[Show abstract][Hide abstract] ABSTRACT: The objectives of this study were to investigate pharmacokinetic and pharmacogenetic parameters during the conversion on a 1:1 (mg:mg) basis from a twice-daily (Prograf) to once-daily (Advagraf) tacrolimus formulation in pediatric kidney transplant recipients.
Twenty-four-hour pharmacokinetic profiles were analyzed before and after conversion in 19 stable renal transplant recipients (age 7-19 years). Tacrolimus pharmacokinetic parameters [area under the concentration-time curve (AUC0-24), minimum whole-blood concentration (Cmin), maximum whole-blood concentration (Cmax), and time to achieve maximum whole-blood concentration (tmax)] were compared between Tac formulations and between CYP3A5 and MDR1 genotypes after dose normalization.
Both AUC0-24 and Cmin decreased after conversion (223.3 to 197.5 ng.h/ml and 6.5 to 5.6 ng/ml; p = 0.03 and 0.01, respectively). However, the ratio of the least square means (LSM) for AUC0-24 was 90.8 %, with 90 % CI limits of 85.3 to 96.7 %, falling within bioequivalence limits. The CYP3A5 genotype influences the dose-normalized Cmin with the twice-daily formulation only.
Both tacrolimus formulations are bioequivalent in pediatric renal recipients. However, we observed a decrease in AUC0-24 and Cmin after the conversion, requiring close pharmacokinetic monitoring during the conversion period.
[Show abstract][Hide abstract] ABSTRACT: Preterm neonates are exposed at birth to high oxygen concentrations relative to the intrauterine environment. We have previously shown in a rat model that a hyperoxic insult results in a reduced nephron number in adulthood. Therefore, the aim of this study was to determine the effects of transient neonatal hyperoxia exposure on nephrogenesis. Sprague-Dawley rat pups were raised in 80% O2 or room air from P3 to P10. Pups (n = 12/group, 6 males and 6 females) were sacrificed at P5 (during active nephrogenesis) and at P10 (after the completion of nephrogenesis). Hyperoxia exposure resulted in a significant reduction in both nephrogenic zone width and glomerular diameter at P5, and a significantly increased apoptotic cell count; however, nephron number at P10 was not affected. HIF-1α expression in the developing kidney was significantly reduced following hyperoxia exposure. Systemic administration of the HIF-1α stabilizer dimethyloxalylglycine (DMOG) resulted in enhanced expression of HIF-1α and improved nephrogenesis: kidneys from hyperoxia-exposed pups treated with DMOG exhibited a nephrogenic zone width and glomerular diameter similar to room-air controls. These findings demonstrate that neonatal hyperoxia exposure results in impaired nephrogenesis, which may be at least in part HIF-1α-mediated. Although nephron number was not significantly reduced at the completion of nephrogenesis, early indicators of maldevelopment suggest the potential for accelerated nephron loss in adulthood. Overall, this study supports the premise that prematurely born neonates exposed to high oxygen levels after birth are vulnerable to impaired renal development.
PLoS ONE 12/2013; 8(12):e82421. · 3.53 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Supportive care as a bridge to transplant or recovery remains challenging in children suffering from acute liver failure (ALF). We report our experience in children using the Molecular Absorbent Recirculating System (MARS®).
Retrospective data from children receiving therapy using MARS® from October 2009 to October 2012 were included in this single-center retrospective study. Patient characteristics, clinical presentation and complications of ALF, clinical and biological data before and after each MARS® session, technical modalities and adverse events were recorded.
A total of six children underwent 17 MARS® sessions during the study period. Two adolescents were treated with the adult filter MARSFLUX® and four infants were treated with the MiniMARS® filter. The mean PEdiatric Logistic Dysfunction (PELOD) score at admission was 19 (range 11-33). All patients were mechanically ventilated, and four had acute kidney injury. The neurological course improved in one case, judged as stable in two cases and worsened in one case; data were unavailable in two cases. Mean serum ammonia levels decreased significantly following treatment with MARS® from an initial 89 ± 29 to 58 ± 35 mcmol/L (p = 0.02). No other significant biological improvement was observed. Hemodynamic status improved/remained unchanged in the adolescent group, but in the infants four of the seven sessions were poorly tolerated and two sessions were aborted. Three patients died, two were successfully transplanted and one recovered without transplantation.
