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UNSAFE ANÆSTHETIC SUPPLY SYSTEMS
560 of this man’s abnormal biochemistry and confusion chronic inadequate intake of both sodium and food. In contrast to their series, this patient showed signs of severe extracellular volume depletion, in that he had
cause
was a
severe
postural hypotension.
City Hospital, Hucknall Road, Nottingham NG5 1PB.
D. C. BANKS B. R. F. LECKY.
UNSAFE ANÆSTHETIC SUPPLY SYSTEMS
SIR,-No person concerned with the supply of anxsthetic gases can remain complacent under the present arrangeThe essential problem is the failure to adopt a system of supply which is inherently " failsafe ", and notably the use of identical pipes to supply different gases. All systems of flexible supply-pipes are potentially fallible so long as oxygen and nitrous oxide are fed through identical pipes. The only safe answer is to supply anxsthetic gases through pipes of differing size and colour, which cannot be physically interchanged. This system is used in Sweden. My commendation of it to the Health Department was met by the comment that only antistatic piping can be used in theatres, and coloured piping is not necessarily antistatic. I would suggest that, since the antistatic requirement presumably applies to the possibility of a static charge being transmitted from the anaesthetic machine to earth, it would be satisfactory for one pipe to be black antistatic rubber and another pipe to be plastic of an entirely different colour, as in the Swedish system.
ticular disease. Bran appears to modify fsecal flow patterns by acting as a vehicle for molecular or gel water in normal people3 and as a vehicle for interstitial water in diverticular disease.4 This source of fibre enhanced colonic filling and reduced the intraluminal pressure to various stimuli in the distal colon in patients with diverticular disease. The reduction in pressure is more evident with coarse bran.s Therefore we agree with your editorial (July 5, p. 18) that a bulkier stool may be a more readily passed stool. Wolfson Gastrointestinal Laboratories, Western General Hospital, Edinburgh EH4 2XU.
ments.
Lewisham Hospital, London SE13 6LH.
MARTIN EASTWOOD W. D. MITCHELL A. N. SMITH.
STOOL WEIGHTS IN NORTH INDIANS
SIR,-Several articles and letters in your journal have shown an interest in stool weights in different communities. Small stool weights and prolonged transit-times in the Europeans and Americans seem to be related to the low fibre content of their diets and are being considered as a cause of several diseases of the Western world, such as appendicitis, ischaemic heart-disease, diverticular disease of the colon, carcinoma of the colon, &c. 6,7 Since many of these diseases are relatively uncommon in India and the food eaten here much less refined, we studied the stool weights of healthy Indians in the human-nutrition unit of our hospital. 24-hour stool weights of 550 individuals STOOL WEIGHTS IN NORMAL NORTH INDIANS
(g.
PER
24
HOURS)
J. M. CUNDY.
STRAINING, SITTING, AND SQUATTING AT STOOL
SIR,--Dr Trowell (Sept. 6, p. 456) says that little is known of the bulk-forming properties of different forms of dietary bulk. This is not the case. It has been shown by Williams and Olmstedt1 that in normal individuals, when there is an increased dietary intake of cellulose, hemicellulose, or lignin, there is a variable effect on stool weight. They also produce a table of ability of various plant sources to’increase stool weight; cotton-seed wholes have the least effect, then in increasing efficacy cellulose, alfalfa, leaf meal, wheat, bran, canned peas, corn-germ meal, sugar-beet pulp, cabbage, carrots, and finally agaragar. There is a twenty-fold difference in capacity to bind water between cotton-seed wholes and agar-agar. In considering dietary sources of fibre the amount of fibre taken with a vegetable will vary. Turnip and celery contain 4% dry material whereas bran contains 85% dry material. Fibre obtained from wheat bran holds five times its own weight of water, yet fibre from carrot and turnip will hold between 27 and 30 times its own weight in water. Thus, if an allowance is made for the fibre content of the original raw plant and the water-holding capacity of the dried material, 100 g of bran, despite its very modest water-holding capacity, will have a superior overall hydrophilic property (450 g water per fibre in 100 g raw material), mango 320 g water per 100 g raw material, carrot 220 g water; apple (180 g water) and brussel sprout have potent that can be utilised in increasing hydrophilic properties stool weight.2 Our studies with unprocessed bran showed increased stool weight in normal subjects and patients with diver1. 2.
