**6. The choice of the therapeutic modality**

#### **6.1 Intermittent hemodialysis**

Like HF, it requires a dialysis catheter, dialysis machine, and filter as well as a water treatment system. It may be preferred for hemodynamically stable patients with acute poisoning or acute decompensation of CKD to avoid costly and time-consuming continuous use.

In children with intermittent hemodialysis lasting <6 hours, blood flow should start at 3 ml/kg per minute and reach 5 ml/kg per minute in subsequent sessions, and dialysate flow should be at least 300 ml/min up to twice the blood flow in ml/min [15].

Another method, sustained low-efficiency dialysis (SLED), is a form of prolonged intermittent renal replacement therapy (PIRRT), combines the advantages of intermittent hemodialysis and CKRT, although the literature on the use of PIRRT in children is limited [16].

#### **6.2 When to start a dialysis session?**

EER should be initiated without delay in life-threatening situations (hyperkalemia, metabolic acidosis, lysis syndrome, pulmonary edema refractory to medical therapy [17]).

In children, water and sodium overload of more than 10% and most likely more than 20% should be considered as a criterion for initiating an ERA.

Several series published in the literature have shown that water overload before RRT is a risk factor for mortality [12, 17–22].

However, despite the absence of specific studies, the benefit of ERA in acute prognostic situations seems reasonable, which explains why most experts recommend using RRT in these situations [15, 23, 24].

The best time to start an RRT remains an unresolved question. Very few studies have assessed the potential benefits of an early start to RRT.

The study of Gettings [25] in polytrauma patients treated with continuous techniques shows greater survival when ERA was started before urea reached 20 mmol/l.

The beneficial impact of the dialysis dose on prognosis would be to start very early. However, a start after relative hemodynamic stability has been achieved might be more reasonable. Whatever the situation, the only certainty is that it is not necessary to wait for the complications of nitrogen retention before starting the purification [26].

*Dialytic Treatment of Acute Renal Failure in Children DOI: http://dx.doi.org/10.5772/intechopen.111621*

A prospective randomized study by Bouman [27] compared an early onset of hemofiltration within 12 h of diagnosis of AKI to a later onset (urea greater than 40 mmol l<sup>−</sup><sup>1</sup> , serum potassium greater than 6.5 mmol l<sup>−</sup><sup>1</sup> , presence of pulmonary edema).

Time from diagnosis of ARF to onset of hemofiltration averaged 6 h in the early group and 42 h in the late group. Survival between the two groups was identical.

A meta-analysis of 12 studies with 4880 participants of all ages found no significant difference between early or late-onset dialysis in terms of survival but in terms of cost [28].

## **7. Impact of choice of dialysis modality**

The choice of continuous therapy varies widely in the pediatric literature [29].

HDI has the obvious advantage of rapid ultrafiltration or solute removal over the DP or RRTC.

In hemodynamically stable patients, no RRT modality is better suited than HDI for rapid removal of an offending solute. This method of treatment is particularly important in the following cases: cases of ingestion of drug toxicity, tumor lysis syndrome, and hyperammonemia observed in the pediatric population [30–32].

For the ability to adjust the composition of the dialysate to treat various electrolytes (i.e., hyperkalemia, hypernatremia) HD is a major advantage over DP or RRTC [33].

In some literature series, most hypernatremic dehydration in children was treated with PD [34, 35].

Bunchman et al. [36] reviewed survival outcomes in 226 pediatric patients receiving various forms of RRT, including PD, IHD, and CRRT, over 7 years. Patients were treated with CRRT (n = 106), IHD (n = 61), or PD (n = 59).

The survival rate is 54% of the overall population studied: 40% survival in the group treated with hemofiltration, 49% in the group treated with peritoneal dialysis, and 81% survival in the group treated with intermittent hemodialysis. (P < 0.01 HD vs. HF or PD).

In a series of 62 children with organ dysfunction syndrome (22-fold related to septic shock), continuous hemodiafiltration was more effective in controlling fluid overload than peritoneal dialysis (Lowrie) [37].

The hemodynamic tolerance of intermittent hemodialysis has been studied in adults [38, 39] but not in children, but in the Maghreb countries personal experience has led us to take into consideration what the literature has offered us by taking specific measures (with respect to volume, reduction of the temperature of the dialysis baths and sodium enrichment of the dialysis bath in particular, and daily dialysis session [40]).

A new machine can perform KRT in neonates and young infants using low extracorporeal blood volume and a slow blood flow rate while permitting precise calibration of ultrafiltration (CARPEDIEM) NIDUS developed in French and countries developed and confirming their safety and feasibility in infants with AKI [41, 42].

These machines are not marketed in india [43] and in the a Maghreb and in our country we use Prismaflex ®, to deliver CKRT to infants.

## **8. Conclusion**

The data for RRT modality choice in the treatment of pediatric AKI are limited. At the present time, there have been no randomized clinical trials comparing PD vs. IHD vs. CRRT for the treatment of children with AKI and no prospective studies have evaluated the effect of dialysis modality on the outcomes of children with AKI in the ICU setting.

The decision about dialysis modality should therefore be based on local expertise, resources available, and the patient's clinical status.
