193

required for 100 patients at a mean cost of z1885 per patient, or [,5. 80/week of a paced patient’s life. Similarly the costs with the lithium/iodine and the nicke!/ cadmium pacemakers work out at 4-02 and jC5-S3, respectively. The table can be redrawn as follows on the assumption that 8% of patients originally paced die each year: makers would be

CALCULATION OF PACEMAKER COSTS

I

I

I

I

The lowest cost type on this calculation remains as with Mr Norman’s calculation the lithium/iodine powered pacemaker, but the isotope unit appears the most expensive. It is important when choosing a pacemaker to try to assess the patient’s expectation of life. If the outlook is poor, the mercury/zinc unit may be suitable and would prove least costly. Cardiac Department, St George’s Hospital, London SW1X 7NB.

You recommend peripheral phlebography in the investigation of these patients. We have found this procedure to be hazardous in these circumstances since it may lead to extension of the thrombotic process. It may also be misleading; the internal iliac veins, which are the source of emboli in about 10% of patients, are seldom demonstrated, and the thrombotic process is often so rapidly advancing that the state of affairs that is depicted no longer applies a few hours later. For these reasons we feel that peripheral phlebography should be abandoned, as should partial occlusion of the peripheral veins in the treatment of this condition. Cavography seems to be harmless and is useful to exclude a double or left-sided inferior vena cava which occurs in about 2% of patients. The price of the protection afforded by partial caval occlusion by clip is a 6% frequency of persistent leg swelling, usually of minor degree. This swelling is usually the result of peripheral venous thrombosis to which partial caval occlusion predisposes. This predisposition is not the result of back-pressure ; it seems likely to be the result of a change from the normal pulsatile flow to a relatively smooth flow pattern in the veins peripheral to the partial occlusion. The type of smooth clip to be used is probably immaterial. We use a silicone-covered model (Penlon Ltd.). A gap of 5.55 mm affords satisfactory protection. Torbay Hospital, Torquay, Devon TQ2 7AA

A. M. N. GARDNER M. J. TURNER

HAROLD SIDDONS

INTERRUPTION OF THE INFERIOR VENA CAVA

SIR,-We are concerned that your editorial of Jan. 3 (p. 25) is misleading and may prejudice the use of interruption of the inferior vena cava in circumstances where it might save lives in danger from pulmonary embolism. We agree that the main indications for this treatment are elective when anticoagulation either fails or is contraindicated, but like others,’ having found the technique to be safe and simple, we feel there is also a place for prophylactic partial caval occlusion in certain high-risk patients undergoing, for example, mandatory operations in the presence of thromboembolic disease, especially when anticoagulant therapy cannot be used. We were surprised that you state that, of the various techniques of partial occlusion, plication with interrupted sutures is the method of choice. In a comparative study by one of US2 of caval plications, clips, and filters, carried out on patients found at operation to have abdominal carcinomatosis and so to be at special risk from embolism, partial occlusion by a smooth silicone clip proved clearly more effective and easier to perform than plication or filter. Plications tend to become blocked by the arrest on their "pillars" of the small insignificant emboli that are the rule rather than the exception in ill and elderly patients; such small emboli pass through the slits of smooth clips. Furthermore, plications when they do remain patent tend to distort, and the channels enlarge until they can no longer arrest emboli of lethal size (7-5 mm diameter or

more). In contrast with your contentions, in our experience of several hundred cases3 the application of a clip is a safe operation disturbing the patient no more than any other simple intra-abdominal procedure. We have had one operative death in a woman whose duodenal ulcer perforated a few hours after a massive pulmonary embolism.4 Two other patients died from septic thrombophlebitis not affecting the clip site. One further patient died of pulmonary embolism, the embolus having

CÆSAREAN SECTION

SiR,—The report on the results from a well-known obstetric

hospital in 1974, includes the following paragraph: "The operative technique of section has become well standardised and with few exceptions a high degree of operative skill is not required. The long term indications of the operation are, however, serious and the decision to perform the primary requires the most careful consideration.""

