have undergone radical prostatectomy. The results of histological examination have confirmed intracapsular disease. The final results of this study will be available before the end of the year. It does, however, seem that the screening programme is both practical and effective, and it may form the basis of a more extensive study. The advantages of screening for cancer of the prostate on a large scale are twofold. In the first place it would generate a larger number of patients with localised disease who could be entered into trials of curative treatment. One such trial could compare radical prostatectomy with no treatment. Such a trial would yield invaluable data on the natural course of localised disease and, because of local treatment policies, would probably be considered unethical in the United States and in some parts of Europe. The second advantage of an extensive screening study is that it could be designed to include a control group. This would allow an assessment of the benefits of screening and is the only valid method of showing any improvement in survival that might result from a screening programme. D CHADWICK D A GILLATT J C GINGELL P H ABRAMS

Department of Urology, Southmead Hospital,

ment and that that is one of the reasons why osteoporosis is so widespread, in the Western world at least. The introduction of energy expenditure into the debate is simply a red herring. What evidence is there that energy deficiency leads to osteoporosis? In our paper we reviewed some prospective studies of the effect of calcium supplementation on fracture rates. If Drs Kanis and Passmore had' read our paper as carefully as we have read their review articles there might be less room for misunderstanding. B E C NORDIN Institute of Medical and Veterinary Science, Adelaide, South Australia ROBERT P HEANEY Creighton University, Omaha, Nebraska, United States

1 Kanis JA, Passmore R. Calcium supplementation of the diet. BrMed3 1990;300:1523. (9 June.) 2 Kanis JA, Passmore R. Calcium supplementation of the diet. BrMedj 1989;298: 137-40,205-8. 3 Nordin BEC, Polley KI. Metabolic consequences of the menopause. Calcif Tissue Int 1987;41:S1-40. 4 Nordin BEC, Heaney RP. Calcium supplementation of the diet: justified by present evidence. Br Med J 1990;300:1056-60. (21 April.)

***This correspondence is now closed. -ED, BM7.

Bristol BS1O 5NB

1 Pedersen KV, Carlsson P, Varenhorst E, Lofman 0, Berglund K. Screening for carcinoma of the prostate by digital rectal examination in a randomly selected population. Br Med J 1990;300:1041-4. (21 April.) 2 Correspondence. Screening for carcinoma of the prostate. BrMedJ 1990;300:1585-6. (16 June.) 3 Silverberg E, Lubera JA. Cancer statistics 1989. CA 1989;39: 3-20. 4 Imai K, Zinbo S, Shimizu A, et al. Clinical characteristics of prostate cancer detected by mass screening. Prostate 1988;12: 199-207. 5 Thompson IM, Rounder JB, Teague JL, et al. Impact of routine screening for adenocarcinoma of the prostate on stage distribution. 7 Urol 1987;137:424-6. 6 Love RR, Fryback DG, Kimbrough SR. A cost-effective analysis of screening for carcinoma of the prostate by digital examination. Med Decis Making 1985;5:263-78.

Calcium supplementation of the diet SIR,-The recognition by Drs John A Kanis and Reg Passmore that "pharmacological doses of calcium delay the rate of bone loss" in postmenopausal women' represents a considerable shift from the views expressed in their review articles, which were entitled "Calcium supplementation of the diet" and subtitled "Not justified by present evidence."' What is the difference between a calcium supplement and a pharmacological dose of calcium? Their reference to an adaptation process "which may take several years to complete" (and which has never been shown in women) is a two edged weapon. Such slow adaptation (if it occurs) must entail several years of negative calcium balance and therefore some unspecified degree of osteoporosis. There is ample evidence that negative calcium balance is most severe close to the menopause and becomes less severe with advancing age.' If this is to be regarded as a long term process of adaptation it is clearly too slow to protect the aging population against osteoporosis and fractures. As far as the calcium requirement is concerned, we made it clear in our paper that our calculations were based on American and European studies of calcium balance.4 The recommended allowance of 800-1000 mg applies to Western populations. It is quite possible that Third World populations with lower protein and salt intakes have a lower requirement. We believe, however, that the calcium intake of a large proportion of elderly Western women is inadequate for their require-