In our experience, treatment with MARS® is associated with encouraging results in adolescents, but it needs modification for very sick infants to improve tolerance.
[Show abstract][Hide abstract] ABSTRACT: Incident vertebral fractures and lumbar spine bone mineral density (BMD) were assessed in the 12 months following glucocorticoid initiation in 65 children with nephrotic syndrome. The incidence of vertebral fractures was low at 12 months (6 %) and most patients demonstrated recovery in BMD Z-scores by this time point.
Vertebral fracture (VF) incidence following glucocorticoid (GC) initiation has not been previously reported in pediatric nephrotic syndrome.
VF was assessed on radiographs (Genant method); lumbar spine bone mineral density (LS BMD) was evaluated by dual-energy X-ray absorptiometry.
Sixty-five children were followed to 12 months post-GC initiation (median age, 5.4 years; range, 2.3-17.9). Three of 54 children with radiographs (6 %; 95 % confidence interval (CI), 2-15 %) had incident VF at 1 year. The mean LS BMD Z-score was below the healthy average at baseline (mean ± standard deviation (SD), -0.5 ± 1.1; p = 0.001) and at 3 months (-0.6 ± 1.1; p < 0.001), but not at 6 months (-0.3 ± 1.3; p = 0.066) or 12 months (-0.3 ± 1.2; p = 0.066). Mixed effect modeling showed a significant increase in LS BMD Z-scores between 3 and 12 months (0.22 SD; 95 % CI, 0.08 to 0.36; p = 0.003). A subgroup (N = 16; 25 %) had LS BMD Z-scores that were ≤-1.0 at 12 months. In these children, each additional 1,000 mg/m(2) of GC received in the first 3 months was associated with a decrease in LS BMD Z-score by 0.39 at 12 months (95 % CI, -0.71 to -0.07; p = 0.017).
The incidence of VF at 1 year was low and LS BMD Z-scores improved by 12 months in the majority. Twenty-five percent of children had LS BMD Z-scores ≤-1.0 at 12 months. In these children, LS BMD Z-scores were inversely associated with early GC exposure, despite similar GC exposure compared to the rest of the cohort.
Osteoporosis International 08/2013; · 4.04 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Identity development represents a central task of adolescence. Identity achievement is characterized by a coherent sense of who one is following a period of exploration and can help navigate the challenges of adulthood. This study examined identity within a quality of life (QOL) context in 85 adolescents with a renal transplant or with Type 1 diabetes in comparison to 90 healthy controls. Results revealed significant differences in ideological identity, with patients showing higher levels of diffusion and controls showing higher levels of foreclosure. No differences with respect to interpersonal identity, QOL, perceived control over the QOL domains, and perceived opportunities for growth and development were found. Future research should assess identity and QOL over a longer period of time to determine whether differences between chronically ill and healthy young adults can be detected.
Journal of Clinical Psychology in Medical Settings 05/2013; · 1.49 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Hepatorenal tyrosinemia (HT1, fumarylacetoacetate hydrolase deficiency, MIM 276700) can cause severe hepatic, renal and peripheral nerve damage. In Québec, HT1 is frequent and neonatal HT1 screening is practiced. Nitisinone (NTBC, Orfadin ®) inhibits tyrosine degradation prior to the formation of toxic metabolites like succinylacetone and has been offered to HT1 patients in Québec since 1994.
We recorded the clinical course of 78 Québec HT1 patients born between 1984 and 2004. There were three groups: those who never received nitisinone (28 patients), those who were first treated after 1month of age (26 patients) and those treated before 1month (24 patients). Retrospective chart review was performed for events before 1994, when nitisinone treatment began, and prospective data collection thereafter.
No hospitalizations for acute complications of HT1 occurred during 5731months of nitisinone treatment, versus 184 during 1312months without treatment (p<0.001). Liver transplantation was performed in 20 non-nitisinone-treated patients (71%) at a median age of 26months, versus 7 late-treated patients (26%, p<0.001), and no early-treated patient (p<0.001). No early-treated patient has developed detectable liver disease after more than 5years. Ten deaths occurred in non-nitisinone treated patients versus two in treated patients (p<0.01). Both of the latter deaths were from complications of transplantation unrelated to HT1. One probable nitisinone-related event occurred, transient corneal crystals with photophobia.
Nitisinone treatment abolishes the acute complications of HT1. Some patients with established liver disease before nitisinone treatment eventually require hepatic transplantation. Patients who receive nitisinone treatment before 1month had no detectable liver disease after more than 5years.
