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CONTINUOUS CAUDAL ANALGESIA
19
Annotations CONTINUOUS CAUDAL ANALGESIA Dr. Robert A. Hingson, of the Johns Hopkins Hospital, Baltimore, has established a reputation on this side of the Atlantic through his published work on obstetric analgesia in general and continuous caudal analgesia in particular. On June 16, at Oxford, he delivered his first lecture in Europe. He spoke on continuous caudal analgesia in obstetrics, and the audience who came to hear an expert lecture on his own subject were amply rewarded. He has records of 600,000 labours managed in this way, and has himself used the technique more than 12,000 times. In the U.S.A., where analgesia and amnesia by narcosis have been pursued with greater enthusiasm than in this country, the value of his method is probably higher than it would be here ; for the high forceps-rate associated with it fits in with the American management of labour, which expects a forceps-rate of 70-80%, Such a rate would be an embarrassment to the maternity services in this country, and this is doubtless one of the reasons why we have not adopted caudal analgesia more widely. It is therefore all the more important to know of experiences such as that of one obstetrician, quoted by Hingson, who lowered his foetal-mortality rate in breech labour from 6-9% to 1-2% when he changed to continuous caudal analgesia. The foetal-mortality rate of 1-2% was from a series of 186
cases.
The possibilities of using caudal block for purposes other than relief of pain have not been fully appreciated. The anaesthetist is nowadays called on with increasing frequency to put in a nerve block as a diagnostic test or as a therapeutic measure. The relatively short duration of the effect of local anaesthetic drugs sometimes cramps his style, and an indwelling catheter which allows a nerve block to be maintained for the " hour, day, or week " may be very useful. The plastic catheter used in this way is remarkably inert in the tissues : a fragment of the plastic material was put in the anterior chamber of a rabbit’s eye and remained there a year without evoking any reaction. Hingson told of his experience with continuous caudal block for eclampsia. The block lowers the blood-pressure, which is then regulated to that level found most suitable for each individual patient. Convulsions cease when the bloodpressure is controlled, though the albuminuria may not subside until after delivery. In 76 cases of eclampsia he lost 3 mothers ; 2 had intraventricular haemorrhages, the other very severe hepatic and renal changes. The fcetal-death rate was 12%, which is worthy of note. In severe pre-eclamptic toxaemia he has controlled the blood-pressure for a matter of weeks when it was thought desirable that the pregnancy should continue for the sake of the baby. He has found a maintained block useful in oliguria ; the increased blood-supply to the kidney is followed by increase in urinary output. He has also used continuous caudal block for increasing the blood-supply to the legs in cases of chronic ulcers of vascular origin, with excellent effect on healing. Further he has used it for assessing the value of sympathectomy in hypertensive states. Dr. Hingson is lecturing in Cambridge, London, Leeds, Newcastle, and Edinburgh, besides speaking at the B.M.A. meeting at Harrogate, before going home via Geneva, Paris, and Stockholm. His visits will stimulate interest in continuous caudal analgesia in this country, and perhaps it will now be more widely employed. Careful study of the effect of nerve block can illuminate some aspects of physiological function, and it may well shed light on such problems as the nervous pathways to the uterus and the processes concerned in conditions such as pre-eclamptic -toxaemia and anuria. ’
SIZE AND FITNESS OF 1939 RECRUITS WHEN the first batch of military trainees were called up in 1939 a vast pile of medical records accumulated, and though much of this was unusable as biological material some was of great interest. Now, ten years afterwards, Dr. W. J. Martin, of the Medical Research Council’s statistical research unit, has published a concise, simple, and illuminating analysis of the height, weight, chest circumference, medical grade, and visual acuity of some 90,000 of these young men.! This group represents about a third of all those registered for call-up, since at the outbreak of war only this proportion had been examined, and conditions rapidly changed. Though it is not a perfect random sample of the male population aged 20-21 years, because a