Affiliation:
1. Department of Otolaryngology – Head & Neck Surgery, The Hospital for Sick Children University of Toronto Ontario Toronto Canada
Abstract
ObjectivesDetermine percentage of subglottic stenosis using current endotracheal tube (ETT) cross‐sectional areas as actual, compared with previously published ETT cross‐sectional areas as expected, and determine if style of ETT could result in a change in percentage of stenosis or Myer‐Cotton grade.Study TypeCross‐sectional study.DesignProspective analysis.MethodsEight styles of uncuffed pediatric ETT from four manufacturers ranging from 2.0 to 6.0 inner diameter (ID) were evaluated. ID and outer diameter (OD) measurements were obtained from each company's specification sheets. Cross‐sectional area was calculated for each ETT using the formula (Area = πr2). The cross‐sectional areas of each current ETT (actual) were compared with those of previously published ETTs (expected) based on age, and the degree of stenosis was calculated using the formula [1‐ (Area actual/Area expected)] × 100%. Ranges of percentage for each style of ETT were calculated.ResultsThere was an increase in range of OD and area with increasing size of ETT ID, with the largest range in OD being 0.8 mm, and the largest range in area being 10.55 mm2. The median interquartile range (IQR), range of percentage stenoses was 11 (5%), ranging from 0% to 21%. Seven of 28 (25%) ranges were found to span two Myer‐Cotton grades.ConclusionsThe Myer‐Cotton grade of subglottic stenosis depends on the style of ETT used. Using updated values from currently available ETTs aims to keep this grading system valid with respect to surgical approach and outcomes following surgery.Level of EvidenceNA Laryngoscope, 133:2808–2812, 2023