- Email: [email protected]
PARALYSIS OR SEDATION FOR CONTROLLED VENTILATION?
715 colitis following bowel disease in cases of pseudomembranous I ing trivial exposure to antibacterial drugs.
Addenbrooke’s Hospital, Cambridge CB2 2QQ
ANITA RAMPLING W. G. EVERETT O. A. SILLS
second dimension? We would like to answer this whatever the outcome of the haemophilia carrier data. Section of Hematology Research, Mayo Clinic and Mayo Foundation,
Rochester, Minnesota 55901, U.S.A.
question
E. J. W. BOWIE D. N. FASS
CÆSAREAN SECTION FACTOR VIII ANTIGEN PRE-PEAK
SIR,-Like Bowie and Fass2 we have noted
a
in
pre-peak
many of our crossed-immunoelectrophoretic runs. However, this pre-peak was not restricted to plasma samples from ha:mophiliacs or carriers. We found pre-peaks of variable proportion in about 50% of crosses-in samples of normal plasma, serum, and cryoprecipitate. Also, unlike Bowie and Fass, we found the pre-peak in plasma samples from two haemophiliacs with antibodies to factor VIII. The same sample would sometimes show a pre-peak and sometimes not. We were unable to associate the presence of the pre-peak with any disease state, method of sample preparation, or storage condition. In several runs where the well was emptied after the first dimension electrophoresis, the pre-peak was not observed. We feel that this pre-peak is due to an inconsistent technical factor and that caution should be exercised before attaching diagnostic significance to it. Department of Medicine, Monash Medical School, Alfred Hospital, Prahran, Victoria 3181, Australia
MARGARET A. HOWARD
JEAN PERKIN J. KOUTTS
SIR,-Dr Girolami and his colleagues (Feb. 2, p. 263) and now Dr Howard and her co-workers feel that the pre-peak of factor VIII antigen which we reported is an artifact. Of course, we also think it is an artifact; and we pointed out in our paper that we see it in other conditions. It is curious, however, that the artifact is present in a high percentage of haemophiliacs and carriers; we have seen it in only 2 out of 60 normal samples. We are grateful for the suggestions of Girolami et al. about eliminating the artifact, but at this moment we are interested in preserving it and investigating its potential usefulness. We hope to be able to explain the pre-peak-and as soon as we can define the conditions for its production, it will cease to be an artifact. Our findings may represent alterations in the molecule that have been reported by at least two other
SiR,-Your Feb. 23 editorial asking Should Childbirth be a Cutting Experience? implies criticism of the increase in the use ofcaesarean section for failing to reduce perinatal mortality. From another viewpoint the facts, as presented, highlight the deficiencies inherent in the use of perinatal mortality as an index of modern obstetric practice. The aim of the obstetrician is surely to produce a healthy mother and a baby whose quality of life is potentially normal. Mortality statistics are unable to reflect either of these features. It can be inferred that low mortality will be accompanied by low morbidity, but since in recent years the falling perinatal mortality rate has been increasingly bolstered by an apparently irreducible number of lethal congenital defects, a now static rate could well be concealing a continued fall in morbidity. A baby whose condition is poor at birth has only to stagger through a mere week of life before dying
or remaining severely handicapped not to appear perinatal statistic at all. Improvements in anaesthetic techniques, particularly the wider use of epidural anaesthesia for c2esarean section, mean that an immature, growth retarded infant can be handed to the neonatal pxdiatrician in prime condition, unaffected by the undoubted trauma that often accompanies a vaginal deliv-
as a
ery in such babies. You quote Alexander Pope as saying "First follow nature, and your judgement frame by her just standard". Charles Darwin negated that argument: surely, if you adopt Nature blindly you must accept her natural wastage. An easy means of gauging infant morbidity may be beyond our grasp but if we are to continue, in the meantime to use perinatal mortality, it would be far more revealing if the limits were extended considerably beyond the first week of life. To use perinatal mortality data to criticise the use ofcaesarean section is, I believe, invalid. Louise
footnote to figure). In contrast Howard et al. found the prepeak in approximately 50% of samples of normal plasma, serum, and cryoprecipitate. There is a discrepancy here, and one possibility is that we are all using different methods. There are many ways of doing crossed immunoelectrophoresis, and for this reason The Lancet asked us to give our technique in minute detail. Howard et al. advise caution, but we would emphasise that our article was a preliminary report and one which stated that the pre-peak is observed in other conditions and that it may be helpful. We are interested in the pre-peak because it presents a question that seems to have escaped your correspondents. Why is the antigenic material retained in the well but is, nevertheless, able to escape from the well when electrophoresed in the 1. Bartlett
JG. Antibiotic-associated colitis. Clins m Gastroenterol 1979; 8: 783. 2. Bowie EJW, Fass DN. Factor VIII-related antigen (VIII R:Ag) in hæmophiliac patients and in carriers. Lancet 1979; ii: 1049. 3. London FS, Shapiro SS. Distribution of factor VIII coagulant, antigen and ristocetin cofactor activity in normals and hemophiliacs. Fed Proc 1978; 37: 326 abstr. 611. 4. Tan HK, Andersen JC. Human factor VIII: Morphometric analysis of purified material in solution. Science 1977; 198: 932..
