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base (or buffer anion) concentration changes. When thepartial pressure of C02, and hence the concentration ofcarbonic acid, changes, the total buffer base concentra-tion does not change but the distribution does:

Thus, a rise in Pc02 increases the concentration of

HCO but reduces the concentration of Hb- by analmost equal amount.Therefore measurement of the HC03 concentration

([HC03)) alone will not distinguish between respiratory(gaseous) disturbances and those caused by accumula-tion of non-volatile acid or base (the non-respiratory,non-gaseous or metabolic disturbances). This isunfortunate because measurement of [HC03] is relativelyeasy. Attempts to resolve the difficulty in describing thenon-respiratory component of acid/base disturbanceshave followed two main lines; first, the measurement of[HC03] under conditions which eliminate or correctfor variations in Pco2; secondly, estimation of totalbuffer base concentration. The first of these approachesis simpler and has led to the

" standard bicarbonate "

(which has largely replaced theC02 combining-powerand the alkali reserve). The second approach has led to" buffer base " and " base excess ".

ASTRUP has been a leader both in the developmentof these methods and in the employment of a termin-ology based on them. The history, physicochemicalderivation, and interrelationships are well described

by SIGGAARD-ANDERSEN,3 who is a pupil of ASTRUP. Forthe non-specialist the climax will be the diagram onp. 58 in which he uses his modification of the ASTRUP-NEIL log Pco2/pH diagram to display various measure-ments which can be used to describe non-respiratory(non-gaseous, metabolic) acid/base disturbances: thereare no less than fourteen. Anyone who followsSIGGAARD-ANDERSEN up to this point will be wellversed in the subject; and if he can then derive thefourteen points on one of the other acid/base diagramshe will be up for honours. He will also realise that the

grasp is all-or-none, in that adequate appreciation ofthe meaning of one of the points provides an under-standing of the others.SCHWARTZ and RELMAN 4 attack the approach of

ASTRUP and the earlier similar approach by SINGER 5 ontwo grounds. First, they challenge the validity of themore sophisticated analyses of buffer base or baseexcess as more accurate descriptions of the organismthan one confined to Pc02, [HC03] (or total C02), andpH (or [H+]). ASTRUP 6 has replied to part of the chargeby pointing out that he has maintained only that hisanalysis gives a better description of the blood and notof the organism as a whole. But, although SCHWARTZ andRELMAN’s argument may not be fully justified, it isnevertheless true, as SIGGAARD-ANDERSEN’S observations 7in dogs have shown, that this fuller description of the5. Singer, R. B., Hastings, A. B. Medicine, Baltimore, 1948, 27, 223.6. Astrup, P. New Engl. J. Med. 1963, 269, 817.7. Siggaard-Andersen, O. Scand. J. clin. Lab. Invest. 1962, 14, suppl. 66.

state of the blood does not significantly improveevaluation of the whole organism. Whether or notone adopts it really rather depends on the techniquesavailable and on the mode of description to which theworker is accustomed.SCHWARTZ and RELMAN’s second and more far-

reaching criticism is concerned with the use of the terms" metabolic " and " respiratory ", " acidosis " and" alkalosis ". ASTRUP, SINGER, and their collaborators,and many others use these terms to describe thechemical state of the blood. SCHWARTZ and RELMAN

argue that the terms should describe disturbances ofmechanism. An example from recent experience willindicate the difference. The arterial blood of a patientwas found to have the following values: Pc02 30 mm. Hg;standard bicarbonate 17 mN, pH 7-37 (H+ 43 nN).ASTRUP and SINGER would say that this patient had botha respiratory alkalosis and a metabolic acidosis.SCHWARTZ and RELMAN would say that this patienthad either a respiratory alkalosis or a metabolic acidosisor both. (Those, if there still be any, who only use theterms acidosis or alkalosis when the [H+] or pH is

abnormal, would say that the patient had neither.)ASTRUP and SINGER would like more information butdo not require it before using the terms to describe thestate of the blood. SCHWARTZ and RELMAN would not