Molecular Genetics and Metabolism 07/2012; 107(1-2):49-54. · 2.83 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Bone mineral content (BMC) is known to be greater in the dominant arm after the age of 8 years. We studied a group of children and found that BMC sidedness gradually increased up to the age of 6 years and then remained stable into late adolescence. INTRODUCTION: Bone mineral content (BMC) exhibits sidedness in the arms after the age of 8 years, but it is not known whether BMC is greater in the dominant arm from birth or whether lateralization develops in early childhood. To address this, we examined bone mineral status in relation to handedness and age. METHODS: Subjects (N = 158) were children recently initiating glucocorticoids for underlying disease (leukemia 43 %, rheumatic conditions 39 %, nephrotic syndrome 18 %). Handedness was determined by questionnaire and BMC by dual-energy X-ray absorptiometry. RESULTS: Median age was 7.2 years (range, 1.5 to 17.0 years), 49 % was male, and the spine BMD Z-score was -0.9 (SD, 1.3). By linear regression, BMC sidedness in the arms was significantly related to age (r = 0.294, p = 0.0005). Breakpoint analysis revealed two lines with a knot at 6.0 years (95 % CI, 4.5-7.5 years). The formula for the first line was: dominant:nondominant arm BMC ratio = 0.029 × age [in years] + 0.850 (r = 0.323, p = 0.017). The slope of the second line was not different from 0 (p = 0.332), while the slopes for the two lines were significantly different (p = 0.027). CONCLUSIONS: These results show that arm BMC sidedness in this patient group develops up to age 6 years and then remains stable into late adolescence. This temporal profile is consistent with mechanical stimulation of the skeleton in response to asymmetrical muscle use as handedness becomes manifest.
Osteoporosis International 06/2012; · 4.04 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: To determine whether parental reporting of malodorous urine is associated with urinary tract infection (UTI) in children.
We conducted a prospective consecutive cohort study in the emergency department of a pediatric hospital from July 31, 2009 to April 30, 2011. All children aged between 1 and 36 months for whom a urine culture was prescribed for suspected UTI (ie, unexplained fever, irritability, or vomiting) were assessed for eligibility. A standardized questionnaire was administered to the parents by a research assistant. The primary outcome measure was a UTI.
Three hundred ninety-six children were initially enrolled, but 65 were excluded a posteriori either because a urine culture, although prescribed, was not done (11), was collected by bag (39), and/or showed gross contamination (25). Therefore, 331 children were included in the final analysis. Their median age was 12 months (range, 1-36). Criteria for UTI were fulfilled in 51 (15%). A malodorous urine was reported by parents in 57% of children with UTI and in 32% of children without UTI. On logistic regression, malodorous urine was associated with UTI (odds ratio 2.83, 95% confidence interval: 1.54-5.20). This association remained statistically significant when adjusted for gender and the presence of vesicoureteral reflux (odds ratio 2.73, 95% confidence interval: 1.46-5.08).
Parental reporting of malodorous urine increases the probability of UTI among young children being evaluated for suspected UTI. However, this association is not strong enough to definitely rule in or out a diagnosis of UTI.
[Show abstract][Hide abstract] ABSTRACT: Aims. To assess trends in the incidence of pediatric diarrhea-associated hemolytic uremic syndrome (D(+) HUS) and document long-term renal sequelae. Methods. We conducted a retrospective cohort study of children with D(+) HUS admitted to a tertiary care pediatric hospital in Montreal, Canada, from 1976 to 2010. In 2010, we recontacted patients admitted before 2000. Results. Of 337 cases, median age at presentation was 3.01 years (range 0.4-14). Yearly incidence peaked in 1988 and 1994-95, returning to near-1977 levels since 2003. Twelve patients (3.6%) died and 19 (5.6%) experienced long-term renal failure. Almost half (47%) The patients required dialysis. Need for dialysis was the best predictor of renal sequelae, accounting for 100% of severe complications. Of children followed ≥1 year (n = 199, mean follow-up 8.20 ± 6.78 years), 19 had severe and 18 mild-to-moderate kidney injury, a total sequelae rate, of 18.6%. Ten years or more after-HUS (n = 85, mean follow-up 15.4 ± 5.32 years), 8 (9.4%) patients demonstrated serious complications and 22 (25.9%) mild-to-moderate, including 14 (16%) microalbuminuria: total sequelae, 35.3%. Conclusions. Patients with D(+) HUS should be monitored at least 5 years, including microalbuminuria testing, especially if dialysis was required. The cause of the declining incidence of D(+)HUS is elusive. However, conceivably, improved public health education may have played an important role in the prevention of food-borne disease.