P. T. GARDNER
PARALYSIS OR SEDATION FOR CONTROLLED VENTILATION?
-
groups.3,4 In an earlier report it was found that the pre-peak occurred only in a minority of normal and abnormal plasma samples (Zimmerman et al., Proc Natl Acad Sci USA 1975; 72: 5121,
Margaret Maternity Hospital,
Aldershot GU11 2AP
SIR,-I was interested to read Dr Miller Jones’ letter (Feb. 9, p. 312) and Dr Gilston’s comment (March 1, p. 480). Miller Jones has brought an age-old problem out into the open. Howan agent such as pancuronium is solely muscle relaxant is surely open to question. Forbes and his colleagues’ have demonstrated that pancuronium, surprisingly, reduces halothane requirement in man to the same extent as does 70% nitrous oxide in oxygen. In their series, the minimum alveolar anxsthetic concentration for halothane was reduced from 0-7 to 0-5. The reason for this is not clear, but is suggested to lie in deafferentation by abolition of muscle spindle input to the reticular activating system. This view is suggested by I. Donald who maintains that the inability to struggle lessens the pain: "Struggling, groaning and protesting, which make pain worse, are prevented by curare". Thus should we not consider that muscle relaxants in the intensive care setting are useful adjuncts to other sedative therapy, rather than the ogre that Miller Jones implies them to be?
ever, the concept that a
Department of Anaesthesia and Intensive Care, King’s College Hospital, London SE5 9RS 1. Forbes
D. GREEN
AR, Cohen NH, Eger EI. Pancuronium reduces halothane requireAnesthesiology 1979; 51: suppl SI.
ment in man.
Addenbrooke’s Hospital, Cambridge CB2 2QQ
ANITA RAMPLING W. G. EVERETT O. A. SILLS
second dimension? We would like to answer this whatever the outcome of the haemophilia carrier data. Section of Hematology Research, Mayo Clinic and Mayo Foundation,
Rochester, Minnesota 55901, U.S.A.
question
E. J. W. BOWIE D. N. FASS
CÆSAREAN SECTION FACTOR VIII ANTIGEN PRE-PEAK
SIR,-Like Bowie and Fass2 we have noted
a
in
pre-peak
many of our crossed-immunoelectrophoretic runs. However, this pre-peak was not restricted to plasma samples from ha:mophiliacs or carriers. We found pre-peaks of variable proportion in about 50% of crosses-in samples of normal plasma, serum, and cryoprecipitate. Also, unlike Bowie and Fass, we found the pre-peak in plasma samples from two haemophiliacs with antibodies to factor VIII. The same sample would sometimes show a pre-peak and sometimes not. We were unable to associate the presence of the pre-peak with any disease state, method of sample preparation, or storage condition. In several runs where the well was emptied after the first dimension electrophoresis, the pre-peak was not observed. We feel that this pre-peak is due to an inconsistent technical factor and that caution should be exercised before attaching diagnostic significance to it. Department of Medicine, Monash Medical School, Alfred Hospital, Prahran, Victoria 3181, Australia
MARGARET A. HOWARD
JEAN PERKIN J. KOUTTS
SIR,-Dr Girolami and his colleagues (Feb. 2, p. 263) and now Dr Howard and her co-workers feel that the pre-peak of factor VIII antigen which we reported is an artifact. Of course, we also think it is an artifact; and we pointed out in our paper that we see it in other conditions. It is curious, however, that the artifact is present in a high percentage of haemophiliacs and carriers; we have seen it in only 2 out of 60 normal samples. We are grateful for the suggestions of Girolami et al. about eliminating the artifact, but at this moment we are interested in preserving it and investigating its potential usefulness. We hope to be able to explain the pre-peak-and as soon as we can define the conditions for its production, it will cease to be an artifact. Our findings may represent alterations in the molecule that have been reported by at least two other
