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SKIN-GRAFTING LEG ULCERS

SIR,-Mr. Chilvers and Dr. Freeman describe a simpletechnique for applying skin-grafts to venous ulcers in theoutpatient department (Nov. 22, p. 1087). One wonders,however, why transplanted skin should thrive when theneighbouring skin has failed to grow across the ulcer.

Bisgaard bandages, as used at St. Thomas’s, are veryeffective if used correctly, but not otherwise, and it is

possible that the success of the grafts was partly due to theadditional support given by the bandage applied over them.

I should like to ask Mr. Chilvers and Dr. Freeman how

many of the grafted ulcers lay above the ankle-joint, andhow many below, for ulcers above the ankle-joint canalways be healed by compression, and grafting can do nomore than hasten healing of a large ulcer. The few difficultulcers lie below the ankle-joint, and if grafting is effectivein these it is a valuable treatment indeed.

It may be that grafting is of limited value and, as Dr.Rivlin suggests (Dec. 13, p. 1310), never essential, but it isridiculous to suggest that the application of a layer of skinwill complicate a later operation. Perhaps Dr. Rivlin is

confusing the method advocated with the old, and onehopes defunct, excision-and-graft procedure.

It is also alarming, in 1969, to see such a statement as" 70% of ulcers are due to varicose veins " and " 20% aredue to deep-vein thrombosis." The lack of correlationbetween an history of deep-vein thrombosis and theclinical post-thrombotic syndrome, and variations inincidence with geography, standard of living, and time, allmake such bald statistics meaningless. More serious, how-ever, are the implications of this statement in relation totreatment, for any venous ulcer, whether post-thromboticor otherwise, with or without varicose veins, is alwaysassociated with incompetent perforating veins. If these

perforating veins are not ligated (or sclerosed) then thetreatment of the ulcer is inadequate in conception or faultyin execution.

JULIAN TOWNSEND.St. Albans City Hospital,

Herts.

OCCULT BLOOD IN FÆCES

SIR,-Further to the letter of Nov. 15 (p. 1072), we havecompleted a parallel study of four tests for occult blood.Comparative tests were made on 104 consecutive fmcal

specimens from inpatients in our acute geriatric assessmentwards using benzidine 1,2 and orthotolidine 2 (both in

glacial acetic acid), ’ Hematest ’ tablets, and the modifiedguaiacum test.3 The results are set out in the accompanyingtable. The guaiacum test, whilst showing a similar degreeof sensitivity to the other three tests, was found to be

marginally less sensitive. In only two cases, however, was apositive result with one or more of the other three testsaccompanied by a negative result with the guaiacum test.Our preference is for the benzidine or orthotolidine

(measured powders dissolved in glacial acetic acid) tests,but those substances, although still available, are regardedas carcinogenic and may only be handled with such strin-gent precautions as would render the tests unacceptable.The hematest tablet test is unsatisfactory, and will shortlybecome unavailable. Of all the tests that may safely be usedin testing for occult blood, the modified guaiacum test

seems to be the best that we have. Wilkinson and Penfold 3

have already emphasised that the guaiacum (in glacial aceticacid) and the hydrogen peroxide solutions ought to be re-placed every month, and that they ought to be stored in thedark. The solutions are contained in plastic dropper bottleswhose nozzles ought to be fine and long enough to

1. Needham, C. D., Simpson, R. G. Q. Jl Med. 1952, 21, 123.2. Simpson, R. G. Br. med. J. 1963, i, 1162.3. Wilkinson, R. H., Penfold, W. A. F. Lancet, 1969, ii, 847.

COMPARATIVE TESTING OF FACAL SAMPLES USING FOUR TESTS FOR

OCCULT BLOOD

deliver only one drop at a time. For those who have beenaccustomed to using the benzidine or orthotolidine liquidtests, subtle differences in the colour reaction of the

guaiacum test should be noted. The colour reaction

(smoky blue) is not vivid and the " flash point " is not sosharp as in the other two tests, and the colour does notdiffuse so readily into the filter-paper surrounding thefxcal smear. Although the guaiacum test serves a usefulpurpose at the present time, there is an obvious need for abetter and safe clinical side-room test for occult blood.

