Elisabeth M Hodson

Antibiotic Prophylaxis and Recurrent Urinary Tract Infection in Children

BACKGROUND Antibiotics are widely administered to children with the intention of preventing urinary tract infection, but adequately powered, placebo-controlled trials regarding efficacy are lacking. This study from four Australian centers examined whether low-dose, continuous oral antibiotic therapy prevents urinary tract infection in predisposed children. METHODS We randomly assigned children under the age of 18 years who had had one or more microbiologically proven urinary tract infections to receive either daily trimethoprim-sulfamethoxazole suspension (as 2 mg of trimethoprim plus 10 mg of sulfamethoxazole per kilogram of body weight) or placebo for 12 months. The primary outcome was microbiologically confirmed symptomatic urinary tract infection. Intention-to-treat analyses were performed with the use of time-to-event data. RESULTS From December 1998 to March 2007, a total of 576 children (of 780 planned) underwent randomization. The median age at entry was 14 months; 64% of the patients were girls, 42% had known vesicoureteral reflux (at least grade III in 53% of these patients), and 71% were enrolled after the first diagnosis of urinary tract infection. During the study, urinary tract infection developed in 36 of 288 patients (13%) in the group receiving trimethoprim-sulfamethoxazole (antibiotic group) and in 55 of 288 patients (19%) in the placebo group (hazard ratio in the antibiotic group, 0.61; 95% confidence interval, 0.40 to 0.93; P = 0.02 by the log-rank test). In the antibiotic group, the reduction in the absolute risk of urinary tract infection (6 percentage points) appeared to be consistent across all subgroups of patients (P > or = 0.20 for all interactions). CONCLUSIONS Long-term, low-dose trimethoprim-sulfamethoxazole was associated with a decreased number of urinary tract infections in predisposed children. The treatment effect appeared to be consistent but modest across subgroups. (Australian New Zealand Clinical Trials Registry number, ACTRN12608000470392.)

Antiviral medications to prevent cytomegalovirus disease and early death in recipients of solid-organ transplants: a systematic review of randomised controlled trials

BACKGROUND Antiviral prophylaxis is commonly used in recipients of solid-organ transplants with the aim of preventing the clinical syndrome associated with cytomegalovirus infection. We undertook a systematic review to investigate whether this approach affects risks of cytomegalovirus disease and death. METHODS Randomised controlled trials of prophylaxis with antiviral medications for cytomegalovirus disease in solid-organ-transplant recipients were identified. Data were combined in meta-analyses by a random-effects model. FINDINGS Compared with placebo or no treatment, prophylaxis with aciclovir, ganciclovir, or valaciclovir significantly reduced the risks of cytomegalovirus disease (19 trials, 1981 patients; relative risk 0.42 [95% CI 0.34-0.52]), cytomegalovirus infection (17 trials, 1786 patients; 0.61 [0.48-0.77]), and all-cause mortality (17 trials, 1838 patients; 0.63 [0.43-0.92]), mainly owing to lower mortality from cytomegalovirus disease (seven trials, 1300 patients; 0.26 [0.08-0.78]). Prophylaxis also lowered the risks of disease caused by herpes simplex or zoster virus, bacterial infections, and protozoal infections, but not fungal infection, acute rejection, or graft loss. Meta-regression showed no significant difference in the risk of cytomegalovirus disease or all-cause mortality by organ transplanted or cytomegalovirus serostatus; no conclusions were possible for cytomegalovirus-negative recipients of negative organs. In trials of direct comparisons, ganciclovir was more effective than aciclovir in preventing cytomegalovirus disease. Valganciclovir and intravenous ganciclovir were as effective as oral ganciclovir. INTERPRETATION Prophylaxis with antiviral medications reduces the risk of cytomegalovirus disease and associated mortality in recipients of solid-organ transplants. This approach should be used routinely in cytomegalovirus-positive recipients and in cytomegalovirus-negative recipients of organs positive for the virus.