apply the terms to the state of the blood but wouldreserve them until they knew what was going on.SCHWARTZ and RELMAN maintain that the use of the

terms to describe the chemical state of the blood couldlead to errors in treatment. If, for example, the bi-carbonate retention which occurs as a secondary responseto underventilation is called a metabolic alkalosis it

may cause treatment to be given which would interferewith a desirable adaptation. But it is doubtful whether

any notation can guarantee protection against suchignorance. Nevertheless, we agree with AsTRUP’s

suggestion that some effort should be made to bringexperts together to try to produce an agreed termino-logy. As with other summit meetings the success of thisone would probably depend on careful preliminarypreparation, good chairmanship, and participants beingfew. We suspect that little will be gained by jugglingwith " acidosis " and " alkalosis ", certainly as

far as the reaction of the blood is concerned, " sincethe expressions increased cH ’ and ’ lowered cH ’ maybe used with equal convenience and somewhat greateraccuracy" .1

Qualification as Consultant—IIACADEMIC bodies must be free to make their own rules;

but confusion arises when they attach different meaningsto the same word. What does " membership " of a collegeimply ? Now that there are so many colleges in this andother Commonwealth countries, it would be convenientif their terminology were more consistent.

Excluding members of the Royal College of Surgeons(who might properly be called licentiates), the two oldest"

memberships " in Britain are those of the London andEdinburgh Colleges of Physicians. These are alike in

being strongly coveted, both at home and overseas. They

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are alike, too, in attracting many candidates who are n01yet ready for the examination, and who should somehowbe deterred from attempting it until they are betterprepared. But they are unlike in that Edinburghcandidates can take the examination partly in a selecteesubject, whereas in London all the papers and clinicaltests are the same whatever the candidate’s interestsThe Edinburgh examination caters for men and womeralready well advanced in specialist training, but the;London one does not: it is meant to be taken earlierThis was publicly explained by the London college a:

long as fourteen years ago, when the M.R.c.p. examina-tion was described as " a test in general medicine, on level higher than that required for qualification ". Its

purpose, said the college, is to select young doctorssuitable for training as consultants, and it shoulc

normally be taken about two years after qualification.!This concept of the membership examination as s

screening test for the newly qualified is educationallyreasonable, and the college has kept to it firmly: candi-dates are encouraged to present themselves as soon aeighteen months after qualification, at a time when the)are still thinking in terms of general medicine rather thana specialty. Yet, for all its educational good sense, it isa concept that has never been fully accepted-whetheiby the public, by those who sponsor candidates, by theprofession as a whole, by candidates, or even by some oithe college’s examiners. And the reason is not far to seek,Say what you will, if a man is admitted to membership of aCollege of Physicians, the outsider will suppose that thecollege has recognised him as a physician. In distantcountries particularly, he will inevitably be regarded as aspecialist. The examiner, being well aware of this, canhardly be blamed if, consciously or unconsciously, helooks for the kind of knowledge to be expected of E

specialist, rather than the kind of knowledge to be;

expected of a candidate for training. When he accord-ingly asks far-ranging questions, he is doing just what thepublic thinks proper in examining for a membership:but he is also preventing his college from realising itsconcept of the examination as something to be takenearly. Hearing of the difficult questions, many aspirantspostpone their candidature until they have been qualifiedfor several years. And by this time anyone who hasembarked on a specialty, such as pathology or psychiatry,.is under a handicap that may prevent his taking themembership at all.The London college may be right in wishing its

examination to be general, and in wanting the futurephysician to get it over before beginning his specialisedpostgraduate education. The Edinburgh college may beright in seeing advantages in an examination later in

training. Equally, all the colleges offering membership-physicians, obstetricians, general practitioners, patho-logists-are entitled to decide what examinations theyrequire and when these are to be taken. But a great manydifficulties would be resolved if all of them, whatevertheir internal arrangements, were to agree that actual

membership shall in future mean what it appears to mean1. Lancet, 1949, ii, 252.

