Postgrad Med J: first published as 10.1136/pgmj.31.357.345 on 1 July 1955. Downloaded from

345

BIOCHEMICAL DISTURBANCES IN EARLY LIFE By R. H. WILKINSON, M.D. Department of Chemical Pathology, Th? Hospitalfor Sick Children, Great Ormndi Street, London

Biochemical changes occur in a wide range of continue with periods of remission until dehydra- diseases in paediatric practice. It is amazing what tion becomes marked. When examined, the child tremendous deviations from normality are com- shows no characteristic clinical features. The patible with life. This section will be confined to weight is below normal. The child is listless, the use of chemical aids in the differential diagnosis muscle tone is poor and the signs of dehydration of a difficult problem in infancy, that of failure to are seen. Radiography may show medullary renal thrive. The differential diagnosis ranges from calcification. A specimen of urine may contain maternal mismanagement to galactosaemia. some protein, white cells and pathogenic organ- Causes of failure to thrive in early life are: isms, but not enough to suggest a severe urinary I. Nutritional, e.g. feeding technique and in- infection. The reaction of the urine may be acid adequate quantity or quality of food. if the child is dehydrated, but after this has been 2. Infective, e.g. gastro-enteritis, miliary tubercu- corrected the urine is alkaline or neutral. The keyby copyright. losis and otitis media. to the diagnosis is the finding of a plasma bicar- 3. Anatomical abnormalities, e.g. hiatus hernia, bonate less than i8 m.Eq./l. together with an obliteration of bile ducts and urethral obstruction. alkaline or neutral urine, It is good practice to 4. General diseases. (a) Fibrocystic disease of repeat these'initial findings two or three days later, pancreas; (b) Diseases listed because of bio- after the patient has been further hydrated. Some chemical interest, e.g. infantile renal acidosis, apparently normal children when dehydrated have hypercalcaemia, diabetes insipidus renalis, gener- an initially low plasma bicarbonate with a neutral alized aminoaciduria and cystinosis in infants, urine. This reverts to normal after rehydration. galactosaemia and sucrosuria. If the findings of acidosis and neutral or alkalinehttp://pmj.bmj.com/ Groups i to 4 (a) need not concern us here. urine persist (even after any urinary infection has Group 4 (b) lists some causes of failure to thrive been cured), the diagnosis is that of infantile renal which require chemical investigation for their acidosis. differentiation, as the clinical picture is not The treatment of the condition is oral rehydra- characteristic. tion and sufficient alkalizing salts to correct the The picture of failure to thrive has common acidosis, such as a modified Shohl's solution (io features: No in difficult cent. sodium citrate and 6 per cent. citric acid, gain weight, very feeding per on September 30, 2021 by guest. Protected due to anorexia with vomiting and constipation. i ml. = i m.Eq.) sodium citrate, sodium lactate The vomiting and lack of fluid produces dehydra- and sodium acetate (the latter tastes the least salty). tion and this contributes to the constipation. In Sodium bicarbonate may be used but often causes some cases with renal dysfunction, thirst and tympanites. Most cases require 15 m.Eq. q.d.s. polyuria are present also. Fever may accompany This dose may be increased by 15 m.Eq. a day, the dehydration. Renal, cardiac, hepatic and each week, until the plasma bicarbonate rises to respiratory failure, intercurrent infection or pro- 20 m.Eq./l. The clinical picture becomes strik- gressive biochemical abnormalities may be the ingly normal and this symptomatic treatment .is outcome. continued until the weight gain has been satis- factory for several months. The plasma bicar- Infantile Renal Acidosis (Lightwood, Payne and bonate tends to rise above 25 m.Eq./l. when re- Black, 1953) covery occurs. The dosage of alkali is halved, From about the fourth month a seemingly and if no acidosis appears after a fortnight, the healthy infant commences to vomit and refuses dose is halved again. If no acidosis recurs the food. The child becomes constipated, ceases to alkali treatment is stopped. The urinalysis should gain weight and is miserable. These symptoms be normal. The prognosis is excellent. Postgrad Med J: first published as 10.1136/pgmj.31.357.345 on 1 July 1955. Downloaded from

