1235
Obstetric anaesthetists do not regard epidural analgesia as merely optional form of pain relief in normal labour, but rather as an important part of our management of sick mothers and babies. Moreover, to deny a woman epidural analgesia on a random basis is to expose her unnecessarily to the greater risk of general anaesthesia, should operative delivery become necessary." Perhaps the only remaining opportunity would be to fmd a centre that has no epidural service, and move in to provide one on a fully randomised basis to such mothers as would consent to take part. We would be delighted to publish the results of such a trial, irrespective of outcome. an
Department of Anaesthetics, St Thomas’s Hospital, London SE1 7EH, UK
FELICITY REYNOLDS
Medical Centre, Winston-Salem, North Carolina, USA
DAVID DEWAN
Queen Charlotte’s London
BARBARA MORGAN
Wake Forest
University
Hospital,
1. Howell CJ, Chalmers I. A review
of prospectively controlled companson of epidural with non-epidural forms of pain relief during labour. Int J Obstet Anesth 1992; 1: 93-110. 2. Reynolds F. Epidural analgesia in obstetncs: pros and cons for mother and baby. Br Med J 1989; 299: 751-52. 3. Robinson JO, Rosen M, Evans JN, Revill SI, David H, Rees GAD. Maternal opinion about analgesia for labour: a controlled trial between epidural block and intramuscular pethidine combined with inhalation. Anaesthesia 1980; 35: 1173-81. 4. Report on Confidential Enquiries into Maternal Deaths in England and Wales 1982-84. Department of Health. London: HM Stationery Office, 1989.
Surgical careers and female students SIR,-Whilst I agree with Miss Clarke (April 18, p 994) that the number of female surgeons in the UK is pitifully low, I think that her argument that this is because of discriminatory discouragement from seniors is not sustainable. I am sure that if Miss Clarke had distributed an identical questionnaire to male medical students, similar responses would have been obtained to those reported in her letter. My advice to all medical students and recently qualified doctors who ask about a career in surgery is identical, irrespective of gender: consider all other options first and, if surgery still seems the most apealing option, enter the career fully aware of the difficulties. These difficulties include numerous examinations (FRCS part 1, FRCS part 2, and intercollegiate assessment), the necessity to obtain a higher surgical degree, placement of the rate limiting step at the end of training, and a nomadic existence until about 40. Until surgical training is improved in quality and reduced in duration, it would be dishonest to alter such advice. Perhaps the real reason that there are so few female surgeons in the UK is that women have more sense than men in appreciating the hazards of a career in surgery. Association of Surgeons 10 Warneford Road, Oxford OX4 1LU, UK
in
Training,
R. A. COBB
Clinical management of trisomy 18 SIR,-We agree with the points Dr Bos and colleagues (April 11, p 913) and your accompanying editorial make about the avoidance of emergency surgery in babies with trisomy 18. We should like to make two further comments and add a cautionary tale. First, Bos et al underemphasise the clinical diagnosis of trisomy 18, although we applaud their policy of asking a surgical geneticist to see every newborn baby referred to paediatric surgery with a malformation. There should be few surprise diagnoses of trisomy 18 on karyotyping. Unexplained intrauterine growth retardation is an important alerting sign, and a high frequency of fingertip arch patterns (the finding of six or more is rare in the general population and usual in trisomy 18) is corroborative. Second, we have been impressed by the importance to parents of taking their baby home when a very limited prognosis has been given. In a few cases of trisomy 18 and trisomy 13 in which this has been possible it seems to have helped greatly in the parents’ subsequent acceptance of their loss. Finally, the cautionary tale. A female infant weighing 2-28 kg after 42 weeks’ gestation had an occipital encephalocoele, a perimembranous ventricular septal defect without serious
haemodynamic consequences, and a bicuspid aortic valve. A diagnosis of trisomy 18 was suggested by her facial features, hands, and feet, although the signs were rather subtle. Routine blood lymphocyte karyotyping at age 2 weeks showed non-disjunctional trisomy 18 in all 30 cells examined. The parents were given the devastating prognosis that Bos et al and your editorial outline; however, over the next 6 months her weight and head circumference increased parallel to but below the third centile and she made developmental progress. At 8 months she had reached a 5-6 month level of development. At 2-5 years she is walking, feeding herself, using 2 or 3 words with meaning and responding to simple commands. The peripheral blood karyotype was repeated when the baby was 6 months old and again showed trisomy 18 in all 50 cells examined. A skin fibroblast culture, however, showed a normal karyotype in 44 out of 50 cells and trisomy 18 in 6 cells. It is well known that serious chromosome abnormalities may occasionally be detected in skin fibroblasts but not in blood lymphocytes. The situation we report, in which only the abnormal cell line of a mosaic is seen in peripheral blood, is likely to be less common, but chromosome analysis of skin fibroblasts should be considered in any baby with trisomy 18 who is showing an