While agreeing with the last sentence, I disagree with the first. If it is true of this one hospital, it is not true of England and Wales as a whole. The Confidential Reports on Maternal Mortality in England and Wales 1970-1972 rightly deplores maternal deaths resulting from inexpert surgery and postoperative management, and cites one operation by an inexperienced surgeon that took four hours. It was considered that avoidable factors were present in 51 out of 111deaths after caesarean section. I would emphasise the following two simple points that are often overlooked by inexperienced surgeons. The uterine incision should be sited over the greatest diameter of the presenting part, and it should not be allowed to tear into the great vessels, but, if need be, should be extended upwards medial to the uterine vessels if greater access is required (for this avoids much bleeding and protects the ureters). When the incision is sutured the first suture should be sited in the intact uterus beyond the extremity of the incision, which ensures haemostasis at this point. The second layer of sutures should not extend further laterally than the first. If I seem to be excessively concerned with an operative detail, I simply rejoin that it is an important detail-yet often overlooked to the patient’s disadvantage. There must be, in a modern obstetric hospital a competent surgeon in the labour rooms at all times. John Radcliffe Hospital, Maternity Department, Headington, Oxford OX3 9DU.

E. A. WILLIAMS

passed through a faulty clip. ECTOPIC PREGNANCY AND THE I.U.D. 1 Moretz, W. H., Still, J. M., Griffin, C. H., Jennings, W. D., Wray, C. H. Surgery, 1972, 71, 710. 2 Gardner, A. M. N. Ann. R. Coll. Surg. 1970, 47, 260. 3 Askew, A. R., Harse, H. R., Wilmshurst, C. C., Turner, M. J. Surgery Gynec. Obstet. 1974, 138, 17. 4 Gardner, A. M. N. Proc. R. Soc. Med. 1974, 67, 43.

SIR,-We would like to comment further on your excellent editorial (Nov. 15, p. 963) and the valuable remarks of Mr Weeks and Dr Sutherst (Dec. 6, p. 1144). The incidence of ectopic pregnancy is indeed higher among l.U.C.D. wearers

194 than for other women. Lehfeldt et al.’ suggested that this is because the antifertility effect of the i.u.c.D. is due to enzymatic or chemical action, possibly flowing retrogradely from the endometrium outwards. Hence the antifertility effect is greatest in the endometrium, weaker in the tubes, and absent beyond that. We suggested2 that the chemical action might be due to a substance resembling prostaglandins which is secreted abundantly from the endometrium, causing contractions and preventing implantation. Prostaglandin is also secreted from the fallopian tubes in less amounts. However, the non-contractile ovaries produce far less. Alternatively, we thought that the l.U.C.D. might alter the ratio of the prostaglandins secreted, so that tubal peristalsis is reversed and the ovum is carried the

opposite way.2 Although we agree with Mr Weekes and Dr Sutherst regarding the role of pelvic inflammatory disease, we would like to point out that this complication decreases with time from as high as 7-7/100 women during the first 15 days ofi.u.c.D. protection, to 0-9/100 women in the fourth to sixth years.3 Mishell et al.4 have shown that even when bacteria are introduced by I.U.C.D. insertion into the normally sterile uterus, the uterus becomes sterile once again within 30 days. Also it is generally agreed that pelvic infection which occurs later than the first month after I.U.C.D. insertion is usually due to venereal or intercourse-related causes.4-6 We believe that I.U.C.D. wearers are exposed to a greater risk of pelvic inflammatory disease because of more frequent and prolonged bleeding, which breaks down the normal cervical defences against the ascent of bacteria. Broadgreen Hospital, Liverpool. Department of Obstetrics and Gynæcology, University of Liverpool,

Liverpool.

