Skip to main content

Prediction of post-extubation failure by portable ICU ultrasound


Stridor and vocal cord oedema are common in ICU patients. Currently, the cuff leak volume test is a standard technique to assess these complications [1, 2]; however, wide variations in terms of its sensitivity and specificity have been demonstrated in many studies. Recently, ultrasound is a promising noninvasive method widely used in ICU patients and allows visualization of the vocal cords and larynx [3]. Thus, we would like to determine the diagnostic accuracy of portable ultrasound for detection of these post-extubation complications.


We conducted a prospective, observational study from December 2010 to September 2011 using portable critical care ultrasound to examine air-column width differences of vocal cords before and after deflation of a endotracheal cuff balloon. All patients also underwent cuff leak volume tests and vocal cord examination by direct video laryngoscopy.


We enrolled 101 patients with planned extubation. The overall prevalence of post-extubation stridor and/or vocal cord oedema was 17%. Age, gender, duration of intubation and BMI were not different between patients with and without post-extubation complications. The average sizes of endotracheal tubes were similar in both groups (No. 7.5). The mean difference of increasing of air-column width in patients without complications was considerably higher than those with complications (1.9 mm vs. 1.1 mm; P < 0.001). The sensitivity and specificity at air-column width differences ≥1.6 mm were 0.706 and 0.702 respectively. The positive predictive value and negative predictive value were 0.324 and 0.922. The area under the ROC curve of tracheal ultrasound was 0.823 (95% CI: 0.698 to 0.947) and that of the cuff leak volume test was 0.840 (95% CI: 0.715 to 0.964).


Portable ICU ultrasound visualising air-column width differences between pre and post deflation cuff balloon is a promising objective tool which aids in prediction of successful extubation.


  1. De Bast Y, De Backer D, Moraine JJ, et al.: The cuff leak test to predict failure of tracheal extubation for laryngeal edema. Intensive Care Med 2002, 28: 1267-1272. 10.1007/s00134-002-1422-3

    Article  PubMed  Google Scholar 

  2. Chung YH, Chao TY, Chiu CT, et al.: The cuff-leak test is a simple tool to verify severe laryngeal edema in patients undergoing long-term mechanical ventilation. Crit Care Med 2006, 34: 409. 10.1097/01.CCM.0000198105.65413.85

    Article  PubMed  Google Scholar 

  3. Ding LW, Wang HC, Wu HD, et al.: Laryngeal ultrasound: a useful method in predicting post-extubation stridor. A pilot study. Eur Respir J 2006, 27: 384. 10.1183/09031936.06.00029605

    Article  PubMed  Google Scholar 

Download references

Author information

Authors and Affiliations


Rights and permissions

This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons licence, and indicate if changes were made. The images or other third party material in this article are included in the article's Creative Commons licence, unless indicated otherwise in a credit line to the material. If material is not included in the article's Creative Commons licence and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this licence, visit The Creative Commons Public Domain Dedication waiver ( applies to the data made available in this article, unless otherwise stated in a credit line to the data.

Reprints and Permissions

About this article

Cite this article

Sutherasan, Y., Theerawit, P., Hongpanat, T. et al. Prediction of post-extubation failure by portable ICU ultrasound. Crit Care 16, P130 (2012).

Download citation

  • Published:

  • DOI:


  • Vocal Cord
  • Objective Tool
  • Video Laryngoscopy
  • Deflation Cuff
  • Successful Extubation