346 POSTGRADUATE MEDICAL JOURNAL July 1955 Idiopathic Hypercalcaemia in Infants (Light- sponsive to pitressin, high values for serum sodium wood, 1952; Payne, 1952) and chloride, high skin resistance, rapid dehydra- This condition resembles infantile renal acidosis tion if fluids are restricted or withheld, inability to clinically. The symptoms of failure to thrive are excrete urine of high specific gravity, familial present, sometimes with thirst and polyuria. The incidence and occurrence in boys only.' child is often dehydrated but is cheerful and has a The clinical picture may be mistaken for gastro- good skin colour, which is a point of clinical enteritis, a general or local infection with a pyrexia differentiation from renal acidosis. Hypotonia and rising to 103° F., meningitis since neck rigidity constipation with scybalae palpable in the abdomen may be found, or a renal lesion as the blood urea is are well-marked features. Urinalysis shows some raised. When it is found that the child does well evidence of infection but not enough to diagnose a on large amounts of fluids and that there is a primary urinary infection. Chemical analysis polyuria, the case can be investigated systematic- shows the diagnostic signs of: Raised serum cal- ally. As rehydration proceeds, the fever subsides, cium (over 1.5 mg. and usually 12 to 14 mg. per the high plasma chloride and sodium and blood Ioo ml.), raised blood urea (over 40 mg. and up to urea fall to nearly normal levels. The urine is pale 120 mg. per Ioo ml.) and a normal plasma bicar- and of low specific gravity (Iooi to I007). If bonate. Again it is wise to repeat these readings to fluids are curtailed dehydration, fever, loss of secure a firm diagnosis, as when possible errors are weight and malaise rapidly follow in about six eliminated, raised calcium levels occur on admission to twelve hours, but the specific gravity of the to hospital and are normal two days later. Radio- urine does not rise above 1007. graphy often shows an increase in density in the The critical point is the child's reaction to renal areas and dense epiphyseal lines. pitressin (anti-diuretic hormone, A.D.H.). He is Treatment is purely symptomatic. The de- given hourly an amount of fluid equal to the daily hydration is corrected and adequate clear fluids are intake of fluid divided by I2, starting at 6 a.m. and given. These are usually taken readily. A low continuing until 3 p.m. A catheter is inserted at calcium diet is given and a commercial low calcium 8 a.m. This procedure may inhibit urine forma-by copyright. milk powder, free from vitamin D, can be used. tion for up to one and a half hours. Hourly speci- Cortisone by mouth may be used to reduce the mens of urine are collected from io a.m. till 12 serum calcium. midday and serve as controls. Pitressin (Parke The disease may last one or two years in the Davis) watery solution, 0.5 B.P. unit per sq. m. uncomplicated case and the prognosis is good. A of body surface is injected subcutaneously at 12 complete gradation may be found from this type of midday. Hourly specimens of urine are collected case to the complicated one of hypercalcaemia, till 3 p.m. The pitressin solution should have been basicranial osteosclerosis and craniostenosis, car- tested on a normal subject and proved to be active. diac murmur, hypertension, mental retardation The normal reaction is a fall in the hourly volume http://pmj.bmj.com/ and hypercholesterolaemia, described by Fanconi of the urine and a rise in the concentration of et al. (1952). Some cases also have an episode of chlorides, although the amount of salt excreted per renal acidosis and some cases of renal acidosis may hour is not altered. have a transient hypercalcaemia. The cases of The child whose kidney is resistant to the anti- hypercalcaemia may be thought of as a simple diuretic action of the pitressin shows no reaction to group, a complicated group and a very small group the test, and the dose may be increased tenfold. associated with renal acidosis. The prognosis in The patient is much more sensitive than a normal the complicated group has not been good. infant to the vasopressor effect of the preparation on September 30, 2021 by guest. Protected in these high doses. Since the water loss cannot Diabetes Insipidus Renalis (Pitressin resistant be controlled with pitressin the only treatment is diabetes insipidus) to teach the parents to supply the infant with large Infants who are failing to thrive become de- quantities of fluid while giving enough food. hydrated and all benefit by the ample fluid intake given in hospital. One group of cases however Generalized Aminoaciduria and Cystinosis requires a fluid intake of up to 200 oz. per day. in Infants (Bickel et al., 1953) The accompanying polyuria may be missed easily Generalized aminoaciduria occurs in a group of when the infant is given a normal fluid intake infants showing a wide range of clinical pictures unless the above condition is kept in mind. The and cystinosis may or may not be demonstrated. description by Waring, Kajdi and Tappan (1945) The infant fails to thrive after the age of about six of this congenital defect in water metabolism is months, when vomiting, anorexia, constipation, ' onset after birth, erratic and unexplained fever, marked thirst and polyuria appear. The thirst is persistent constipation, vomiting in the first three so marked that known cases of cystinosis are given months of life, polydipsia and polyuria not re- cups of water when seen as out-patients. Loss of Postgrad Med J: first published as 10.1136/pgmj.31.357.345 on 1 July 1955. Downloaded from July 1955 WILKINSON: Biochemical Disturbances in Early Life 347 weight is noticed. The child appears small, de- from the diet and commercial dried milks