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DESIGN OF HOSPITAL BEDS
1169
far-reaching. The erythrocyte-sedimentation rate (E.S.R.) is a very accurate measure of the suspension stability of blood,3 but not during extracorporeal circulation 4 or after trauma.1 In these circumstances intravascular aggregation and changes in the E.S.R. are not correlated. Most measurements of viscosity are still based on the reasoning of Poiseuille 5; few will admit that blood is a non-
newtonian fluid and that Poiseuille’s law cannot apply to capillaries because they have a diameter less than 03 mm. It is therefore essential to develop shear-rate viscometers to 6 believes that shear-stress measure blood-viscosity. Bernstein is the tangential force per unit area on a fluid plane causing sliding; it is related to the frictional forces during flow and its magnitude is determined by the viscous characteristics of the fluid. The shear-rate is the velocity gradient between adjacent planes of layers of fluid during flow. The ratio of shearstress over shear-rate is a quantitative indication of the flowproperty of any fluid. If this ratio is constant over any shearrate the fluid is simple (newtonian). But in blood, shear-stress must be measured as specified rates of shear. Jevons7 emphasised the importance of the static electrical charge in the mutal repulsion of red blood-cells. Microelectrophoretic chambers now confirm this. Electron microscopy of aggregated red blood-cells consistently reveals a coating on the cell8 The envelope of the red blood-cell in intravascular aggregation and the mechanism by which L.M.W.D. influences this protein capsule have been discussed by Lee.9 L.M.W.D.
provides
a
clinically significant
answer to
the
problem of intravascular aggregation. Hexham General Hospital, Hexham, Northumberland.
PATRICK G. H.
J. BOSLEY.
MEMORIAL TO SIR RONALD FISHER SIR,-R. A. Fisher, who died in 1962, was among the greatest of the men of science of this century. The
methods which he introduced for agricultural trials have been the basis of clinical trials and much else besides. The Sir Ronald Fisher Memorial Committee of Great Britain, under my chairmanship, has launched an appeal for funds to establish a Fisher memorial lecture to be given at intervals in Great Britain, or occasionally abroad, by persons distinguished for contributions to natural knowledge or scientific methodology in one of the fields which had been of interest to him. Contributions are invited to a fund which will enable this to be established in perpetuity; the money will a fee for the lecturer and for his expenses and may be provide spent in other suitable ways by a board of trustees. Cheques, which should be made out to the Fisher Memorial Committee, and inquiries as to deeds of covenant, should be addressed to
lectureship
here
mf
Institute of Animal Physiology (Agricultural Research Council),
Babraham, Cambridge.
JOHN GADDUM.
DESIGN OF HOSPITAL BEDS
Mr. L. B. ARCHER writes from the Royal College of Art School of Industrial Design (Engineering), Kensington
Gore, London, S.W.7: In arriving at a design specification for the general-purpose hospital bedstead, we require to know the degree of foot-high "
tilt which would cater for the extreme in medical conditions necessitating this postural slant. Simplicity of the mechanism 2. 3. 4.
Bosley, P. G. H. J. Bbl. Anat. 1961, 1, 229. Fåhraeus, R. Physiol. Rev. 1929, 9, 241. Long, D. M., Jr., Sanchez, L., Varco, R. L., Lillehei, C. W. Surgery, 1961, 50, 12. 5. Poiseuille, J. L. M. C.R. Acad. Sci. 1840, 11, 961, 1041. 6. Bernstein, E. F. Proceedings of the Conference on Evaluation of LowMolecular-Weight Dextran: National Academy of Science, Division of Medical Science, National Research Council, U.S.A.; p. 53, 1962. 7. Jevons, W. Trans. Manch. phil. Soc. 1870, 78. 8. Bloch, E. H., Powell, A. Science, 1952, 115, 46. 9. Lee, W. H. Proceedings of the Conference on Evaluation of LowMolecular-Weight Dextran: National Academy of Science, Division of Medical Science, National Research Council, U.S.A.; p. 40, 1962.
and the ease and speed by which nurses and others can position the bed is fundamental to a good design specification, and it seems that there must be an optimum of foot-high tilt beyond which the patient’s physical condition is no longer benefited. Medical opinion and/or guidance on sources of research information on this clinical matter is sought, and any help which your readers might care to give us would be greatly
appreciated."
