A Research Method Of Ultrasound To Measure Oropharyngeal Diameter During Intubation With The Visual Hard Optical Stylet

Objective: To establish a research method of ultrasound to measure oropharyngeal diameter of upper airway in the anesthesia,and explore the clinical values of using the method to measure oropharyngeal diameter of upper airway during intubation with the Visual Hard Optical Stylet.Methods: Random selection 50 patients with tracheal intubation under general anesthesia.All patients were adults without teeth missing,who aged 18 to 65 years,the American Society of Anesthesiologists(ASA)grade ? ~ ?,the Mallampati grade ? ~ ?,the Cormach-Lehane grade ? ~ ?,the patient's body mass index(BMI)of 18~25Kg/m2.Patients lied in operation table,their heads were in the middle supine position,and let their head-and-neck fall backward for thirty degrees.We used the ALOKA ?10 color ultrasound measure oropharyngeal Anterior-Posterior Diameter in epiglottis level by putting the convex array probe in the right of mandibular angle and parallel with marginal mandibular,and also measured oropharyngeal Lateral Diameter in epiglottis level by putting the convex array probe over and clinging to hyoid.Respectively measured oropharyngeal Anterior-Posterior and Lateral Diameters in four states(at the end of expiratory in waking period,after anesthesia induction,on the exposure of glottis with ordinary laryngoscope and the Visual Hard Optical Stylet).To compare the changes of oropharyngeal Anterior-Posterior and Lateral Diameters in end expiratory with waking period and after anesthesia induction.And the same measure on the exposure of glottis with ordinary laryngoscope and the Visual Hard Optical Stylet.Results: The Anterior-Posterior Diameter measured by ultrasound was(16.5±1.4)mm at the end of expiratory in waking period,which was(12.8±1.5)mm after anesthesia induction,a statistically significant difference(P ? 0.001).The Lateral Diameter compared in same groups were(37.3±4.9)mm and(37.0±4.7)mm,which was no statistical significance(P?0.05).The Anterior-Posterior Diameter measured by ultrasound was(34.1±4.3)mm on the exposure of glottis with ordinary laryngoscope,which was(28.6±2.2)mm on the exposure of glottis with the Visual Hard Optical Stylet,a statistically significant difference(P ? 0.001).The Lateral Diameter compared in the same groups were(45.8±4.6)mm and(42.3±4.8)mm,with statistical significance(P?0.001).Conclusions: ALOKA ?10 color ultrasound can measure the oropharyngeal diameter of upper airway during anesthesia induction and tracheal intubation with different instruments.The oropharyngeal Anterior-Posterior Diameter after anesthesia induction is less than the diameter at the end of expiratory in waking period,which indicate that glossocoma is the major factor to this change.It is not necessary to expose the glottis with bigger Anterior-Posterior and Lateral Diameters,which indicate that tracheal intubation with the Visual Hard Optical Stylet can reduce the intensity of exposure of glottis and decrease the risk of upper respiratory tract injury.