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Journal of the Royal Society of Medicine Volume 84 August 1991

being treated for acute occlusion following PTCA, by stenting, no deaths or myocardial infarctions ocurred in the patients satisfying the inclusion criteria. One of these patients experienced reocclusion 3 months after the procedure3. None of the patients required bypass surgery. Stents may also be used to prevent or treat, restenosis following PTCA. These usually occur within 6 months of the procedure. In a study of 42 patients who underwent arteriography 7 months after placement of a coronary stent only -three (7%) were shown to have developed arteriographic restenosis4 compared to reported incidence of up to 40% for PTCA. Stents have been shown experimentally to become incorporated into the wall of the artery and be covered by an endothelial lining within 2 weeks5. Finally the role of stenting as a primary procedure in coronary disease is promising6 and is currently under evaluation. One of the disadvantages of stenting is that all patients receiving stents need to be aggressively anticoagulated and receive antiplatelet agents for a period of up to -6 months depending on the type of stent. Controlled randomized clinical trials are currently under, way to clarify fully the role and indications of stenting in coronary arterial disease. S K SHAMi Department of Surgery University College and Middlesex School D A SHIELDS of Medicine S SARIN The Middlesex Hospital, Mortimer Street,' London WlN 8AA References 1 Dotter CT. Transluminally placed coilspring endarterial tube grafts: long term patency in canine popliteal artery. Invest Radiol 1969;4:329-31 2 Pompa JJ, Ellis SG. Intracoronary stents: clinical and angiographic results. Hertz 1990;15:307-18 3 Sigwart U, Urban P, Golf S, et al Emergency stenting for acute occlusion after coronary balloon angioplasty. Circulation 1988;78:1121-7 4 Sigwart U. The self-expanding mesh stent. In: Topol EJ, ed. Textbook of interventional car#diology. Philadelphia: W B Saunders, 1990:605-22 5 Roubin GS, Robinson KA, King SB, et at Early and late results of intracoronary arterial stenting after coronary angioplasty in dogs. Circulation 1987;76:891-7 6 Ellis SG, Roubin GS, King SB, et al. Intracoronary stenting to prevent restenosis: preliminary results of a multicenter study using the Palmaz-Schatz stent suggest benefit in selected high risk patients (abstract). JAm Coll Cardiol 1990;15:118A

Accident flying squads and emergencies The paper by Cope et al (March 1991 JRSM, p 144) argues that 'accident flying, squads are cleared for take off'. However, their evidence does not appear to support this. They were unable to demonstrate a significant benefit in terms of survivals and we are given insufficient information to know whether those patients who did respond to life-saving treatment might not also have done so if treated by suitablytrained ambulance staff. The training value whic they sugs - experiencing how to intubate in the-dark- under an ovrerturned lorry - seems far removed from wShat is required in everyday clinical practice, and there is good evidence that resuscitation skills require regular updating. While it is indicated that the vehicle is provided for by voluntary donationls, it is not clear that all of the

other costs are covered, including perhaps higher staffing levels. Is it really true that there is no cost to the health authority? Finally at a time when there is increasing concern about the hours of work of junior doctors, and the consequences of 'Achieving a Balance', is it really sensible to have highly trained and expensive staff spending time driving around the countryside? One hope that air trafflc control will seek a further evaluation before giving the final clearance for take-off. MARTIN MCKEE

Department of Public Health and Policy Health Services Research Unit London School of Hygiene and Tropical Medicine Keppel Street, London WC1E 7HT

Accident proneness Surely in embracing the, I had thought discredited, concept of accident proneness, Engel (March 1991 JRSM, p 163) is indulging in the practice that we are all now encouraged to eschew, that of blaming the patient for the disease. Accidents occur to people a4d objects because the organizat4onal structure around them has not done both of two things, anticipated the possibility of accidents and taken suitable preventive action. Suitable preventive action includes matching ability to the task. The report of a recent investigation of injuries in a Dutch shipyard concluded that hearing loss and alcohol consumption were safety hazards1. It is up to whover is in authority in the enterprise to ensure that workpeople with less than normal, hearing or under the -influence of alcohol do not get into situations where their disabilities present a risk to themselves or anyone else. Accidents represent a failure in the managerial system of the organization in which the accident occurs. Whether those charged with the management of the organization are deemed culpable can only be a matter ofjudgement of whether it could be reasonably expected that the conditions which gave rise to the accident could have been foreseen. There could be a strong case for not giving the directors of London Underground the benefit of the doubt over King's Cross nor, now the late, Arnold Hammer for Piper Alpha. If, as suggested by Vickers and Reeve in the same issue (p 180), 35% of doctors are in the wrong niche in terms of personality does that not represent a possible explanation for the other phenomenon Engel refers to, the returning patient? Perhaps the patients .wopl4dn't be returning if the physicians were, in the organizational rather than the therapeutic sense, competent to manage them in the first place. 3 Crossfell Road JOHN GREEN Hemel Hempstead HertA HP3 8RB

Reference

1 Moll van Charante AW, Mulder PGIL Perceptual acuity

and the risk of industrial accidents. Am J Epidemiol 1990;131:652-63

-Long-ter benzodiazepine use and painl We were very pleased to see the paper by Hardo and Kennedy (;February 1991, JRSM, p 73) conerning the problem of long-term benzodiazepiBe use by patients