Pediatric nephrologists face significant challenges in managing infants requiring maintenance dialysis. Factors such as difficulties feeding and maintaining fluid balance, growth failure, increased risk of infection, and possible comorbid conditions contribute to the management hurdles in children younger than 1 year. Due in part to these challenges, infants with kidney failure on maintenance dialysis have higher mortality rates than older children on dialysis.
During the past few decades, the number of infants treated with renal replacement therapy has increased; according to the 2011 North American Pediatric Renal Trials and Collaborative Studies report, 13.2% of patients on maintenance dialysis were younger than 2 years at initiation of dialysis therapy.
The preferred treatment modality in infants is maintenance peritoneal dialysis, with potentially better preservation of residual kidney function, fewer dietary restrictions, avoidance of central vascular access placement, and the option to perform dialysis at home. Hemodialysis in infants is technically difficult and requires skilled nursing staff. However, there are cases where peritoneal dialysis is contraindicated and hemodialysis is the only alternative treatment prior to kidney transplantation.
There are few data reporting on comparisons of long-term outcomes of the two modalities in infants. Enrico Vidal, MD, PhD, and colleagues conducted a cohort study designed to compare clinical characteristics and outcomes of peritoneal dialysis and hemodialysis patients in a large cohort of patients initiating dialysis therapy prior to age 1 year. Results were reported in the American Journal of Kidney Diseases [2017;69(5):617-625].
Utilizing the European Society for Pediatric Nephrology(EPN)/European Renal Association-European Dialysis and Transplant Association (ERA-EDTA) Registry, the researchers identified 1063 infants initiating dialysis therapy at 12 months or younger from January 1, 1991, to December 21, 2013, who met inclusion criteria. Of the 1063 infants, 919 started on peritoneal dialysis and 144 started on hemodialysis therapy. At day 30, 14 patients had switched from peritoneal dialysis to hemodialysis and 12 had switched from hemodialysis to peritoneal dialysis. Fourteen patients died prior to day 30 (12 in the peritoneal dialysis group and two in the hemodialysis group).
Sixty-one percent of the infants (n=649) were started on dialysis therapy at age 0 to 6 months, and 39% (n=414) at age 7 to 12 months. Median age at initiation of dialysis therapy was 4.5 months and median body weight was 5.7 kg. The proportion of hypoalbuminemic infants was higher in the peritoneal dialysis group; the likely explanation for this is the increased protein losses via the peritoneal membrane that is characterized by a hyperpermeable state in infants in this age group. Infants on hemodialysis presented with significantly lower hemoglobin levels, possibly related to substantial blood loss with the extracorporeal systems, or, more likely, due to fluid overload at the time of blood sampling (performed immediately prior to a dialysis session).
The 5-year crude mortality rate overall in the total cohort was 52.3 deaths per 1000 patient-years. The overall cumulative incidence of death at 1, 2, and 5 years was 10.0% (95% confidence interval [CI], 8.10%-11.7%), 13.1% (95% CI, 11.0%-15.2%), and 16.1% (95% CI, 13.8%-18.5%), respectively. Causes of death were infections (25.1%), cardiovascular disease (13.6%), withdrawing renal replacement therapy (6.8%), respiratory failure due to fluid overload (3.1%), cerebrovascular accident (5.8%), malignancy (2.1%), miscellaneous (23.6%), and unknown/unavailable causes (19.9%).
A significant risk factor for death was younger age at initiation of dialysis therapy; there was a 5% lower risk per month of later initiation (hazard ratio [HR], 0.95; 95% CI, 0.90-0.97; P<.001). Patients with non-congenital anomalies of kidney and urinary tract diseases had a significantly higher risk for death (HR, 1.49; 95% CI, 1.08-2.04; P=.03). There was no significant morality risk difference by sex (female vs male: HR, 1.28; 95% CI, 0.95-1.71) or between infants initiating dialysis therapy before and after 2000 (2000 or later vs pre-2000: HR, 0.93; 95% CI, 0.67-1.29).
A comparison of mortality risk based on dialysis modality found crude 5-year mortality rates of 51.0 deaths per 1000 patient-years for peritoneal dialysis and 62.2 deaths per 1000 person-years for hemodialysis. In the intention-to-treat analysis, while censoring for transplantation, there was no significant difference between the treatment groups in crude (HR, 1.08; 95% CI, 0.69-1.68) and adjusted (aHR, 1.06; 95% CI, 0.67-1.67). There were no significant differences in HRs for hemodialysis versus peritoneal dialysis between infants initiating dialysis therapy before and from 2000 onwards (P for interaction=.06).
In the group whose initial dialysis modality was peritoneal dialysis, 135 of 143 deaths occurred while still on peritoneal dialysis and eight infants died while switched to hemodialysis therapy. In the initial hemodialysis group, 19 of 23 deaths occurred while still on hemodialysis and four occurred while switched to peritoneal therapy.
The mortality risk and likelihood of transplantation were equal in peritoneal dialysis patients and hemodialysis patients. The risk for changing dialysis modality was higher in hemodialysis patients (adjusted HR, 1.64; 95% CI, 1.17-2.31).
Limitations to the study cited by the authors included the inability to control for unmeasured confounders not included in the Registry database and missing data such as comorbid conditions. The study has low statistical power due to the relatively small number of participants.
In conclusion, the researchers said, “Thus study provides evidence that may help physicians in the decision-making process when facing the management of chronic kidney failure in infants. According to our results, patient survival and access to kidney transplantation appeared similar for infants initiating dialysis therapy on peritoneal dialysis or hemodialysis, suggesting that hemodialysis may represent a safe and effective alternative dialysis modality in infants with chronic kidney failure. The choice of dialysis modality in this age group should take into account specific benefits and drawbacks of either technique, this individualizing the choice that best fits the needs of the patient and family.”
- Management of infants with chronic kidney failure carries significant challenges for pediatric nephrologists; the preferred modality for renal replacement therapy in children younger than 1 year is peritoneal dialysis.
- Researchers in Europe conducted a study to compare long-term outcomes of peritoneal dialysis with hemodialysis in a large cohort of patients who initiated dialysis therapy before 1 year of age.
- Patient survival and access to kidney transplantation were similar for infants initiating dialysis therapy on peritoneal dialysis or hemodialysis; hemodialysis may be a safe and effective alternative dialysis modality in this patient population.