Williams, R. D., Olmstedt, W. H. J. Nutr. 1936, 11, 433. McConnell, A. A., Eastwood, M. A., Mitchell, W. D. J. Sci. Fd Agric. 1974, 25, 1457.
measured by averaging 3 days’ stool collection, starting at least 3 days after being on the hospital diet, which was very similar to their usual diet. The hospital diet contained 10-12 g. of crude fibre, 40 g. of fat, 360 g. of carbohydrates, and 60 g. of protein per day, totalling an energy intake of about 2000 Cal. per day. The mean and range of stool weights of these subjects are shown in the table. Only 168 subjects had stool weights of 200 g. or less, which is the upper limit in most Western communities.* The rest had much higher stool weights, 41 of them 700 g. or more. Teenage boarding-school pupils in the U.K. passed on average 110 g. of stool per day, and English adults on a typical European diet passed 104 g. per day.’ It is of interest to note that the dietary fibre intake of our subjects was 10-12 g. per day, compared with 5 g. per day in the Western diet.9 The stool weights in our subjects are, on the other hand, comparable to those of 275 g. in rural schoolchildren and 470 g. in adult villagers in Africa.’ The crude-fibre intake in these rural Africans averages as high as 248 g. per day.10 Between these two extremes of stool weights-i.e., in ’those on Westernised diet and those on full fibre diet as in Africa and India-there are several communities occupying intermediate positions.7 The general pattern of stool were
Findlay, J. M., Smith, A. N., Mitchell, W. D., Anderson, A. J. B., Eastwood, M. A. Lancet, 1974, i, 146. 4. Findlay, J. M., Mitchell, W. D., Eastwood, M. A., Anderson, A. J. B. Smith, A. N. Gut, 1974, 15, 207. 5. Kirwan, W. O., Smith, A. N., McConnell, A. A., Mitchell, W. D., Eastwood, M. A. Br. med. J. 1974, ii, 187. 6. Painter, N. S. Proc. R. Soc. Med. 1970, 63, suppl. p. 144. 7. Burkitt, D. P., Walker, A. R. P., Painter, N. S. Lancet, 1972, ii, 1408. 8. Steigman, F. Am. J. dig. Dis. 1942, 19, 423. 9. Antar, M. A., Ohlson, M. A., Hodges, R. E. Am. J. clin. Nutr. 1964, 14, 169. 10. Lubbe, A. M. S. Afr. med. J. 1971, 45, 1289. 3.
cause
was a
severe
postural hypotension.
City Hospital, Hucknall Road, Nottingham NG5 1PB.
D. C. BANKS B. R. F. LECKY.
UNSAFE ANÆSTHETIC SUPPLY SYSTEMS
SIR,-No person concerned with the supply of anxsthetic gases can remain complacent under the present arrangeThe essential problem is the failure to adopt a system of supply which is inherently " failsafe ", and notably the use of identical pipes to supply different gases. All systems of flexible supply-pipes are potentially fallible so long as oxygen and nitrous oxide are fed through identical pipes. The only safe answer is to supply anxsthetic gases through pipes of differing size and colour, which cannot be physically interchanged. This system is used in Sweden. My commendation of it to the Health Department was met by the comment that only antistatic piping can be used in theatres, and coloured piping is not necessarily antistatic. I would suggest that, since the antistatic requirement presumably applies to the possibility of a static charge being transmitted from the anaesthetic machine to earth, it would be satisfactory for one pipe to be black antistatic rubber and another pipe to be plastic of an entirely different colour, as in the Swedish system.
ticular disease. Bran appears to modify fsecal flow patterns by acting as a vehicle for molecular or gel water in normal people3 and as a vehicle for interstitial water in diverticular disease.4 This source of fibre enhanced colonic filling and reduced the intraluminal pressure to various stimuli in the distal colon in patients with diverticular disease. The reduction in pressure is more evident with coarse bran.s Therefore we agree with your editorial (July 5, p. 18) that a bulkier stool may be a more readily passed stool. Wolfson Gastrointestinal Laboratories, Western General Hospital, Edinburgh EH4 2XU.
ments.
Lewisham Hospital, London SE13 6LH.
MARTIN EASTWOOD W. D. MITCHELL A. N. SMITH.