few occupational groups were omitted or deferred, it is as near as we are ever likely to get. Growth in stature is nowadays practically complete by this age, and the average height for all Great Britain in this group was 67-5 in. or 5 ft. 71/2 in. The average weight (unclothed) was 135-7 Ib. or 9 st. 91/2 lb. Comparison with the previous generation is made very difficult by the lack of just such standardised extensive data as this represents. The 18-year-old conscripts of 1918 were 2 in. shorter, but mature height was achieved later then, and this may accountfor some of the difference. It is, at least, certain that in physical fitness, as judged by medical boards, the 1939 recruits were superior to those of 1918 ; out of four possible grades, 81% of the 1939 group were placed in the best. There are several other clear-cut results concerning physique. A remarkable one is that migrants-defined as all those, examined at age 20 in a different region from where they were born-were 03 in. taller and 2 lb. heavier than the stay-at-homes. This was an extremely consistent finding, seen in every region of It seems improbable -that environment the country. could account for it, though, it is difficult to be sure, since we do not know what happened to those who migrated before -school-leaving. age, and those, selfselected for boldness, who left later. An analysis of the London data into four environmental groups by boroughs (Hampstead v. Bermondsey, for example) shows a not absolutely regular and not very large size difference. The men from the poorest boroughs were less than 1/2 in. shorter and only 1 lb. lighter than those from the richest. Social-occupation classes show a much greater difference ; Martin quotes data giving a difference in height of at least 2 in. between professional men and labourers. It might seem that heredity had more to do with these latter differences than environment, but on this topic Martin merely says that it remains controversial and indeed emotionally coloured." Countrymen are in all regions slightly larger than townsmen, and slightly fitter medically and visually. But the differences between one part of the country and another were surprisingly small. The men from the English southern counties were slightly larger than those from the northern counties (the maximum regional difference was 1 in. and 7 lb.), and the English as a whole were 1/2 in. taller than the Welsh or Scots (Highlanders were larger, but relatively few), though only 1 lb. heavier. The Englishman of 20-21 must be somewhat slenderer than the Welsh or the Scot, and here a whole tantalisingly untouched field for inquiry appears. Could not this excellent though limited analysis be extended in the future to cover differences of shape as well as size ?Medical examinations of recruits continuep a random sample of each year’s intake is not beyond. the wit of statistician and administrator to secure; and the newer photographic techniques of anthropometry make the time needed per recruit a matter of two or three minutes only. Dr. Martin has shown the value of ,
"
1. The Physique of Memo. no. 20.
Young Adult Males. Medical Research Council H.M. Stationery Office. 1s. 3d. 1949.
Annotations CONTINUOUS CAUDAL ANALGESIA Dr. Robert A. Hingson, of the Johns Hopkins Hospital, Baltimore, has established a reputation on this side of the Atlantic through his published work on obstetric analgesia in general and continuous caudal analgesia in particular. On June 16, at Oxford, he delivered his first lecture in Europe. He spoke on continuous caudal analgesia in obstetrics, and the audience who came to hear an expert lecture on his own subject were amply rewarded. He has records of 600,000 labours managed in this way, and has himself used the technique more than 12,000 times. In the U.S.A., where analgesia and amnesia by narcosis have been pursued with greater enthusiasm than in this country, the value of his method is probably higher than it would be here ; for the high forceps-rate associated with it fits in with the American management of labour, which expects a forceps-rate of 70-80%, Such a rate would be an embarrassment to the maternity services in this country, and this is doubtless one of the reasons why we have not adopted caudal analgesia more widely. It is therefore all the more important to know of experiences such as that of one obstetrician, quoted by Hingson, who lowered his foetal-mortality rate in breech labour from 6-9% to 1-2% when he changed to continuous caudal analgesia. The foetal-mortality rate of 1-2% was from a series of 186
cases.