SAMIA T. A. SAAFAN D. H. DARWISH

POSTOPERATIVE FEEDING AND METABOLISM

SIR,-We have applied the principles stated in your editorial’ to the management of an infant with intractable diarrhoea. The term intractable diarrhoea is applied by us to persistent diarrhoea in small infants associated with total sugar intolerance and poor absorption of protein and fat. These infants, if they are to survive, require prolonged parenteral nutrition. Intractable diarrhoea is a not infrequent problem in Malaysia. The infant, a male aged 1 month and weighing 2.5 kg was maintained for 1 week on ’Intralipid’ (4 g/kg), L-aminoacid (as ’Sohamin’) (550 mg nitrogen/kg), and 5% glucose. Volume requirements were based on 150 ml/kg. Over this period of 7 days, the infant received 80 cal/kg/day. The solutions were administered via peripheral veins. Morbidity was low compared with that noted in infants receiving aminoacid and 10% glucose solutions. During the period of 7 days the baby gained 300 g in weight. No cedema was noted, and protein, electrolyte, and acid-base studies during this period ranged as follows: plasma sodium 131-139, potassium 4.1-5.2, chloride 90-100, and serum-bicarbonate 22 mmol/1; blood-glucose 40 mg/dl; blood pH 7-33-7-40; serum total proteins 6.8and albumin

3.6 g/dl. We believe that this regimen requires further study, and we embarking on detailed metabolic studies of infants with intractable diarrhoea who are on this type of parenteral nutrition. are

Department of Pædiatrics, University Hospital, Kuala Lumpur, Malaysia. 1. 2.

N. IYNGKARAN M. J. ROBINSON

Lehfeldt, H., Tietze, C., Garstein, F. Am. J. Obstet. Gyn. 1970, 108, 1005. Darwish, D. H., Saafan, S. T. A. Brit. med. J. 1975, iv, 143. 3. Tietze, C. Stud. Family Plann. 1970, 55, 1. 4. Mishell, D. R., Bell, J. H., Good, R. G., Moyer, D. L. Am. J. Obstet. Gyn. 1966, 96, 119. 5. Kleinman, R. L. (editor) Intrauterine Contraception; p. 399. International Planned Parenthood Federation, London, 1972. 6. Statham, R., Morton, R. S. Br. med. J. 1968, iv, 623. 7. Lancet, 1975, ii, 263.

GROWTH-HORMONE RESPONSE TO BROMOCRIPTINE IN PARKINSONISM

SIR,-Dopaminergic mechanisms play a major role in hypothalamic function’ and are important regulators of growth hormone (G.H.) secretion.2 Oral levodopa given to parkinsonian patients causes a significant rise in G.H. concentrations after acute3 and chronic4 administration. Untreated parkinsonian patients have defective basal G.H. levels’ and impaired G.H. release with insulin-induced hypoglycaemia,6 possibly related to central dopamine deficiency. Levodopa increases G.H. levels in healthy people7 but in acromegaly it leads to a paradoxical reduction.8 Bromocriptine lowers G.H. levels in acromegalics9 10 and increases G.H. levels in normals." Little is known about the effects of bromocriptine on G.H. levels in parkinsonism. Debono et al.’ found an increase in G.H. concentrations in two out of seven patients after a single oral dose of 2’S5 mg bromocriptine. We report our findings in patients on maximum tolerated therapy. Nine patients with Parkinson’s disease who entered a therapeutic trial of bromocriptine" were studied. Patients were fasted overnight and confined to bed for 24 h to allow maximum resting conditions. Baseline evaluation was performed before therapy and again when the patient had received maximum tolerated dosage for at least 6 weeks. Bromocriptine (mean total dose 40 mg daily) was administered in three equally divided doses. Blood-samples for G.H. measurement were taken at 9 A.M. (fasting, 2 h after drug), noon (3 h after breakfast, 5 h after drug), and 5.30 P.M. (30 min before supper, 30 min and 41 h after drug), and a mean of the three values in each of the 2-day study periods was calculated. The average mean G.H. concentration before therapy was 19 mU/i (range 1’0-4-3) and during treatment was 3.1 mU/1 (range 1.8-5.0). The standard deviation of the differences was 179; p

Letter: Ectopic pregnancy and the I.U.D.

193 required for 100 patients at a mean cost of z1885 per patient, or [,5. 80/week of a paced patient’s life. Similarly the costs with the lithium/io...
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