British Journal of Anaesthesia, 2002, Vol. 89, No. 1 184
© 2002 The Board of Management and Trustees of the British Journal of Anaesthesia
Correspondence |
Transtracheal high frequency jet ventilation and iatrogenic injury
Editor—We read with interest the article by Bourgain and colleagues,1 who reported an 8.4% incidence of subcutaneous emphysema and 1% incidence of pneumothoraces with jet ventilation via the transtracheal route. Transtracheal catheter placement is an extremely useful technique for patients with significant glottic pathologies such as obstructing glottic tumours, and can be lifesaving. We do, however, have concerns over its use in patients with simple benign vocal cord pathologies, such as small polyps or nodules. With this technique, there is a 1 in 12 (8.4%) chance of developing iatrogenic subcutaneous emphysema, which can cause a severe painful swelling in the neck. These patients are also at risk of direct injury to the larynx and trachea from catheter placement.In our hospital, we undertake over 500 microlaryngoscopy, biopsy or laser laryngeal procedures for benign and malignant airway lesions each year. We reserve the use of transtracheal jet ventilation for those patients in whom significant difficulty with airway maintenance is anticipated. In these cases, we insert the transtracheal catheter under local anaesthetic with the patient awake.
For simple benign vocal cord pathology, there are a number of well-established methods of airway maintenance, which do not have the same incidence of iatrogenic injury as that associated with transtracheal catheter placement. These include:
1.Ventilation via a microlaryngoscopy tube or laser resistant tube.
2.Supraglottic jet ventilation via a jet needle attached to a suspension laryngoscope.
3.Subglottic jet ventilation via a catheter introduced orally, through the glottis and into the trachea.
None of these techniques cause disruption of the tissues between the skin and anterior tracheal wall as can occur with transtracheal catheter placement, and which accounts for the high subcutaneous emphysema rate with the latter technique. In our hospital over the last year there have been no cases of subcutaneous emphysema or pneumothoraces when using one of these three standard techniques and an automated jet ventilator.
Transtracheal jet ventilation is an extremely useful anaesthetic technique but carries a high incidence of morbidity related to barotrauma. We believe that the balance of risk vs benefit is only acceptable in those patients with significant pathology and airway compromise, but is unacceptable for patients with simple lesions, which can be managed by other techniques.
When using transtracheal high frequency jet ventilation, patient selection is essential to prevent unnecessary iatrogenic injury.
A. Patel
N. Randhawa
R. A. Semenov
London, UK
Editor—Thank you for Dr Patel and colleagues’ comments concerning our study on ‘Transtracheal high frequency jet ventilation for endoscopic airway surgery’.1 Subcutaneous emphysema was limited to the neck in 8.4% of our patients and extended to the face or the thorax in 14 patients (2%). It was more frequent after difficult tracheal punctures, especially in patients with a malignant tumour and with previous cervical radiotherapy. Airway management of these patients using the transglottic approach may also produce serious difficulties. Pneumothorax occurrences have been reported after tracheal intubation (0.04%), but at a lower incidence than when using jet ventilation (0.2%).2 The higher incidence of subcutaneous emphysema that we reported in our study was probably related to the high proportion of patients with difficult airways.
Limited subcutaneous emphysema did not cause any pain and most of the cases were identified by careful postoperative examination. Extension of the emphysema to the face and to the mediastinum resulted in discomfort and thoracic pain, which were controlled by routine analgesic treatment.
As the cricothyroid membrane is situated below the vocal cords, direct injury to the larynx should not be a complication of transtracheal ventilation. The rate of complications is higher when experience of jet ventilation is limited; an in-depth understanding of the technique is necessary for its successful use. Therefore, routine use of this technique will probably reduce the rate of complications.
J.-L. Bourgain
Villejuif, France
References
1 Bourgain JL, Desruennes E, Fischler M, Ravussin P. Transtracheal high frequency jet ventilation for endoscopic airway surgery: a multicentre study. Br J Anaesth 2001; 87: 870–5
2 Cozine K, Stone JG, Shulman S, Flaster ER. Ventilatory complications of carbon dioxide laser laryngeal surgery. J Clin Anesth 1991; 3: 20–5[Medline]
CiteULike 
Connotea 
Del.icio.us What's this?
| ||||||||||||||||||||||||||||||||||||||||||||||||||