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ANTENATAL SCREENING FOR DOWN'S SYNDROME
423 ill-informed and irresponsible statements present a serious threat to that improvement of services for the community which has been slowly and patiently achieved in the last few years. Health services must be preserved from such local political considerations, and the best way of achieving this is for us to welcome the present N.H.S. Bill and to see that the medical contribution to the new structure is an active and helpful one. Hope Hospital, Eccles Old Road, Salford M6 8HD.
HUGH FREEMAN.
ANTENATAL SCREENING FOR DOWN’S SYNDROME
SIR,-Dr Stein and others (Feb. 10, p. 305) have analysed the feasibility of a screening programme for the prevention of Down’s syndrome for New York City. They have shown that such a programme is desirable because of the increasing prevalence of Down’s syndrome due to the increasing lifespan of affected individuals. We agree with these authors that there is no justification in delaying the decision to undertake a diagnostic screening programme for Down’s syndrome. If such a scheme can be shown to be feasible in New York City, we can see no reason why it should not be feasible in the United Kingdom and made readily available through the National Health Service. The technique of amniotic-cell culture is well established, and for the antenatal diagnosis of Down’s syndrome the success-rate is high and will probably be increased as more experience is gained. The nucleus of laboratory facilities and skill are generally available in the United Kingdom and phase i of the programme suggested by Stein et al. could probably be undertaken with only minimum expansion of existing services, since only about 2% of the pregnant population would be involved.1 An additional benefit of such a scheme would be the prevention of other chromosome abnormalities, many of which also increase with maternal age and most of which have some associated morbidity.22 Whether we could agree with stages ill and iv of the scheme proposed by Stein et al. is doubtful at present, as the cost of these stages would be high in relation to the benefits obtained, and the exposure of fetuses, which have only a very low risk of cytogenetic abnormality, to the small but finite hazards of amniocentesis may not be
justified. Only one small series of diagnostic amniocenteses in early pregnancy has been published in this country so far.3 Does this reflect the general unpopularity of views such as those of Stein et al. and similar ones put forward by others ?1
Surely it is time for the evaluation in both economic and human considerations of a screening programme for the prevention of Down’s syndrome in the United terms
Kingdom.
If such a programme was limited to stages I and 11 of Stein et al., it would pay for itself more than twice over,4and unless good reasons are found for not doing so, should be started forthwith. Department of Pathology, Royal Hospital for Sick Children and the University of Edinburgh, Edinburgh EH9 1LF.
A. D. BAIN G. R. SUTHERLAND.
1. Amniocentesis: ad-hoc meeting of experts. Report of M.R.C. conference. London, 1970. 2. Sutherland, G. R. Aust. J. ment. Ret. 1972, 2, 85. 3. Ferguson-Smith, M. E., Ferguson-Smith, M. A., Nevin, N. C., Stone, M. Br. med. J. 1971, iv, 69. 4. Tech. rep. Ser. Wld Hlth Org. 1972, no. 497.
TRAINING .&.l"1.&J.’.I.J.’BJ" OF ’-I’&" SURGEONS SURGEONS.
SIR,-I should like to congratulate Professor McColl (Feb. 3, p. 254) on the introduction of his comprehensive surgical training programme into the United Kingdom. I am sure it will go a long way to boost morale among the junior staff fortunate enough to be selected for the Guy’s scheme. Before the old guard says that it is impossible to train a surgeon fully in seven years, let me say it is possible to train a highly competent surgeon in five years, given the will and the facilities. Briefly, this requires a more intensive period of instruction, the embryo surgeon being taught with his instructor always on the other side of the operating-table, except for the most minor operations, and perhaps on occasions during his fifth and final year. Our department also provides, as a minimum weekly basis of instruction, at least two clinical resident teaching rounds, a morbidity-
mortality conference,
a
gastrointestinal conference, general
hour’s basic-science instruction. These conferences are mandatory for all full-time staff and trainees; and there is usually a large contingent of other surgeons and physicians taking part. I cannot remember any programme in the U.K. that came anywhere near this level of formal instruction, but I am sure Professor McColl envisages something on these lines. I have seen over the past two years such a programme as I have outlined produce perfectly well-trained and competent general surgeons at the end of five years. Since in the U.K. additional skill is required in genitourinary surgery, seven years seems a reasonable training period. I wish Professor McColl success with his bold experiment and urge his surgical colleagues to back him in every possible way. It will require hard work and full-time staff adequately rewarded for their efforts.
rounds, and
an
Wayne State University School of Medicine, 540 East Canfield Avenue, Detroit, Michigan 48201, U.S.A.
JOHN C. PLANT.
AIR-EMBOLISM
SIR,-I read with interest the article by Dr Campkin and Dr Perks (Feb. 3, p. 235) and readily agree that continuous monitoring of the intra-arterial blood-pressure could be of value in detecting air-embolism. However, as the object of monitoring is the prompt detection of small emboli, in order that their port of entry can be plugged before a large serious embolism can develop, it seems logical to employ a more sensitive method for their recognition if it is possible. Techniques which depend on the use of ultrasound and the Doppler principle are, as Edmonds-Seal and his colleagueshave shown, 50 times more sensitive in detecting air-embolism than changes in the blood-pressure, and, therefore, have a lot to recommend them. EdmondsSeal has now apparently suggested that " surgical diathermy produces complete electrical interference with ultrasonic detectors. This is misleading and not always correct; the amount of interference depends on the type of apparatus employed. For example, a spark-gap diathermy is much more prone to produce interference than a valve-operated I routinely employ ultrasonic monitoring diathermy. during posterior-fossx explorations and find that the valve-operated surgical diathermy does not distort the sound sufficiently to prevent satisfactory monitoring for embolism also. After the electrocardiogram and the intraarterial-pressure-meter reading have been blocked when the surgeon is employing diathermy near the floor of the "
1.
