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LONG-TERM INTRAVENOUS FEEDING
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is conceived also on the motor side of the corticocortical arc, to allow of initiation of movements as well as individual muscular contractions. Yet another system that could lend itself to stimulatory influences is the regulation of muscular tone by cerebellar structures. COOPER 18 has reported the effects of stimulation via indwelling electrodes placed on the anterior lobe of the cerebellum and connected to a subcutaneous receiver. Stimulation at 200 c/s decreased ipsilateral hypertonic states, whereas a frequency of 10 c/s ameliorated convulsive disorders. Subsequently he applied the same technique to the posterior lobe, to relieve spasticity.19 The newer techniques employ inductance coils, so that the apparatus can be completely buried in the patient. Earlier methods could be controlled by radio but depended upon wires leading through the skin to a receiver strapped to the body. This allowed accurate measurement of the stimulus delivered, but inductance techniques are clearly preferable, and the estimated stimulus can be gauged sufficiently for practical purposes. The observations that have already been made with these techniques are interesting enough but are clearly only a beginning. If a young clinician wished to embark on a rewarding and neatly circumscribed research project he might well consider stimulating methods. Investigation in animals is straightforward but self-limited. Application to human beings must be slow to keep within strict ethical bounds, but the examples given are irreproachable, and do not begin to exhaust the possibilities. sort
LONG-TERM INTRAVENOUS FEEDING IT is now possible to feed people more or less indefinitely by the intravenous route.20 In addition to the basic requirements for fat, carbohydrate, and aminoacids, we know that patients on prolonged intravenous feeding need vitamins, minerals, and trace elements.al-24 The chief technical problems have been related to the method of administration and the attendant hazards of infection and thrombophlebitis. 25 These now seem to have been largely overcome by workers in Seattle and Montpelier. Broviac and Scribner2used an infusion pump with an indwelling ’ Silastic’ catheter inserted into the right atrium. Sixteen patients have fed themselves intravenously at home for periods up to 34 months. All these patients had severe bowel disease, six having the short-bowel syndrome. Most of them successfully maintained their weight and wellbeing; only 18. Cooper, I. S. Lancet, 1973, i, 206. 19. Cooper, I. S. ibid. p. 1321. 20. Lancet, 1973, ii, 1179. 21. Lee, H. A. Br. J. Hosp. Med. 1974, 11, 719. 22. Dudrick, S. J., Wilmore, D. W., Varis, H. M., Rhoads, J. E. Ann. Surg. 1969, 69, 974. 23. Scribner, B. H., Cole, J. J., Christopher, G., Vizzo, J. E., Atkins, R. C., Blagg, C. R. J. Am. med. Ass. 1970, 212, 457. 24. Jeejeebhoy, K. N., et al. Gastroenterology, 1973, 65, 811. 25. Savege, T. M. Resuscitation, 1973, 2, 83. 26. Broviac, J. W., Scribner, B. H. Surgery Gynec. Obstet. 1974, 139, 24.
died as a result of the technique-from septicaemia. Because glucose was the sole calorie source, the long daily infusion-time of 12 hours was necessary ; use of a fat emulsion such asIntralipid’ could have shortened the daily infusion-time to 8 hours (perhaps during sleep). A similar technique was employed by Solassol and his colleagues in Montpelier,27 who inserted a ’Teflon’-tipped siliconerubber catheter, under the anterior chest wall, into A portable a deep collateral of the subclavian vein. infusion apparatus was strapped to the body. It is hard to tell, from their article, why all their 75 patients Its needed this extremely expensive technique. application in total and prolonged bowel failure may be justified by analogy with dialysis in renal failure, but the Montpelier group seem to have used it where supplementary or tube feeding would have answered just as well. Even in the short-bowel syndrome intravenous feeding may not always be necessary if the remaining small bowel is not diseased. McMichael28 has suggested that a short length of small bowel may be adequate if food is presented to it slowly enough. Accordingly, he instructs the patient to pass his own Ryle’s tube each night and to allow a tube-feeding mixture to drip slowly into the stomach during sleep. This has proved not only cheap but also effective. It is now clear that intravenous feeding can be carried on indefinitely, and it may be life-saving in those few patients for whom no other method is possible. The American and French workers have also provided a valuable lesson in how to make intravenous feeding, in general, a safer procedure. one
/’
THALLIUM
THE wise provisions laid down in the Poisons and Pharmacy Act aim to ensure that deadly substances are used for limited purposes and by trained personnel, and that records are kept of their sale and distribution. Thallium and strychnine are two such substances, both highly lethal, the former being perhaps more offensive by being slower in its action and more various in its effects. There still seems to be a demand for thallium, particularly for killing moles that may damage well-kept lawns, cricket pitches, or agricultural land. Obtaining thallium for this purpose is rightly difficult, but errors on the human side inevitably arise-such as careless and inaccurate recording of amounts released or used, or slovenly handling by operators who should know better, or who should have been better instructed. For these reasons, although thallium poisoning is rare in the United Kingdom, the physician should be aware that thallium is still being used, and by whom. The diagnosis in the early stages is difficult,29 and of the textbook triad of symptoms-gastroenteritis, peripheral neuropathy, and alopecia-only the first occurs at the outset when therapy may have some chance of success. The neuropathy may take a week or more to develop and the alopecia may be delayed for three weeks or 27.
