Dialysis and pediatric acute kidney injury: choice of renal support modality

Continuous renal replacement therapy in neonates and small infants: development and first-in-human use of a miniaturised machine (CARPEDIEM)

BACKGROUND

Peritoneal dialysis is the renal replacement therapy of choice for acute kidney injury in neonates, but in some cases is not feasible or effective. Continuous renal replacement therapy (CRRT) machines are used off label in infants smaller than 15 kg and are not designed specifically for small infants. We aimed to design and create a CRRT machine specifically for neonates and small infants.

METHODS

We prospectively planned a 5-year project to conceive, design, and create a miniaturised Cardio-Renal Pediatric Dialysis Emergency Machine (CARPEDIEM), specifically for neonates and small infants. We created the new device and assessed it with in-vitro laboratory tests, completed its development to meet regulatory requirements, and obtained a licence for human use. Once approved, we used the machine to treat a critically ill neonate

FINDINGS

The main characteristics of CARPEDIEM are the low priming volume of the circuit (less than 30 mL), miniaturised roller pumps, and accurate ultrafiltration control via calibrated scales with a precision of 1 g. In-vitro tests confirmed that both hardware and software met the specifications. We treated a 2·9 kg neonate with haemorrhagic shock, multiple organ dysfunction, and severe fluid overload for more than 400 h with the CARPEDIEM, using continuous venovenous haemofiltration, single-pass albumin dialysis, blood exchange, and plasma exchange. The patient's 65% fluid overload, raised creatinine and bilirubin concentrations, and severe acidosis were all managed safely and effectively. Despite the severity of the illness, organ function was restored and the neonate survived and was discharged from hospital with only mild renal insufficiency that did not require renal replacement therapy.

INTERPRETATION

The CARPEDIEM CRRT machine can be used to provide various treatment modalities and support for multiple organ dysfunction in neonates and small infants. The CARPEDIEM could reduce the range of indications for peritoneal dialysis, widen the range of indications for CRRT, make the use of CRRT less traumatic, and expand its use as supportive therapy even when complete renal replacement therapy is not indicated.

FUNDING

Associazione Amici del Rene di Vicenza.

Laboratory predictors of acute dialysis in hemolytic uremic syndrome

BACKGROUND

Strict guidelines on use of dialysis in children with post-diarrheal hemolytic uremic syndrome (D + HUS) are lacking. This study investigated laboratory predictors of acute dialysis because they are more objective than clinical features. Added to this, given that urine output is also an objective parameter, its ability to predict dialysis requirements was also investigated.

METHODS

Out of 153 D + HUS children reviewed, 88 received dialysis and 65 did not. Initial laboratory parameters and diuresis between both groups were analyzed.

RESULTS

Dialyzed patients had higher creatinine, urea, alanine aminotransferase, hematocrit and leukocyte count; and lower sodium, bicarbonate, and pH compared to non-dialyzed ones. Serum creatinine was the only independent predictor (P = 0.003) of dialysis; therefore, its ability to predict dialysis was estimated on receiver operating characteristic (ROC) curve analysis and using the Acute Kidney Injury Network (AKIN) staging system. Area under the ROC curve was 0.92 (95% confidence interval [95%CI]: 0.83-1) with a creatinine cut-off of 1.25 mg/dL (sensitivity, 100%; specificity, 76.5%) for children <1 year, and 0.93 (95%CI: 0.88-0.98) with a threshold of 2 mg/dL (sensitivity, 91%; specificity, 87.5%) for older children. AKIN stage 3 at admission predicted dialysis with a sensitivity of 92% and specificity of 84.2%. Urine output had the highest accuracy for dialysis prediction (sensitivity, 100%; specificity, 95.3%).

CONCLUSIONS

Initial serum creatinine concentration was the best laboratory predictor of dialysis, but the first 24 h diuresis was even better for this purpose. But, given that serum creatinine is an immediate available parameter, the cut-offs identified may label D + HUS children who will probably need dialysis, prompting early referral to centers able to provide dialysis.

Efficacy and safety of intermittent hemodialysis in infants and young children with inborn errors of metabolism

BACKGROUND

Intermittent hemodialysis (IHD) is the most efficient form of renal replacement therapy (RRT) for removing toxic substances from patients' bodies. However, the efficacy and safety of IHD in infants and young children with inborn errors of metabolism are still not clear.

