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ALUMINIUM AND DIALYSIS ENCEPHALOPATHY
98 ALUMINIUM AND DIALYSIS ENCEPHALOPATHY of
SIR,-Interest in the possibility that aluminium is the cause dialysis encephalopathy (D.E.) has arisen because Alfrey et
al.’ found high concentrations of aluminium in the cerebral grey-matter of patients who had died from the disease. This has been confirmed for whole brain by Flendrig2 and ascribed either to the use of aluminium hydroxide as a phosphate binder or to a high concentration of aluminium in the water used for the preparation of dialysate. We have observed 10 patients with this syndrome. D.E. and fractures were more common among dialysis patients in the soft-water area near Sheffield city than in the rest of our region where the water contains more calcium (table I). All these patients dialysed at TABLE I-EXPERIENCE OF D.E. AND FRACTURES IN
74
PATIENTS ON HOME
DIALYSIS IN THE TRENT REGION
It is therefore surprising that the concentration of aluminium in the grey-matter of two of our patients (emission spectrography) was only slightly increased and less than the amount found by Alfrey et al. in their dialysis patients without D.E. Bone aluminium in two of our patients was much increased. In 1973 we suggested4 that D.E. and multiple fractures in dialysis patients were related to a toxin in soft water which was removed by a water softener. Our latest findings support this impression. We regard the role of aluminium in the causation of D.E. and pathological fractures as not proven, though it seems possible that a metal in water is responsible for the syndrome. Pierides et all suggested that phosphate depletion may be responsible for these complications. Our patients who took aluminium hydroxide may have been phosphate depleted, but there was no evidence of this in the patients who did not take aluminium hydroxide. Academic Division of Medicine,
Royal Hospital, Sheffield S1 3SR
M. M. PLATTS
Analytical Research and Development, Atomic Energy Establishment, Harwell
J. S. HISLOP
*
7 other patients had D.E. and fractures. t These patients had been on dialysis for at least
3 years.
mg/!. Figures in parentheses show numbers using water softeners.
tCalcium<30
home after initial hospital training in Sheffield. Two pairs of patients with D.E. had used the same houses in Sheffield at different times (table n). The regular use of a water softener seems to afford some protection. Analyses carried out by the local water authorities showed that the mean concentration of aluminium in the domestic water of patients with multiple fractures (0-24 mg/1) was that of patients with single fractures greater than (p<0.05) (mean 0.02 mg/1) or no fracture (0-10 mg/1). Mean concentrations of calcium and fluorine in water supplied to patients with D.E. were significantly lower than in that supplied to the other two groups. 5 of our patients with D.E. had never taken aluminium hydroxide but there were high concentrations of aluminium in their tap water (table n). A water softener removes some but not all of the aluminium from water. A. C., LeGendre, G. R., Kaehny, W. D. New Engl. J. Med. 1976, 94, 184. 2. Flendrig, J. A., Kruis, H., Das, H. A. Lancet, 1976, i, 1235. 3. Tipton, I. H., Cook, M. J. Hlth Phys. 1963, 9, 103. 1.
Alfrey,
DOG BITES IN CHILDREN
SiR,—Throughout May, 1976, details of children under the age of 15 attending the three casualty units of the Sunderland Area Health Authority were recorded. Children were assessed according to age, sex, area of residence, social group, and type of accident. 120 children had sought hospital advice after a dog bite. These children accounted for 10% of all accidents to children during the month of May. 73% of the children were in the 1-10 years age range (see table), and it is thought that these children may be more susceptible to rabies infection than an older child or adult. Bites in densely innervated areas such as the face, hand, or arm may also increase the risk of rabies. 53% of the children (43% of the boys and 78% of the girls) were in this high-risk category. Of the children aged 5 or less, 80% were bitten in the face, hand, or arm. This group of younger children would be at very high risk should they be bitten by a rabid dog. The Sunderland A.H.A. serves approximately 350 000 people. For the purpose of this study of accidents the area was subdivided into sixty-eight residential zones. Exactly 50% of the children with dog bites came from six zones, each one 4. Platts, M. M., Moorhead, P. J., Grech, P. Lancet, 1973, ii, 159. 5. Pierides, A. M., Ward, M. K., Kerr, D. N. S. ibid. 1976, i, 1234.
