WOUND INFECTION AFTER APPENDICECTOMY

930

embolism risk than the combined preparations, and they were not considered further. This left 920 reports. From market-research data Inman et al. worked out the numbers of incidents to be expected from each preparation assuming that the associated risk of thromboembolism was the same for each brand irrespective of its constitution. The observed/expected ratio decreased as the oestrogne content fell from 150 g. to 50pLg. But there were notable breaks in this pattern, and it may be that the progestogen in the combination affects the risk associated with the oestrogen. Especially odd was the very low ratio for a high-dose oestrogen (100 ;jLg. mestranol) combined with a progestogen (norethynodrel) which may itself have oestrogenic activity. One combination of 75 .g. mestranol and 2-5 mg. lyncestrenol emerged better from the analysis than did Of greater imporsome low-dose oestrogen brands. the two low-dose tance, however, are preparations which yielded observed/expected ratios of close to unity, instead of less than one as might have been expected from the general trend. An association between the pill and coronary thrombosis is not yet proven, but this latest report contains an indication of such a relationship. Inman et al. examined 63 reports of coronary thrombosis (25 fatal). 61 of these related to women taking combined preparations, and it is interesting that, in oestrogen-dose trend, the observed/expected ratios for coronary thrombosis behaved in much the same way as did those for venous thromboembolism. This does not mean that oral con-

precipitate coronary thrombosis, but, taken with Oliver’s findings 35 of a high proportion of pill-takers in a series of young women with myocardial infarction, it does suggest that this aspect merits further investigation. Similarly, cerebral thrombosis remains an unconfirmed though not unlikely side-effect of oral contraceptives, and the 7 cases summarised by Dr. Atkinson and his colleagues on p. 914 suggest that traceptives

can

thrombosis of the cerebral veins merits attention as cerebral-artery thrombosis.

as

much

It is difficult to see why the committee’s earlier warning could not have been accompanied by at least some of the statistical material provided by Inman et al. For one thing it seems that the difference between high and low dose oestrogen is nothing like as great as was at first feared: incidents were 30% more likely with 100 g. oestrogen or more, and 20% less likely at oestrogen doses below 100 g. If doctors prescribe lowdose oestrogen combinations the committee predicts a 50% reduction in mortality and a 25% reduction in major morbidity from thromboembolism. The total of about 1500 reports received in this 41/2-year period may represent a true average incidence of 3300 per annum (since the committee believes that only 10% of incidents are reported to it). Without the committee’s warning 5000 women on oral contraceptives would be expected to experience thromboembolism in 1970. It has been suggested that alarm generated by the Scowen committee’s earlier warning may have persuaded many women to an over-hasty decision to stop taking the pill, and that this might affect the birthrate or the abortion-rate. Nothing much can be said about the birth-rate until later this year, but there is a 35. Oliver, M. F. ibid.

p. 210.

suggestion (little more) that the notification-rate for abortions has increased lately. Most legal terminations of pregnancy are done at 10-14 weeks’ gestation, so some effect of unplanned conceptions since midDecember may appear in the abortion figures for the end of February onwards. For the last quarter of 1969, the weekly average for notifications of abortions was 1131, and in the first 4 weeks of this year it was 1099. However, the next 5 weeks yielded an average of 1436, and the mean for the 4 weeks ended March 31 was 1540.

WOUND INFECTION AFTER APPENDICECTOMY

APPENDICECTOMY for acute appendicitis or suspected appendicitis is the commonest emergency operation in general surgical units in this and many other countries. Most district hospitals serving a population of about 250,000 people can expect to admit around 250 such patients each year. Those who are treated by timely operation and who have no complications will acute

usually recover after two or three days of not too severe pain or upset, and they will be able to vacate their acute hospital bed after seven to ten days. Depending on age, occupation, personal circumstances, and inclination, they will resume their normal activities in a few weeks, with little chance of permanent disability, apart from a small adhesions.

scar

and

a remote

risk of obstruction from

Unfortunately this smooth course is by no means invariable, and complications lead to a small but definite mortality and a not insignificant morbidity.l.2 Not unnaturally, these complications, which usually stem from infection in the first instance, tend to be commoner in the very young,3.4 the elderly,5 and those debilitated by other disease. Peritonitis, whether generalised or confined to the pelvis or subphrenic region, is responsible for nearly all the deaths, either directly or indirectly, and also for much of the more serious morbidity. Other serious complications, such as intestinal obstruction, paralytic ileus, fistula formation, chest complications, and pulmonary embolus, usually arise in cases where peritonitis was already established by the time of operation. Infection of the wound develops in at least 10% of most series of appendicectomies and, although not usually life-threatening unless caused by very virulent organisms, it does delay discharge from hospital and return to employment. Wound infection may also predispose to dehiscence or incisional hernia; and the final scar is often very unsightly. In a new study of wound infection after appendicectomy, Brumer6 examined the records of an Australian teaching hospital and found significant wound infection in 40 (9-9%) of 404 cases operated on over three years. The first and most obvious factor which predisposed to wound infection was the severity of the appendicitis, which was presumably a measure of the virulence of the organism in relation to the 1. Wright, R. B. Lancet, 1963, ii, 475. 2. Pledger. H. G., Buchan, R. Br. med. J. 1969, iv, 466. 3. Jackson, R. H. ibid. 1963, ii, 277. 4. Fields, I. A., Cole, N. M. Am. J. Surg. 1967, 113, 269. 5. Williams, J. S., Hale, W. H. Ann. Surg. 1965, 162, 208. 6. Brumer, M. Br. J. Surg. 1970, 57, 93.