METHODS

This retrospective study included patients with urea cycle disorders, maple syrup urine disease, and methylmalonic acidemia who received IHD or non-IHD RRT at our hospital between 2001 and 2012 to remove ammonia, leucine, or methylmalonic acid. Both the efficacy and safety of the RRT were evaluated.

RESULTS

Thirty-five courses of RRT, including 25 courses of IHD and ten courses of non-IHD RRT, for 15 patients were included in the analysis. Before 2006, non-IHD RRT procedures, including peritoneal dialysis (PD) and continuous venous-venous hemofiltration (CVVH), were the most often used; from 2006 onwards IHD was used. There was one procedure-unrelated death. Catheter penetration occurred in one course of IHD. The efficacy data revealed that both the median duration of dialysis and the median 50 % toxin reduction time were shorter in IHD than in non-IHD RRT.

CONCLUSIONS

In infants and young children with inborn errors of metabolism, IHD is safe and more efficient than non-IHD RRT at removing toxins.

Indications and outcomes in children receiving renal replacement therapy in pediatric intensive care

PURPOSE

We aimed to describe patient characteristics, indications for renal replacement therapy (RRT), and outcomes in children requiring RRT. We hypothesized that fluid overload, not classic blood chemistry indications, would be the most frequent reason for RRT initiation.

MATERIALS AND METHODS

A retrospective cohort study of all patients receiving RRT at a single-center quaternary pediatric intensive care unit between January 2004 and December 2008 was conducted.

RESULTS

Ninety children received RRT. The median age was 7 months (interquartile range, 1-83). Forty-six percent of patients received peritoneal dialysis, and 54% received continuous renal replacement therapy. The median (interquartile range) PRISM-III score was 14 (8-19). Fifty-seven percent had congenital heart disease, and 32% were on extracorporeal life support. The most common clinical condition associated with acute kidney injury was hemodynamic instability (57%; 95% confidence interval [CI], 46-67), followed by multiorgan dysfunction syndrome (17%; 95% CI, 10-26). The most common indication for RRT initiation was fluid overload (77%; 95% CI, 66-86). Seventy-three percent (95% CI, 62-82) of patients survived to hospital discharge.

CONCLUSIONS

Hemodynamic instability and multiorgan dysfunction syndrome are the most common clinical conditions associated with acute kidney injury in our population. In the population studied, the mortality was lower than previously reported in children and much lower than in the adult population.

Improvised peritoneal dialysis in an 18-month-old child with severe acute malnutrition (kwashiorkor) and acute kidney injury: a case report

Introduction

Severe acute malnutrition is common in developing countries. Children with severe acute malnutrition are prone to complications, including electrolyte imbalance and infections. Our patient was an 18-month-old boy who had severe acute malnutrition (kwashiorkor) and developed acute kidney injury, which was managed with peritoneal dialysis using improvised equipment. This case report illustrates the importance of improvisation in resource-limited settings in providing lifesaving treatment. To the best of our knowledge, this is the first case report on peritoneal dialysis in a child with severe acute malnutrition (kwashiorkor).

Case presentation

We report a case of an 18-month-old Bantu-African Tanzanian boy who had severe malnutrition and developed anuric acute kidney injury. He had severe renal dysfunction and was managed with peritoneal dialysis using an improvised catheter and bedside constituted fluids (from intravenous fluids) and was diuretic after 7 days of peritoneal dialysis, with complete recovery of renal functions after 2 weeks.

Conclusion

Children with severe acute malnutrition who develop acute kidney injury should be offered peritoneal dialysis, which may be provided using improvised equipment in resource-limited settings, as illustrated in this case report.

Pediatric acute kidney injury assessed by pRIFLE as a prognostic factor in the intensive care unit

BACKGROUND

In this study we applied the pediatric version of the RIFLE criteria (pRIFLE) to an at-risk hospital population, analyzed the incidence and association of acute kidney injury (AKI) with mortality and length of stay in both the intensive care unit (ICU) and the hospital, and evaluated the applicability of pRIFLE as a prognostic tool in the ICU.

METHODS

This study was a prospective single-center cohort study in which 126 patients were enrolled. The affected group included patients who were diagnosed with AKI. Subgroups of the diagnosed patients were established according to their maximum pRIFLE strata, which were defined as the worst pRIFLE score attained during the study period.