TABLE II-DETAILS OF D.E. CASES IN TRENT REGION
*
Values for dry weight approximately 5 x higher. t Same house. t Same house.
SIR,-Interest in the possibility that aluminium is the cause dialysis encephalopathy (D.E.) has arisen because Alfrey et
al.’ found high concentrations of aluminium in the cerebral grey-matter of patients who had died from the disease. This has been confirmed for whole brain by Flendrig2 and ascribed either to the use of aluminium hydroxide as a phosphate binder or to a high concentration of aluminium in the water used for the preparation of dialysate. We have observed 10 patients with this syndrome. D.E. and fractures were more common among dialysis patients in the soft-water area near Sheffield city than in the rest of our region where the water contains more calcium (table I). All these patients dialysed at TABLE I-EXPERIENCE OF D.E. AND FRACTURES IN
74
PATIENTS ON HOME
DIALYSIS IN THE TRENT REGION
It is therefore surprising that the concentration of aluminium in the grey-matter of two of our patients (emission spectrography) was only slightly increased and less than the amount found by Alfrey et al. in their dialysis patients without D.E. Bone aluminium in two of our patients was much increased. In 1973 we suggested4 that D.E. and multiple fractures in dialysis patients were related to a toxin in soft water which was removed by a water softener. Our latest findings support this impression. We regard the role of aluminium in the causation of D.E. and pathological fractures as not proven, though it seems possible that a metal in water is responsible for the syndrome. Pierides et all suggested that phosphate depletion may be responsible for these complications. Our patients who took aluminium hydroxide may have been phosphate depleted, but there was no evidence of this in the patients who did not take aluminium hydroxide. Academic Division of Medicine,
Royal Hospital, Sheffield S1 3SR
M. M. PLATTS
Analytical Research and Development, Atomic Energy Establishment, Harwell
J. S. HISLOP
*
7 other patients had D.E. and fractures. t These patients had been on dialysis for at least
3 years.
mg/!. Figures in parentheses show numbers using water softeners.
tCalcium<30
home after initial hospital training in Sheffield. Two pairs of patients with D.E. had used the same houses in Sheffield at different times (table n). The regular use of a water softener seems to afford some protection. Analyses carried out by the local water authorities showed that the mean concentration of aluminium in the domestic water of patients with multiple fractures (0-24 mg/1) was that of patients with single fractures greater than (p<0.05) (mean 0.02 mg/1) or no fracture (0-10 mg/1). Mean concentrations of calcium and fluorine in water supplied to patients with D.E. were significantly lower than in that supplied to the other two groups. 5 of our patients with D.E. had never taken aluminium hydroxide but there were high concentrations of aluminium in their tap water (table n). A water softener removes some but not all of the aluminium from water. A. C., LeGendre, G. R., Kaehny, W. D. New Engl. J. Med. 1976, 94, 184. 2. Flendrig, J. A., Kruis, H., Das, H. A. Lancet, 1976, i, 1235. 3. Tipton, I. H., Cook, M. J. Hlth Phys. 1963, 9, 103. 1.
Alfrey,
DOG BITES IN CHILDREN
SiR,—Throughout May, 1976, details of children under the age of 15 attending the three casualty units of the Sunderland Area Health Authority were recorded. Children were assessed according to age, sex, area of residence, social group, and type of accident. 120 children had sought hospital advice after a dog bite. These children accounted for 10% of all accidents to children during the month of May. 73% of the children were in the 1-10 years age range (see table), and it is thought that these children may be more susceptible to rabies infection than an older child or adult. Bites in densely innervated areas such as the face, hand, or arm may also increase the risk of rabies. 53% of the children (43% of the boys and 78% of the girls) were in this high-risk category. Of the children aged 5 or less, 80% were bitten in the face, hand, or arm. This group of younger children would be at very high risk should they be bitten by a rabid dog. The Sunderland A.H.A. serves approximately 350 000 people. For the purpose of this study of accidents the area was subdivided into sixty-eight residential zones. Exactly 50% of the children with dog bites came from six zones, each one 4. Platts, M. M., Moorhead, P. J., Grech, P. Lancet, 1973, ii, 159. 5. Pierides, A. M., Ward, M. K., Kerr, D. N. S. ibid. 1976, i, 1234.
TABLE II-DETAILS OF D.E. CASES IN TRENT REGION
*
Values for dry weight approximately 5 x higher. t Same house. t Same house.