A review of acute renal failure in children: incidence, etiology and outcome.

We reviewed our experience of children with acute renal failure. St James's University Hospital, Leeds, UK is a tertiary referral center that serves a relatively stable regional population (former Yorkshire region). It is a mixed rural and urban population providing a unique profile of the nature of the cases and workload experienced. The data is expressed as a function of age and compared against a previous era of paediatric nephrology and current adult incidence data. Over an 8-year period (1984-1991) 227 children were referred for dialysis management of acute renal failure. The yearly incidence was 0.8 per 100,000 total population. Acute renal failure in the child population was almost a fifth of the adult incidence. Age-related incidence however shows the highest incidence in the neonate/infant population and is comparable to adult data. The intensive care unit was needed for nearly half the children. For all ages hemolytic uremic syndrome was the commonest cause (45%). Surgery for congenital heart disease was predominant (63%) in the neonate group. The overall mortality was 25%. Primary renal disease accounts for only 7% of the etiologies and was the source for the majority that went on to require chronic renal replacement therapy. Acute renal failure is nearly always a secondary event in the face of other organ failure and the majority of the mortality arises from surgery for congenital heart disease. If the underlying condition is treatable, the prognosis for recovery from acute renal failure with appropriate supportive care is excellent.

Epidemiology of Munchausen syndrome by proxy, non-accidental poisoning, and non-accidental suffocation.

A two year prospective study was performed to determine the epidemiology of Munchausen syndrome by proxy, non-accidental poisoning, and non-accidental suffocation in the UK and the Republic of Ireland. Cases were notified to the British Paediatric Association Surveillance Unit from September 1992 to August 1994 if a formal case conference had been held for the first time during that period to discuss any of the above conditions. A total of 128 cases were identified: 55 suffered Munchausen syndrome by proxy alone, 15 poisoning, and 15 suffocation; 43 suffered more than one type of abuse. The majority of children were aged under 5 years, the median age being 20 months. On 85% of occasions the perpetrator was the child's mother. In 42% of families with more than one child, a sibling had previously suffered some form of abuse. Eighty five per cent of notifying paediatricians considered the probability of their diagnosis as virtually certain before a case conference was convened. The commonest drugs used to poison were anticonvulsants; opiates were the second commonest. Sixty eight children suffered severe illness of whom eight died. The combined annual incidence of these conditions in children aged under 16 years is at least 0.5/100,000, and for children aged under 1, at least 2.8/100,000.

Nocturnal enuresis: a placebo controlled trial of two antidepressant drugs.

A multicentre, randomised, double blind treatment trial was set up comparing imipramine (a tricyclic antidepressant with anticholinergic action), mianserin (a quadricyclic antidepressant without anticholinergic activity), and placebo, (a) possibly to identify an effective alternative drug and (b) to elucidate the action of imipramine in enuretic children. Eighty children (65 boys, 15 girls) aged 5-13 years, wet three or more nights a week, were studied. Exclusions were a urinary tract infection or abnormality, other organic illness, or severe emotional disorders. After a four week assessment, 25 children were randomised to eight weeks' treatment with imipramine 25 mg, 26 to mianserin 10 mg and 29 to placebo, followed by four weeks without treatment. Dry nights and a wetness score were recorded throughout. During treatment, imipramine was superior to both placebo and mianserin (p < 0.001) in achieving dry nights and reducing wetness scores. It led to a definite improvement in 72% of children. Mianserin produced a mildly beneficial effect that was not superior to placebo. No side effects were recorded. Mianserin would not be a satisfactory alternative treatment for nocturnal enuresis. The efficacy of imipramine is unlikely to be the result of its antidepressant activity.

Combined treatment with enuresis alarm and desmopressin for nocturnal enuresis.

