The development of the Belgian paediatric clinical trial network.

Paediatric clinical trials are critical to ensure that medications prescribed to children are safe and effective. However, evidence-based dosing and labelling of such medications remain limited, and most clinical trials in paediatrics fail. Factors for lack of trial completion include performance at site level (limited patient recruitment, limited site staff experience and lack of infrastructure), the sponsor team (limited paediatric specific expertise in design, uncertainties on robustness of biomarkers or outcome variables) as well as regulatory and administrative burdens. As a result of the growing demand for site support, the Belgian Paediatric Clinical Research Network (BPCRN) established in 2009 has been relaunched in 2018 to improve paediatric clinical trials, with the support of innovative-medicines-initiative 2 (IMI2) pan-European network conect4children (c4c) and the transatlantic network I-ACT for Children (US).This paper highlights the formation of the BPCRN and the practical insights it offers for advancing paediatric clinical trials through national networks. A national network can improve trial quality, safety and efficiency, provide clinical research expertise, identify suitable sites, and help with troubleshooting of common trial issues. The BPCRN's centralized approach has advanced paediatric clinical trials by streamlining communication and standardizing trial conduct. Challenges and opportunities have arisen, including a relaunch in 2018, orphan medicine trials, and network sustainability. Collaboration between network activities, government support, site-level improvements, efficient communication, and interaction with industry are key to achieve lasting transformation in paediatric medicine research.

Population Pharmacokinetics of Unbound and Total Teicoplanin in Critically Ill Pediatric Patients.

BACKGROUND AND OBJECTIVES: Teicoplanin is a highly protein-bound antibiotic, increasingly used to treat serious Gram-positive infections in critically ill children. Maturational and pathophysiological intensive care unit-related changes often lead to altered pharmacokinetics. In this study, the objectives were to develop a pediatric population-pharmacokinetic model of unbound and total teicoplanin concentrations, to investigate the impact of plasma albumin levels and renal function on teicoplanin pharmacokinetics, and to evaluate the efficacy of the current weight-based dosing regimen. METHODS: An observational pharmacokinetic study was performed and blood samples were collected for quantification of unbound and total concentrations of teicoplanin after the first dose and in assumed steady-state conditions. A population-pharmacokinetic analysis was conducted using a standard sequential approach and Monte Carlo simulations were performed for a probability of target attainment analysis using previously published pharmacokinetic-pharmacodynamic targets. RESULTS: A two-compartment model with allometric scaling of pharmacokinetic parameters and non-linear plasma protein binding best described the data. Neither the inclusion of albumin nor the renal function significantly improved the model and no other covariates were supported for inclusion in the final model. The probability of target attainment analysis showed that the standard dosing regimen does not satisfactory attain the majority of the proposed targets. CONCLUSIONS: We successfully characterized the pharmacokinetics of unbound and total teicoplanin in critically ill pediatric patients. The highly variable unbound fraction of teicoplanin could not be predicted using albumin levels, which may support the use of therapeutic drug monitoring of unbound concentrations. Poor target attainment was shown for the most commonly used dosing regimen, regardless of the pharmacokinetic-pharmacodynamic target evaluated.

Acid-base disturbances in dehydrated patients with cystic fibrosis : four case reports with review of literature.

Most episodes of vomiting, reduced intake and diarrhoea in children can be evaluated and treated without additional tests. However, when the degree of clinical dehydration is not in line with the patient's medical history, other diagnoses should be suspected. In the presence of a hyponatraemic hypochloraemic metabolic alkalosis, cystic fibrosis (CF) should be included in the differential diagnosis, especially if there is failure to thrive even in the absence of respiratory symptoms. Furthermore, young patients diagnosed with CF have a higher risk for an acute electrolyte decompensation caused by increased salt and fluid losses. We present 4 paediatric cases to raise the awareness of electrolyte disturbances in CF patients.

The long-term added value of voiding school for children with refractory non-neurogenic overactive bladder: an inpatient bladder rehabilitation program.