Solassol, Cl., Joyeux, H., Etco, L., Pujol, H., Romieu, C. Ann. Surg. 1974, 179, 519. 28. McMichael, H. B. Unpublished. 29. Cavanagh, J. B., Fuller, N. H., Johnson, H. R. M., Rudge, P. Q. Jl Med. 1974, 43, 293.
is conceived also on the motor side of the corticocortical arc, to allow of initiation of movements as well as individual muscular contractions. Yet another system that could lend itself to stimulatory influences is the regulation of muscular tone by cerebellar structures. COOPER 18 has reported the effects of stimulation via indwelling electrodes placed on the anterior lobe of the cerebellum and connected to a subcutaneous receiver. Stimulation at 200 c/s decreased ipsilateral hypertonic states, whereas a frequency of 10 c/s ameliorated convulsive disorders. Subsequently he applied the same technique to the posterior lobe, to relieve spasticity.19 The newer techniques employ inductance coils, so that the apparatus can be completely buried in the patient. Earlier methods could be controlled by radio but depended upon wires leading through the skin to a receiver strapped to the body. This allowed accurate measurement of the stimulus delivered, but inductance techniques are clearly preferable, and the estimated stimulus can be gauged sufficiently for practical purposes. The observations that have already been made with these techniques are interesting enough but are clearly only a beginning. If a young clinician wished to embark on a rewarding and neatly circumscribed research project he might well consider stimulating methods. Investigation in animals is straightforward but self-limited. Application to human beings must be slow to keep within strict ethical bounds, but the examples given are irreproachable, and do not begin to exhaust the possibilities. sort
LONG-TERM INTRAVENOUS FEEDING IT is now possible to feed people more or less indefinitely by the intravenous route.20 In addition to the basic requirements for fat, carbohydrate, and aminoacids, we know that patients on prolonged intravenous feeding need vitamins, minerals, and trace elements.al-24 The chief technical problems have been related to the method of administration and the attendant hazards of infection and thrombophlebitis. 25 These now seem to have been largely overcome by workers in Seattle and Montpelier. Broviac and Scribner2used an infusion pump with an indwelling ’ Silastic’ catheter inserted into the right atrium. Sixteen patients have fed themselves intravenously at home for periods up to 34 months. All these patients had severe bowel disease, six having the short-bowel syndrome. Most of them successfully maintained their weight and wellbeing; only 18. Cooper, I. S. Lancet, 1973, i, 206. 19. Cooper, I. S. ibid. p. 1321. 20. Lancet, 1973, ii, 1179. 21. Lee, H. A. Br. J. Hosp. Med. 1974, 11, 719. 22. Dudrick, S. J., Wilmore, D. W., Varis, H. M., Rhoads, J. E. Ann. Surg. 1969, 69, 974. 23. Scribner, B. H., Cole, J. J., Christopher, G., Vizzo, J. E., Atkins, R. C., Blagg, C. R. J. Am. med. Ass. 1970, 212, 457. 24. Jeejeebhoy, K. N., et al. Gastroenterology, 1973, 65, 811. 25. Savege, T. M. Resuscitation, 1973, 2, 83. 26. Broviac, J. W., Scribner, B. H. Surgery Gynec. Obstet. 1974, 139, 24.
died as a result of the technique-from septicaemia. Because glucose was the sole calorie source, the long daily infusion-time of 12 hours was necessary ; use of a fat emulsion such asIntralipid’ could have shortened the daily infusion-time to 8 hours (perhaps during sleep). A similar technique was employed by Solassol and his colleagues in Montpelier,27 who inserted a ’Teflon’-tipped siliconerubber catheter, under the anterior chest wall, into A portable a deep collateral of the subclavian vein. infusion apparatus was strapped to the body. It is hard to tell, from their article, why all their 75 patients Its needed this extremely expensive technique. application in total and prolonged bowel failure may be justified by analogy with dialysis in renal failure, but the Montpelier group seem to have used it where supplementary or tube feeding would have answered just as well. Even in the short-bowel syndrome intravenous feeding may not always be necessary if the remaining small bowel is not diseased. McMichael28 has suggested that a short length of small bowel may be adequate if food is presented to it slowly enough. Accordingly, he instructs the patient to pass his own Ryle’s tube each night and to allow a tube-feeding mixture to drip slowly into the stomach during sleep. This has proved not only cheap but also effective. It is now clear that intravenous feeding can be carried on indefinitely, and it may be life-saving in those few patients for whom no other method is possible. The American and French workers have also provided a valuable lesson in how to make intravenous feeding, in general, a safer procedure. one
/’
THALLIUM
THE wise provisions laid down in the Poisons and Pharmacy Act aim to ensure that deadly substances are used for limited purposes and by trained personnel, and that records are kept of their sale and distribution. Thallium and strychnine are two such substances, both highly lethal, the former being perhaps more offensive by being slower in its action and more various in its effects. There still seems to be a demand for thallium, particularly for killing moles that may damage well-kept lawns, cricket pitches, or agricultural land. Obtaining thallium for this purpose is rightly difficult, but errors on the human side inevitably arise-such as careless and inaccurate recording of amounts released or used, or slovenly handling by operators who should know better, or who should have been better instructed. For these reasons, although thallium poisoning is rare in the United Kingdom, the physician should be aware that thallium is still being used, and by whom. The diagnosis in the early stages is difficult,29 and of the textbook triad of symptoms-gastroenteritis, peripheral neuropathy, and alopecia-only the first occurs at the outset when therapy may have some chance of success. The neuropathy may take a week or more to develop and the alopecia may be delayed for three weeks or 27.
Solassol, Cl., Joyeux, H., Etco, L., Pujol, H., Romieu, C. Ann. Surg. 1974, 179, 519. 28. McMichael, H. B. Unpublished. 29. Cavanagh, J. B., Fuller, N. H., Johnson, H. R. M., Rudge, P. Q. Jl Med. 1974, 43, 293.