Two decades’ experience of renal replacement therapy in paediatric patients with acute renal failure

During the past 20 years, childhood renal replacement therapy (RRT) and the treatment of underlying diseases experienced extensive advances. We reviewed the data of our critically ill patients with acute renal failure (ARF) and RRT, comparing two decades from 1985 to 1994 and from 1995 to 2004. There were 87 patients with a mortality rate of 45% in the first decade, decreasing to 28 patients with a mortality rate of 39% in the second decade. The mortality rate decreased from 51% to 20% in patients older than one year, while the mortality rate in patients younger than one year increased from 38% to 88%. Yet, the absolute number of these non-survivors younger than one year decreased from 16 to seven patients. The decrease of RRT was mainly caused by a decrease of ARF secondary to heart surgery, oncologic disorders and sepsis. Whereas the majority of patients (75%) were treated with continuous haemofiltration in the first decade, 75% of patients were treated with continuous haemodiafiltration in the second decade.In conclusion, advances in the diagnosis and treatment of underlying disorders have reduced the need for RRT in critically ill paediatric patients during the past 20 years. In addition, there was a tendency for a decrease in the overall mortality, which might be caused by changing treatment policies and advances in RRT technology. Nevertheless, the high mortality rate in small infants is challenging.     

Does peak systolic velocity correlate with renal artery stenosis in a pediatric renal transplant population?

PSV of renal transplant vessels, calculated during allograft ultrasonography, has previously been shown to correlate with TRAS. Controversy exists regarding the threshold PSV value (adult range: 1.5-3.0 ms), which should prompt further, more invasive investigations to confirm the diagnosis of TRAS. Furthermore, there is a paucity of literature regarding PSV values in the pediatric renal transplant population. In a group of pediatric renal transplant patients, we correlated post-operative renal transplant PSV values with BP, renal function (serum creatinine) and TRAS. All patients who underwent cadaveric or living-related renal transplantation at the HSC between 2001 and 2004 with at least 6 months of follow-up were reviewed through the HSC multi-organ transplant database. Post-operative allograft Doppler ultrasonography was performed during routine follow-up. PSV values obtained were correlated with BP and serum creatinine performed concomitantly. Finally, we correlated PSV in those patients who underwent more intensive investigations, including magnetic resonance and conventional angiography. Fifty-three patients underwent transplantation during the study period. Complete data available for 50/53 demonstrated a mean PSV of 2.13 m/s (range: 0.9-6.1 m/s) for all patients. Of six patients who underwent MRA for suspicion of TRAS, two (with mean PSV values of 1.93 m/s) were found to have clinically significant stenoses. Four of six without angiographic evidence of TRAS had mean PSV values of 2.22 m/s. Patients suspected of having TRAS demonstrated elevated median serum creatinine values compared with those without clinical suspicion of TRAS. However, both mean PSV and BP were not found to be statistically different in both patient subgroups. Furthermore, there was no correlation identified between PSV and serum creatinine and BP in these patient populations. Despite the utility of PSV for monitoring adult renal transplant patients, we did not find that PSV correlated with BP, nadir creatinine or identify those patients who, through subsequent investigations, were found to have TRAS in this pediatric population. Maintaining cognizance in conjunction with close clinical follow-up may identify patients at risk for this rare but potentially morbid complication of transplantation.     

Metastatic renal abscess mimicking Wilms’ tumour

Renal abscesses are uncommon in children, and usually present with a high fever and flank pain. We report a 9-year-old girl who presented with abdominal pain and cough. While the finding of multiple lung nodules and a renal mass prompted the initial diagnosis of Wilms tumour, biopsy showed multiple renal abscesses with secondary lung involvement. The imaging findings and pathology correlation are provided.     

Does antenatal pelvic dilation predict renal scarring?

Moderate antenatal renal pelvic dilation (5-15 mm) may suggest vesicoureteric reflux, but it is not known to predict renal scarring. Dimercaptosuccinic acid scans on such children aged over 4 years showed a scarring rate (0/133 boys, 1/56 girls) similar to our local population. Investigation and treatment of moderate dilation may not be required.     

Can renal leukemic infiltration cause hypertension in children?

Out of 334 children with acute lymphoblastic leukemia who were treated with St Jude Total XI and Total XIII chemotherapy protocols were investigated and 21 (6.3%) were hypertensive. The incidence of tumor lysis syndrome was higher in the hypertensive group than in the nonhypertensive group (28.6% vs. 11.5%) (P = 0.035). There were no differences between patients treated with high-dose methylprednisolone and prednisolone St Jude Total XI and Total XIII, St Jude Total XIII LR and St Jude Total XIII HR groups in respect of the above-mentioned parameters. Central nervous system involvement, skeletal system involvement, abdominal lymphadenopathy, elevated lactate dehydrogenase and leukocyte count, French-American-British types and immunophenotypes were not found to be statistically significant to the development of hypertension (P > 0.05). We found that renal leukemic infiltration is a risk factor in hypertension development (P = 0.04) and hypertension is a risk factor for renal parenchymal disorder in the follow-up period (P = 0.0001). Six patients presenting with hypertension in the first week of disease therapy were evaluated for renal parenchymal disorder and glomerular filtration rate abnormality in the follow-up period. Glomerular filtration rate abnormality was found in 1 and renal scintigraphic dimercaptosuccinic acid abnormalities (reduced uptake and dilated hypoactivity) were found in 4 patients. Hypertension was also found to be a risk factor for renal parenchymal disorder in the follow-up period.     

Acyclovir-induced acute renal failure: An under-estimated secondary effect?

The increasing use of oral or IV acyclovir to treat infections caused by herpesviridae family involves a rise in the number of observed adverse effects. Neuro- and nephrotoxicity are most serious observed and reported secondary effects. The monitoring of renal function is essential to detect these cases since it develops as a non-oliguric renal failure. Because of this, the outpatient and oral use of the drug can result in an underestimation of the number of cases reported. We report two patients with genital herpes and viral encephalitis that required IV acyclovir. Both inpatients developed an acute renal failure that resolved after the drug was withdrawn.     

Does percutaneous nephrolithotomy in children cause significant renal scarring?

ObjectiveTo determine the frequency of renal parenchymal damage following percutaneous nephrolithotomy (PCNL) in children.Patients and methodsFifty-six children undergoing PCNL in 60 renal units between January 2000 and December 2004 were included in this prospective study, and were subjected to postoperative technetium-99m dimercaptosuccinic acid (^99mTc-DMSA). Using a standard questionnaire, demographics, number, size and location of stones, procedure details, outcome as indicated by clearance with PCNL alone or additional procedures, and follow up were documented. Presence of focal renal damage and its association with the PCNL tract were examined.ResultsOut of 60 renal units, cortical defects on ^99mTc-DMSA scan were seen in 10 renal units (17%). In three of these kidneys, the site of focal defect corresponded to the access site for tract formation during PCNL. Two additional kidneys had scarring at multiple sites, one of which corresponded to the access site during PCNL. In the remaining five kidneys no association between focal renal damage and nephrostomy tract site could be ascertained. No association was seen between renal damage and the size of nephroscope used during PCNL.ConclusionThere exists a risk of focal damage to renal parenchyma from the formation of the nephrostomy tract. In our series, focal damage was seen in 5% of patients; this may be an overestimate since preoperative ^99mTc-DMSA scans were not available for our patients. Meticulous technique is important combined with a smaller nephroscope to minimize renal damage. Long-term follow up of such children is required to assess how many are left with permanent renal scars.