Public Health A CASE OF TYPHOID IN CAMBERWELL ON Jan. 29, 1964, a Jamaican child, aged 10 months, who had been admitted to a children’s hospital a week earlier was notified as a case of typhoid fever (phage-type
El). The child lived in
a
house in which there
were
thirteen
people, all Jamaicans. The front room on the first floor was occupied by a man and his wife (Mrs. A) and their daughter, aged 10 years. The back room was occupied by a woman, her daughter, aged 2½ years, and her son who was the sick child admitted to hospital. The other occupants were spread over rooms on the ground and second floors. They are interrelated and, generally speaking, they live as one famiy, Mrs. A doing most of the food preparation. There is a kitchen on the ground floor which is the one mainly used, and another on the second floor which is used occasionally by some of the occupants of the upper rooms. There are also two w.c.s-one on the ground floor, and one on the second floor - both of which are used in common by all members of the household. The house has no bathroom, and there are no washbasins. Personal ablutions are carried out in the two kitchens, each of which has a sink and water supply. The occupants were clean in their habits, and their standards above average. They had all been living in this house since September, 1963, and in this country for 3 or more years. None of them gave a history of recent illness, and all were well at the time of the first and subsequent visits. The sick child had been in the care of a registered daily minder; another child in the house went to a day-nursery, and another attended school. All the contacts of these children were well, and faecal examination on three occasions revealed no pathogenic
were
organisms. Examination of the house
contacts
gave two positive results 10. They lived in the
(Feb. 5)-Mrs. A and her daughter, aged
the mother and sister of the boy who had been taken ill, and took meals with them. Both were symptomless, and gave no history of recent illness. Mrs. A and another woman living in the house had been employed in a local pickle factory for more than a year. The sick child was transferred from the Belgrave Hospital to St. George’s Hospital, Tooting, and recovered from typhoid fever. He received chloramphenicol for 14 days, and nine stool and urine cultures were negative after treatment had ended. His Widal reaction remained negative throughout the illness. Mrs. A and her daughter were also admitted to St. George’s Hospital. Mrs. A came to this country in 1956, and in 1960 had an illness diagnosed as acute cholecystitis; she had severe abdominal pain but no headache, fever, or diarrhoea. She was admitted to hospital for a few days and was discharged free of symptoms. She was readmitted in October, 1963, after several months of upper abdominal pain and flatulence. After investigation her gallbladder, which was full of stones, was removed, and she had remained well since then. At St. George’s Hospital Salmonella typhi was isolated from the stools; but three specimens of urine were negative on culture. The patient’s serum gave the following result in agglutination tests. S. typhi 0 1/20; S. typhi H 1/1280; S. typhi Vi 1/40; all other agglutinaroom next to
far-reaching. The erythrocyte-sedimentation rate (E.S.R.) is a very accurate measure of the suspension stability of blood,3 but not during extracorporeal circulation 4 or after trauma.1 In these circumstances intravascular aggregation and changes in the E.S.R. are not correlated. Most measurements of viscosity are still based on the reasoning of Poiseuille 5; few will admit that blood is a non-
newtonian fluid and that Poiseuille’s law cannot apply to capillaries because they have a diameter less than 03 mm. It is therefore essential to develop shear-rate viscometers to 6 believes that shear-stress measure blood-viscosity. Bernstein is the tangential force per unit area on a fluid plane causing sliding; it is related to the frictional forces during flow and its magnitude is determined by the viscous characteristics of the fluid. The shear-rate is the velocity gradient between adjacent planes of layers of fluid during flow. The ratio of shearstress over shear-rate is a quantitative indication of the flowproperty of any fluid. If this ratio is constant over any shearrate the fluid is simple (newtonian). But in blood, shear-stress must be measured as specified rates of shear. Jevons7 emphasised the importance of the static electrical charge in the mutal repulsion of red blood-cells. Microelectrophoretic chambers now confirm this. Electron microscopy of aggregated red blood-cells consistently reveals a coating on the cell8 The envelope of the red blood-cell in intravascular aggregation and the mechanism by which L.M.W.D. influences this protein capsule have been discussed by Lee.9 L.M.W.D.
provides
a
clinically significant
answer to
the
problem of intravascular aggregation. Hexham General Hospital, Hexham, Northumberland.
PATRICK G. H.
J. BOSLEY.
MEMORIAL TO SIR RONALD FISHER SIR,-R. A. Fisher, who died in 1962, was among the greatest of the men of science of this century. The
methods which he introduced for agricultural trials have been the basis of clinical trials and much else besides. The Sir Ronald Fisher Memorial Committee of Great Britain, under my chairmanship, has launched an appeal for funds to establish a Fisher memorial lecture to be given at intervals in Great Britain, or occasionally abroad, by persons distinguished for contributions to natural knowledge or scientific methodology in one of the fields which had been of interest to him. Contributions are invited to a fund which will enable this to be established in perpetuity; the money will a fee for the lecturer and for his expenses and may be provide spent in other suitable ways by a board of trustees. Cheques, which should be made out to the Fisher Memorial Committee, and inquiries as to deeds of covenant, should be addressed to
lectureship
here
mf
Institute of Animal Physiology (Agricultural Research Council),
Babraham, Cambridge.