Antibiotics and surgery for vesicoureteric reflux: a meta-analysis of randomised controlled trials

Aims: To evaluate the benefits and harms of treatments for vesicoureteric reflux in children. Methods: Meta-analyses of randomised controlled trials using a random effects model. Main outcome measures were incidence of urinary tract infection (UTI), new or progressive renal damage, renal growth, hypertension, and glomerular filtration rate. Results: Eight trials involving 859 evaluable children comparing long term antibiotics with surgical correction of reflux (VUR) and antibiotics (seven trials) and antibiotics compared with no treatment (one trial) were identified. Risk of UTI by 1–2 and 5 years was not significantly different between surgical and medical groups (relative risk (RR) by 2 years 1.07; 95% confidence interval (CI) 0.55 to 2.09, RR by 5 years 0.99; 95% CI 0.79 to 1.26). Combined treatment resulted in a 60% reduction in febrile UTI by 5 years (RR 0.43; 95% CI 0.27 to 0.70) but no concomitant significant reduction in risk of new or progressive renal damage at 5 years (RR 1.05; 95% CI 0.85 to 1.29). In one small study no significant differences in risk for UTI or renal damage were found between antibiotic prophylaxis and no treatment. Conclusion: It is uncertain whether the identification and treatment of children with VUR confers clinically important benefit. The additional benefit of surgery over antibiotics alone is small at best. Assuming a UTI rate of 20% for children with VUR on antibiotics for five years, nine reimplantations would be required to prevent one febrile UTI, with no reduction in the number of children developing any UTI or renal damage.

Pre-emptive Treatment for Cytomegalovirus Viremia to Prevent Cytomegalovirus Disease in Solid Organ Transplant Recipients

Background. Cytomegalovirus (CMV) is a significant cause of morbidity and mortality in solid organ transplant recipients. Preemptive treatment with antiviral agents of patients with CMV viremia has been widely adopted as an alternative to routine prophylaxis to prevent CMV disease. This study was conducted to evaluate the efficacy of pre-emptive treatment in preventing symptomatic CMV disease. Methods. The Cochrane CENTRAL Registry, MEDLINE, EMBASE, and reference lists were searched for randomized trials of preemptive treatment in solid organ transplant recipients. Two authors extracted all data; analysis was with a random effects model and results expressed as relative risk (RR) and 95% confidence intervals (CI). Results. Ten eligible trials (476 patients) were identified, six of preemptive treatment versus placebo or standard care (treatment of CMV when disease occurred), three of preemptive treatment versus antiviral prophylaxis and one of oral versus intravenous preemptive treatment. Compared with placebo or standard care, preemptive treatment significantly reduced the risk of CMV disease (6 trials, 288 patients, RR 0.29, 95% CI 0.11 to 0.80) but not acute rejection (3 trials, 185 patients, RR 1.06, 95% CI 0.64 to 1.76) or all-cause mortality (2 trials, 176 patients, RR 1.23, 95% CI 0.35 to 4.30). Comparative trials of preemptive therapy versus prophylaxis showed no significant difference in the risks of CMV disease (2 trials, 151 patients, RR 0.42, 95% CI 0.07 to 2.65), acute rejection (1 trial, 70 patients, RR 0.94, 95% CI 0.42 to 2.09) or all-cause mortality (3 trials, 151 patients, RR 1.86, 95% CI 0.61 to 5.72). Conclusions. Few randomized trials have evaluated the effects of preemptive therapy to prevent CMV disease. Preemptive therapy is effective compared with placebo or standard care, but additional head-to-head trials are required to determine the relative benefits and harms of preemptive therapy and prophylaxis to prevent CMV disease in solid organ transplant recipients.

Comparative Accuracy of Renal Duplex Sonographic Parameters in the Diagnosis of Renal Artery Stenosis: Paired and Unpaired Analysis

