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PATHOLOGY TESTS—TOO MUCH OF A GOOD THING
1278
single shock of 240 J ruptured the coronary sinus of a dog-but in all the other dogs even repeated shocks of 200 J caused no such damage. The high success rate of endocavitary ablation and the ease with which it can be repeated (if necessary) means that endocavitary ablation will be used increasingly. This being so, we need to know much In
one
study16
a
about how the ablation is achieved. We also need catheters that have been designed to withstand the high energies; possibly the electrodes should be smaller and positioned along one edge, rather than a series of complete rings, so that the discharge can be directed rather than dissipated into the blood pool. Finally alternative approaches must be considered. Electrocautery, via modern flexible catheters, and the use of lasers" offer the possibility of controlled and limited destruction of selected areas so that tachycardia is prevented while conduction continues unimpaired. more
PATHOLOGY TESTS—TOO MUCH OF A GOOD THING IT is not
only history that repeats itself. The same laboratory investigations on the same patients are repeated with monotonous regularity and this practice is one of the main factors in the increased workload of hospital laboratories. Each year in England and Wales haematology requests rise by 7—14%, microbiology tests by 6-10%, and chemical pathology tests by 10-17%. (There was an apparent fall in 1974 coincident with the reorganisation of the health services, but this was undoubtedly due to failure to collect proper data rather than to an unexpected benefit from that exercise.) At the same time in England the number of requests per patient has increased substantially.’ About 10% of the laboratory workload originates from general practitioners. Clinical chemistry and haematology laboratories have accepted this increased workload philosophically because of the availability of automated equipment that can handle large numbers of samples. Microbiologists, however, have not had the benefit of such equipment. New therapies such as organ transplantation and intensive cytotoxic therapy for neoplasia bring with them a large increase in laboratory work but the general increase in workload is common to hospitals without such units. An 800-bed district general hospital can expect to process between 1000 and 1500 samples each day in its laboratories. On Mondays half to two-thirds of in-patients will have blood samples taken to be distributed among the laboratories. An Irish survey of 371 patients discharged from medical wards2 showed that routine blood counts seldom affected management. More than half the tests performed were repeat tests, many of them for those whose initial results were normal. Indeed 78% of the repeat tests provided no new or different information. R, Fisher JD. Technique for ablation of anomalous conduction using catheter placed in coronary sinus: canine studies. Circulation 1982; 66: II-217. Narula OS, Bharati S, Chan MC, Embi AA, Lev M Laser micro transection of the His bundle a pervenous catheter technique. JACC 1984, 3: 537. Fleming PR, Zilva JF. Work-loads in chemical pathology: too many tests? Health
16 Brodman 17 I
Trends 1981, 13: 46-49 2. Ajeel NAH, McCormick J. The 100-01.
use
of routine blood
counts.
Irish Med J
1984, 77:
The
for the flood of laboratory investigations are complex. Firstly, the attitude of the consultant is crucial in setting the climate. If recent data are required on each ward round and if junior staff are neither rebuked for unnecessary investigations nor questioned about the rationale for an investigation, then there is nothing to discourage irrelevant or repetitious testing. Secondly, the laboratories have been made to take on a screening role rather than providing a diagnostic service. This is particularly so in clinical chemistry where the pressure of equipment manufacturers has, in the past, dictated the pattern of investigations performed. One of the newer automated blood counters provides fifteen pieces of information on a routine blood count, at least four of which have not, as yet, been shown to have any relevance to clinical medicine. Some of the newer machines, however, allow greater discretion in the performance of tests and permit only those tests which are relevant to be selected. Thirdly, in general, organisation of investigations is left to the most junior member of the medical team. It is all too easy to fill out a large number of forms in the early evening for the phlebotomist to pick up in the morning. In many hospitals the doctor no longer even takes the blood sample. Finally, there is no pressure on the consultant to rationalise his pattern of investigation. The facilities of the service departments are all at his or her behest. It all seems to be "for free". A requirement by the laboratory that all out-of-hours requests by house officers in a London hospital be screened by their own registrars resulted in a halving of the number of tests and a very considerable saving in fees paid to technicians for after-hours work. Perhaps the allocation of budgets to medical teams so that they will "buy" their investigations may help. But, other than a paper exercise, this may be difficult to implement within the present organisation of National Health Service hospitals. Useful savings can be achieved only if there is a fall in workload, of at least 20%, such as to allow a reduction in staff numbers. Small decline in specimen numbers will merely save the cost of syringes, needles, specimen bottles, and diluent. A large reduction in workload is possible only with much more discriminating use of laboratories by clinicians. One hopes that it could be achieved simply by the practice of good medicine. But financial pressures may help to sharpen the mind. reasons
TREATMENT OF LEAD POISONING IN CHILDREN IN management of lead poisoning one of the difficult decisions concerns chelation therapy. Such treatments are not without hazard, and in young children, the most vulnerable section of the population to the adverse effects of lead, it is particularly important that the right decision is made.’ Blood lead concentrations of less than 30 µg/dl are usually classed as within normal limits, although the range 20-30 µg/dl probably indicates some degree of overexposure ; and when the blood lead exceeds 70 jLtg/dl there is general agreement on the need for intervention. Most of the dispute about treatment is centred on the narrow territory between these figures. Clearly, the first course is to remove the exposed person from the source of exposure. Then comes the decision for or against chelation therapy (which has in the 2 past been combined with haemodialysis). Preventing lead poisoning in young children. Atlanta, Georgia: U S. Department of Health, Education and Welfare, 1978. Pedersen RS. Lead poisoning treated with haemodialysis Scand J Urol Nephrol 1978;
1. Center for Disease Control. 2
12: 189-90.