unusually benign course. Clinical Genetics, Princess Anne Hospital, Southampton SO9 4HA, UK
N. R. DENNIS
Wessex Regional Genetics Laboratory, Odstock Hospital, Salisbury
ANNETTE COCKWELL
Aluminium and dementia SIR,-Your March 21 editorial is a concise outline of the suggested link between environmental aluminium exposure and the development of dementia. Extension of the results of the studies you cite to their implementation as part of public health policy is premature because of methodological limitations. Basic facts about the epidemiology of presenile Alzheimer’s disease and environmental exposure to aluminium over long periods are not known. Indeed, neither geographical nor temporal variation of incidence of any subtype of dementia has been reliably demonstrated, even for categories (eg, alcoholic dementia) in which the environmental factor is beyond dispute. We suggest that environmental studies are potentially flawed by bias introduced when results for populations in small geographical areas are extrapolated to national populations without consideration of the effects of population migration, temporal and geographical variation in risk exposure, validity of diagnostic criteria, or dynamic changes in health-care provision. It is the absence of high-quality population-based data that most seriously impedes progress in the investigation of Alzheimer’s presenile dementia. In the UK, distinct geographical areas cannot be identified in which all cases of Alzheimer’s presenile dementia have been reliably ascertained and in which exposure to putative environmental toxins has been continuously recorded during the proposed lag period for the disease. On the basis of our experience in Scotland, we have found inconsistencies in the diagnosis of presenile Alzheimer’s disease. As part of a national epidemiological survey of all types of presenile demential we examined 5856 hospital records of patients with dementia: 1851 patients had presenile dementia and 468 of these had probable presenile Alzheimer’s disease. Only 65% of patients with probable Alzheimer’s disease had this diagnosis stated in their hospital record,2 which casts doubt 3 on the validity of diagnosis based on computer tomographic data. water is a lack of information about the of There quality public supply that can be used to assess exposure to environmental toxins within small geographical regions. Information on current concentrations of toxins in tap water is unsatisfactory since temporal changes over a prolonged lag period have probably taken place (eg, the effects of acid rain increasing aluminium leaching4). In addition, the effects of population migration within this period for Alzheimer’s disease cannot be ignored. We examined the residential stability of a random sample of 100 of the 468 people with Alzheimer’s disease by reference to electoral registers. 40 people had been at the same address at 13 years, 52 at 8 years, and 69 at 3 years (cumulative figures) before presentation to the health services.
Obstetric anaesthetists do not regard epidural analgesia as merely optional form of pain relief in normal labour, but rather as an important part of our management of sick mothers and babies. Moreover, to deny a woman epidural analgesia on a random basis is to expose her unnecessarily to the greater risk of general anaesthesia, should operative delivery become necessary." Perhaps the only remaining opportunity would be to fmd a centre that has no epidural service, and move in to provide one on a fully randomised basis to such mothers as would consent to take part. We would be delighted to publish the results of such a trial, irrespective of outcome. an
Department of Anaesthetics, St Thomas’s Hospital, London SE1 7EH, UK
FELICITY REYNOLDS
Medical Centre, Winston-Salem, North Carolina, USA
DAVID DEWAN
Queen Charlotte’s London
BARBARA MORGAN
Wake Forest
University
Hospital,
1. Howell CJ, Chalmers I. A review
of prospectively controlled companson of epidural with non-epidural forms of pain relief during labour. Int J Obstet Anesth 1992; 1: 93-110. 2. Reynolds F. Epidural analgesia in obstetncs: pros and cons for mother and baby. Br Med J 1989; 299: 751-52. 3. Robinson JO, Rosen M, Evans JN, Revill SI, David H, Rees GAD. Maternal opinion about analgesia for labour: a controlled trial between epidural block and intramuscular pethidine combined with inhalation. Anaesthesia 1980; 35: 1173-81. 4. Report on Confidential Enquiries into Maternal Deaths in England and Wales 1982-84. Department of Health. London: HM Stationery Office, 1989.