OBJECTIVE The purpose of this study was to evaluate the test performance of duplex sonographic parameters in screening for hemodynamically significant renal artery stenosis, which occurs in approximately 5% of persons with hypertension. MATERIALS AND METHODS A comprehensive literature search was conducted to find studies on the diagnosis of renal artery stenosis in which duplex sonography and intraarterial angiography were compared and in which sensitivity and specificity were calculated. MEDLINE (1966-2005), EMBASE (1988-2005), and reference lists were searched and the authors contacted. Data were subjected to meta-analysis according to the hierarchical summary receiver operating characteristic curve model. Heterogeneity in test performance relating to population and design features was investigated. RESULTS From 1,357 titles, 88 studies involving 9,974 arteries in 8,147 patients were included. The following four parameters were evaluated: peak systolic velocity (21 studies), acceleration time (13 studies), acceleration index (13 studies), and renal-aortic ratio (13 studies). The corresponding diagnostic odds ratios (ORs) were 60.9 (95% CI, 28.3-131.2), 28.9 (95% CI, 7.1-117.2), 16.0 (95% CI, 5.1-50.6), and 29.3 (95% CI, 12.7-67.7). Results based on studies in which parameters were directly compared showed that peak systolic velocity had greater accuracy than renal-aortic ratio (relative diagnostic OR, 1.8; p = 0.03; nine studies) and acceleration index (relative diagnostic OR, 5.3; p < 0.001; five studies). Acceleration time versus acceleration index showed no evidence of a difference in accuracy (relative diagnostic OR, 1.1; p = 0.65; nine studies). Analysis of peak systolic velocity used in combination with other parameters compared with peak systolic velocity alone (seven studies) showed evidence of a shift in test positivity (p < 0.001) but only weak evidence of improvement in accuracy (relative diagnostic OR, 1.6; p = 0.09). CONCLUSION Sonography is a moderately accurate screening test for renal artery stenosis. The single measurement, peak systolic velocity, has the highest performance characteristics, an expected sensitivity of 85% and specificity of 92%. Additional measurements do not increase accuracy.

Interventions for Hemolytic Uremic Syndrome and Thrombotic Thrombocytopenic Purpura: A Systematic Review of Randomized Controlled Trials

BACKGROUND Hemolytic uremic syndrome (HUS) and thrombotic thrombocytopenic purpura (TTP) are related conditions with similar clinical features of variable severity. The objective of this systematic review is to evaluate the benefits and harms of available interventions for HUS and TTP. SELECTION CRITERIA FOR STUDIES MEDLINE (1966 to June 2006), EMBASE (1980 to June 2006), the Cochrane Central Register, conference proceedings, and reference lists were searched to find randomized controlled trials (RCTs) of any intervention for HUS or TTP in patients of all ages selected for inclusion for this systematic review. INTERVENTIONS Trials that compared an intervention with placebo, an intervention with supportive therapy, or one or more different interventions for HUS or TTP. OUTCOMES For TTP trials, failure of remission at 2 weeks or less and at 1 month or longer, all-cause mortality rate, and relapse rate. For HUS trials, all-cause mortality, chronic reduced kidney function, and persistent proteinuria or hypertension at last follow-up. RESULTS For TTP in adults, we found 6 RCTs of 331 patients. Two trials compared plasma infusion with plasma exchange using fresh frozen plasma and showed failure of remission at 2 weeks (2 trials, 140 patients; relative risk, 2.87; 95% confidence interval, 1.41 to 5.84), and all-cause mortality (relative risk, 1.91; 95% confidence interval, 1.09 to 3.33) occurred more frequently in the plasma infusion group. Three trials compared plasma exchange using cryosupernatant plasma with plasma exchange using fresh frozen plasma, and a meta-analysis of these trials showed no difference. Seven RCTs in 476 young children with postdiarrheal HUS have been conducted. None of the evaluated interventions (fresh frozen plasma transfusion, heparin with or without urokinase or dipyridamole, Shiga toxin-binding protein, and steroid) were superior to supportive therapy alone for any outcomes. LIMITATIONS Limitations of this review include the small number and suboptimal quality of reporting of included trials, possibility of publication bias, small number of participants with atypical HUS, and failure to report results for patients with atypical and typical HUS separately. CONCLUSIONS No additional therapy has been shown to increase efficacy over plasma exchange for TTP. No intervention has been shown to be superior to supportive therapy in patients with postdiarrheal HUS.