RESULTS

Fifty-eight (46 %) of our patients developed AKI. The lengths of stay in the ICU and in the hospital were longer in the affected group than in the unaffected group. The advanced strata of pRIFLEmax were associated with longer stays in the ICU and hospital and higher median Pediatric Index of Mortality II scores. The hospital mortality rate of AKI patients was 12-fold higher than that of the patients without AKI (36 vs. 3 %).

CONCLUSION

The incidence of AKI in this population was both significant and directly associated with hospital mortality and the length of stay in the ICU and hospital. The pRIFLE classification facilitated the definition of AKI, indicating that it a significant prognostic predictor.

Pediatric renal replacement therapy in the intensive care unit

Renal replacement therapy (RRT) is used in a wide variety of pediatric populations. In this article, we will review the advantages and disadvantages of the different RRT modalities and the technical aspects of providing pediatric RRT. In addition, we will review the use of RRT with extracorporeal membrane oxygenation, the use of continuous RRT in the critically ill child with acute kidney injury and fluid overload, and the use of RRT for the removal of toxins and treatment of inborn errors of metabolism.

Modality of choice for renal replacement therapy for children with acute kidney injury: Results of a survey

Information on current practices in India for management of renal replacement therapy (RRT) in acute kidney injury (AKI) is lacking. We mailed a questionnaire to 26 pediatric nephrology centers across India to obtain information on the current choice of dialysis modality for management of AKI in children. Acute intermittent peritoneal dialysis was available at all centers surveyed, whereas intermittent hemodialysis and continuous RRT were available in 86% and 17% centers, respectively. Peritoneal dialysis was the predominant modality (accounting for more than 80% of all dialysis) in 14 of the 22 centers, while 4 centers used hemodialysis more commonly. The most important factors influencing the modality choice were patient size, hemodynamic stability, and duration of AKI. These results provide insight into the choice of modality and factors influencing their selection in the management of pediatric AKI in our country.

Continuous renal replacement therapy in neonates weighing less than 3 kg

PURPOSE

Continuous renal replacement therapy (CRRT) is becoming the treatment of choice for supporting critically ill pediatric patients. However, a few studies present have reported CRRT use and outcome in neonates weighing less than 3 kg. The aim of this study is to describe the clinical application, outcome, and complications of CRRT in small neonates.

METHODS

A retrospective review was performed in 8 neonatal patients who underwent at least 24 hours of pumped venovenous CRRT at the Samsung Medical Center in Seoul, Korea, between March 2007 and July 2010. Data, including demographic characteristics, diagnosis, vital signs, medications, laboratory, and CRRT parameters were recorded.

RESULTS

The data of 8 patients were analyzed. At the initiation of CRRT, the median age was 5 days (corrected age, 38(+2) weeks to 23 days), and the median body weight was 2.73 kg (range, 2.60 to 2.98 kg). Sixty-two patient-days of therapy were reviewed; the median time for CRRT in each patient was 7.8 days (range, 1 to 37 days). Adverse events included electrolyte disturbances, catheter-related complications, and CRRT-related hypotension. The mean circuit functional survival was 13.9±8.6 hours. Overall, 4 patients (50%) survived; the other 4 patients, who developed multiorgan dysfunction syndrome, died.

CONCLUSION

The complications of CRRT in newborns are relatively high. However, the results of this study suggest that venovenous CRRT is feasible and effective in neonates weighing less than 3 kg under elaborate supportive care. Furthermore, for using potential benefit of CRRT in neonates, efforts are required for prolonging filter survival.

Temporary peritoneal dialysis in newborns and children: a single-center experience over five years

AIM

To evaluate the indications, complications, and outcomes of temporary peritoneal dialysis (TPD) in children with acute renal failure (ARF).

PATIENTS AND METHODS

All patients undergoing TPD between February 2006 and January 2011 in a children's hospital were included in the study. Patient characteristics, indications, complications, and duration of TPD (DPD), requirement of re-operation, length of stay, presence of sepsis, and outcome were recorded.

RESULTS

There were 21 newborns (14 prematures), 9 infants, and 9 children. The main nephrotoxic agents were gentamicin (n = 7), netilmisin (n = 5), vancomycin (n = 3), and ibuprophen (n = 3). Patients with multiorgan failure (n = 9) had significantly higher blood urea nitrogen (BUN) and creatinine levels than those without multiorgan failure (n = 30) [BUN: 94 ± 27.3 vs. 34.3 ± 4.9) and creatinine: 4.1 ± 0.8 vs. 1.9 ± 0.2)]. The mean DPD was longer in mature patients than in prematures (newborn: 3.7; children: 7.1). Nine complications were observed (23%) (leakage in three and poor drainage in six patients). Twenty-five patients (64.1%) responded to TPD treatment and were discharged, and 14 patients (10 newborns and 7 of them were premature) died (35.9%). Mortality rate was higher in prematures (n = 7) and patients with a history of nephrotoxic agent (n = 10).