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Allergy to peanuts SIR,-The papers by Drs E S K Assem and colleagues' and Drs Kieron L Donovan and J Peters,2 describing severe anaphylactic reactions to peanuts, make depressing reading. It is generally agreed that the initial treatment of anaphylaxis should be adrenaline (0 5 ml of adrenaline solution 0-1% for adults) by deep subcutaneous injection or, if the patient is severely shocked, by intramuscular injection.' 4 In his editorial Dr Tony Smith recommended that, if necessary, the injection of adrenaline should be repeated after 15 to 20 minutes.5 Such a delay, however, may permit the development of irreversible changes. While a single injection of adrenaline is often effective within one to two minutes, it may need to be repeated rapidly. If the patient appears to be deteriorating a further injection of the same quantity of adrenaline should be given without delay and the patient should be observed continuously. If improvement is not apparent five minutes after the initial injection and no further adrenaline has been given a second injection should be administered. In exceptional cases further injections may be required, depending on the progress of the patient while being transferred to an intensive care unit. There is no generally accepted scheme of treatment, and the frequency of injections should be determined by the clinical condition of the patient-the dosage suggested above would be appropriate for cases of severe anaphylaxis. Readministration of adrenaline after such short intervals is not as dangerous as it may sound. Patients suffering from anaphylactic shock may have severe peripheral circulatory failure, which will result in poor absorption of the drug. Furthermore, adrenaline causes intense vasoconstriction in the tissues immediately surrounding the injection site and thereby delays absorption further. Finally, an intravenous line should be established immediately after the first injection of adrenaline. It may take a considerable time to get into a vein in a shocked patient-time during which adrenaline, had it been given first, could have been producing a beneficial effect and could perhaps have arrested the progress of the

anaphylaxis. Only one of the patients described had been given adrenaline for self administration. Syringes

pre-charged with adrenaline should be given with suitable instructions to patients who have suffered from anaphylaxis from any unavoidable cause. The use of such syringes will save valuable time and may be life saving. J F ACKROYD

Allergy Clinic, St Mary's Hospital, London W2 lNY I Assem ESK, Gelder CM, Spiro SG, Baderman H, Armstrong RF. Anaphylaxis induced by peanuts. Br Med ] 1990;300: 1377-8. (26 Miay.) 2 Donovan KL, Peters J. V'egetableburger allergy: all was nut as it

appeared. BrMed3 1990;300:1378. (26 May.) 3 Ackrovd JF. Adrenaline for bee stings. Lancet 1980;ii: 1190-1. 4 Ackroyd JF. Treatment of severe anaphylactic reactions to insect stings. I R Soc Med 1981;74:567-9. 5 Smith T. Allergy to peanuts. BrMedj 1990;300: 1354. (26 Mav.)

Percutaneous cholecystolithotomy SIR,-As correctly stated by Mr S G Chiverton and colleagues,' techniques for treating gall stones such as percutaneous cholecystolithotomy, dissolution therapy, and extracorporeal shock wave lithotripsy leave the gall bladder in situ and run the risk of recurrent symptoms and stones. In our-experience the new technique of laparoscopic cholecystectomy is the treatment of choice for most patients with gall stones. This technique offers several advantages for the patient, including the avoidance of the need for dissolution therapy and elimination of the risk of stone recurrence. Between October 1989 and January 1990 laparoscopic cholecystectomy was attempted in 50 patients with symptomatic gall stones (42 women, eight men; mean age 49, range 25-76) by a modification of the technique described by Dubois et al.' The procedure was successful in 49 patients with no major postoperative complications. In one patient the procedure was converted to the conventional open method owing to an iatrogenic leak in the common bile duct, which was successfully managed with a T drain. Most patients were free from nausea and fully mobilised on the second postoperative day. The mean length of stay in hospital was three days. During the postoperative period the pain experienced by these patients decreased remarkably compared with that in patients who had had conventional open cholecystectomy as judged on a visual analogue scale. Laparoscopic cholecystectomy eliminates the risk of incisional hernia, and the cosmetic advantage is evident. Though in this series no patient had a history of acute cholecystitis or pancreatitis, we have now modified our selection criteria to include most such patients. We are assessing a further group of patients who had endoscopic retrograde cholangiopancreatography and papillotomy with extraction of stones from the common bile duct before successful laparoscopic cholecystectomy. With care and ever evolving technology this procedure should considerably benefit the patient and cholecystectomy will remain the treatment of choice for gall stones. JAMES COLEMAN WOLFGANG SPANGENBERGER

ANDREAS PAUL JURGEN KLEIN HANS TROIDL

Second Department of Surgery, University Hospital Koin-Merheim, Cologne 5000, West Germany 1 Chiverton SG, Inglis JA, Hudd C, Kellett MJ, Russell RCG, Wickham JEA. Percutaneous cholecystolithotomy: the first 60 patients. ArMedj 1990;300:1310-2. (19 May.) 2 Dubois F, Kard P, Berthelot G, Levard H. Coclioscopic cholecystectomy: preliminary report of 36 cases. Ann Surg

1990;211:60-2.

SIR,-The report by Mr S G Chiverton and colleagues of the first 60 patients receiving percutaneous cholecystolithotomy at the Middlesex

BMJ VOLUME 301

14 JULY 1990

Calcium supplementation of the diet.

have undergone radical prostatectomy. The results of histological examination have confirmed intracapsular disease. The final results of this study wi...
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