Correspondence not be guaranteed. The Citanest 5 % Heavy ampoules used by D r Hillman were resterilised at St Bartholomew’s Hospital in accordance with our recommendations and when assayed by Astra contained 50.7 mg prilocaine hydrochloride per ml, which is well within the specification limits applied by our quality control department and marginally higher than the initial assay on the batch which was 50.4 mg/ml. During re-autoclaving the level of utoluidine increased from 67.6 pg/ml (0.14% of prilocaine hydrochloride content) to 91.6 pg/ml
69
(0.18%). In view of these results it is difficult t o explain Dr Hillman’s ‘patchy’ anaesthesia in terms of a deficiency in the product. I t must be stressed that the formation of utoluidine and subsequent formation of insoluble products is restricted to solutions of prilocaine hydrochloride containing glucose and that other presentations of Citanest are not affected. Astra Ltd, Ki,lg George,s Avenue, wa,,urd
A.K. WATSON
wD17 a R
Disintegration of a tracheostomy tube I would like to report a potentially fatal fault in a disposable tracheostomy tube. The tube, a 33 gauge Blue Line cuffed tracheostomy tube (Portex Ltd, Hythe, Kent) had been inserted a t tracheostomy 4 days earlier t o allow IPPV to be given to an elderly patient with multiple injuries, including bilateral fractured ribs. It was suddenly noticed that the expired tidal volume had fallen by half and, on investigation, a large and audible leak was found at the site of the tracheostomy. The swivel connector appeared to be attached firmly to the tube and the cuff satisfactorily inflated. Therefore it was decided to replace the tube whereupon the fault was eliminated, and the patient suffered no ill-effects from the episode. On inspection of the original tracheostomy tube it was found that the flange, which forms the base of the swivel mount, and the shaft of the tube had come
apart (Fig. I). Presumably the bonding between these two components of the tube was insufficiently strong to withstand the usual mechanical stresses associated with normal tracheostomy and ventilator care. Total separation did not occur due to the presence of the pilot tube of the cuff; an uncuffed tube would have come apart completely. University Hospital of the W.G. NOTCUTT West Indies, Mona, St Andrew, Jamaica.
A replyjrom Purtex Ltd We have not been able t o examine the tracheostomy
tube complained of, so accurate diagnosis is a little difficult. Such observations that we can make based on a close study of the photograph (Fig. I ) are that
Fig. 1.
69
(0.18%). In view of these results it is difficult t o explain Dr Hillman’s ‘patchy’ anaesthesia in terms of a deficiency in the product. I t must be stressed that the formation of utoluidine and subsequent formation of insoluble products is restricted to solutions of prilocaine hydrochloride containing glucose and that other presentations of Citanest are not affected. Astra Ltd, Ki,lg George,s Avenue, wa,,urd
A.K. WATSON
wD17 a R
Disintegration of a tracheostomy tube I would like to report a potentially fatal fault in a disposable tracheostomy tube. The tube, a 33 gauge Blue Line cuffed tracheostomy tube (Portex Ltd, Hythe, Kent) had been inserted a t tracheostomy 4 days earlier t o allow IPPV to be given to an elderly patient with multiple injuries, including bilateral fractured ribs. It was suddenly noticed that the expired tidal volume had fallen by half and, on investigation, a large and audible leak was found at the site of the tracheostomy. The swivel connector appeared to be attached firmly to the tube and the cuff satisfactorily inflated. Therefore it was decided to replace the tube whereupon the fault was eliminated, and the patient suffered no ill-effects from the episode. On inspection of the original tracheostomy tube it was found that the flange, which forms the base of the swivel mount, and the shaft of the tube had come
apart (Fig. I). Presumably the bonding between these two components of the tube was insufficiently strong to withstand the usual mechanical stresses associated with normal tracheostomy and ventilator care. Total separation did not occur due to the presence of the pilot tube of the cuff; an uncuffed tube would have come apart completely. University Hospital of the W.G. NOTCUTT West Indies, Mona, St Andrew, Jamaica.
A replyjrom Purtex Ltd We have not been able t o examine the tracheostomy
tube complained of, so accurate diagnosis is a little difficult. Such observations that we can make based on a close study of the photograph (Fig. I ) are that
Fig. 1.