CONCLUSION

TPD is effective especially in neonates with ARF and it is a reliable alternative to the hemodialysis or other continuous renal replacement therapies but it is not free of complications. It has limited effects, particularly in patients with multiorgan failure.

Management of acute kidney injury

Acute kidney injury is common in hospitalized children and is associated with siginficant morbidity and mortality especially in critically ill children. A complete evaluation is necessary for all children with AKI as early recognition and treatment is paramount. Apart from clinical evaluation, urinalysis, biochemical investigations and imaging studies helps in the diagnosis of the specific cause of AKI and assessing its severity. Attention should be given to assessment of volume status and fluid administration because volume depletion is a common and modifiable risk factor for AKI. Prevention or prompt management of complications like fliud overload, hyperkalemia and metabolic acidosis improves outcomes. Immediate initiation of renal replacement therapy (RRT) is indicated in the presence of life threatening changes in fluid, electrolyte and acid-base balance. Other measures like treating the underlying cause of AKI, adapting dosage of drugs to renal function, treatment of infections and providing adequate nutrition is important. Children with AKI should be followed up as they are at risk for development of chronic kidney disease.

Peritoneal dialysis in childhood acute kidney injury: experience in southwest Nigeria

BACKGROUND

The choices for renal replacement therapy (RRT) in childhood acute kidney injury (AKI) are limited in low-resource settings. Peritoneal dialysis (PD) appears to be the most practical modality for RRT in young children with AKI in such settings. Data from sub-Saharan Africa on the use of PD in childhood AKI are few.

METHODS

We performed a retrospective study of children who underwent PD for AKI at a tertiary-care hospital in southwest Nigeria from February 2004 to March 2011 (85 months).

RESULTS

The study included 27 children (55.6% female). Mean age was 3.1 ± 2.6 years, with the youngest being 7 days, and the oldest, 9 years. The causes of AKI were intravascular hemolysis (n = 11), septicemia (n = 8), acute glomerulonephritis (n = 3), gastroenteritis (n = 3), and hemolytic uremic syndrome (n = 2). Peritoneal dialysis was performed manually using percutaneous or adapted catheters. Duration of PD ranged from 6 hours to 12 days (mean: 5.0 ± 3.3 days). The main complications were peritonitis (n = 10), pericatheter leakage (n = 9), and catheter outflow obstruction (n = 5). Of the 27 patients, 19 (70%) survived till discharge.

CONCLUSIONS

In low-resource settings, PD can be successfully performed for the management of childhood AKI. In our hospital, the use of adapted catheters may have contributed to the high complication rates. Peritoneal dialysis should be promoted for the management of childhood AKI in low-resource settings, and access to percutaneous or Tenckhoff catheters, dialysis fluid, and automated PD should be increased.

Acute dialysis-associated peritonitis in children with D+ hemolytic uremic syndrome

Acute peritoneal dialysis (PD) is the preferred therapy for renal replacement in children with post-diarrheal hemolytic uremic syndrome (D+ HUS), but peritonitis remains a frequent complication of this procedure. We reviewed data from 149 patients with D+ HUS who had undergone acute PD with the aim of determining the prevalence and risk factors for the development of peritonitis. A total of 36 patients (24.2%) presented peritonitis. The median onset of peritonitis manifestations was 6 (range 2-18) days after the initiation of dialysis treatment, and Gram-positive microorganisms were the predominant bacterial type isolated (15/36 patients). The patients were divided into two groups: with or without peritonitis, respectively. Univariate analysis revealed that a longer duration of the oligoanuric period, more days of dialysis, catheter replacement, stay in the intensive care unit, and hypoalbuminemia were significantly associated to the development of peritonitis. The multivariate analysis, controlled by duration of PD, identified the following independent risk factors for peritonitis: catheter replacement [p = 0.037, odds ratio (OR) 1.33, 95% confidence interval (CI) 1.02-1.73], stay in intensive care unit (p = 0.0001, OR 2.62, 95% CI 1.65-4.19), and hypoalbuminemia (p = 0.0076, OR 1.45, 95% CI 1.10-1.91). Based on these findings, we conclude that the optimization of the aseptic technique during catheter manipulation and early nutritional support are targets for the prevention of peritonitis, especially in critically ill patients.