SiR,-Your Feb. 23 editorial asking Should Childbirth be a Cutting Experience? implies criticism of the increase in the use ofcaesarean section for failing to reduce perinatal mortality. From another viewpoint the facts, as presented, highlight the deficiencies inherent in the use of perinatal mortality as an index of modern obstetric practice. The aim of the obstetrician is surely to produce a healthy mother and a baby whose quality of life is potentially normal. Mortality statistics are unable to reflect either of these features. It can be inferred that low mortality will be accompanied by low morbidity, but since in recent years the falling perinatal mortality rate has been increasingly bolstered by an apparently irreducible number of lethal congenital defects, a now static rate could well be concealing a continued fall in morbidity. A baby whose condition is poor at birth has only to stagger through a mere week of life before dying
or remaining severely handicapped not to appear perinatal statistic at all. Improvements in anaesthetic techniques, particularly the wider use of epidural anaesthesia for c2esarean section, mean that an immature, growth retarded infant can be handed to the neonatal pxdiatrician in prime condition, unaffected by the undoubted trauma that often accompanies a vaginal deliv-
as a
ery in such babies. You quote Alexander Pope as saying "First follow nature, and your judgement frame by her just standard". Charles Darwin negated that argument: surely, if you adopt Nature blindly you must accept her natural wastage. An easy means of gauging infant morbidity may be beyond our grasp but if we are to continue, in the meantime to use perinatal mortality, it would be far more revealing if the limits were extended considerably beyond the first week of life. To use perinatal mortality data to criticise the use ofcaesarean section is, I believe, invalid. Louise
footnote to figure). In contrast Howard et al. found the prepeak in approximately 50% of samples of normal plasma, serum, and cryoprecipitate. There is a discrepancy here, and one possibility is that we are all using different methods. There are many ways of doing crossed immunoelectrophoresis, and for this reason The Lancet asked us to give our technique in minute detail. Howard et al. advise caution, but we would emphasise that our article was a preliminary report and one which stated that the pre-peak is observed in other conditions and that it may be helpful. We are interested in the pre-peak because it presents a question that seems to have escaped your correspondents. Why is the antigenic material retained in the well but is, nevertheless, able to escape from the well when electrophoresed in the 1. Bartlett
JG. Antibiotic-associated colitis. Clins m Gastroenterol 1979; 8: 783. 2. Bowie EJW, Fass DN. Factor VIII-related antigen (VIII R:Ag) in hæmophiliac patients and in carriers. Lancet 1979; ii: 1049. 3. London FS, Shapiro SS. Distribution of factor VIII coagulant, antigen and ristocetin cofactor activity in normals and hemophiliacs. Fed Proc 1978; 37: 326 abstr. 611. 4. Tan HK, Andersen JC. Human factor VIII: Morphometric analysis of purified material in solution. Science 1977; 198: 932..
P. T. GARDNER
PARALYSIS OR SEDATION FOR CONTROLLED VENTILATION?
-
groups.3,4 In an earlier report it was found that the pre-peak occurred only in a minority of normal and abnormal plasma samples (Zimmerman et al., Proc Natl Acad Sci USA 1975; 72: 5121,
Margaret Maternity Hospital,
Aldershot GU11 2AP
SIR,-I was interested to read Dr Miller Jones’ letter (Feb. 9, p. 312) and Dr Gilston’s comment (March 1, p. 480). Miller Jones has brought an age-old problem out into the open. Howan agent such as pancuronium is solely muscle relaxant is surely open to question. Forbes and his colleagues’ have demonstrated that pancuronium, surprisingly, reduces halothane requirement in man to the same extent as does 70% nitrous oxide in oxygen. In their series, the minimum alveolar anxsthetic concentration for halothane was reduced from 0-7 to 0-5. The reason for this is not clear, but is suggested to lie in deafferentation by abolition of muscle spindle input to the reticular activating system. This view is suggested by I. Donald who maintains that the inability to struggle lessens the pain: "Struggling, groaning and protesting, which make pain worse, are prevented by curare". Thus should we not consider that muscle relaxants in the intensive care setting are useful adjuncts to other sedative therapy, rather than the ogre that Miller Jones implies them to be?
ever, the concept that a
Department of Anaesthesia and Intensive Care, King’s College Hospital, London SE5 9RS 1. Forbes
D. GREEN
AR, Cohen NH, Eger EI. Pancuronium reduces halothane requireAnesthesiology 1979; 51: suppl SI.
ment in man.