title: Proper depth of placement of nasotracheal tubes in adults prior to radiographic confirmation.
abstract: OBJECTIVE
  To determine the optimal initial depth of tube placement in nasotracheal intubation (NTI) of adult patients, measured at the naris, prior to obtaining a chest radiograph (CXR).
  
  
  METHODS
  Part 1: A prospective, observational study was performed to compare the initial depth of NTI, measured at the naris, with the observed height of the endotracheal tube (ETT) tip above the carina on the initial CXR. Optimal depths were predicted by gender. Part 2: Results from Part 1 were prospectively validated by measuring the frequency of adequate placement when ETTs were placed to this depth. ETT placement was considered adequate if the tip was at least 2 cm above the carnia and below the larnx on the CXR.
  
  
  RESULTS
  Part 1: The mean depth measured at the naris was 27.5 +/- 1.5 cm in women (n = 50) and 27.8 +/- 1.0 cm in men (n = 74). The mean distance of the tip of the ETT to the carina was 3.9 +/- 2.7 cm in women and 6.4 +/- 2.2 cm in men. Initial tube position was adequate in 39 (78%) of the women and 72 (97%) of the men. It was determined that if a depth of 26 cm had been used in the women and 28 cm in the men, 45 (90%) of the women and 70 (95%) of the men would have had adequate tube placement, resulting in statistically significant improvement in the women (p < 0.05; McNemar chi 2). Part 2: These calculated depths (26 and 28 cm) were then prospectively applied in 26 women and 52 men. Twenty-five (96%) of 26 women and 51 (98%) of 52 men had adequate placement, with a mean height above the carina of 4.5 +/- 1.4 cm in women and 5.6 +/- 1.8 cm in men.
  
  
  CONCLUSIONS
  Initial placement of NTI at 26 cm in women and 28 cm in men, measured at the naris, resulted in adequate initial placement for most adult patients.
authors.affiliation: Department of Emergency Medicine, Hennepin County Medical Center, Minneapolis, MN 55415-1829, USA. clint005@tc.umn.edu
authors.forename: D B
authors.initials: DB
authors.lastname: Reed
authors.forename: J E
authors.initials: JE
authors.lastname: Clinton
mesh_terms: D000328:Adult; D000886:Anthropometry / Q000379:methods*; D001824:Body Constitution; D004635:Emergency Medicine; D005260:Female; D006801:Humans; D007442:Intubation, Intratracheal / Q000379:methods* / Q000592:standards; D008297:Male; D009666:Nose / Q000033:anatomy & histology* / Q000000981:diagnostic imaging; D011237:Predictive Value of Tests; D011446:Prospective Studies; D011859:Radiography; D015203:Reproducibility of Results; D012727:Sex Characteristics; D013249:Sternum / Q000033:anatomy & histology* / Q000000981:diagnostic imaging; D014132:Trachea / Q000033:anatomy & histology* / Q000000981:diagnostic imaging