Intensive Care Med (1992) 18:317-318

Intensive Care Medicine

Correspondence Surgical emphysema, minitracheostomy and HFJV

9 Springer-Verlag 1992

M e c h a n i c a l ventilation in acute respiratory failure - thinking the unthinkable

Sirs,

Dear Sir,

Further to the report by Iapichino et al. [11 and the subsequent correspondence [2] about the safety of minitracheotomy in the presence of both CPAP and IPPV, I would like to comment on the importance of several safeguards which are necessary in the care of a minitracheotomy in the presence of positive airway pressure. Since 1984, when the combination of high frequency jet ventilation (HFJV) and minitracheotomy was first described [3], I have used the technique to support ventilation in 35 patients. Duration of ventilation ranged from 12 h to 14 days. The Bromsgrove Humidified Jet Ventilator (Penlon, Abingdon, UK) and the Mini-Trach II (Portex, Hythe, UK) were used in all cases. In the last 6 patients, the latest version of the Mini-Trach with the Seldinger insertion modification has been used. Surgical emphysema, as a complication of the minitracheotomy, occurred in 3 cases. In one case the procedure was attempted by an inexperienced doctor who placed the Mini-Trach in the para-tracheal tissues and commenced HFJV without confirming correct placement of the tube. In both the other cases, insertion of the minitracheotomy tube was technically difficult and more than one cricothyroid puncture was required. The resulting surgical emphysema was immediate in onset, impressive in appearance and resolved quickly on cessation of HFJV via the minitracheotomy. All 3 patients already had endotracheal tubes in situ and HFJV was continued via the endotracheal without further emphysema occurring. As a result of this early experience of surgical emphysema with the combined technique of HFJV and minitracheotomy, a list of safeguards was produced in conjunction with the manufacturers for inclusion with the jet ventilation and oxygen administration adaptor for the MiniTrach II. These include:

The value of mechanical ventilation in severe acute respiratory failure (ARF) is so widely accepted that to withhold it when it is indicated could be regarded as unethical. But what does 'indicated' mean? Some workers have selected values for different aspects of respiratory function and mechanics to show how to determine scientifically the need for mechanical ventilation, but these values are totally arbitrary. There is no evidence they are optimal for recovery rate, for morbidity or for mortality. Only occasionally is there reference to the patient's clinical state, in particular signs which cannot be measured, arid this omission includes case histories in the literature. Can we believe Intensivists practice respiratory therapy in this rigid way, rather than carefully examining the patient and making a final, but again arbitrary decision at the bedside on the basis of both numerical data and non-quantifiable clinical and radiological information? Despite advances in technology, so called 'scientific' medicine remains a chimera [1]. The mortality of the Adult Respiratory Distress Syndrome (ARDS) has remained virtually unchanged since its description 25 years ago. Some have attributed this to a deterioration in the clinical population, but we now recognise that ARDS is only one manifestation of a multiorgan failure syndrome, respiratory therapy alone being insufficient for improvement in survival. It is also possible that the initial benefits of mechanical ventilation, in particular the abolition/reduction of excessive respiratory work (assessed at the bedside) and probably less important, improvement in lung function, are within a few days overshadowed by the risk of pulmonary sepsis and eventual multi-organ failure, the route of death in most cases of ARDS. Dare we ask whether PEEP itself, a technique whose therapeutic benefit in ARF has never been established [2] also plays a role in this disappointing situation through its ill-effects, of which there is increasing evidence? Nowadays we hear little of 'super PEEP'. Should we as a priority in ARF try both to promote cardiac performance and its tolerance of the increasing respiratory workload and at the same time promote positive oxygen balance through aggressive therapy [3], including the use of powerful sympathomimetic agents such as noradrenaline and adrenaline at an early stage in pulmonary deterioration, before there is any evidence of cardiac embarrassment or in sepsis, hypotension? Such therapy would perhaps also benefit a situation of pathological oxygen supply dependancy. Is it time perhaps that we became less enthusiastic about mechanical ventilation and reviewed our personal criteria for its use (the major problem in any discussion of this topic) and unless there is a serious cardiac problem tried to postpone and even avoid its use? My personal experience suggests this is possible in some cases. Face-mask CPAP is not the answer as it is unsuitabIe for routine use. Ambient high frequency oscillation inside a patient chamber might be an alternative to mechanical ventilation though less practical.

9 Ensure accuracy of Mini-trach placement by test aspiration and radiological confirmation. 9 Avoid multiple insertion stabs of the cricothyroid membrane. 9 Ensure adequate haemostatis after insertion. The development of a Seldinger insertion procedure for the Mini-Trach has, in my experience, reduced the incidence of difficult insertions and should therefore contribute to an overall lessening of risk from high pressure gas mixtures being delivered by whichever means via minitracheostomies. I would agree with Drs. Woodcock and Iapachino that the Seldinger procedure is preferable to the older technique and that, as with any invasive procedure, close monitoring of the patient during and after the procedure is essential. Yours faithfully, H. B. J. Fischer

Yours faithfully, A. Gilston

References 1. Iapachino G, Gavazzeni V, Mascheroni D, Bordone G, Solca M (1991) Combined use of mask CPAP and minitracheotomy as an alternative to endotracheal intubation. Intensive Care Med 17:57- 59 2. Woodcock T (1991) Mask CPAP and minitracheotomy, a cautionary tale. Intensive Care Med 17:436 3. Matthews H, Fischer H, Hopkinson R (1984) Minitracheostomy and jet ventilation - a new technique. Thorax 39:688 Dr. H.B.J. Fischer, Department of Anaesthesia and Intensive Care, Alexandra Hospital, Woodrow Drive, Redditch, Worcs, UK

References 1. Jacobs CD, Pinto HA (1992) Clinical problem solving, a new feature in the Journal. N Engl J Med 326:60-61 2, Gilston AV (1990) PEEP and oxygen balance. Where are the Emperor's clothes? Intensive Crit Care Digest 9:7-13 3. Gutierrez G, Palzas F, Daglio G e t al (1992) Gastric intramucosal pH as a therapeutic index of tissue oxygenation in critically ill patients. Lancet 339:195-199 Dr. A. Gilston, 20 Hocroft Avenue, London NW2 2EH, UK

Mechanical ventilation in acute respiratory failure--thinking the unthinkable.

Intensive Care Med (1992) 18:317-318 Intensive Care Medicine Correspondence Surgical emphysema, minitracheostomy and HFJV 9 Springer-Verlag 1992 M...
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