INTRODUCTION & BACKGROUND: Despite adequate management, 20% of children with overactive bladder (OAB) syndrome fail to improve their bladder function. To approach the need for alternative strategies, an inpatient bladder rehabilitation 'voiding school' program was established. OBJECTIVE: The objective of this study was to evaluate the short- and long-term (1-year follow-up) outcome of this voiding school program in children with refractory OAB. In addition, the authors aimed to identify which children achieved the best outcomes with this voiding school program. STUDY DESIGN: The charts of all children (n = 357, mean age: 9.7 ± 2.0 years, 63.6% boys) with refractory OAB who attended voiding school between 2000 and 2010 were reviewed. A linear mixed model with random intercept was used to evaluate the incontinence (expressed by enuresis and daytime incontinence voiding scores) and maximal voiding volume (MVV). RESULTS & DISCUSSION: This study demonstrated an overall beneficial long-term effect of the inpatient program on day- and night-time incontinence, in which 36.6% of children achieved dryness during day- and night-time. In addition, the mean overall decline in the number of wet nights and days declined with 4 extra dry days and/or nights per week, in comparison with the level of continence before attending the voiding school program. In contrast, only a temporary increase in MVV was seen, however, without relapse incontinence. At last, the authors identified the negative impact of decreasing age, male sex, dysfunctional voiding and nocturnal polyuria on the overall outcome of the inpatient program. CONCLUSION: An inpatient rehabilitation 'voiding school' program is a successful and safe treatment modality for children with refractory OAB that results in long-term significant increase of continence, as well as amelioration in degree of severity. The worst outcomes of this voiding school program were detected in children with young age, who were boys, or had associated nocturnal polyuria, dysfunctional voiding, and/or faecal incontinence.

Circadian Rhythm of Glomerular Filtration and Solute Handling Related to Nocturnal Enuresis.

PURPOSE: Although nocturnal polyuria in patients with monosymptomatic enuresis can largely be explained by the decreased nocturnal vasopressin secretion hypothesis, other circadian rhythms in the kidney also seem to have a role. We recently documented an absent day/night rhythm in a subgroup of desmopressin refractory cases. We explore the importance of abnormal circadian rhythm of glomerular filtration and tubular (sodium, potassium) parameters in patients with monosymptomatic enuresis. MATERIALS AND METHODS: In this retrospective study of a tertiary enuresis population we collected data subsequent to a standardized screening (International Children's Continence Society questionnaire), 14-day diary for nocturnal enuresis and diuresis, and 24-hour concentration profile. The study population consisted of 139 children with nocturnal enuresis who were 5 years or older. Children with nonmonosymptomatic nocturnal enuresis were used as controls. RESULTS: There was a maintained circadian rhythm of glomerular filtration, sodium, osmotic excretion and diuresis rate in children with monosymptomatic and nonmonosymptomatic nocturnal enuresis, and there was no difference between the 2 groups. Secondary analysis revealed that in patients with nocturnal polyuria (with monosymptomatic or nonmonosymptomatic nocturnal enuresis) circadian rhythm of glomerular filtration, sodium and osmotic excretion, and diuresis rate was diminished in contrast to those without nocturnal polyuria (p <0.001). CONCLUSIONS: Circadian rhythm of the kidney does not differ between patients with nonmonosymptomatic and monosymptomatic enuresis. However, the subgroup with enuresis and nocturnal polyuria has a diminished circadian rhythm of nocturnal diuresis, sodium excretion and glomerular filtration in contrast to children without nocturnal polyuria. This observation cannot be explained by the vasopressin theory alone.

Propylthiouracil induced ANCA-associated vasculitis in a 14-year-old girl.

BACKGROUND: Antineutrophil cytoplasmic antibodies (ANCAs) are the serologic hallmark of ANCA-associated primary small-vessel vasculitides (AAVs), but these antibodies have also been described in other autoimmune diseases such as inflammatory bowel diseases. Furthermore, different drugs are linked to the induction of ANCA, including propylthiouracil (PTU). However progression into clinical overt vasculitis is less common. CASE-DIAGNOSIS/TREATMENT: We describe the case of a young girl with Graves' disease presenting with fatigue, fever, episcleritis and arthritis. The unexpected double myeloperoxidase/proteinase 3-ANCA positivity triggered a multidisciplinary diagnostic work-up and resulted in the diagnosis of a clinically overt PTU-induced AAV. After PTU-withdrawal and treatment with high-dose corticosteroids, a favorable clinical and biochemical evolution was obtained. CONCLUSIONS: The use of PTU in the management of hyperthyroidism is not considered first-line treatment in Europe and is even less commonly used in children. Nevertheless, pediatricians should be aware of the possibility of PTU-induced AAV, especially in the presence of multiple ANCA reactivities. Therefore, the use of this drug should be weighed carefully in children.