[Show abstract][Hide abstract] ABSTRACT: We evaluated the pharmacokinetic profile of intravenous ganciclovir and oral valganciclovir in transplant children. Median AUC0-24 concentrations obtained after intravenous and oral formulations were 22.9 µg•h/mL (range, 17-65.2) and 34.55 µg•h/mL (range, 20.8-84.2), respectively. After normalization on a 20 mg/kg/d valganciclovir dosage, the median AUC0-24 concentration was 37.6 µg•h/mL (range, 23.6-68).
[Show abstract][Hide abstract] ABSTRACT: Objective The objective of this article was to critically evaluate the causes of adverse drug events during the nurse medication administration process in paediatric care units in order to identify and prioritize interventions that need to be implemented. Methodology This is a failure mode, effects and criticality analysis (FMECA) study. A multidisciplinary committee composed of nurses, pharmacists, physicians and risk managers evaluated through consensus the process of administering medications at the Centre hospitalier universitaire de Sainte-Justine. By mapping the process, all the failure modes were identified and associated with at least one cause each. Using a summary grid, each failure mode was evaluated by rating frequency (from 1 to 9), likelihood of failure detection (from 0 to 100%) and severity (from 1 to 9) using adapted versions of already published scales. Results A 10-member committee was set up, and it met eight times between January and April 2010. In the two specialized paediatric units selected (n = 38 beds), an average number of approximately 20 000 drug doses was administered monthly from about 400 non-proprietary names. Through consensus, the committee identified 16 processes and 53 failure modes. While frequency and severity were based on perceptions that could be objectivized with local data and scientific documentation, the likelihood of detection was mainly based on individual perception. Conclusion FMECA is a useful approach to improve the medication process.
Journal of Evaluation in Clinical Practice 12/2011; · 1.58 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: In adults, small (< 50%) serum creatinine (SCr) increases predict mortality. It is unclear whether different baseline serum creatinine (bSCr) estimation methods affect findings of acute kidney injury (AKI)-outcome associations. We characterized pediatric AKI, evaluated the effect of bSCr estimation approaches on AKI-outcome associations and evaluated the use of small SCr increases to predict AKI development.
We conducted a retrospective cohort database study of children (excluding postoperative cardiac or renal transplant patients) admitted to two pediatric intensive care units (PICUs) for at least one night in Montreal, QC, Canada. The AKI definition was based on the Acute Kidney Injury Network staging system, excluding the requirement of SCr increase within 48 hours, which was impossible to evaluate on the basis of our data set. We estimated bSCr two ways: (1) the lowest SCr level in the three months before admission or the average age- and gender-based norms (the standard method) or (2) by using average norms in all patients. Outcomes were PICU mortality and length of stay as well as required mechanical ventilation. We used multiple logistic regression analysis to evaluate AKI risk factors and the association between AKI and mortality. We used multiple linear regression analysis to evaluate the effect of AKI on other outcomes. We calculated diagnostic characteristics for early SCr increase (< 50%) to predict AKI development.
Of 2,106 admissions (mean age ± SD = 5.0 ± 5.5 years; 47% female), 377 patients (17.9%) developed AKI (using the standard bSCr method) during PICU admission. Higher Pediatric Risk of Mortality score, required mechanical ventilation, documented infection and having a bSCr measurement were independent predictors of AKI development. AKI was associated with increased mortality (adjusted odds ratio (OR) = 3.7, 95% confidence interval (95% CI) = 2.1 to 6.4, using the standard bSCr method; OR = 4.5, 95% CI = 2.6 to 7.9, using normative bSCr values in all patients). AKI was independently associated with longer PICU stay and required mechanical ventilation. In children with no admission AKI, the initial percentage SCr increase predicted AKI development (area under the curve = 0.67, 95% CI = 0.60 to 0.74).
AKI is associated with increased mortality and morbidity in critically ill children, regardless of the bSCr used. Paying attention to small early SCr increases may contribute to early AKI diagnosis in conjunction with other new AKI biomarkers.