single shock of 240 J ruptured the coronary sinus of a dog-but in all the other dogs even repeated shocks of 200 J caused no such damage. The high success rate of endocavitary ablation and the ease with which it can be repeated (if necessary) means that endocavitary ablation will be used increasingly. This being so, we need to know much In
one
study16
a
about how the ablation is achieved. We also need catheters that have been designed to withstand the high energies; possibly the electrodes should be smaller and positioned along one edge, rather than a series of complete rings, so that the discharge can be directed rather than dissipated into the blood pool. Finally alternative approaches must be considered. Electrocautery, via modern flexible catheters, and the use of lasers" offer the possibility of controlled and limited destruction of selected areas so that tachycardia is prevented while conduction continues unimpaired. more
PATHOLOGY TESTS—TOO MUCH OF A GOOD THING IT is not
only history that repeats itself. The same laboratory investigations on the same patients are repeated with monotonous regularity and this practice is one of the main factors in the increased workload of hospital laboratories. Each year in England and Wales haematology requests rise by 7—14%, microbiology tests by 6-10%, and chemical pathology tests by 10-17%. (There was an apparent fall in 1974 coincident with the reorganisation of the health services, but this was undoubtedly due to failure to collect proper data rather than to an unexpected benefit from that exercise.) At the same time in England the number of requests per patient has increased substantially.’ About 10% of the laboratory workload originates from general practitioners. Clinical chemistry and haematology laboratories have accepted this increased workload philosophically because of the availability of automated equipment that can handle large numbers of samples. Microbiologists, however, have not had the benefit of such equipment. New therapies such as organ transplantation and intensive cytotoxic therapy for neoplasia bring with them a large increase in laboratory work but the general increase in workload is common to hospitals without such units. An 800-bed district general hospital can expect to process between 1000 and 1500 samples each day in its laboratories. On Mondays half to two-thirds of in-patients will have blood samples taken to be distributed among the laboratories. An Irish survey of 371 patients discharged from medical wards2 showed that routine blood counts seldom affected management. More than half the tests performed were repeat tests, many of them for those whose initial results were normal. Indeed 78% of the repeat tests provided no new or different information. R, Fisher JD. Technique for ablation of anomalous conduction using catheter placed in coronary sinus: canine studies. Circulation 1982; 66: II-217. Narula OS, Bharati S, Chan MC, Embi AA, Lev M Laser micro transection of the His bundle a pervenous catheter technique. JACC 1984, 3: 537. Fleming PR, Zilva JF. Work-loads in chemical pathology: too many tests? Health
16 Brodman 17 I
Trends 1981, 13: 46-49 2. Ajeel NAH, McCormick J. The 100-01.
use
of routine blood
counts.
Irish Med J
1984, 77:
The
for the flood of laboratory investigations are complex. Firstly, the attitude of the consultant is crucial in setting the climate. If recent data are required on each ward round and if junior staff are neither rebuked for unnecessary investigations nor questioned about the rationale for an investigation, then there is nothing to discourage irrelevant or repetitious testing. Secondly, the laboratories have been made to take on a screening role rather than providing a diagnostic service. This is particularly so in clinical chemistry where the pressure of equipment manufacturers has, in the past, dictated the pattern of investigations performed. One of the newer automated blood counters provides fifteen pieces of information on a routine blood count, at least four of which have not, as yet, been shown to have any relevance to clinical medicine. Some of the newer machines, however, allow greater discretion in the performance of tests and permit only those tests which are relevant to be selected. Thirdly, in general, organisation of investigations is left to the most junior member of the medical team. It is all too easy to fill out a large number of forms in the early evening for the phlebotomist to pick up in the morning. In many hospitals the doctor no longer even takes the blood sample. Finally, there is no pressure on the consultant to rationalise his pattern of investigation. The facilities of the service departments are all at his or her behest. It all seems to be "for free". A requirement by the laboratory that all out-of-hours requests by house officers in a London hospital be screened by their own registrars resulted in a halving of the number of tests and a very considerable saving in fees paid to technicians for after-hours work. Perhaps the allocation of budgets to medical teams so that they will "buy" their investigations may help. But, other than a paper exercise, this may be difficult to implement within the present organisation of National Health Service hospitals. Useful savings can be achieved only if there is a fall in workload, of at least 20%, such as to allow a reduction in staff numbers. Small decline in specimen numbers will merely save the cost of syringes, needles, specimen bottles, and diluent. A large reduction in workload is possible only with much more discriminating use of laboratories by clinicians. One hopes that it could be achieved simply by the practice of good medicine. But financial pressures may help to sharpen the mind. reasons
TREATMENT OF LEAD POISONING IN CHILDREN IN management of lead poisoning one of the difficult decisions concerns chelation therapy. Such treatments are not without hazard, and in young children, the most vulnerable section of the population to the adverse effects of lead, it is particularly important that the right decision is made.’ Blood lead concentrations of less than 30 µg/dl are usually classed as within normal limits, although the range 20-30 µg/dl probably indicates some degree of overexposure ; and when the blood lead exceeds 70 jLtg/dl there is general agreement on the need for intervention. Most of the dispute about treatment is centred on the narrow territory between these figures. Clearly, the first course is to remove the exposed person from the source of exposure. Then comes the decision for or against chelation therapy (which has in the 2 past been combined with haemodialysis). Preventing lead poisoning in young children. Atlanta, Georgia: U S. Department of Health, Education and Welfare, 1978. Pedersen RS. Lead poisoning treated with haemodialysis Scand J Urol Nephrol 1978;
1. Center for Disease Control. 2
12: 189-90.