Pituitary adenylate cyclase-activating polypeptide deficiency associated with increased platelet count and aggregability in nephrotic syndrome.

BACKGROUND: Pituitary adenylate cyclase-activating polypeptide (PACAP) was recently identified as an inhibitor of megakaryopoiesis and platelet aggregability. OBJECTIVE: We studied PACAP levels in children with nephrotic syndrome (NS), which is associated with thrombocytosis, platelet hyperaggregability, and an increased risk of thrombosis. PATIENTS/METHODS: In four children with congenital NS (CNS) and 24 children with idiopathic NS (INS), plasma and urine levels of PACAP and ceruloplasmin were measured, as were platelet counts and platelet aggregation responses to collagen. In CNS patients, in vitro megakaryopoiesis and nuclear factor-κB expression in platelet lysates were also measured. All tests were performed during the nephrotic state and the non-nephrotic state. RESULTS: Urinary losses of PACAP and ceruloplasmin were observed during the nephrotic state, and disappeared during the non-nephrotic state. Plasma PACAP deficiency was more pronounced in CNS patients than in INS patients. Thrombocytosis was observed in all CNS patients and in 11 of 29 INS patients during the nephrotic state. During the PACAP-deficient state, in vitro megakaryopoiesis was increased for CNS patients, and this effect could be reversed by the addition of recombinant PACAP. Platelet hyperaggregability was observed during the nephrotic state in both CNS and INS patients. In INS patients, the addition of recombinant PACAP to patients' platelets was studied, and resulted in decreased aggregation during the nephrotic state. Platelet aggregation correlated inversely with plasma PACAP levels, but not with serum albumin levels. CONCLUSIONS: We demonstrate urinary losses of PACAP and plasma PACAP deficiency in children with NS, associated with thrombocytosis and platelet hyperaggregability.

Arterial hypertension related to the injection of onabotulinumtoxinA in the detrusor.

OBJECTIVE AND IMPORTANCE: We want to report on a first case reported of a 50-year-old female with repetitive and clinical significant hypertension after each injection of onabotulinumtoxinA. This is a retrospective chart review and prospective evaluation of the natriuresis and blood pressure at baseline and after injection therapy. The aim was to explore the mechanism of action of this apparent onabotulinumtoxinA related hypertension. CASE PRESENTATION: Retrospectively hypertension appeared after 7 days and vanished after 4-5 months following injection of 300 units of onabotulinumtoxinA in the detrusor, bladder symptoms disappeared after 2 weeks and reoccurred after 5 months. Urological, nephrological, cardiological and endocrinological evaluations were normal. INTERVENTION: In the prospective evaluation a 3-day bladder diary at baseline revealed a bladder capacity of 131 ± 57 ml and at 1 month when full effect was experienced 173 ± 50 ml. At 1 month there were no leakages with six episodes of intermittent catheterization per day. The 24-hour blood pressure registration demonstrated the onset of hypertension at day 7 together with a reversal of the urinary sodium/creatinine ratios on the renal function profile. CONCLUSION: The increasing natriuresis coinciding with the hypertension is a normal compensatory mechanism suggesting that the hypertension has a central cause rather than it is caused by haematogenous spreading.

Sleep fragmentation and increased periodic limb movements are more common in children with nocturnal enuresis.

AIM: To determine sleep fragmentation in children with nocturnal enuresis (NE). METHODS: Paediatricians assessed NE parameters in children referred to an enuresis clinic. Control subjects, matched by age and gender and without incontinence or (un)treated NE, were recruited from the paediatric sleep clinic regardless of their sleep problem. Sleep was investigated by one overnight video-polysomnography in both groups. RESULTS: The study group comprised 67 children with proven NE (50 boys and 17 girls between six and 16 years: 11.1 ± 2.8 SD). They were matched with 67 control subjects (47 boys and 20 girls aged between six and 16 years: 11.0 ± 2.9 SD). Children with NE had a higher incidence of periodic limb movements associated with cortical arousals in their sleep. They displayed significant higher periodic limb movement index, arousal index and awakening index than the control group. CONCLUSION: Children with NE displayed higher sleep fragmentation and periodic limb movements in sleep than the control children with a possible sleep disorder without NE. The findings emphasise the central involvement of the pathophysiology of NE and the multifactorial nature of the condition.