Critical care (London, England) 06/2011; 15(3):R146. · 5.04 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Hyperammonemia results from reduction of hepatocyte function or enzyme of urea cycle deficiency. Hyperammonemia contributes to cerebral edema that may lead to cerebral herniation. The threshold of toxicity of ammonemia is unknown.
We conducted a retrospective observational study in our pediatric intensive care unit. All children who developed hyperammonemia from January 2000 to April 2009 were included. Clinical and laboratory data at admission, specific treatments implemented, and ammonemias the first 7 days after inclusion were collected. The outcome assessed was 28 day mortality. Risk of mortality was estimated by a logistic regression model.
Ninety patients with liver failure (63.3%) and primary or secondary urea cycle defect (23.3%) were included. Patients with urea cycle defects were more likely to receive ammonia scavengers than patients with liver failure (47.6% versus 3.5%). The 28 day mortality rate was 31.1%. Risk of mortality increased according to the ammonemia within 48 h: odds ratio 1.5, 1.9, 3.3, 2.4 for ammonemia above 100, 150, 200, and 300 μmol/L, respectively. Peak ammonemia ≥200 μmol/L within the first 48 h was an independent risk factor for mortality, with greater risk found in liver failure than in urea cycle defect.
Our study identifies a threshold of exposure to ammonia (≥200 μmol/L) above which mortality increases significantly, especially in liver failure. Specific treatments of hyperammonemia are rarely used in liver failure when compared with urea cycle defect even though use of ammonia scavengers may help to decrease ammonemia.
Journal of Hepatology 05/2011; 56(1):123-8. · 9.86 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: The management and optimal care for the pediatric patient with chronic kidney disease requires attention not only to medical management, but also special focus on the psychosocial and developmental factors of children which is complicated by the presence of other disease-related complications. In recent years, specialized chronic kidney disease and predialysis clinics have been set up to facilitate and improve the quality of care of these patients with a multidisciplinary organisation and coordinated management approaches of a renal team. We present our experience in establishing such a renal management clinic named “Prévoir” for children with chronic kidney disease at Sainte-Justine Hospital.
[Show abstract][Hide abstract] ABSTRACT: The management and optimal care for the pediatric patient with chronic kidney disease requires attention not only to medical management, but also special focus on the psychosocial and developmental factors of children which is complicated by the presence of other disease-related complications. In recent years, specialized chronic kidney disease and predialysis clinics have been set up to facilitate and improve the quality of care of these patients with a multidisciplinary organisation and coordinated management approaches of a renal team. We present our experience in establishing such a renal management clinic named "Prévoir" for children with chronic kidney disease at Sainte-Justine Hospital.
[Show abstract][Hide abstract] ABSTRACT: To describe attitudes of paediatricians and paediatric nephrologists regarding antibiotic prophylaxis for urinary tract infection (UTI) and determine the factors associated with its use.
A self-administered questionnaire was mailed to Canadian paediatricians (1136) and paediatric nephrologists (42).
The response rate was 58.1% (684 physicians); 436 who had made a decision about antibiotic prophylaxis for childhood UTI in the previous year were included in the analysis. Of these, 407 (93.3%) were certified in paediatrics and 29 (6.7%) were paediatric nephrologists. Most respondents prescribed prophylaxis for children with grade III-V vesicoureteral reflux (VUR) (96.5%-98%); 69.8 and 92.8% prescribed it for children with grades I and II VUR, respectively. Factors significantly associated with use of prophylaxis for children with grade I VUR were frequency of decision-making about prophylaxis, city size and province. Fifteen percent of physicians felt that their practice regarding antibiotic prophylaxis for children with VUR was evidence based. A hundred one respondents (24.3%) prescribed prophylaxis for infants with a first febrile UTI in the absence of VUR. Nineteen percent felt that their practice regarding antibiotic prophylaxis for these infants was evidence based. Prescription of prophylaxis for children >12 months with recurrent UTI in the absence of VUR was influenced by frequency of pyelonephritis (88.5% of respondents) and presence of voiding dysfunction (53.8%). Nine percent of physicians felt that their practice for these children was evidence based.
Opinions of Canadian paediatricians and paediatric nephrologists regarding antibiotic prophylaxis for UTI in children vary widely, probably because of the paucity of solid evidence about prophylaxis.
Journal of Paediatrics and Child Health 10/2008; 44(10):572-8. · 1.19 Impact Factor