DIANA C. HOLTR. G. SIMPSON.

Geriatric Unit,Perth Royal Infirmary.

AN APPEAL TO DOCTORS

SIR,-Sir George Thomson’s suggestion (Dec. 20,p. 1353) that doctors should avoid the " useless prolongingof dying " rests upon the widely held assumption thatdoctors are always successful in carrying out their inten-tions. But this is not necessarily the case.The notion of voluntary euthanasia implies that a doctor

can end a person’s life without pain or violence or loss ofdignity-and with certainty. How true is this ? No doubtsome medical procedures are 99% effective in 99°o of cases,but there are few, if any, which carry an absolute guaranteeof success in a particular case. How are we to kill people ifvoluntary euthanasia becomes legal ? Will it be by theinjection of fifty times the minimum lethal dose of (say)morphine ? Or a hundred times ? And if, owing to somerare abnormality, or mistake, even this does not kill, whatthen ? In such an event, we may be compelled to use sur-gical measures; so should these be used only as a last resort,or should the surgeon be called in ab initio ? Medical

technology has an apparently irreversible tendency towardsspecialisation. Who would be the specialists in euthanasia ?Technique always improves with practice; so does thismean that we have to accept the likelihood that our

early attempts at killing will be unsuccessful, or

violent-dysthanasia rather than euthanasia ? And will

patients consent to euthanasia if they are not assured that itwill be administered by the medical attendant theynominate ? ?,The capacity of human life to persist in spite of the

gravest accidental or pathological insults has always been asource of wonder to me, and I at least would need a courseof instruction (including some practice, to overcome thehabits of years) before I felt qualified to administer thecoup de grdce with the certainty (not merely a reasonablechance) of success. I wonder who would be prepared tooffer-such instruction ?

If it is less than certain that doctors can be sure of killingwhen they intend to, is it, on the other hand, true that theycan be held responsible for prolonging life beyond what isconsidered " ethically " desirable ? Is it certain, for instance,that the use of specific drugs for the treatment of pneumoniain the elderly does actually prolong life ? Some years agoI had charge of a ward for elderly men in a mental hospital,and I followed a policy of making patients whom I regardedas having terminal illness as comfortable as possible, withoutregard for their survival-time. Although I have no figuresto validate it, I was surprised to get the impression that my

40

patients tended to live longer as a result of this policy thanthey would have if I had focused attention upon treatingtheir illnesses. Perhaps my policy transiently arrested thedecline in their homoeostasis " across the board ", to useDr. Comfort’s phase. I

Professor McKeown has said that " the striking increasein life expectation in Britain, which has often been largelyattributed to advances in medical research, has in fact beenmainly a byproduct of general social betterment 11.2 Are wereally certain that it is curative medicine that is responsiblefor what so many people feel to be the misery of prolongeddying-or is it the result of some other factor such as greaterinnate vitality ?

It seems to be possible that laymen-and sometimesdoctors too-are cherishing an illusion when they assumethat the results of medical technology in either ending, orprolonging, the life of an individual are 100% predictable.It is, of course, an illusion which is more forgivable in aphysicist than in a biologist.

Perhaps we need to think out the practical implicationsof such a measure as euthanasia as a first approach toreaching an ethical judgment upon it.

JAMES R. MATHERS.

PSEUDOMONAS IN VENTILATORS

SIR,-Mechanical ventilators are known to be potentialsources of cross-infection with Pseudomonas aeruginosa.3They provide a warm moist environment which encouragesthe organism to multiply, and may rapidly become heavilycontaminated, so that organisms are pumped directly intothe patient’s trachea. It is therefore essential for ventilatorsto be adequately disinfected.During an outbreak of infection by Ps. aruginosa in an

intensive-care unit, this organism was isolated from a Capeventilator, the highest degree of contamination being in thehumidifier and the inspiratory tubing. The ventilator wasdisinfected with formaldehyde by filling the humidifier withformalin and circulating formaldehyde through the entireventilator. Cultures from the surfaces of the humidifier andthe expiratory and inspiratory ports were examined. Theports were sterile but Ps. aruginosa was isolated from thehumidifier. The disinfecting process was repeated, butagain failed to kill all the organisms in the humidifier.The humidifier on the ventilator is an enclosed metal

