[Aspiration of a broken silver cannulas into the trachea]

A case in which a silver cannula broke and was aspirated into the trachea is presented. Examination of the silver cannula in the Institute of Technology in Jutland revealed that the soldering of the throat plate was defective. In addition, the cannula was made of nickel silver plated with silver. It is proposed that only cannulae made of precious metal should be employed and that the construction of cannulae made if precious should be altered e.g. the throat plate could be surrounded with muff a 4-5 mm in height which would provide a greater soldering area and thus increase the strength of the connection. An example of poor soldering with increased risk of breaking is shown so that the stocks of cannulae can be inspected and sorted out.