931

reaction of the host; and it would also greatly influence the extent of contamination of the wound during the operation. Strangely, little correlation existed between wound infection and the turbidity or otherwise of the free peritoneal fluid, but perhaps a more useful prognostic sign would be whether the fluid was foul-

smelling

or

not.

The standard grid-iron incision seemed to be less prone to infection than either a paramedian incision or a grid-iron incision which had had to be extended by muscle cutting. This difference can probably be attributed to opening and closing the rectus sheath in the paramedian wound and to the need to suture and therefore injure muscle. All appendicectomies cannot be safely carried out through grid-iron incisions, and muscle cutting will be necessary from time to time. Similarly, an acutely inflamed appendix has occasionally to be removed through a paramedian laparotomy wound when the diagnosis was not expected. Tube drainage of the peritoneal cavity and the administration of systemic antibiotics were both found to be associated with a slightly increased liability to wound infection. The presence of a drainage tube inevitably means continuous recontamination of the wound, since organisms and discharges pass along the outside of the tube as readily as along the lumen, especially since the lumen is often quite quickly sealed off inside the peritoneal cavity. That the wound infection-rate should be higher in patients who have had systemic antibiotics is less easy to understand, especially after the evidence produced by Polk and Lopez-Mayorbut the choice of antibiotic may have been faulty or dosage inadequate. To drain the peritoneal cavity a Penrose or corrugated drain is probably as efficient as a tube which blocks readily even when made of non-irritant material and with multiple side-openings. A case can be made for directing the infected drainage material away from the main wound by bringing it out of a separate stab incision; and, in view of the tendency for organisms to travel in both directions along tubes, perhaps general surgeons should follow the urologists and use a closed system of drainage into a sterile disposable plastic collecting bag attached to the drain in theatre. Greatly to be deplored is the not uncommon sight of inadequately padded dressings and fluid soaking through to the bedclothes from a peritoneal drain cut short. As was reiterated in a recent discussionof infection after colon operations, the observation of important points in technique helps a wound to resist infection: minimal trauma to the tissues, careful hxmostasis and suturing, and the least possible amount of foreign material buried in the wound. Non-absorbable suture material has little place in appendicectomy wounds. Evidence has been accumulating that the use of topical antibiotics, especially ampicillin, 9,10 may help to reduce overt infection, and so may such antiseptic agents as

noxythiolin.The use of delayed primary suture such as recommended by Grosfield and Solit 11 has attractions 7. Polk, H. C., Lopez-Mayor, J. F. Surgery, St. Louis, 1969, 66, 97. 8. See Lancet, March 7, 1970, p. 509. 9. Nash, A. G., Hugh, T. B. Br. med. J. 1967, i, 471. 10. Rickett, J. W. S., Jackson, B. T. ibid. 1969, iv, 206. See also Lancet, 1969, ii, 1285. 11. Grosfield, J. L., Solit, R. W. Ann. Surg. 1968, 168, 891.

in certain circumstances where the wound is obviously grossly contaminated, but it can hardly be applicable in many appendicectomies. Even with these measures, wounds still become infected, and the last word has certainly not been written. Regular monitoring of infection-rates and further well-designed investigations are to be encouraged.

SEX RATIO IN PHENYLKETONURIA

PHENYLKETONURIA (P.K.U.) is transmitted as an autosomal recessive condition,’ and, as would be expected with this type of inheritance, the sex ratio in the classical cases, usually ascertained because of the patient’s mental retardation, has been close to unity. However, in a series of 90 cases identified by screening in the United States there were 60 boys and 30 girls. Dr. David Hsia’s report of this intriguing observation appears on p. 905 of this issue. Babies up to 121 days old were tested, and the criteria for inclusion in the series were a plasma-phenylalanine level of 20 mg. or more per 100 ml. (at least two tests, not less than a day apart) and a plasma-tyrosine level below 5 mg. per 100 ml. The diagnosis was confirmed at 3 months by a challenge with either a phenylalanine load or a normal diet. In a family study of 83 of the 90 index patients 17 sibs (8 males and 9 females) were found to have P.K.U. In addition there were 36 normal male and 40 normal female sibs. The altered sex ratio, therefore, was confined to the index patients. Dr. Hsia has surveyed the literature and confirmed that there is no excess of males among cases of classical P.K.u. ascertained by mental retardation, family studies, and pilot screening programmes. The male excess is, however, seen in some other series picked up by screening alone, there being in sum 91 males and 65 females. In addition he notes that there is an excess of males among cases of hyperphenylalaninaemia ascertained by

screening. The excess of males in these series suggests to Dr. Hsia that some female patients are being missed on the screening tests. Indeed, in a count from the literature, 7 patients with a delayed rise in phenylalanine, picked up from family studies but missed by screening tests, were all girls. Dr. Hsia concludes that those concerned with neonatal screening for P.K.U. should include a Guthrie test not earlier than forty-eight hours after birth and only after feeding for twenty-four hours with protein, and that the test should be repeated a month later. In this country Dr. Hsia’s first recommendation is

already in operation, following the recommendation of 2 a Medical Research Council working-party.2 The Guthrie test is being carried out six to fourteen days after birth, when the child has been on protein for at least forty-eight hours; a repeat test a month later is considered necessary. A level of at least 6 mg. per 100 ml., if confirmed on a repeat test, is taken to require further study. Probably few, if any, girls with classical P.K.U. will be missed by this screening procedure, and not

1. Penrose, L. S. Lancet, 1935, 2. Br. med. J. 1968, iv, 7.

i, 192.