The complexity of dialytic therapy in hyperammonemic neonates

Abstract

The utilization of renal replacement therapy (RRT) in the setting of hyperammonia is a rare and complicated occurrence. Data demonstrate that the quicker the ammonia level is normalized, the better the neurological outcome. The optimal form of RRT is often decided by local practice. The recent work by Picca and colleagues details a larger series of children who underwent RRT for hyperammonia and adds some credence to the use of peritoneal dialysis (PD) in this population. While these authors conclude that PD is not optimal, they do note that the use of PD may be an option when other forms of RRT are not available. The results reinforce the general maxim that you should continue to do that which you do well and often, which in this context refers to continuing to use your form of RRT until alternative modalities are available. Keywords Infant . Inborn error of metabolism . Renal replacement therapyThe recent paper by Picca and colleagues identified a series of 45 neonates over a 21-year span who underwent extracorporeal therapy or peritoneal dialysis (PD) for hyperammonemia due to an inborn error of metabolism (IBM) [1]. One of the aim of the authors was to examine the question of whether PD can play a role in hyperammonemia therapy and if so, then how does PD compare to either hemodialysis (HD) or continuous renal replacement therapy (CRRT) in the form of continuous venovenous hemofiltration or continuous venoarterial hemofiltration. The latter modalities have been referred to as extracorporeal therapy.

A surviving 24-month-old patient with neonatal-onset carnitine palmitoyltransferase II deficiency

“…PD is easy to initiate and manage, facilitating early treatment. Accordingly, PD is a potential therapeutic option for the future [8], [9]. It is possible that CHD is effective for the recovery of metabolic decompensation related to metabolic acidosis and hyperammonemia.…”

The Role of RRT in Hyperammonemic Patients

“…The authors concluded that peritoneal dialysis is often readily available and easy to initiate, and therefore, it may be a viable option in centers where ECT may not be readily available (52). In one editorial on the work by Picca et al (52), Bunchman (53) agreed that it is reasonable to start with peritoneal dialysis until ECT is available but that peritoneal dialysis is "only a stop gap measure" and should not be used as the sole dialytic therapy (53).…”

Uso de Hemofiltración veno-venosa continua en neonatos con hiperamonemia. Serie clínica

“…Since PD is depuratively less efficient than vascular techniques, it would not be the first-line alternative in situations of blood accumulation in the "dangerous" range of an exogenous or endogenous toxic substance, unless there was no other alternative available 2,8,9 . Intermittent hemodialysis offers the most efficient and fastest way to remove ammonia from the blood, but it is technically complex to perform in young children because of the hemodynamic instability it produces, in addition to a rapid rebound of ammonia when it stops 7,10 .…”