title: [A comparison of degree of precision of auscultation, partial pressure of carbon dioxide in end-expiration, and transillumination technique in verifying accurate position of endotracheal tube].
abstract: OBJECTIVE
  To evaluate the effect of auscultation, partial pressure of carbon dioxide in end-expiration (P(ET)CO2), transillumination technique to judge whether the endotracheal tube is misplaced into the esophagus.
  
  
  METHODS
  A blinded randomized controlled trial was conducted. Sixty patients with American Society of Anesthesiology (ASA) grade I - II undergoing endotracheal intubation in Fengxian Central Hospital admitted from September 2014 to February 2015 were enrolled. Two endotracheal tubes with the same size were respectively inserted into the trachea and esophagus for the same depth after general anesthesia by the same person. Two blinded anesthetists with different experience checked the tube position using three methods including auscultation, P(ET)CO2, and transillumination technique, respectively. The order of the tubes tested (trachea or esophagus) and the method used were randomized according to randomise numbers table. The experienced anesthetists conducted the test first, followed by an inexperienced anesthetist conducting the same methods. The numbers of right and wrong determinations with different methods by different anesthetists were recorded.
  
  
  RESULTS
  Sixty patients underwent the procedures for 180 times, with intratracheal intubation for 90 times, and esophageal intubation for 90 times. It was shown that the results were not different in two groups [96.7% (174/180) vs. 92.2% (166/180), χ2 = 3.500, P = 0.057]. By using auscultation, the correct rate of experienced anesthetist was higher than that of inexperienced (95.0% vs. 78.3%, χ2 = 5.786, P = 0.013). Using P(ET)CO2, both anesthetists were correct in all cases, and the accuracy was 100%. Using transillumination, the experienced anesthetist was mistaken in 3 cases (accuracy was 95.0%), while the inexperienced mistook in 1 case (accuracy was 98.3%), and no significant difference was found between two groups χ2 = 0.500, P = 0.250). The correct rate of using transillumination was significantly higher than that of using auscultation χ2 = 7.563, P = 0.004). The sensitivity and specificity of the auscultation was 70.0% and 80.0%, that of transillumination technique was 96.7% and 93.3%, and P(ET)CO2 was 100%, respectively, for two groups.
  
  
  CONCLUSIONS
  P(ET)CO2 is the most reliable method for determining tube position, and it is superior to auscultation and transillumination. Transillumination technique is superior to auscultation, irrespective of anesthetists' experience, while the accuracy of auscultation showed an obvious relationship with the anesthetists' experience.
authors.forename: Le
authors.initials: L
authors.lastname: Qi
authors.forename: Rong
authors.initials: R
authors.lastname: Liu
authors.forename: Enhui
authors.initials: E
authors.lastname: Tang
authors.forename: Shouchun
authors.initials: S
authors.lastname: Li
authors.forename: Jun
authors.initials: J
authors.lastname: Jin
authors.forename: Xihuan
authors.initials: X
authors.lastname: He
authors.forename: Shaojun
authors.initials: S
authors.lastname: Lyu
authors.forename: Hao
authors.initials: H
authors.lastname: Weng
mesh_terms: D000768:Anesthesia, General; D001314:Auscultation; D002245:Carbon Dioxide / Q000032:analysis*; D004947:Esophagus; D006801:Humans; D007442:Intubation, Intratracheal / Q000379:methods*; D015588:Observer Variation; D010313:Partial Pressure; D012680:Sensitivity and Specificity; D014132:Trachea; D014172:Transillumination
chemical_list: D002245:Carbon Dioxide