JOHN GADDUM.
DESIGN OF HOSPITAL BEDS
Mr. L. B. ARCHER writes from the Royal College of Art School of Industrial Design (Engineering), Kensington
Gore, London, S.W.7: In arriving at a design specification for the general-purpose hospital bedstead, we require to know the degree of foot-high "
tilt which would cater for the extreme in medical conditions necessitating this postural slant. Simplicity of the mechanism 2. 3. 4.
Bosley, P. G. H. J. Bbl. Anat. 1961, 1, 229. Fåhraeus, R. Physiol. Rev. 1929, 9, 241. Long, D. M., Jr., Sanchez, L., Varco, R. L., Lillehei, C. W. Surgery, 1961, 50, 12. 5. Poiseuille, J. L. M. C.R. Acad. Sci. 1840, 11, 961, 1041. 6. Bernstein, E. F. Proceedings of the Conference on Evaluation of LowMolecular-Weight Dextran: National Academy of Science, Division of Medical Science, National Research Council, U.S.A.; p. 53, 1962. 7. Jevons, W. Trans. Manch. phil. Soc. 1870, 78. 8. Bloch, E. H., Powell, A. Science, 1952, 115, 46. 9. Lee, W. H. Proceedings of the Conference on Evaluation of LowMolecular-Weight Dextran: National Academy of Science, Division of Medical Science, National Research Council, U.S.A.; p. 40, 1962.
and the ease and speed by which nurses and others can position the bed is fundamental to a good design specification, and it seems that there must be an optimum of foot-high tilt beyond which the patient’s physical condition is no longer benefited. Medical opinion and/or guidance on sources of research information on this clinical matter is sought, and any help which your readers might care to give us would be greatly
appreciated."
Public Health A CASE OF TYPHOID IN CAMBERWELL ON Jan. 29, 1964, a Jamaican child, aged 10 months, who had been admitted to a children’s hospital a week earlier was notified as a case of typhoid fever (phage-type
El). The child lived in
a
house in which there
were
thirteen
people, all Jamaicans. The front room on the first floor was occupied by a man and his wife (Mrs. A) and their daughter, aged 10 years. The back room was occupied by a woman, her daughter, aged 2½ years, and her son who was the sick child admitted to hospital. The other occupants were spread over rooms on the ground and second floors. They are interrelated and, generally speaking, they live as one famiy, Mrs. A doing most of the food preparation. There is a kitchen on the ground floor which is the one mainly used, and another on the second floor which is used occasionally by some of the occupants of the upper rooms. There are also two w.c.s-one on the ground floor, and one on the second floor - both of which are used in common by all members of the household. The house has no bathroom, and there are no washbasins. Personal ablutions are carried out in the two kitchens, each of which has a sink and water supply. The occupants were clean in their habits, and their standards above average. They had all been living in this house since September, 1963, and in this country for 3 or more years. None of them gave a history of recent illness, and all were well at the time of the first and subsequent visits. The sick child had been in the care of a registered daily minder; another child in the house went to a day-nursery, and another attended school. All the contacts of these children were well, and faecal examination on three occasions revealed no pathogenic
were
organisms. Examination of the house
contacts
gave two positive results 10. They lived in the
(Feb. 5)-Mrs. A and her daughter, aged
the mother and sister of the boy who had been taken ill, and took meals with them. Both were symptomless, and gave no history of recent illness. Mrs. A and another woman living in the house had been employed in a local pickle factory for more than a year. The sick child was transferred from the Belgrave Hospital to St. George’s Hospital, Tooting, and recovered from typhoid fever. He received chloramphenicol for 14 days, and nine stool and urine cultures were negative after treatment had ended. His Widal reaction remained negative throughout the illness. Mrs. A and her daughter were also admitted to St. George’s Hospital. Mrs. A came to this country in 1956, and in 1960 had an illness diagnosed as acute cholecystitis; she had severe abdominal pain but no headache, fever, or diarrhoea. She was admitted to hospital for a few days and was discharged free of symptoms. She was readmitted in October, 1963, after several months of upper abdominal pain and flatulence. After investigation her gallbladder, which was full of stones, was removed, and she had remained well since then. At St. George’s Hospital Salmonella typhi was isolated from the stools; but three specimens of urine were negative on culture. The patient’s serum gave the following result in agglutination tests. S. typhi 0 1/20; S. typhi H 1/1280; S. typhi Vi 1/40; all other agglutinaroom next to