-namely, recognition of the member as a specialist fullytrained in the subject or subjects covered by the college.If a college postponed full membership until it wassatisfied that the appropriate course had been completed,its acceptance of a member would give him (honorary)consultant status-now seldom obtainable in this coun-

try except from the appointment committees that awardhospital posts 2 in the National Health Service. Candi-dates successful in examinations at an earlier stage couldbe given some such title as associate member. In the

eyes of the public this would make sense. People cannotunderstand a system in which this much-prized awardfor intellectual mountaineering is made to those whohave yet to make part of the ascent.

Even in our Commonwealth, colleges differ so much inage and origin and customs that consistency may seemhardly worth pursuing. But the same trends are in factdiscernible in both old and new. The Colleges ofGeneral Practitioners both here and in Australia appearto have decided that full membership shall be reservedfor those who go through a specified training; and thenew College of Pathologists is applying the same

principle.3 That surgeons should grant fellowshipswhere physicians grant memberships is an inconveniencehardly likely to be remedied; but both are now givingmore thought to the period of training that at presentfollows the bestowal of these honours.4 Might it not bebetter if the fellowship were conferred only at the end ofthe course, when the candidate has completed (absitomen) the tertiary as well as the primary and secondarystages of his surgical education ?

For some colleges, this bestowal of consultant statuswould be a new departure; and it certainly carries

dangers. The first is that bodies undertaking the newtask might feel unable to fulfil it without yet anotherexamination. If this were anything like the examinationsthat already punctuate the medical curriculum, it mightnot only spoil the last years of training but also inhibitinitiative at a time when original work is most likely to befruitful. Even if a college relied wholly on evidence thatthe candidate had gone through an approved course satis-factorily, it could still do much damage to Medicine bybeing too rigid about the nature of that course. (With alltheir merits, the American specialist boards have beenaccused of stereotyping the career of young men andwomen just when they most need to follow their ownbent.) Besides these dangers, some may see a practicaldifficulty. If applicants to the Colleges of Physicians inthis country were denied full membership until they hadfinished their training to the college’s satisfaction, mightnot those from overseas be handicapped ? If the title ofmember were made equivalent to that of consultant,might not the colleges feel obliged to stipulate that atleast a substantial part of the experience required shouldbe gained in this country ? For our part, we do not seethis as an insuperable obstacle. Certainly a collegewould wish the training to take place in a hospital whosestandards were acceptable; but already the Royal College

2. ibid. Sept. 14, 1963, p. 561.3. ibid. Nov. 9, 1963, p. 993.4 Edwards, H. ibid. Oct. 12, 1963, p. 791.

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of Surgeons and the Conjoint Board have arrangementsfor recognising overseas posts as appropriate for particularkinds of training.Some doctors dislike the idea of higher qualifications

for anybody-physician, psychiatrist, or anyone else.Not without reason, these critics distrust all qualificationsother than palpable merit, and they think that if we wantto go on producing real doctors we must quickly put astop to the compartmental elaboration of specialist train-ing. Even to replace chaos by cosmos would give nopleasure to those who have come to feel that more couldbe done for Medicine by getting rid of fellowships andmemberships than by improving them. At the meetingof the Royal Medico-Psychological Association reportedon p. 1113, one speaker said that, as a measure of con-sultant status, the conception of a higher qualification is

losing ground. Against this, it would be widely agreedthat the average consultant (not necessarily the genius)gains competence from a planned course of training-provided the plan is stimulating rather than restrictive.Furthermore, under any medical system, posts have tobe filled, and somebody has to say who is qualified tofill them. In determining whether a man is fully trainedfor his future work, the decisions of colleges should bemore reliable than those of hospital appointments com-mittees, which consist partly of laymen and usuallydecide by judging between competitors.The plan we have outlined is a natural development

of present trends, and as such it needs to be faced anddiscussed. Once more it brings us up against the perils,for Medicine, of organisation or even order. Yet orderis a necessity.

