title: Incremental change in cross sectional area in small endotracheal tubes: A call for more size options.
abstract: OBJECTIVE
  To elucidate the relatively large incremental percent change (IPC) in cross sectional area (CSA) in currently available small endotracheal tubes (ETTs), and to make recommendation for lesser incremental change in CSA in these smaller ETTs, in order to minimize iatrogenic airway injury.
  
  
  METHODS
  The CSAs of a commercially available line of ETTs were calculated, and the IPC of the CSA between consecutive size ETTs was calculated and graphed. The average IPC in CSA with large ETTs was applied to calculate identical IPC in the CSA for a theoretical, smaller ETT series, and the dimensions of a new theoretical series of proposed small ETTs were defined.
  
  
  RESULTS
  The IPC of CSA in the larger (5.0-8.0 mm inner diameter (ID)) ETTs was 17.07%, and the IPC of CSA in the smaller ETTs (2.0-4.0 mm ID) is remarkably larger (38.08%). Applying the relatively smaller IPC of CSA from larger ETTs to a theoretical sequence of small ETTs, starting with the 2.5 mm ID ETT, suggests that intermediate sizes of small ETTs (ID 2.745 mm, 3.254 mm, and 3.859 mm) should exist.
  
  
  CONCLUSIONS
  We recommend manufacturers produce additional small ETT size options at the intuitive intermediate sizes of 2.75 mm, 3.25 mm, and 3.75 mm ID in order to improve airway management for infants and small children.
authors.affiliation: Colgate University, Hamilton, NY, USA.
authors.forename: Caroline L
authors.initials: CL
authors.lastname: Mortelliti
authors.affiliation: Division of Pediatric Otolaryngology, Department of Otolaryngology & Communication Sciences, SUNY Upstate Medical University, Syracuse, NY, USA. Electronic address: mortella@upstate.edu.
authors.forename: Anthony J
authors.initials: AJ
authors.lastname: Mortelliti
mesh_terms: D058109:Airway Management / Q000295:instrumentation*; D002648:Child; D002675:Child, Preschool; D004867:Equipment Design; D006801:Humans; D007223:Infant; D007442:Intubation, Intratracheal / Q000295:instrumentation*
keywords: Cricoid; Cross sectional area; Endotracheal tube; Options; Sizing; Subglottic stenosis