Prospective evaluation of clinical voiding reeducation or voiding school for lower urinary tract conditions in children.

PURPOSE: We conducted a prospective controlled study evaluating the results of a clinical voiding reeducation program (voiding school) for treatment of lower urinary tract conditions in children compared to no treatment. MATERIALS AND METHODS: A total of 38 children with nonneurogenic lower urinary tract conditions were included in the study. Controls, consisting of 15 children on the waiting list for the same program, received no treatment. The clinical voiding reeducation program consisted of instruction on voiding and drinking, individualized voiding diaries, pelvic floor biofeedback training, uroflowmetry, alarm therapy, cognitive therapy and psychological support. Data on voiding, drinking, pelvic floor control, voided volume, uroflow, incontinence and stool habits were gathered before the program, during the program and 6 months after the program. In the control group the same data were gathered. RESULTS: In the study group a positive effect of voiding school was observed in 92% of children, with 42% becoming completely dry, 24% improving from incontinence during the day and night to incontinence during the day or night only, and 26% remaining incontinent. In all patients the number and amount of incontinence episodes decreased. In the control group no differences were observed between the start of study and 6 months later. The study group did significantly better on voided volume and incontinence compared to controls. CONCLUSIONS: In this prospective controlled study a positive effect was noted on voided volume and incontinence with a clinical voiding reeducation program (voiding school).

Oral lyophylizate formulation of desmopressin: superior pharmacodynamics compared to tablet due to low food interaction.

PURPOSE: Desmopressin is a standard treatment for monosymptomatic nocturnal enuresis. Different formulations are promoted as bioequivalent, although these claims are not supported by comparative pharmacodynamic data in children. Food interaction is known to influence the bioavailability of desmopressin. We compared the pharmacodynamics of the 2 most frequently used desmopressin formulations, tablet and lyophilizate, with a standardized meal, allowing extrapolation to clinical reality, where the interval between evening meal and medication intake is limited for school-age children. We hypothesized there would be a faster pharmacodynamic response, and greater concentrating and antidiuretic activity for the fast dissolving (melt) formulation compared to the tablet with simultaneous food intake. MATERIALS AND METHODS: Two tests were performed on separate days in identical standardized conditions, starting with a 15 ml/kg water load. After achieving maximal diluting capacity a standardized meal was administered, followed by desmopressin tablet (t test) or melt (M-test). Diuresis rate and urinary osmolality were measured hourly. Paired data from 4 girls and 15 boys with a mean age of 12.1 years were obtained. RESULTS: In the early response phase more than 25% of patients had a higher diuresis rate with tablet vs melt formulation, reaching statistical significance in the plateau phase (urine collected at hours 3 to 5, p <0.02) and in duration of action (urine collected at hours 5 to 8, p <0.005). For desmopressin melt smaller standard deviations in diuresis rate were remarkable. Concentrating capacity demonstrated no significant differences between formulations in the early response phase, in contrast to the plateau phase (p <0.036) and duration of action (p <0.001). CONCLUSIONS: With meal combination desmopressin melt formulation has a superior pharmacodynamic profile to tablet, making it more suitable for the younger age group with a limited interval between meal and drug administration.

Neurocognitive functioning in school-aged cystinosis patients.