Treatment of critically ill children with kidney injury by sustained low-efficiency daily diafiltration

BACKGROUND

Continuous renal replacement therapy (CRRT) and intermittent hemodialysis (IHD) offer diverse benefits and drawbacks for critically ill children with acute kidney injury (AKI). Sustained low-efficiency daily diafiltration (SLEDD-f) involves a conceptual and technical hybrid of CRRT and IHD. We report our SLEDD-f application to critically ill children in the pediatric intensive care unit (PICU).

METHODS

SLEDD-f was delivered by the new Fresenius 5008 therapy system with blood flow 5 ml/kg/min, dialysate flow 260 ml/min, hemofiltration 35 ml/kg/h for 8-10 h daily. Changes in blood pressure, blood gas, electrolyte, hemoglobulin (Hb), and hematocrit (Hct) were closely monitored.

RESULTS

From February 2010 to June 2011, 14 critical patients with a total of 60 SLEDD-f sessions were studied retrospectively. Heparin was used in 46 sessions (76.6%) with no bleeding complications. Hypertension above 135 mmHg returned to normal, hypotension below 90 mmHg showed no drop. Metabolic acidosis and hyperkalemia normalized. Elevated Hb, Hct, and their ratio revealed improving hemodilution. Three episodes of intradialytic hypotension (5.0%) and one of circuit clotting (1.7%) led to premature termination. The 28-day survival rate was 71.4%.

CONCLUSIONS

This pilot investigation demonstrates that SLEDD-f provides good hemodynamic tolerance and correction of fluid overload, pH, and electrolyte imbalance for critically ill children with AKI.

Acute renal replacement therapy in pediatrics

Acute kidney injury (AKI) independently increases morbidity and mortality in children admitted to the hospital. Renal replacement therapy (RRT) is an essential therapy in the setting of AKI and fluid overload. The decision to initiate RRT is complex and often complicated by concerns related to patient hemodynamic and thermodynamic instability. The choice of which RRT modality to use depends on numerous criteria that are both patient and treatment center specific. Surprisingly, despite decades of use, no randomized, controlled trial study involving RRT in pediatrics has been performed. Because of these factors, clear-cut consensus is lacking regarding key questions surrounding RRT delivery. In this paper, we will summarize existing data concerning RRT use in children. We discuss the major modalities and the data-driven specifics of each, followed by controversies in RRT. As no standard of care is in widespread use for RRT in AKI or in multiorgan disease, we conclude in this paper that prospective studies of RRT are needed to identify best practice guidelines.

Use of peritoneal dialysis after surgery for congenital heart disease in children

Acute kidney injury (AKI) is a common complication in children after surgery for congenital heart disease, and peritoneal dialysis (PD) is usually the renal replacement therapy (RRT) of choice, especially in very young children. The aim of the present study was to describe our experience of using PD to treat AKI after cardiac surgery. We retrospectively analyzed children 1 week to 16 years of age undergoing cardiac surgery during 2000-2008 and found the incidence of AKI treated with PD to be 2.3%. In the 23 patients treated with PD (13 male; average age: 29 ± 48.4 months; weight: 9.1 ± 8.1 kg), the indications for PD initiation were oliguria (n = 13), anuria (n = 9), and acidosis (n = 1). The average time between cardiac surgery and AKI was 4.8 ± 16.8 hours, and between AKI and PD initiation, it was 12 ± 16.8 hours. Patients were treated for a mean of 4.8 ± 3.8 days. Two patients developed peritonitis, and mechanical dysfunction of the PD catheter occurred in 1 patient. In-hospital mortality was 43.4%. Patients treated with PD weighed less (p = 0.004) and had longer bypass time (p = 0.004), inotrope use (p = 0.000), and mechanical ventilation (p = 0.000). However, in a regression analysis, only cardiopulmonary bypass time (odds ratio: 1.021; 95% confidence interval: 0.998 to 1.027; p = 0.032) remained predictive of a subsequent need for PD. We conclude that PD is an efficacious RRT for AKI in children undergoing cardiac surgery and that, in this setting, bypass time is the strongest predictor of a subsequent need for RRT.