Seventy-one children with nocturnal enuresis were enrolled in a controlled trial. The children were allocated to two matched groups. Children in both groups used an enuresis alarm until the end of treatment. Children in the first group were treated with 40 micrograms of intranasal desmopressin (Desmospray) for up to 6 weeks at the start of treatment with the alarm. During the observation period treatment there were 2.3 dry nights per week in both groups. At the end of treatment there was a significant difference in the mean number of dry nights per week between the two groups (6.3 in the alarm and desmopressin group and 4.8 in the alarm group) and also in the number of children becoming reliably dry. The combination of desmopressin and alarm was particularly helpful for children with severe wetting and those with family and behavioural problems.

Munchausen syndrome by proxy.

Munchausen Syndrome by Proxy has been recognised for almost two decades. This review considers the definition, clinical features, consequences (to both victim and perpetrator), diagnosis and outcome of the syndrome.

Follow up of victims of fabricated illness (Munchausen syndrome by proxy).

Fifty four children were studied 1-14 (mean 5.6) years after fabrications of illness had been identified. Thirty of the 54 children were living in families with their biological mothers and 24 were with other family members or in substitute families. Further fabrications were identified for 10 children who had been living with their mothers and there were 'other concerns' for a further eight children. Thirteen children residing with mother and 14 not residing with mother at follow up had a range of disorders including conduct and emotional disorders, and problems related to school, including difficulties in attention and concentration and non-attendance. Overall, 20 children (49% of those successfully followed up) had outcomes that were considered to be unacceptable.

Desmopressin for bed wetting: length of treatment, vasopressin secretion, and response.

Fifty five children with nocturnal enuresis referred to a hospital enuresis clinic entered a controlled trial to compare the efficacy of one month and three month courses of intranasal desmopressin (Desmospray). There was no significant difference in outcome between the two groups. Overall 36% improved by at least two dry nights/week during treatment, but only five children (18%) in the one month group and three (11%) in the three month group became completely dry and only one in each group remained dry after treatment. To determine whether nocturnal polyuria was associated with a therapeutic response to desmopressin, the nocturnal urine volume, osmolality, and vasopressin concentration were measured in desmopressin responsive enuretics, desmopressin non-responders, and non-enuretic control children. There were no significant differences between the three groups. A three month course of desmopressin is no more effective than a one month course. Although many children will improve during treatment, only a small number become dry and most will relapse when treatment is stopped.

Co-morbidity associated with fabricated illness (Munchausen syndrome by proxy).

Fifty six children who had been victims of fabricated illnesses and 82 of their 103 siblings were studied. In addition to the index fabrication, 64% of index children had had other illnesses fabricated by their mothers. Twenty nine per cent of the index children had a history of failure to thrive and 29% a history of non-accidental injury, inappropriate medication, or neglect. Seventy three per cent of the index children had been affected by at least one of these additional problems. Eleven per cent of the siblings had died in early childhood, the cause of death not being identified. Thirty nine per cent of siblings themselves had had illnesses fabricated by their mothers, and 17% had been affected by either failure to thrive, non-accidental injury, inappropriate medication, or neglect.

Day wetting.

About 1% of healthy children over the age of 5 years have troublesome daytime wetting. Two-thirds of those who wet by day are reliably dry at night. The problem is more common in girls and is usually the result of urge incontinence. Although the wetting may be exacerbated by giggling and/or stress, pure giggle micturition and isolated stress incontinence are both rare. There is a strong association with bacteriuria (50% prevalence) in girls who wet by day. A potentially important relationship exists between day wetting, infection, reflux and upper tract damage, which is expressed in an extreme form in the syndromes of incoordinated voiding and progressive renal damage. Most children who wet by day have unstable bladders. Many of them adopt characteristic "holding" postures. There is an increased incidence of emotional disorder compared with children who merely wet the bed. Between 10% and 15% of children who wet by day become dry during the next 12 months. The acquisition of dryness is accelerated by eradication of bacteriuria and a sympathetic and energetic management regime, which should place responsibility on the child and result in the child voiding more frequently and completely. Reminder alarms and other behaviour therapies have proved effective. There is no satisfactory evidence for the efficacy of drugs. More complex behavioural training regimes including biofeedback are valuable for severe cases.

Purine enzyme defects as a cause of acute renal failure in childhood.