INTRODUCTION: Cystinosis is an autosomal recessive disorder leading to intralysosomal cystine accumulation in various tissues. It causes renal Fanconi syndrome and end stage renal failure around the age of 10 years if not treated with cysteamine. Children with cystinosis seem to have a normal intelligence but frequently show learning difficulties. These problems may be due to specific neurocognitive deficits rather than impaired renal function. Whether cysteamine treatment can improve cognitive functioning of cystinosis patients is thus far unknown. We aim to analyze neurocognitive functioning of school-aged cystinosis patients treated with cysteamine in order to identify specific deficits that can lead to learning difficulties. PATIENTS AND METHODS: Fourteen Dutch and Belgian school-aged cystinosis patients were included. Glomerular filtration rate was estimated using the Schwartz formula. Children were tested for general intelligence, visual-motor integration, inhibition, interference, sustained attention, accuracy, planning, visual memory, processing speed, motor planning, fluency and speed, and behavioural and emotional functioning using standardized methods. RESULTS: Glomerular filtration rate ranged from 22 to 120 ml min(-1) 1.73 m(-2). Median full-scale intelligence was below the average of a normal population (87, range 60-132), with a discrepancy between verbal (median 95, range 60-125) and performance (median 87, range 65-130) intelligence. Over 50% of the patients scored poorly on visual-motor integration, sustained attention, visual memory, planning, or motor speed. The other tested areas showed no differences between patients' and normal values. CONCLUSION: Neurocognitive diagnostics are indicated in cystinosis patients. Early recognition of specific deficits and supervision from special education services might reduce learning difficulties and improve school careers.

Desmopressin resistant nocturnal polyuria may benefit from furosemide therapy administered in the morning.

PURPOSE: There is increasing evidence that a subgroup of patients with monosymptomatic nocturnal enuresis and nocturnal polyuria resistant to desmopressin may have an abnormal circadian rhythm of renal tubular sodium handling. The pathogenesis of this phenomenon remains to be elucidated. If the increased sodium excretion overnight results in desmopressin resistance, decreasing the sodium excretion overnight may result in subsequently better desmopressin response. MATERIALS AND METHODS: We conducted a pilot study of the anti-enuretic and antidiuretic effects of desmopressin combined with 0.5 mg/kg furosemide daily in patients with desmopressin resistant nocturnal polyuria despite dietary sodium and protein restriction. Values were plotted against the reference frame of a desmopressin responsive enuresis group. RESULTS: Baseline values revealed significantly lower urinary osmolality and higher diuresis rate overnight compared to the reference population (monosymptomatic nocturnal enuresis desmopressin responders). Introduction of desmopressin resulted in normalization of nocturnal urinary osmolality. However, nocturnal polyuria persisted, despite reaching maximal urinary concentration overnight. Although protein and sodium restriction resulted in a significant decrease in urinary osmolality and diuresis rate, the difference was not clinically important enough to reach normal values or to achieve continence. Furosemide in the morning resulted in a significant increase in diuresis and osmotic and sodium excretion during the day, and decreased nighttime diuresis and osmotic excretion. In 9 of 12 patients the nocturnal antidiuretic effect resulted in an anti-enuretic effect, defined as enuresis less than 1 wet night per month. In 3 patients insufficient anti-enuretic effects were obtained despite significant antidiuresis. CONCLUSIONS: This pilot study clearly demonstrates that introduction of early morning furosemide results in a significantly lower nocturnal diuresis rate. Reduced diuresis associated with unchanged urinary osmolality results in decreased nocturnal osmotic excretion in compensation for increased osmotic (sodium) excretion during the daytime.

Nocturnal polyuria is related to 24-hour diuresis and osmotic excretion in an enuresis population referred to a tertiary center.

PURPOSE: Primary nocturnal enuresis is a heterogeneous disorder, causing a mismatch between overnight diuresis volume and functional bladder capacity. Despite increasing insights in pathogenesis, lack of efficacy of the available treatments is a major problem. We evaluated characteristics of bladder volume and diuresis rate in patients with nocturnal enuresis referred to a tertiary enuresis center. MATERIALS AND METHODS: Noninvasive screening including maximal voided volume, 24-hour circadian rhythm of diuresis and osmotic excretion from 1,000 consecutive patients. RESULTS: Of the patients referred as having monosymptomatic nocturnal enuresis 32% were subsequently classified as having nonmonosymptomatic nocturnal enuresis. Differences in bladder volume and nocturnal diuresis characteristics between the monosymptomatic nocturnal enuresis and nonmonosymptomatic nocturnal enuresis groups were minimal. CONCLUSIONS: The most common observation is a nocturnal diuresis volume greater than maximal voided volume, which in both groups can be caused by nocturnal polyuria or small bladder volume for patient age. The most striking observation is that the positive correlation between nocturnal diuresis volume rate and nocturnal osmotic excretion and 24-hour fluid intake is significantly higher than with the inversed urinary osmolality overnight, which is not only unexpected based on the theory of the primary suppression of vasopressin levels overnight, but also points to a more important role for nutritional and fluid intake than accepted, if not in the primary pathogenesis, then at least in therapy resistance.