Acute kidney injury: controversies revisited

This paper addresses the epidemiology of AKI specifically in relation to recent changes in AKI classification and revisits the controversies regarding the timing of initiation of dialysis and the use of peritoneal dialysis as a renal replacement therapy for AKI. In summary, the new RIFLE/AKIN classifications of AKI have facilitated more uniform diagnosis of AKI and clinically significant risk stratification. Regardless, the issue of timing of dialysis initiation still remains unanswered and warrants further examination. Furthermore, peritoneal dialysis as a treatment modality for AKI remains underutilised in spite of potential beneficial effects. Future research should be directed at identifying early reliable biomarkers of AKI, which in conjunction with RIFLE/AKIN classifications of AKI could facilitate well-designed large randomised controlled trials of early versus late initiation of dialysis in AKI. In addition, further studies of peritoneal dialysis in AKI addressing dialysis dose and associated complications are required for this therapy to be accepted more widely by clinicians.

Continuous flow peritoneal dialysis: first experience in children with acute renal failure

BACKGROUND AND OBJECTIVES

Acute renal failure can be treated with different dialysis modalities, depending on patient characteristics and hospital resources. Peritoneal dialysis (PD) can be first choice in situations like hypotension, disturbed coagulation, or difficult venous access. The main disadvantage of PD is the relatively limited efficacy. The aim of this study was to investigate whether continuous flow peritoneal dialysis (CFPD) is a more effective treatment than conventional PD in acute renal failure.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

A pilot study was performed at The Red Cross University Hospital in Cape Town in six patients. Patients were treated with both CFPD and conventional PD for 8 to 16 hours. CFPD was performed with two bedside-placed catheters. After initial filling, dialysate flow rate (100 ml/1.73 m2 per minute) was maintained with an adapted continuous venovenous hemofiltration machine. Ultrafiltration flow rate was set at 2.5 ml/1.73 m2 per minute.

RESULTS

Mean ultrafiltration was 0.20 ml/1.73 m2 per minute with conventional PD versus 1.8 ml/1.73 m2 per minute with CFPD. Mean clearances of urea and creatinine were 5.0 and 7.6 ml/1.73 m2 per minute with conventional PD versus 15.0 and 28.8 ml/1.73 m2 per minute with CFPD, respectively. No complications occurred.

CONCLUSIONS

In this first report of CFPD in six pediatric patients with acute renal failure, CFPD was on average three to five times more effective for urea and creatinine clearance and ultrafiltration than conventional PD, without any complications observed. CFPD has the ability to improve therapy for acute renal failure.

Pediatric renal supportive therapies: the changing face of pediatric renal replacement approaches

PURPOSE OF REVIEW

The term 'renal replacement therapy' has been employed for describing dialytic interventions for acute and chronic patients. The implications of this terminology do not correctly reflect the extent that we are able to address native renal function. Provision of correct terminology to describe dialytic therapies may provide insight and investigation into the 'nonreplaceable' aspects of renal function in the acute and chronic settings.

RECENT FINDINGS

The terms 'chronic kidney disease' and 'acute kidney injury' have replaced the terms chronic renal failure and acute renal failure, respectively. Changing terminology has improved definitions and clinical care in these patient groups. Improvements in dialytic therapies have not been paralleled by changes in our understanding of the native renal function components that are not replaced during dialysis.

SUMMARY

A paradigm shift in our understanding of replacement of renal function is necessary. The terminology of 'renal replacement therapy' should be supplanted by more appropriate terminology, 'renal supportive therapy'. The benefits of employing terminology that adequately reflects the extent to which we can offer supportive dialytic treatment to our acute and chronic patients may be realized as a significant stimulus for scientific investigation and clinical care improvements.

Clinical course and mortality risk factors in critically ill children requiring continuous renal replacement therapy

OBJECTIVE

To study the clinical course in children requiring continuous renal replacement therapy (CRRT) and to analyse factors associated with mortality.

DESIGN

Prospective observational study.

SETTING

Paediatric intensive care department of a tertiary university hospital.

PATIENTS

Critically ill children with CRRT were included in the study.

INTERVENTION

Continuous renal replacement therapy.

