Effect of Head Extension Angle to Glottis Exposure : A Simulation Evaluation Based on CT Reconstruction Images of Upper Airway / 医学研究杂志

ABSTRACT

Objective To investigate the effect of head extension angle to glottis exposure by using three-dimensional CT reconstruction sagittal plane images of upper airway.Methods There were 80 patients,aged 7-78 years old,who had been scanned by helical CT in the head and neck.Reconstructed images were obtained by AW4.4 workstation and the following parameter was measured:angle α(A0 group),the angle created by the upper central incisor and root of epiglottis(angular vertex) and midpoint of glottis.Reconstructed images were printed according to the actual size of human body in a ratio of 1∶ 1,then the images were cut off from the upper central incisor to root of epiglottis by a section of arcs.Increasing the degree of angle α by clockwise to hypothetically increase the angle of head extension.The glottis was exposed by using a paper-made laryngoscope(Macintosh) model,and the success rate of glottis exposure was recorded when the degree of angle α was respectively increased 10°(A10 group),20°(A20 group),and 30°(A30 group).Results Compared with A0 group,the success rate of glottis exposure increased significantly in A10 group,A20 group and A30 group.The success rate of glottis exposure in A20 group and A30 group was significantly higher than A10 group.Compared with A20 group,the success rate of glottis exposure obviously increased in A30 group.Conclusion Based on CT reconstruction images of upper airway,we can analog study the effect of head extension angle to glottis exposure.