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.
ABSTRACT
Objective To investigate the effects of angle and length of lightwand in three-dimensional reconstruction images of the upper airway based on computed tomography.Methods A total of 245 patients,aged 18-86 years,were scanned by helical computed tomography in the head and neck.Reconstructed images,obtained by Aw4.4 Workstation,were printed out by the ratio of 1 ∶ 1.The tracheal tube was used to investigate the anatomic structure of the upper airway.The length L and angle α of the tracheal tube were recorded.And two distances (D1,D2) and one angle (β) were recorded:D1,the distance between the upper central incisor and root of epiglottis;D2,the distance between the root of epiglottis and midpoint of glottis;angle β,the angle of line D1 and D2.Results The oα value in male patients was significant higher than that in female patients:(70.02 ± 15.49)° vs.(55.84 ± 14.70)°.The β value in male patients was significant higher than that in female patients:(129.74 ± 14.82)° vs.(120.40 ± 14.19)°.The L value in male patients was significant higher than that in female patients:(12.80 ± 0.85) cm vs.(11.50 ± 0.65) cm.The D1 and D2value in male patients were significant higher than those in female patients:(7.53 ± 0.66) cm vs.(6.76 ± 0.53) cm,(3.13 ± 0.52) cm vs.(2.45 ± 0.32) cm.There were significant differences (P ＜ 0.05).The 245 patients were classified to 2 groups by using the function of hierarchical cluster analysis in the statistical software.The α value in group 2 was significant higher than that in group 1:(75.45 ± 9.53)° vs.(48.17 ± 9.29)°.The 3 value in group 2 was significant higher than that in group 1:(136.27 ± 9.86)° vs.(112.31 ± 8.64)°.The age in group 2 was significant higher than that in group 1:(53.92 ± 19.64) years vs.(36.93 ± 17.21) years.Correlation analysis showed that in 245 patients,angle α was positively correlated to angle β and age (P ＜ 0.05),and angle β was positively correlated to age (P ＜ 0.05).Conclusions The bent length and angle on lightwand can be affected by both the patients' gender and ages.