1. All that seems well is not always well—intermittently malfunctioning flexometallic tracheal tubes 
Arya V.K. , Kumar A. , Radhakrishnan J. , Durairaju A.K.  
British Journal of Anaesthesia 
Volume 93, Issue 3, Pages (September 2004)
DOI: /bja/aeh598
Copyright © 2004 British Journal of Anaesthesia Terms and Conditions

2. Fig 1
Fine surface cuts on a Portex flexometallic ETT extending over the embedded inflation tube (under magnification).
British Journal of Anaesthesia  , DOI: ( /bja/aeh598)
Copyright © 2004 British Journal of Anaesthesia Terms and Conditions

3. Fig 2
Normal check for cuff patency when Portex flexometallic ETT is flexed with the embedded inflation tube on concave side.
British Journal of Anaesthesia  , DOI: ( /bja/aeh598)
Copyright © 2004 British Journal of Anaesthesia Terms and Conditions

4. Fig 3
Occult air leak revealed (cuff deflated, arrow) when Portex flexometallic ETT is flexed with the embedded inflation tube on convex side (arrow).
British Journal of Anaesthesia  , DOI: ( /bja/aeh598)
Copyright © 2004 British Journal of Anaesthesia Terms and Conditions

5. Fig 4
Occult air leak detected (air bubbles) when the Rusch flexometallic ETT is dipped in water, keeping the embedded inflation tube on its convex side.
British Journal of Anaesthesia  , DOI: ( /bja/aeh598)
Copyright © 2004 British Journal of Anaesthesia Terms and Conditions