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 evaluate the effectiveness and advantage of the TruviewTM EVO2(R) optical laryngoscope in comparison with the commonly used laryngoscope for the endotracheal intubation in patients in the emergency setting. Method Thirty-six patients in need for emergency endotracheal intubation in our hospital from February to May 2009 were randomly assigned to give intubation by using a TruviewTM EVO2(R) optical laryngoscope (T group) or a commonly used laryngoscope(R group). Cormack and Lehane laryngoscope grade (the degree of exposure of glottis by using laryngoscope), IDS (Intubation Difficulty Scale) score, the time taken for successful intubation, lowest SpO2 and the complication during intubation were essential factors for comparison between two groups. Results Our data showed that there was no difference in duration of the successful endotracheal intubation attempts between these two groups (respectively 22.73 ± 7.66 s and 19.91 ± 8.03 s, P ＞ 0. 05). However, the glottis exposure condition was significantly improved with TruviewTM EVO2(R) optical laryngoscope (P ＜ 0.01). The average IDS score for patients in T group was 0.33 ± 0.49, which is much lower than those in the R group (4.11± 0.90, P ＜ 0.01). In addition, the average SpO2 value measured in T group during the intubation operation was significantly higher than that in R group (98.87±0.74% and 91.45 ±4.86% respectively, P ＜0.01) and there was less complication observed in patients of T group. Conclusions Using TruviewTM EVO2(R) optical laryngoscope for emergency endotracheal intubation could help to expose the glottis in an ideal view, predominately lower the C/L grade and thus decrease the difficulty in intubation for clinicians. Its specially designed oxygen supplier allows the SpO2 to be maintained at a high level during the operation as well as reduce the incidence of complication. It is therefore extremely useful for emergency tracheal intubation, particularly a difficulty intubation situation.