Nocturnal polyuria is related to absent circadian rhythm of glomerular filtration rate.

PURPOSE: Monosymptomatic nocturnal enuresis is frequently associated with nocturnal polyuria and low urinary osmolality during the night. Initial studies found decreased vasopressin levels associated with low urinary osmolality overnight. Together with the documented desmopressin response, this was suggestive of a primary role for vasopressin in the pathogenesis of enuresis in the absence of bladder dysfunction. Recent studies no longer confirm this primary role of vasopressin. Other pathogenetic factors such as disordered renal sodium handling, hypercalciuria, increased prostaglandins and/or osmotic excretion might have a role. So far, little attention has been given to abnormalities in the circadian rhythm of glomerular filtration rate. We evaluated the circadian rhythm of glomerular filtration rate and diuresis in children with desmopressin resistant monosymptomatic nocturnal enuresis and nocturnal polyuria. MATERIALS AND METHODS: We evaluated 15 children (9 boys) 9 to 14 years old with monosymptomatic nocturnal enuresis and nocturnal polyuria resistant to desmopressin treatment. The control group consisted of 25 children (12 boys) 9 to 16 years old with monosymptomatic nocturnal enuresis without nocturnal polyuria. RESULTS: Compared to the control population, children with nocturnal polyuria lost their circadian rhythm not only for diuresis and sodium excretion but also for glomerular filtration rate. CONCLUSIONS: Patients with monosymptomatic nocturnal enuresis and nocturnal polyuria lack a normal circadian rhythm for diuresis and sodium excretion, and the circadian rhythm of glomerular filtration rate is absent. This absence of circadian rhythm of glomerular filtration rate and/or sodium handling cannot be explained by a primary role of vasopressin, but rather by a disorder in circadian rhythm of renal glomerular and/or tubular functions.

Partial response to intranasal desmopressin in children with monosymptomatic nocturnal enuresis is related to persistent nocturnal polyuria on wet nights.

PURPOSE: The anti-incontinence effect of desmopressin resides in its concentrating capacity and antidiuretic properties. We compared nighttime urine production on wet and dry nights in a highly selected study population of children with monosymptomatic nocturnal enuresis associated with proved nocturnal polyuria who responded only partially to intranasal desmopressin. MATERIALS AND METHODS: We retrospectively analyzed 39 home recordings of nocturnal urine production and maximum voided volume in children 7 to 19 years old (median 8.9) with monosymptomatic nocturnal enuresis with nocturnal polyuria who had a partial response to desmopressin. Nocturnal diuresis volume and maximum voided volume were documented at baseline (14 days) and during 3 months of followup. RESULTS: Baseline nocturnal urine output (439 +/- 39 ml) was significantly higher than the maximum voided volume (346 +/- 93 ml, p <0.01). During desmopressin treatment nocturnal urine output on wet nights (405 +/- 113 ml) differed significantly from that on dry nights (241 +/- 45 ml). During treatment nocturnal urine output on wet nights did not differ from baseline values. CONCLUSIONS: Persistence of nocturnal polyuria on wet nights in partial desmopressin responders may be related to an insufficient antidiuretic effect. In addition to poor compliance and suboptimal dosing, the poor bioavailability of intranasal desmopressin may be a pathogenic factor. Further prospective studies are needed.

Characteristics of a tertiary center enuresis population, with special emphasis on the relation among nocturnal diuresis, functional bladder capacity and desmopressin response.