Surgical careers and female students SIR,-Whilst I agree with Miss Clarke (April 18, p 994) that the number of female surgeons in the UK is pitifully low, I think that her argument that this is because of discriminatory discouragement from seniors is not sustainable. I am sure that if Miss Clarke had distributed an identical questionnaire to male medical students, similar responses would have been obtained to those reported in her letter. My advice to all medical students and recently qualified doctors who ask about a career in surgery is identical, irrespective of gender: consider all other options first and, if surgery still seems the most apealing option, enter the career fully aware of the difficulties. These difficulties include numerous examinations (FRCS part 1, FRCS part 2, and intercollegiate assessment), the necessity to obtain a higher surgical degree, placement of the rate limiting step at the end of training, and a nomadic existence until about 40. Until surgical training is improved in quality and reduced in duration, it would be dishonest to alter such advice. Perhaps the real reason that there are so few female surgeons in the UK is that women have more sense than men in appreciating the hazards of a career in surgery. Association of Surgeons 10 Warneford Road, Oxford OX4 1LU, UK
in
Training,
R. A. COBB
Clinical management of trisomy 18 SIR,-We agree with the points Dr Bos and colleagues (April 11, p 913) and your accompanying editorial make about the avoidance of emergency surgery in babies with trisomy 18. We should like to make two further comments and add a cautionary tale. First, Bos et al underemphasise the clinical diagnosis of trisomy 18, although we applaud their policy of asking a surgical geneticist to see every newborn baby referred to paediatric surgery with a malformation. There should be few surprise diagnoses of trisomy 18 on karyotyping. Unexplained intrauterine growth retardation is an important alerting sign, and a high frequency of fingertip arch patterns (the finding of six or more is rare in the general population and usual in trisomy 18) is corroborative. Second, we have been impressed by the importance to parents of taking their baby home when a very limited prognosis has been given. In a few cases of trisomy 18 and trisomy 13 in which this has been possible it seems to have helped greatly in the parents’ subsequent acceptance of their loss. Finally, the cautionary tale. A female infant weighing 2-28 kg after 42 weeks’ gestation had an occipital encephalocoele, a perimembranous ventricular septal defect without serious
haemodynamic consequences, and a bicuspid aortic valve. A diagnosis of trisomy 18 was suggested by her facial features, hands, and feet, although the signs were rather subtle. Routine blood lymphocyte karyotyping at age 2 weeks showed non-disjunctional trisomy 18 in all 30 cells examined. The parents were given the devastating prognosis that Bos et al and your editorial outline; however, over the next 6 months her weight and head circumference increased parallel to but below the third centile and she made developmental progress. At 8 months she had reached a 5-6 month level of development. At 2-5 years she is walking, feeding herself, using 2 or 3 words with meaning and responding to simple commands. The peripheral blood karyotype was repeated when the baby was 6 months old and again showed trisomy 18 in all 50 cells examined. A skin fibroblast culture, however, showed a normal karyotype in 44 out of 50 cells and trisomy 18 in 6 cells. It is well known that serious chromosome abnormalities may occasionally be detected in skin fibroblasts but not in blood lymphocytes. The situation we report, in which only the abnormal cell line of a mosaic is seen in peripheral blood, is likely to be less common, but chromosome analysis of skin fibroblasts should be considered in any baby with trisomy 18 who is showing an
unusually benign course. Clinical Genetics, Princess Anne Hospital, Southampton SO9 4HA, UK
N. R. DENNIS
Wessex Regional Genetics Laboratory, Odstock Hospital, Salisbury
ANNETTE COCKWELL
Aluminium and dementia SIR,-Your March 21 editorial is a concise outline of the suggested link between environmental aluminium exposure and the development of dementia. Extension of the results of the studies you cite to their implementation as part of public health policy is premature because of methodological limitations. Basic facts about the epidemiology of presenile Alzheimer’s disease and environmental exposure to aluminium over long periods are not known. Indeed, neither geographical nor temporal variation of incidence of any subtype of dementia has been reliably demonstrated, even for categories (eg, alcoholic dementia) in which the environmental factor is beyond dispute. We suggest that environmental studies are potentially flawed by bias introduced when results for populations in small geographical areas are extrapolated to national populations without consideration of the effects of population migration, temporal and geographical variation in risk exposure, validity of diagnostic criteria, or dynamic changes in health-care provision. It is the absence of high-quality population-based data that most seriously impedes progress in the investigation of Alzheimer’s presenile dementia. In the UK, distinct geographical areas cannot be identified in which all cases of Alzheimer’s presenile dementia have been reliably ascertained and in which exposure to putative environmental toxins has been continuously recorded during the proposed lag period for the disease. On the basis of our experience in Scotland, we have found inconsistencies in the diagnosis of presenile Alzheimer’s disease. As part of a national epidemiological survey of all types of presenile demential we examined 5856 hospital records of patients with dementia: 1851 patients had presenile dementia and 468 of these had probable presenile Alzheimer’s disease. Only 65% of patients with probable Alzheimer’s disease had this diagnosis stated in their hospital record,2 which casts doubt 3 on the validity of diagnosis based on computer tomographic data. water is a lack of information about the of There quality public supply that can be used to assess exposure to environmental toxins within small geographical regions. Information on current concentrations of toxins in tap water is unsatisfactory since temporal changes over a prolonged lag period have probably taken place (eg, the effects of acid rain increasing aluminium leaching4). In addition, the effects of population migration within this period for Alzheimer’s disease cannot be ignored. We examined the residential stability of a random sample of 100 of the 468 people with Alzheimer’s disease by reference to electoral registers. 40 people had been at the same address at 13 years, 52 at 8 years, and 69 at 3 years (cumulative figures) before presentation to the health services.
