Iatrogenic Airway Injury
Highlights
- The most common complication from supraglottic airway device (SAD) insertion is transient sore throat and although the incidence may be as high as 17.5%, this is still significantly lower than that seen with tracheal tubes (reported as high as 90%) (View Highlight)
- The early cuffed tracheal tubes could be described as ‘low volume high pressure’, and required high cuff pressures to overcome the compliance of the elastic cuff material. When the cuff was inflated, the measured pressure would bear little relation to the contact pressure between the cuff and the tracheal mucosa. In addition, the circular shape of the cuff could result in points of high contact pressure in the D-shaped trachea (View Highlight)
- Ischaemia of the tracheal mucosa occurs when the cuff or any other section of the tube (such as the tip or entry point of a tracheostomy tube) provide a contact pressure greater than capillary perfusion pressure. The cartilaginous tracheal rings also receive their blood supply from the overlying submucosa and are also susceptible to damage from high cuff pressures. This results in perichondritis and healing takes place by granulation with strictures typically developing over 3–6 weeks (View Highlight)
- The critical contact pressure that causes ischaemia has been estimated at 30 cm H2O, and therefore, it is recommended that HVLP cuffs are operated at pressures below this (View Highlight)
- It has been estimated that the adult tracheal lumen needs to be reduced by 75% before the stenosis becomes symptomatic (View Highlight)
- The biggest risk factor appears to be prolonged intubation and there is a strong correlation between duration of intubation and the development of PITS (View Highlight)
- There is a window of opportunity, usually under 3 months, for stenotic lesions when they can be successfully treated with balloon dilatation. More mature stenosis may need linear grooves cut in the affected segment before balloon dilatation. (View Highlight)