PURPOSE: We evaluated pretreatment values of circadian rhythm of urine production and urine osmolality in children with different subtypes of monosymptomatic nocturnal enuresis, and investigated their predictive value for desmopressin response. MATERIALS AND METHODS: We assessed 125 consecutive patients with monosymptomatic nocturnal enuresis, nocturnal polyuria and normal functional bladder capacity who were treated with desmopressin for a median of 17 months (range 3 to 100). Patients were characterized according to the desmopressin response as full responders or nonfull responders. Baseline parameters were obtained from a 2-week home recording diary. Results were compared with 125 consecutive children with monosymptomatic nocturnal enuresis and reduced functional bladder capacity. RESULTS: No differences in pretreatment values of functional bladder capacity, circadian rhythm of urine production or urine osmolality were found between desmopressin full responders and nonfull responders. Patients with nocturnal polyuria had a significantly higher 24-hour diuresis volume compared to children with reduced functional bladder capacity. Some children with reduced functional bladder capacity also had nocturnal polyuria. CONCLUSIONS: Our findings show that the characteristics of nocturnal polyuria in patients with monosymptomatic nocturnal enuresis and normal functional bladder capacity do not predict desmopressin response. The wide overlap among the different subgroups suggests that dividing patients with monosymptomatic nocturnal enuresis into those with reduced functional bladder capacity and those with desmopressin responsive nocturnal polyuria might be insufficient. Patients with nocturnal polyuria and normal functional bladder capacity have a significantly higher daytime and nighttime diuresis volume compared to children with reduced functional bladder capacity, suggesting a direct correlation between daytime fluid intake and nocturnal diuresis rate. Some children with reduced functional bladder capacity also have nocturnal polyuria.

Renal functional changes in relation to hemodynamic parameters during exercise test in normoalbuminuric insulin-dependent children.

AIM: To examine the relationship between filtration fraction and systemic vasculopathy, in normoalbuminuric insulin-dependent diabetic adolescents. METHODS: We calculated filtration fraction from measured glomerular filtration rate and renal plasma flow during a hypotonic saline perfusion test in 30 normotensive adolescent diabetic patients (9-19 years), with a mean duration of diabetes of 7.4 years. Blood pressure and heart rate were measured in basal conditions, during a 24-h ambulatory monitoring and during a dynamic exercise test on a cycle ergometer and peripheral vascular resistance was calculated. RESULTS: Filtration fraction was increased in the diabetic children compared with controls (30+/-6% vs. 22+/-4%, p<0.001), while renal plasma flow was significantly lower (453+/-133 mL/min/1.73 m2 vs. 593+/-155 mL/min/1.73 m2, p<0.001). Peripheral vascular resistance was significantly higher at peak exercise in diabetic children compared to controls (16.3+/-1.3 mmHg/L min m2 vs. 11.4+/-0.5 mmHg/L min m2, p<0.01). CONCLUSION: These results indicate that in young patients with IDDM, without apparent nephropathy or apparent systemic vasculopathy, filtration fraction is increased, suggesting an increased intraglomerular pressure. The associated reduced decrease of peripheral vascular resistance (increased diastolic blood pressure during exercise) suggests that renal functional abnormalities may be partly explained by a systemic vasculopathy, also present in the kidney.

Renal replacement therapy in acute renal failure in children.

Acute renal failure in children differs from adult patients in incidence, pathogenesis and size of the patient, but outcome is significantly better. Specific problems are access and haemodynamic stability. Where increasing reporting on the use of CRRT in children seems to convince that CRRT is the treatment of choice, we have to stress that there is no evidence for this statement. Part of this misunderstanding is that both peritoneal and haemodialysis techniques from chronic renal replacement therapy (RRT) are simply extrapolated to intensive care setting. In this paper we want to elaborate on several adaptations in the dialysis-prescription of both peritoneal dialysis and haemodialysis in the ARF setting, which may improve efficacy and outcome. Introduction of new peritoneal dialysis catheter techniques, the cyclers, bicarbonate solutions, combined glucose/amino acid solutions, and low sodium-solutions have overcome many of the inconveniences of the old CAPD-technique. Slow SLED haemodialysis, with an ambulant Genius haemodialyser, with the use of ultra pure water adds to the benefits of conventional haemodialysis (monitoring, safetyness) to better haemodynamic stability of CRRT techniques.

Mesalazine interstitial nephritis presenting as colitis ulcerosa exacerbation.

Mesalazine is the first line treatment in paediatric inflammatory bowel disease (IBD). There are several reports in the literature about nephrotoxicity (1/150 treated patients), from renal insufficiency to reversible nephritis. It is currently advised to follow creatinine in patients treated with mesalazine during the first 5 years of treatment; however this may reveal the problem too late. As demonstrated in this paediatric case, a high degree of clinical suspicion is needed to diagnose the side effects before irreversible kidney damage occurs. Since the treatment of IBD exacerbation and mesalazine induced interstitial nephritis is based upon steroids, delayed diagnosis of the latter is at risk.