are avail- hydrated, has a fever and may be cold and cyanotic. able for this purpose. The diagnosis must be Rickets may or may not be present. Albuminuria, made as early as possible so that the danger of glycosuria and pyuria may be found. Blood cataracts and mental deficiency may be minimized. chemistry shows a marked metabolic acidosis and a It is not yet possible to form an opinion of the low inorganic phosphorus. Serum potassium may mental progress in cases which have been treated show low levels associated with fever and a raised early. blood urea level. Any infant who fails to thrive, has marked Sucrosuria thirst and passes a dilute urine containing excess This rare condition again illustrates the use of protein, with or without reducing substances, paper chromatographic analysis of urine. Three should have several specimens examined for cases of sucrosuria with mental defect and hiatus aminoaciduria and sugar excretion by paper hernia were described by Moncrieff and Wilkin- chromatography. If a generalized aminoaciduria son (I954). The infants were all failing to thrive, of a characteristic type is found, the corneae should principally because of hiatus hernia, and were be examined by slit-lamp microscopy for cystalline mentally deficient. Vomiting and failure to gain deposits and marrow smears examined for cystine weight were the principal symptoms. Radio- crystals. The latter may be identified specifically graphy demonstrated the lesion of the lower end by paper chromatography. The urine examination of the oesophagus. It was shown that on ordinary by paper chromatography is the critical examina- milk feeds, containing lactose and sucrose, greatly tion. Treatment is symptomatic, potassium and increased quantities of sucrose, lactose, fructose alkalizing salts are given in doses sufficient to and, to a less extent, glucose and galactose were correct the plasma deficiencies. A dose of up to passed in the urine. The defect appeared to be in 30 g. a day of sodium and potassium citrate may the intestinal absorption of sugars when lactose and be necessary. High doses of vitamin D (50 to sucrose were fed together. These two disacchar- zoo,ooo units) may correct the rickets. ides were absorbed more rapidly than usual and theby copyright. sugars were promptly excreted by the kidney. The Galactosaemia (Cox and Pugh, 1954) hiatus hernia was treated and the children were This disease must be diagnosed as soon as given sucrose-free diets. The sucrosuria ceased possible after birth if the infant is to be given a and this possibly toxic factor was eliminated. Two chance to develop normally. The infant fails to of the cases died and the third case has made slow thrive from birth and the weight gain is poor. physical progress. Feeding is difficult as the baby vomits, is some- times and sometimes irritable and have Summary drowsy may http://pmj.bmj.com/ convulsions. Diarrhoea may occur. Wasting and Six examples are given of the use of chemical dehydration are usual although oedema and aids in the differential diagnosis of failure to thrive ascites are sometimes seen. The early and im- in infancy. Infantile renal acidosis and idiopathic portant signs are those affecting the liver. It is hypercalcaemia require blood analysis for bicar- enlarged very early in the disease, accompanied by bonate, calcium and urea.Diabetes insipidus jaundice and sometimes by splenomegaly. The renalis requires a test of the reaction of the older patient's kidneys to pitressin (A.D.H.). Cystinosis, case may show, unfortunately, the fully and sucrosuria are demonstrated by developed picture of malnutrition, hepatomegaly, galactosaemia on September 30, 2021 by guest. Protected lamellar or nuclear cataracts and mental deficiency. the analysis of urine by paper chromatography. A family history of the disease may be obtained in BIBLIOGRAPHY one-third of the cases. Benedict's reagent is BICKEL, H., BAAR, H. S., ASTLEY, R., DOUGLAS, A. A., reduced the and albuminuria FINCH, E., HARRIS, H., HARVEY, C. C., HICKMANS, strongly by urine, E. M., PHILLPOT, M. G., SMALLWOOD, W. C., and a few cells and casts are seen. SMELLIE, J. M., and TEALL, C. G. (1953), Acta paed., 42, supp. 90. Failure to thrive, hepatomegaly and a reducing COX, P. J. N., and PUGH, R. J. P. (I954), Brit. med. J., ii, 613. substance in the urine of an infant should cause the FANCONI, G., GIRARDET, P., SCHLESINGER, B., BUTLER, N., and BLACK, J. (1952), Helv. paediat. acta, 7, 314. clinician to suspect galactosaemia. Identification LIGHTWOOD, R., PAYNE, W. W., and BLACK, J. A. (i953), of the urinary excretion of galactose in large Paediatrics, x2, 628. amounts is obtained most chroma- LIGHTWOOD, R. (1952), Arch. Dis. Childh., 27, 302. easily by paper MONCRIEFF, A. A., and WILKINSON, R. H. (1954), Actapaed., tography of the urine passed while a diet containing 43, supp. 100, 495. * lactose is fed. Aminoaciduria also be found. PAYNE, W. W. (1952), Arch. Dis. Childh., 27, 302. may WARING, A. J., KAJDI, L., and TAPPAN, V. (1945), Amer. The treatment of the condition is to exclude lactose .7. Dis. Child., 69, 323.