Should renal replacement therapy be offered to all neonates?

Long term peritoneal dialysis of newborn infants has been successfully undertaken in the majority of patients who have isolated renal failure. For many developed countries in 2009, chronic dialysis of newborns has become the standard of clinical care. However, in newborns with co-existing congenital abnormalities, the prognosis may be poor. In these circumstances, palliative care can be discussed with the family and within the multidisciplinary environment.

It is important that the neonatologist/general paediatrician discusses each individual case with the paediatric nephrology service. This will give the parents and referring doctor an opportunity to discuss the relevant issues with the paediatric nephrology team and decide whether long term dialysis is a viable option.

How often does this occur?

The incidence of chronic dialysis from birth is very low; UK figures are 3 per million population per year. In the US, it is 6 per million. These figures are only of those who are offered chronic dialysis. In New Zealand, there have been 3 neonates who started chronic dialysis before age 30 days in the period 2004-9.

There is an increased incidence of prematurity in neonates with chronic renal failure. In a study of infants with GFR < 20ml/min/1.73m2 at the end of the first year of life, (normal at least >60) 26% were preterm; of these 18% were also low birth weight.
 

How will these newborns present?

Newborn infants with renal failure severe enough to need dialysis therapy occur in two situations:

• Acute insult (sepsis, perinatal hypoxic ischaemic injury). This is a common cause for acute renal failure in newborns. The acute renal failure is usually reversible and the need for acute dialysis is uncommon, but maybe required for a short period to support renal function in expectation of recovery. This is usually started after appropriate discussion between the neonatologist and the nephrologist. Where there has been severe hypoxic ischemic insult resulting in severe brain injury long term dialysis is not appropriate.

• Bilateral chronic kidney disease. This is usually due to an obstructive congenital abnormality of the urinary tract resulting in severe damage to both kidneys with renal failure detected shortly after birth. Many of these would have be detected on antenatal ultrasonography, while others will present within the first week or two of life with failure to thrive and are referred for diagnosis and management. The renal disease maybe a part of a constellation of other congenital abnormalities or an isolated problem in an otherwise normal baby. The latter group are potential candidates for long term renal replacement therapy. Where other organ systems are also involved such as major cardiac lesions, significant brain abnormality, severe pulmonary hypoplasia, major abdominal organ involvement, dialysis therapy would generally not be offered because the outcome is universally poor.

In the second scenario, were severe kidney abnormalities are detected in-utero, the paediatric nephrology and urology services should be involved as early as possible so as provide appropriate information on possible treatment and outcome. Ideally discussion should take place antenatally with the opportunity for nephro-urological input at the fetal medicine panel.

What determines outlook?

• The presence of oliguria indicates poor residual renal function and is the most important predictor of outcome.
• The presence of antenatal oligohydramnios indicates severe bilateral renal disease and is associated with a mortality of approximately 30%.
• Non renal co-morbidities such as neurological insults, cardiac problems, and other malformations also contribute to mortality.
   

Dialysis indications

• Biochemical abnormalities that cannot be controlled by medication and nutritional support
• Poor growth
• Fluid overload

Most infants with chronic renal failure have polyuric chronic kidney disease; hence hyperkalemia, fluid overload, and hypertension are uncommon despite very low GFR (renal function). On the other hand, if the baby is oliguric, dialysis is likely to be required to enable adequate nutrition support and growth.

Mortality

Survival of infants on long term dialysis is less than that of older children. Most deaths occur in first year of life. The North American Pediatric Renal Trials Collaborative Study (NAPRTCS) 2007 reported patient survival was 82% at 12 months and 73% at 24 months. For infants in whom treatment has never been started, most will have died before one year and the majority of these deaths are in infants with co-morbidity. The most common causes of death are cardiopulmonary and sepsis.

Outcome of those infants who survive

In the study by Warady, 28 of 34 (79%) infants who were dialysed before 3 months of age, one had significant developmental delay, 15 of the 16 who had reached 5 years of age were attending normal school. In the UK series of 105 children old enough to assess, 91(87%) attended normal school. 85% of children dialysed as infants had developmental scores within the normal range, but 50% had borderline abnormal psychosocial adjustment.

What should be considered when presented with a newborn with severe renal failure?

For those infants who have isolated severe chronic kidney disease, where the possibility of dialysis is being considered, the following issues should be considered and discussed

• Attitude and wishes of the parents, and relatives to undertake long term dialysis for their baby after full presentation and discussion of current data available.
• Assessment by the paediatric nephrology multidisciplinary team as to suitability and appropriateness of long term treatment.
• During the discussion it should be made clear to the parents that appropriateness of treatment will be regularly reviewed and withdrawal of treatment would be recommended if in the treating team’s opinion that ongoing therapy is causing unnecessary suffering with no reasonable possibility of a quality long term outcome.
• The agreement to offer long term dialysis care to a newborn is a partnership between the parents and treatment team.
• A decision not treat or withdraw treatment is made by the nephrology multidisciplinary team in discussion with the parents.
• Discussion and advice from the ADHB clinical ethics committee can be sought.

The paediatric nephrology multidisciplinary team

A team of medical, nursing and allied health professionals is essential to manage a neonate with severe chronic renal failure.

Options for management

Summary

Newborn infants with isolated severe renal failure may be offered long term dialysis but only after careful consideration of a variety of issues which include ethics of initiating or withdrawing such a treatment, resource availability, wishes of the family and expectations of society in general. Each case should be considered on a case by case basis in the nephrology multidisciplinary team.

References