The possibilities of using caudal block for purposes other than relief of pain have not been fully appreciated. The anaesthetist is nowadays called on with increasing frequency to put in a nerve block as a diagnostic test or as a therapeutic measure. The relatively short duration of the effect of local anaesthetic drugs sometimes cramps his style, and an indwelling catheter which allows a nerve block to be maintained for the " hour, day, or week " may be very useful. The plastic catheter used in this way is remarkably inert in the tissues : a fragment of the plastic material was put in the anterior chamber of a rabbit’s eye and remained there a year without evoking any reaction. Hingson told of his experience with continuous caudal block for eclampsia. The block lowers the blood-pressure, which is then regulated to that level found most suitable for each individual patient. Convulsions cease when the bloodpressure is controlled, though the albuminuria may not subside until after delivery. In 76 cases of eclampsia he lost 3 mothers ; 2 had intraventricular haemorrhages, the other very severe hepatic and renal changes. The fcetal-death rate was 12%, which is worthy of note. In severe pre-eclamptic toxaemia he has controlled the blood-pressure for a matter of weeks when it was thought desirable that the pregnancy should continue for the sake of the baby. He has found a maintained block useful in oliguria ; the increased blood-supply to the kidney is followed by increase in urinary output. He has also used continuous caudal block for increasing the blood-supply to the legs in cases of chronic ulcers of vascular origin, with excellent effect on healing. Further he has used it for assessing the value of sympathectomy in hypertensive states. Dr. Hingson is lecturing in Cambridge, London, Leeds, Newcastle, and Edinburgh, besides speaking at the B.M.A. meeting at Harrogate, before going home via Geneva, Paris, and Stockholm. His visits will stimulate interest in continuous caudal analgesia in this country, and perhaps it will now be more widely employed. Careful study of the effect of nerve block can illuminate some aspects of physiological function, and it may well shed light on such problems as the nervous pathways to the uterus and the processes concerned in conditions such as pre-eclamptic -toxaemia and anuria. ’
SIZE AND FITNESS OF 1939 RECRUITS WHEN the first batch of military trainees were called up in 1939 a vast pile of medical records accumulated, and though much of this was unusable as biological material some was of great interest. Now, ten years afterwards, Dr. W. J. Martin, of the Medical Research Council’s statistical research unit, has published a concise, simple, and illuminating analysis of the height, weight, chest circumference, medical grade, and visual acuity of some 90,000 of these young men.! This group represents about a third of all those registered for call-up, since at the outbreak of war only this proportion had been examined, and conditions rapidly changed. Though it is not a perfect random sample of the male population aged 20-21 years, because a few occupational groups were omitted or deferred, it is as near as we are ever likely to get. Growth in stature is nowadays practically complete by this age, and the average height for all Great Britain in this group was 67-5 in. or 5 ft. 71/2 in. The average weight (unclothed) was 135-7 Ib. or 9 st. 91/2 lb. Comparison with the previous generation is made very difficult by the lack of just such standardised extensive data as this represents. The 18-year-old conscripts of 1918 were 2 in. shorter, but mature height was achieved later then, and this may accountfor some of the difference. It is, at least, certain that in physical fitness, as judged by medical boards, the 1939 recruits were superior to those of 1918 ; out of four possible grades, 81% of the 1939 group were placed in the best. There are several other clear-cut results concerning physique. A remarkable one is that migrants-defined as all those, examined at age 20 in a different region from where they were born-were 03 in. taller and 2 lb. heavier than the stay-at-homes. This was an extremely consistent finding, seen in every region of It seems improbable -that environment the country. could account for it, though, it is difficult to be sure, since we do not know what happened to those who migrated before -school-leaving. age, and those, selfselected for boldness, who left later. An analysis of the London data into four environmental groups by boroughs (Hampstead v. Bermondsey, for example) shows a not absolutely regular and not very large size difference. The men from the poorest boroughs were less than 1/2 in. shorter and only 1 lb. lighter than those from the richest. Social-occupation classes show a much greater difference ; Martin quotes data giving a difference in height of at least 2 in. between professional men and labourers. It might seem that heredity had more to do with these latter differences than environment, but on this topic Martin merely says that it remains controversial and indeed emotionally coloured." Countrymen are in all regions slightly larger than townsmen, and slightly fitter medically and visually. But the differences between one part of the country and another were surprisingly small. The men from the English southern counties were slightly larger than those from the northern counties (the maximum regional difference was 1 in. and 7 lb.), and the English as a whole were 1/2 in. taller than the Welsh or Scots (Highlanders were larger, but relatively few), though only 1 lb. heavier. The Englishman of 20-21 must be somewhat slenderer than the Welsh or the Scot, and here a whole tantalisingly untouched field for inquiry appears. Could not this excellent though limited analysis be extended in the future to cover differences of shape as well as size ?Medical examinations of recruits continuep a random sample of each year’s intake is not beyond. the wit of statistician and administrator to secure; and the newer photographic techniques of anthropometry make the time needed per recruit a matter of two or three minutes only. Dr. Martin has shown the value of ,
"
1. The Physique of Memo. no. 20.
Young Adult Males. Medical Research Council H.M. Stationery Office. 1s. 3d. 1949.