the i-gel O2. It contains a supplementary oxygen port for passive oxygen administration. It may be utilised for cardiopulmonary resuscitation. The i-gel O2 Resus Pack is a resuscitation pack provided by the manufacturer. It contains the i-gel O2 LMA, an airway support strap to fix and secure the device in place, a suction tube (12 Fr) and a pack of lubricant. The Resus Pack is available in three adult sizes (3, 4 and 5). The presence of a colour coded hook ring on the LMA allows easy identification of the size during resuscitation.