Annotations

A MILLION BLOOD DONORS

As a general rule the clinician asks for as much bloodas he thinks that he will need. This is provided withoutfuss and bother; and, if he needs more, it usually appearswithout delay. This sort of service is possible only becauseof highly efficient collection, distribution, and processingof the available blood. The attainment of the millionmark by the active donor panel of the National BloodTransfusion Service is a reminder that the whole systemwould break down without an adequate supply of theraw material.On this occasion we should pay tribute to all those

ordinary people who give their blood so readily andquietly, and who neither expect nor gain anything otherthan a sense of personal satisfaction. Who are thesemillion ordinary people living in this land where affluenceis so often equated with selfish materialism ? It is well toremember that the sort of person who is sometimescondemned as a poor citizen may have given many unitsof blood over the years; and this is not something thathe or she would ever brag about.Next in line are the transfusion centres. Their direc-

tors, collecting teams, technicians, and drivers do a

magnificent job; and a visit to one of these centres leavesone with an impression of efficiency unhampered by redtape. Lastly, the pathologists and technical staff of thelaboratories all over the country who, day and night, seethat compatible blood is always there when it is required.Blood is finally administered on the judgment of the

clinician; and this is a time, too, for considering again theindications for transfusion. The wellbeing and esprit-de-corps of the whole transfusion service depends on thecorrect use of blood. With a perishable commodity, somewastage is inevitable; and this we must accept. But weshould not accept misuse of blood: the donor must beconfident that his blood will be used correctly. Thesupply of blood is limited and the demand is alwaysincreasing. As we start on the second million, enrolmentof each new donor becomes more difficult.What, then, are the indications for transfusion ?

Nobody would question the two greatest-massive blood-loss associated with multiple injuries or hxmorrhage intothe gastrointestinal tract, and major surgical procedures(sometimes of a severity undreamt of even in the recentpast). Blood must be conserved for these purposes, and

this can be done most readily by avoiding unnecessarysmall transfusions.

Criteria for transfusion must be stringent 1; when thesole purpose is to expand a moderately depleted blood-volume, alternative infusions should be used. Brushingany cobwebs of unproven clinical impressions from ourminds, we should recognise that blood in small quantitieshas no magical properties: dextran used with discretionis safe,2 and the hazards of small-pool plasma are hardlygreater than those of blood itself. Accurate measure-ment of blood lost at operations may reveal that the

pendulum has swung so that we now tend to over-

estimate the loss.3

Only by continual reappraisal of our blood-transfusionpolicy can we conserve blood. There are now a millionreasons why we should.

CYTOLOGICAL ASPECTS OF JOINT TISSUES

THE application of electron microscopy to the study ofsynovial tissues has already produced results of outstandinginterest. The lining cells of the membrane of mammalianjoints (exemplified by the rabbit and the guineapig)appear in two distinct forms, although some inter-mediate types also occur. The first type is characterised

by a high degree of vacuolation of the cytoplasm and thepresence of a complex arrangement of surface folds,several of which appear in section as finger-like processes.The second cell type lacks both vacuoles and surface

folds, but its cytoplasm is rich in an endoplasmic reticu-lum liberally endowed with ribosomes. The features ofthe vacuolated cells suggest that they could be activelyphagocytic-a suggestion borne out by the studies of

J. A. Chapman, who described his findings at a sym-posium convened in London on Nov. 8 by the EmpireRheumatism Council. Chapman has shown that, shortlyafter an intra-articular injection of iron dextran, typicalferritin granules can be recognised in large numberswithin the cytoplasmic vacuoles. Simultaneously thenumber and complexity of the cytoplasmic folds increaseconsiderably. The second type of surface cells are

apparently non-phagocytic and do not accumulate ferritinafter intra-articular injection of iron dextran. Theestablished relationship between endoplasmic reticulumand protein synthesis suggests that these cells are activelyemployed in some anabolic activity, and, since the most

1. Graham-Stewart, C. W. Lancet, 1960, ii, 421.2. Artz, C. P., Howard, J. M., Frawley, J. P. Surgery, 1955, 37, 612.3. Gardiner, A. J. S., Dudley, H. A. F. Lancet, 1963, ii, 859.