Acute renal failure (ARF) is not listed as a usual form of presentation in hypoxanthine-guanine phosphoribosyltransferase deficiency, despite the gross uric acid overproduction in the defect. We found that a third of such patients may present in ARF when the urinary uric acid/creatinine ratio may be normal, not raised, and the defect may be suspected from the disproportionate increase in plasma uric acid. This is important in view of the potential confusion of uric acid with 2,8-dihydroxyadenine, the even more insoluble purine excreted in the other salvage enzyme disorder, adenine phosphoribosyltransferase deficiency. In that disorder, presentation in ARF is well recognized, the uric acid/creatinine ratio is also normal, but plasma urate is not raised. Our combined experience in these two disorders underlines the importance of early recognition and treatment with carefully adjusted doses of allopurinol, which may reverse or postpone renal failure.

Controlled trial of standard pad and bell alarm against mini alarm for nocturnal enuresis.

Fifty six children aged from 6-16 years who wet their beds at night were entered into a controlled trial of two alarm devices: a traditional alarm using a wet sensor mat on the bed attached to an alarm bell out of reach of the child, and a mini alarm system incorporating a tiny perineal wet sensor attached to a small alarm worn on the child's clothing. A quota allocation system ensured comparability between the two treatment groups. The children were encouraged to use the alarm for four months. Both alarms were equally effective in helping children to become dry. There was no significant difference between the number of children unable to comply with treatment or to be helped by each alarm. The rate of acquisition of dryness was similar for the two groups. The traditional standard alarm was sturdier, more dependable, and easier to maintain, but the mini alarm had some advantages, particularly for girls. Both types of alarm are recommended for general use.

Low dose prednisolone in nephrotic syndrome.

Sixteen patients with steroid responsive nephrotic syndrome were treated on 29 separate occasions with a low dose of prednisolone (30 mg/m2/day). All went into remission within 14 days. The duration of remission in the six patients who had had previous relapses treated with a higher dose of prednisolone was similar.

Successful management of daytime enuresis using alarm procedures: a randomly controlled trial.

Forty four children with daytime wetting were included in a randomly controlled trial of two alarm devices, a contingent one that sounded when wetting occurred and a non-contingent one that went off from time to time unrelated to wetting events. A quota allocation system ensured comparability between treatment groups. Two thirds responded to an alarm by becoming dry. The non-contingent alarm produced as good a response as the contingent one and is recommended for routine use in children with diurnal enuresis. Twenty three per cent of those who responded to treatment relapsed up to two years after completion of the trial.

Height attainment in children with steroid-responsive nephrotic syndrome.

The heights of 80 patients with steroid-responsive nephrotic syndrome (SRNS) were measured 5-24 years after diagnosis. During childhood most patients had received repeated courses of high-dose corticosteroids and prolonged maintenance therapy. Although at the time of taking corticosteroids growth was suppressed, those who had completed growth had a mean height standard deviation score (SDS) of -0.22, equivalent to a height on the 40th centile. Total corticosteroid dose prescribed was correlated only weakly with height SDS; there was no correlation between total dose and height when the post-pubertal patients were studied separately, indicating that their ultimate height attainment was not affected significantly.

Long term prognosis of recurrent haematuria.

A long term follow up study of 100 children referred with recurrent haematuria for at least one year to two regional paediatric nephrology units is described. The mean duration of follow up was 8.2 years. An adequate renal biopsy was obtained in 96 and eight cases of Alport's syndrome and 10 of IgA nephropathy were diagnosed (20% and 26% respectively of the biopsies examined by electron microscopy and immunofluorescence). Five patients developed end stage renal failure and six hypertension requiring treatment, with the occurrence of these complications increasing progressively with increasing duration of follow up (1% at five years compared with 12% at 10 years). Adverse prognostic features were persistence of microscopic haematuria, proteinuria at presentation, and appreciable changes on renal biopsy. Eighty four patients had first degree relatives tested for haematuria; 30% of these families had another affected member. With long term follow up recurrent haematuria is associated with considerable morbidity and potential mortality.