OBSTRUCTION OF ARMORED TUBES USED IN PEDI ATRIC CIRCLE SYSTEMS

A separation of the individual latex layers is a known complication of endotracheal armoured tubes manufactured by immersion technique. This can result in herniation into the lumen with obstruction of the tube. Diffusion of nitrous oxide into the inner hernia considerably intensi fies the obstruction. This can lead to life-threatening situations. We observed a similar herniation caused by layer separation with subsequ ent tube obstruction of silicolatex anaesthesia tubes used in paediatr ic circuit systems. This is caused by manufacturing defects and above all by damage incurred in reprocessing. Therefore it is important to p rocess the tubes carefully. A too-high drying temperature can cause pr emature layer separation. The tubes should never be processed more tha n 80 times. Routine examination of the tubes is imperative, especially at the predilection sites for layer separation.