Dialysis in Neonates

Recently, there was an article in Slate magazine that detailed the very difficult decision that had to be made by a pregnant woman who discovered at 18 weeks gestation that her baby had complete bladder outlet obstruction with resulting bilateral megaureters and likely hypoplastic lungs. One of the questions related to the issue of dialysis in a newborn. In the past, this was generally not offered because of the presumption of a very poor prognosis. However, survival in neonates with ESRD has improved and it is becoming more routine in some units to offer RRT. It seems appropriate then, that KI just published a retrospective analysis of dialysis in neonates over the last 15 years.

In total, 254 patients from 32 countries started dialysis before one month of age and about half were in the first week. The most common causes of ESRD were congenital abnormalities of the kidney and urinary tract, cystic kidneys (mostly ARPKD) and cortical necrosis. More than 90% started with PD with most of the remainder starting HD because there was a contraindication to PD (e.g. recent abdominal surgery). One patient had a transplant in the first week but died shortly afterwards. Fifteen individuals had some later recovery of renal function and were able to come off dialysis, at least temporarily.

Overall, survival was excellent - 2-year survival was 81% and 5-year survival was 76.4%. In cases where the cause of death was known, about 2/3 were due to sepsis. Interestingly, the only factor that was significantly associated with an increased risk of death was the presence of concomitant neurological disorders (HR 5.2, CI 1.7-15.4). This may suggest that there was considerable selection bias with neonates who were considered unlikely to survive due to the presence of severe co-morbidities not being commenced on dialysis.

Long term, 45 patients received a transplant in the first 2 years of life. The 5-year patient and graft survival in these individuals was 84.2%.

As expected, there were significant co-morbidities present in these children. 20% had neurodevelopmental delay and 12% had pulmonary problems, mostly hypoplasia (the kidneys are an important source of amniotic fluid which is required for proper lung development). Birth length was below the 3rd percentile in 43% and 63% had growth retardation at 2 years. About 40% were on antihypertensives at 2 years and about 86% required treatment with EPO.

Overall, survival in this very vulnerable group was much better than I would have expected. Of course, given the presence of multiple co-morbidities, it is uncertain what their longer term outcomes would be. However, it does provide some hope to a group who, not so long ago, would have been considered hopeless. Consider that in 1998, a survey of French neonatologists found that 24% would never consider RRT in a neonate whereas a more recent survey suggested that 98% of neonatologists would offer RRT in at least some patients.