Impaction of suction catheter during paediatric anaesthesia

Abstract

We read with interest articles describing impaction of a gum-elastic bougie in a tracheal tube (TT) and the effects of different types of lubrication on the force needed to retract a stylet from a TT 1, 2. We report a case of catheter impaction during tracheal suction under general anaesthesia. A 6-year-old weighing 16 kg was scheduled for right nephrectomy under general anaesthesia. All routine investigations were within normal limits and physical examination including airway assessment was unremarkable. Laryngoscopy revealed a Cormack and Lehane grade-3 view and the trachea was intubated with a 5-mm cuffed TT after external laryngeal manipulation. The child was positioned in the left lateral decubitus position. Approximately 40 min after intubation, audible crepitations were heard from the TT. A 10-FG PVC suction catheter was introduced into the TT to clear presumed secretions. Insertion was easy but whilst being withdrawn, the suction catheter appeared to become lodged within the TT's lumen. Attempts to remove the catheter proved futile despite gentle traction and rotation of the catheter. Before desaturation occurred, the TT cuff was deflated and the TT was removed with the suction catheter in situ. The lungs were ventilated via a facemask but several attempts at re-intubation failed because obtaining a view of the vocal cords was impossible. Finally the airway was secured with a size-2 LMA. Thereafter, maintenance of and recovery from anaesthesia proceeded uneventfully. No visible abnormality was identified in the TT or suction catheter. Similar impaction has been attributed to an increase in surface tension due to small amounts of condensed vapour between the outer surface of the suction catheter and the inner aspect of the TT's anterior wall 3. Interestingly, use of water as a lubricant to aid easier passage of a suction catheter through the TT has also been advocated. We believe that paediatric TTs, with a smaller lumen and sharper curve, exaggerates the friction between the two and may more readily lead to impaction of the catheter. Selection of an appropriately sized catheter for suctioning is important. The French gauge of the suction catheter should be no more than one and half times the size of the TT's internal diameter in mm. We also believe that the suction catheter should be lubricated, or another option is to use a siliconised suction catheter.