STOOL WEIGHTS IN NORTH INDIANS
SIR,-Several articles and letters in your journal have shown an interest in stool weights in different communities. Small stool weights and prolonged transit-times in the Europeans and Americans seem to be related to the low fibre content of their diets and are being considered as a cause of several diseases of the Western world, such as appendicitis, ischaemic heart-disease, diverticular disease of the colon, carcinoma of the colon, &c. 6,7 Since many of these diseases are relatively uncommon in India and the food eaten here much less refined, we studied the stool weights of healthy Indians in the human-nutrition unit of our hospital. 24-hour stool weights of 550 individuals STOOL WEIGHTS IN NORMAL NORTH INDIANS
(g.
PER
24
HOURS)
J. M. CUNDY.
STRAINING, SITTING, AND SQUATTING AT STOOL
SIR,--Dr Trowell (Sept. 6, p. 456) says that little is known of the bulk-forming properties of different forms of dietary bulk. This is not the case. It has been shown by Williams and Olmstedt1 that in normal individuals, when there is an increased dietary intake of cellulose, hemicellulose, or lignin, there is a variable effect on stool weight. They also produce a table of ability of various plant sources to’increase stool weight; cotton-seed wholes have the least effect, then in increasing efficacy cellulose, alfalfa, leaf meal, wheat, bran, canned peas, corn-germ meal, sugar-beet pulp, cabbage, carrots, and finally agaragar. There is a twenty-fold difference in capacity to bind water between cotton-seed wholes and agar-agar. In considering dietary sources of fibre the amount of fibre taken with a vegetable will vary. Turnip and celery contain 4% dry material whereas bran contains 85% dry material. Fibre obtained from wheat bran holds five times its own weight of water, yet fibre from carrot and turnip will hold between 27 and 30 times its own weight in water. Thus, if an allowance is made for the fibre content of the original raw plant and the water-holding capacity of the dried material, 100 g of bran, despite its very modest water-holding capacity, will have a superior overall hydrophilic property (450 g water per fibre in 100 g raw material), mango 320 g water per 100 g raw material, carrot 220 g water; apple (180 g water) and brussel sprout have potent that can be utilised in increasing hydrophilic properties stool weight.2 Our studies with unprocessed bran showed increased stool weight in normal subjects and patients with diver1. 2.
Williams, R. D., Olmstedt, W. H. J. Nutr. 1936, 11, 433. McConnell, A. A., Eastwood, M. A., Mitchell, W. D. J. Sci. Fd Agric. 1974, 25, 1457.
measured by averaging 3 days’ stool collection, starting at least 3 days after being on the hospital diet, which was very similar to their usual diet. The hospital diet contained 10-12 g. of crude fibre, 40 g. of fat, 360 g. of carbohydrates, and 60 g. of protein per day, totalling an energy intake of about 2000 Cal. per day. The mean and range of stool weights of these subjects are shown in the table. Only 168 subjects had stool weights of 200 g. or less, which is the upper limit in most Western communities.* The rest had much higher stool weights, 41 of them 700 g. or more. Teenage boarding-school pupils in the U.K. passed on average 110 g. of stool per day, and English adults on a typical European diet passed 104 g. per day.’ It is of interest to note that the dietary fibre intake of our subjects was 10-12 g. per day, compared with 5 g. per day in the Western diet.9 The stool weights in our subjects are, on the other hand, comparable to those of 275 g. in rural schoolchildren and 470 g. in adult villagers in Africa.’ The crude-fibre intake in these rural Africans averages as high as 248 g. per day.10 Between these two extremes of stool weights-i.e., in ’those on Westernised diet and those on full fibre diet as in Africa and India-there are several communities occupying intermediate positions.7 The general pattern of stool were
Findlay, J. M., Smith, A. N., Mitchell, W. D., Anderson, A. J. B., Eastwood, M. A. Lancet, 1974, i, 146. 4. Findlay, J. M., Mitchell, W. D., Eastwood, M. A., Anderson, A. J. B. Smith, A. N. Gut, 1974, 15, 207. 5. Kirwan, W. O., Smith, A. N., McConnell, A. A., Mitchell, W. D., Eastwood, M. A. Br. med. J. 1974, ii, 187. 6. Painter, N. S. Proc. R. Soc. Med. 1970, 63, suppl. p. 144. 7. Burkitt, D. P., Walker, A. R. P., Painter, N. S. Lancet, 1972, ii, 1408. 8. Steigman, F. Am. J. dig. Dis. 1942, 19, 423. 9. Antar, M. A., Ohlson, M. A., Hodges, R. E. Am. J. clin. Nutr. 1964, 14, 169. 10. Lubbe, A. M. S. Afr. med. J. 1971, 45, 1289. 3.