tank containing a thermostatically controlled heating ele-ment. It is a separate unit from the ventilator. When the

top, secured by two screws, was removed, a scale was seenon all the surfaces normally covered by water, and a piece ofthe scale yielded a heavy growth of Ps. aeruginosa on directculture. Adequate disinfection with formaldehyde wasachieved after thorough cleaning of the humidifier andremoval of all the scale. Cultures from the humidifier werestill sterile one week later.The ventilator had been in use for 26 months and had

been regularly disinfected with formaldehyde. The humi-difier, which was filled with " soft " tap water and heated to40°C, had not previously been opened. It is now filled withdistilled water.

Mechanical ventilators are disinfected by chemicalmethods because their complex design prevents the use ofmore reliable physical methods.4 It is, therefore, essentialthat the limitation of the chemical antibacterial agents usedfor disinfection must be taken into account. Generallythey only act against vegetative forms of organisms andtheir action is often impaired by the presence of organicmatter, which may neutralise the disinfectant or prevent it

reaching the contaminating organisms. The failure of

1. Comfort, A. Lancet, 1969, ii, 1411.2. McKeown, T. J. chron. Dis. 1965, 18, 1067.3. Phillips, L., Spencer, G. Lancet, 1965, ii, 1325.4. Public Health Laboratory Service. Br. med. J. 1965, i, 408.

chemical disinfection due to the inaccessibility of con-taminating organisms has been shown to be the cause of anoutbreak of infection with Ps. ceruginosa acquired duringurological operations. 5 The practical implication of theseobservations is that items to be disinfected by chemicalmethods must be thoroughly cleaned and if necessarydismantled.The formation of a scale in the ventilator humidifier pro-

vided a nidus of contamination which was not reached bythe formaldehyde. Although distilled water is now used toprevent the formation of scale, the humidifier will be

inspected and cleansed regularly.This episode not only illustrates the care required when

using chemical disinfectants but also emphasises the needfor ventilators which can be cleaned and disinfected moreeasily. 6

RODNEY Y. CARTWRIGHTPAMELA R. HARGRAVE.

Public Health Laboratory, andRoyal Devon and Exeter Hospital,

Exeter, Devonshire.

COMBINED SURGERY AND CHEMOTHERAPY

FOR CARCINOMA OF BRONCHUS

SIR,-Dissatisfied with the poor results of surgicalresection alone for carcinoma of bronchus, in 1963 Idecided to employ cyclophosphamide in addition. Theregimen was as follows: cyclophosphamide, 200 mg. daily,was given by mouth for two days before and for nine daysafter the operation; on the day of operation no oral dosewas given, but 200 mg. was given intravenously by-theanaesthetist while the chest was being opened (before thelung was handled).

TWO-YEAR CRUDE SURVIVAL-RATES OF PATIENTS WITH CARCINOMA

OF BRONCHUS (1960-66) ACCORDING TO METHOD OF TREATMENT

* Rates based on fewer than 10 cases.

To begin with, the white-cell count (w.C.C.) was

measured frequently in each patient; but when I found thatthe count fell to about 3000 per c.mm. in almost allpatients, and that there were no serious untoward effects,this investigation was no longer done as a routine. Somehalf a dozen patients became bald, but in every case hairgrowth returned to the preoperative level within threemonths of operation. No other complications of drugtherapy were observed.

It was hoped that the use of cyclophosphamide in com-bination with surgery would reduce the recurrence-rate,especially in the first six months after operation: I believethat the recurrences-especially distant metastases-whichare so common during this period are often caused by theliberation of malignant cells into the bloodstream when thecarcinoma is handled at operation.The experiment lasted five years-from 1963 to 1968.

Two-year survival rates were compared with my owncases for 1960-63. No patient treated after 1966 is

5. Moore, B., Forman, A. Lancet, 1966, ii, 929.6. Medical Research Council. ibid. 1968, i, 705, 763, 831.