Edmonds-Seal, J., Prys-Roberts, C., Adams, 26, 202.
A. P. Anœsthesia, 1971,
HUGH FREEMAN.
ANTENATAL SCREENING FOR DOWN’S SYNDROME
SIR,-Dr Stein and others (Feb. 10, p. 305) have analysed the feasibility of a screening programme for the prevention of Down’s syndrome for New York City. They have shown that such a programme is desirable because of the increasing prevalence of Down’s syndrome due to the increasing lifespan of affected individuals. We agree with these authors that there is no justification in delaying the decision to undertake a diagnostic screening programme for Down’s syndrome. If such a scheme can be shown to be feasible in New York City, we can see no reason why it should not be feasible in the United Kingdom and made readily available through the National Health Service. The technique of amniotic-cell culture is well established, and for the antenatal diagnosis of Down’s syndrome the success-rate is high and will probably be increased as more experience is gained. The nucleus of laboratory facilities and skill are generally available in the United Kingdom and phase i of the programme suggested by Stein et al. could probably be undertaken with only minimum expansion of existing services, since only about 2% of the pregnant population would be involved.1 An additional benefit of such a scheme would be the prevention of other chromosome abnormalities, many of which also increase with maternal age and most of which have some associated morbidity.22 Whether we could agree with stages ill and iv of the scheme proposed by Stein et al. is doubtful at present, as the cost of these stages would be high in relation to the benefits obtained, and the exposure of fetuses, which have only a very low risk of cytogenetic abnormality, to the small but finite hazards of amniocentesis may not be
justified. Only one small series of diagnostic amniocenteses in early pregnancy has been published in this country so far.3 Does this reflect the general unpopularity of views such as those of Stein et al. and similar ones put forward by others ?1
Surely it is time for the evaluation in both economic and human considerations of a screening programme for the prevention of Down’s syndrome in the United terms
Kingdom.
If such a programme was limited to stages I and 11 of Stein et al., it would pay for itself more than twice over,4and unless good reasons are found for not doing so, should be started forthwith. Department of Pathology, Royal Hospital for Sick Children and the University of Edinburgh, Edinburgh EH9 1LF.
A. D. BAIN G. R. SUTHERLAND.
1. Amniocentesis: ad-hoc meeting of experts. Report of M.R.C. conference. London, 1970. 2. Sutherland, G. R. Aust. J. ment. Ret. 1972, 2, 85. 3. Ferguson-Smith, M. E., Ferguson-Smith, M. A., Nevin, N. C., Stone, M. Br. med. J. 1971, iv, 69. 4. Tech. rep. Ser. Wld Hlth Org. 1972, no. 497.
TRAINING .&.l"1.&J.’.I.J.’BJ" OF ’-I’&" SURGEONS SURGEONS.
SIR,-I should like to congratulate Professor McColl (Feb. 3, p. 254) on the introduction of his comprehensive surgical training programme into the United Kingdom. I am sure it will go a long way to boost morale among the junior staff fortunate enough to be selected for the Guy’s scheme. Before the old guard says that it is impossible to train a surgeon fully in seven years, let me say it is possible to train a highly competent surgeon in five years, given the will and the facilities. Briefly, this requires a more intensive period of instruction, the embryo surgeon being taught with his instructor always on the other side of the operating-table, except for the most minor operations, and perhaps on occasions during his fifth and final year. Our department also provides, as a minimum weekly basis of instruction, at least two clinical resident teaching rounds, a morbidity-
mortality conference,
a
gastrointestinal conference, general
hour’s basic-science instruction. These conferences are mandatory for all full-time staff and trainees; and there is usually a large contingent of other surgeons and physicians taking part. I cannot remember any programme in the U.K. that came anywhere near this level of formal instruction, but I am sure Professor McColl envisages something on these lines. I have seen over the past two years such a programme as I have outlined produce perfectly well-trained and competent general surgeons at the end of five years. Since in the U.K. additional skill is required in genitourinary surgery, seven years seems a reasonable training period. I wish Professor McColl success with his bold experiment and urge his surgical colleagues to back him in every possible way. It will require hard work and full-time staff adequately rewarded for their efforts.
rounds, and
an
Wayne State University School of Medicine, 540 East Canfield Avenue, Detroit, Michigan 48201, U.S.A.
JOHN C. PLANT.
AIR-EMBOLISM
SIR,-I read with interest the article by Dr Campkin and Dr Perks (Feb. 3, p. 235) and readily agree that continuous monitoring of the intra-arterial blood-pressure could be of value in detecting air-embolism. However, as the object of monitoring is the prompt detection of small emboli, in order that their port of entry can be plugged before a large serious embolism can develop, it seems logical to employ a more sensitive method for their recognition if it is possible. Techniques which depend on the use of ultrasound and the Doppler principle are, as Edmonds-Seal and his colleagueshave shown, 50 times more sensitive in detecting air-embolism than changes in the blood-pressure, and, therefore, have a lot to recommend them. EdmondsSeal has now apparently suggested that " surgical diathermy produces complete electrical interference with ultrasonic detectors. This is misleading and not always correct; the amount of interference depends on the type of apparatus employed. For example, a spark-gap diathermy is much more prone to produce interference than a valve-operated I routinely employ ultrasonic monitoring diathermy. during posterior-fossx explorations and find that the valve-operated surgical diathermy does not distort the sound sufficiently to prevent satisfactory monitoring for embolism also. After the electrocardiogram and the intraarterial-pressure-meter reading have been blocked when the surgeon is employing diathermy near the floor of the "
1.
Edmonds-Seal, J., Prys-Roberts, C., Adams, 26, 202.
A. P. Anœsthesia, 1971,