MEASUREMENTS AND RESULTS

Univariate and multivariate analyses were performed to analyse the influence of each factor on mortality. The ability of the PRISM, PIM II and PELOD severity of illness scores to predict mortality was tested using receiver-operating characteristic curve statistics. A total of 174 children aged between 1 month and 22 years were treated with CRRT. Mortality was 35.6%, and multiorgan failure and haemodynamic disturbances were the principal causes of death. Mortality was higher in children less than 12 months of age (44.7%; P = 0.037) and in patients with a diagnosis of sepsis (44.1%; P = 0.001). Haemodynamic disturbances at the time of starting CRRT (hypotension or need for adrenaline >0.6 microg/kg/min) and the presence of multiorgan failure were the factors associated with an increased risk of mortality. The PRISM scale was the severity score with the best predictive capacity, although all three scales underestimated the actual mortality.

CONCLUSIONS

Mortality in children who require CRRT is high. Haemodynamic disturbances and the presence of multiorgan failure at the time of starting the technique are the factors associated with a higher mortality. The clinical severity scores underestimate mortality in children requiring CRRT.

Clinical course of children requiring prolonged continuous renal replacement therapy

A prospective observational study was performed to analyze the clinical course of critically ill children who require continuous renal replacement therapy (CRRT). Variables associated with prolonged CRRT were analyzed. Of the 174 children treated with CRRT, 32 (18.3%) required CRRT for >14 days and 20 (11.5%) for >21 days. Prolonged CRRT was more common in patients with heart disease and those requiring mechanical ventilation, hemodiafiltration, and higher doses of heparin. The same factors were found when patients with CRRT for >14 days and 21 days were studied. Overall mortality rate was 35.6%; it was slightly higher in patients on prolonged CRRT (43.7% with CRRT > 14 days and 45% with CRRT >21 days), though the differences were not statistically significant. We conclude that there were no differences in the pre-CRRT clinical characteristics, severity of illness, and renal function in critically ill children requiring prolonged CRRT. Prolonged CRRT was more frequently required by patients with heart disease and those on mechanical ventilation. Patients with prolonged CRRT required more frequent hemodiafiltration and higher doses of heparin. Mortality was slightly higher in children with longer CRRT, though this difference did not reach statistical significance.

[Acute renal failure in critically ill patients]

BACKGROUND

Acute renal failure is common in critically ill patients and is associated with a high mortality rate. This paper reviews current management of patients with acute renal failure admitted to an intensive care unit.

MATERIAL AND METHODS

Literature search in databases (Medline, Cochrane database of systematic reviews, UpToDate).

RESULTS

The prevalence of acute renal failure is 5-20 % in patients admitted to intensive care units; the associated hospital mortality is 30-60 %. The aetiology is usually multifactorial; inflammation (sepsis, surgery), hypovolaemia and drug toxicity commonly precipitate acute renal failure. There is no effective drug treatment, but early onset of renal replacement therapies with haemodialysis or haemofiltration is likely to prolong survival.

INTERPRETATION

Despite modern intensive care, mortality is high in acute renal failure and preventive measures should therefore be vigorously pursued. Haemodialysis and haemofiltration should be introduced early in acute renal failure, and should be available in all intensive care units.

Complications of continuous renal replacement therapy in critically ill children: a prospective observational evaluation study

Introduction

Continuous renal replacement therapy (CRRT) frequently gives rise to complications in critically ill children. However, no studies have analyzed these complications prospectively. The purpose of this study was to analyze the complications of CRRT in children and to study the associated risk factors.

Methods

A prospective, single-centre, observational study was performed in all critically ill children treated using CRRT in order to determine the incidence of complications related to the technique (problems of catheterization, hypotension at the time of connection to the CRRT, hemorrhage, electrolyte disturbances) and their relationship with patient characteristics, clinical severity, need for vasoactive drugs and mechanical ventilation, and the characteristics of the filtration techniques.

Results

Of 174 children treated with CRRT, 13 (7.4%) presented problems of venous catheterization; this complication was significantly more common in children under 12 months of age and in those weighing less than 10 kg. Hypotension on connection to CRRT was detected in 53 patients (30.4%). Hypotension was not associated with any patient or CRRT characteristics. Clinically significant hemorrhage occurred in 18 patients (10.3%); this complication was not related to any of the variables studied. The sodium, chloride, and phosphate levels fell during the first 72 hours of CRRT; the changes in electrolyte levels during the course of treatment were not found to be related to any of the variables analyzed, nor were they associated with mortality.

Conclusions

CRRT-related complications are common in children and some are potentially serious. The most common are hypotension at the time of connection and electrolyte disturbances. Strict control and continuous monitoring of the technique are therefore necessary in children on CRRT.