Absolute and relative accuracy of rapid urine tests for urinary tract infection in children: a meta-analysis

Rapid urine tests, such as microscopy, for bacteria and white cells, and dipsticks, for leucocyte esterase and nitrites, are often used in children that are unwell to guide early diagnosis and treatment of urinary tract infection. We aimed to establish whether these tests were sufficiently sensitive to avoid urine culture in children with negative results and to compare the accuracy of dipsticks with microscopy. Medline, Embase, and reference lists were searched. Studies were included if urine culture results were compared with rapid tests in children. Data were analysed to obtain absolute and relative accuracy estimates. Data from 95 studies in 95 703 children were analysed. Summary estimates for sensitivity and specificity for microscopy for Gram-stained bacteria were 91% (95% CI 80-96) and 96% (92-98), for unstained bacteria were 88% (75-94) and 92% (84-96), for urine white cells were 74% (67-80) and 86% (82-90), for leucocyte esterase or nitrite positive dipstick were 88% (82-91) and 79% (69-87), and for nitrite-only positive dipstick were 49% (41-57) and 98% (96-99). Microscopy for bacteria with Gram stain had higher accuracy than other laboratory tests with relative diagnostic odds ratio compared with bacteria without Gram stain of 8.7 (95% CI 1.8-41.1), white cells of 14.5 (4.7-44.4), and nitrite of 22.0 (0.7-746.3). Microscopy for white cells should not be used for the diagnosis of urinary tract infection because its accuracy is no better than that of dipstick, laboratory facilities are needed, and results are delayed. Rapid tests are negative in around 10% of children with a urinary tract infection and cannot replace urine culture. If resources allow, microscopy with Gram stain should be the single rapid test used.

Prevention and treatment of renal disease in Henoch-Schönlein purpura: a systematic review

Objective: To determine the benefits and harms of therapies used to prevent or treat renal involvement in Henoch-Schönlein purpura. Design: Systematic review of randomised controlled trials. Setting: Secondary and tertiary paediatric and paediatric nephrology services. Subjects: Ten trials involving 1230 children aged less than 18 years. Main outcome measures: Persistent proteinuria and/or haematuria. Results: Meta-analyses of four trials showed no significant difference in the risk of persistent kidney disease at 6 months (379 children; relative risk (RR) 0.51, 95% CI 0.24 to 1.11) and 12 months (498 children; RR 1.02, 95% CI 0.40 to 2.62) in children given prednisone for 14–28 days at presentation of Henoch-Schönlein purpura compared with placebo or supportive treatment. In children with severe renal disease, there was no significant difference in the risk of persistent renal disease with cyclophosphamide compared with supportive treatment (one trial; 56 children; RR 1.07, 95% CI 0.65 to 1.78) and with cyclosporin compared with methylprednisolone (one trial; 19 children; RR 0.39; 95% CI 0.14 to 1.06). Conclusions: Data from randomised trials for any intervention used to improve renal outcomes in children with Henoch-Schönlein purpura are very sparse except for short-term prednisone, which has not been shown to be effective.

Corticosteroid therapy in nephrotic syndrome: a meta-analysis of randomised controlled trials

AIMS To determine the benefits and toxicity of different corticosteroid regimes in preventing relapse in steroid responsive nephrotic syndrome. DESIGN Meta-analysis of randomised controlled trials. SUBJECTS Twelve trials involving 868 children aged 3 months to 18 years. MAIN OUTCOME MEASURE Frequency of relapse. RESULTS A meta-analysis of five trials, which compared two months of prednisone with three months or more in the first episode, showed that the longer duration significantly reduced the risk of relapse at 12–24 months (relative risk 0.73; 95% confidence interval 0.60 to 0.89) without an increase in adverse events. There was an inverse linear relation (relative risk 1.382 (SE 0.215) − 0.133 (SE 0.048) duration;r 2 = 0.66; p = 0.05) between the duration of treatment and risk of relapse. CONCLUSIONS Children in their first episode of steroid responsive nephrotic syndrome should be treated with prednisone for at least three months, with an increase in benefit being shown for up to seven months of treatment.

Acute renal failure in infants and children: outcome of 53 patients requiring hemodialysis treatment.

Fifty-three children, ages one day to 15 years, were treated with hemodialysis for acute renal failure between 1968 and 1977. Twenty-three had acute tubular necrosis. Nine had ATN associated with catastrophic medical illnesses; all died. Fourteen had ATN following major surgical procedures; ten died. Thirty had ARF due to primary nephrologic disorders; 27 survived. Thus it was not the ARF per se but the underlying and concomitant disorders which had the major influences on survival. As prognostic indications of survival in patients with postoperative ATN cannot be clearly defined, these patients almost always deserve aggressive management, including dialysis therapy. Patients with ATN associated with severe medical illness often have fatal underlying conditions which cannot be influenced by presently available technologies.