Nasotracheal intubation via fiberoptic bronchoscope under snifing position.The snifing position was obtained by placement of a 7-cm cushion under the head of the patient. When the FOB was inserted into Nasal cavity, and the epiglottis and glottis were identified by the FOB. The anterior of FOB was inserted deep into tracheal after the glottis was exposed sufficiently then the tracheal tube was pushed into the trachea via the FOB.

Nasotracheal intubation via fiberoptic bronchoscope under snifing position.The Head Extension was obtained by the occiput of the patient close to the operating table. When the FOB was inserted into Nasal cavity, and the epiglottis and glottis were identified by the FOB. The anterior of FOB was inserted deep into tracheal after the glottis was exposed sufficiently then the tracheal tube was pushed into the trachea via the FOB.

Nasotracheal intubation via fiberoptic bronchoscope under snifing position.The extension position with a 7-cm pillow underneath the shoulder and the occiput close to the operating table. When the FOB was inserted into Nasal cavity, and the epiglottis and glottis were identified by the FOB. The anterior of FOB was inserted deep into tracheal after the glottis was exposed sufficiently then the tracheal tube was pushed into the trachea via the FOB.

Influence of different head position on nasal endotracheal intubation

The primary endpoints were the time to view the vocal cords (TVC) which was taken when the operator indicated verbally that he view the vocal cords and the time to successful tracheal intubation (TSI). TSI was defined as the time taken from insertion of the FOB between the teeth until the appearance of a capnograhy curve.