title: Middle finger length-based tracheal intubation depth improves the rate of appropriate tube placement in children.
abstract: BACKGROUND
  It is challenging for anesthetists to determine the optimal tracheal intubation depth in children. We hypothesize that a measure three times the length of the middle finger can be used for predicting tracheal tube depth in children.
  
  
  METHODS
  Eighty-six children (4-14 years of age) were included in this study. After the children were anesthetized, a fiberoptic bronchoscope (FOB) was inserted into the trachea, the lengths from the upper incisor teeth to carina and vocal cords were measured, and a suitably sized cuffed tracheal tube was inserted into the trachea. Age-based and middle finger length-based formulas were used to determine the tracheal intubation depth.
  
  
  RESULTS
  All 86 children enrolled were included in this study. Compared with the age-based intubation, the rate of appropriate tube placement was higher for middle finger length-based intubation (88.37% vs 66.28%, P = 0.001). The proximal intubation rate was lower in middle finger length-based intubation (4.65% vs 32.56%, P < 0.001). There was only weak evidence for a difference in the distal intubation rate between the two methods (6.97% vs 1.16%, P = 0.054). The correlation coefficient between middle finger length and optimal tracheal tube depth was larger than that between age and optimal tracheal tube depth (0.883 vs 0.845).
  
  
  CONCLUSIONS
  Our data indicate that the appropriate tube placement rate can be improved by using three times the middle finger length as the tracheal intubation depth in children.
authors.affiliation: Department of Anesthesia, Second Affiliated Hospital, School of Medicine, Jiaxing University, Jiaxing, China.
authors.forename: Qing-he
authors.initials: QH
authors.lastname: Zhou
authors.affiliation: Department of Anesthesia, Second Affiliated Hospital, School of Medicine, Jiaxing University, Jiaxing, China.
authors.forename: Wang-pin
authors.initials: WP
authors.lastname: Xiao
authors.affiliation: Department of Anesthesia, Second Affiliated Hospital, School of Medicine, Jiaxing University, Jiaxing, China.
authors.forename: Hong-mei
authors.initials: HM
authors.lastname: Zhou
mesh_terms: D000293:Adolescent; D001837:Body Weights and Measures / Q000379:methods*; D002648:Child; D002675:Child, Preschool; D004867:Equipment Design; D005260:Female; D005385:Fingers / Q000033:anatomy & histology*; D006801:Humans; D007442:Intubation, Intratracheal / Q000295:instrumentation*; D008297:Male; D015203:Reproducibility of Results; D014132:Trachea / Q000033:anatomy & histology*
keywords: child; endotracheal; intubation; middle finger length