Introduction 1 2 3 These guidelines were initiated and discussed at meetings of the group and refined by e-mail discussion to develop a consensus of opinion, on the basis of cumulative clinical experience and reported studies. This paper will discuss the main factors affecting hemodialysis prescription and management in children. 3 4 4 1 5 6 7 8 3 9 10 11 12 13 14 15 13 16 17 18 16 17 18 19 13 19 20 20 3 Guideline 1: the dialysis unit hemodialysis should be delivered in a “pediatric” dialysis center with a multidisciplinary support team which supports individualized and integrated therapy nutrition, growth, and educational support are of major importance 3 4 7 21 22 3 13 19 Guideline 2: water quality adequate in terms of biochemical composition free from microbiological contamination 1 23 2 Table 1 a Dissolved organic material Complications Contaminants:  - Pesticides, herbicides No documentation during dialysis - Chloramines, chlorine compounds Severe hemolytic anemia Bacteria and pyrogens:  - Bacteria Bacteremia or septicemia Fever, chills, shaking Hypotension and death - Pyrogens Pyrogenic reaction-fever Chills, uncontrollable Shaking, vomiting, hypotension a Table 2 70  −1 −1 Cytokine-induction AAMI, water 200 5 + European pharmacopoeia Regular water 100 0.25 + Ultra-pure 0.01 0.03 – Sterile −6 0.03 − 24 25 23 2 23 Guideline 3: the dialysis machine volumetric ultrafiltration control option for both single and double-needle dialysis 3  essential: 24 25 9 26 27 28 All these innovations enable individualized hemodialysis for the children, but their regular application should take into consideration the balance between the expected benefits and the costs. Guideline 4: blood lines available in infants/babies size biocompatible material 3 Guideline 5: principles of blood purification small solute clearance and more, from diffusion process (urea) to convection (other uremic toxins “middle molecules”) mass transport hemodiafiltration is an option to consider to obtain “maximum” dialysis efficiency 3 24 3 K HD K HF K HDF 24 Table 3  Dialyzer membrane permeability: diffusion and convection Diffusion process Convection mass transport Membrane area Q UF Mass-transport coefficient Hydraulic permeability Concentration gradient Transmembrane pressure (TMP; mmHg) Blood flow×extraction coefficient Membrane area \documentclass[12pt]{minimal}
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\begin{document}$$ K_{{\text{HD}}} = Q_{\text{b}} \times \frac{{c_{\text{i}} - c_{\text{o}} }} {{c_{\text{i}} }} $$\end{document} S c i  c o   Molecular permeability  \documentclass[12pt]{minimal}
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\begin{document}$$ S = \frac{{2C_{{\text{UF}}} }} {{c_{\text{i}} + c_{\text{o}} }} $$\end{document}  C UF  \documentclass[12pt]{minimal}
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\begin{document}$$ K_{{\text{HF}}} = Q_{{\text{UF}}} \times S $$\end{document} (postdilution)  \documentclass[12pt]{minimal}
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\begin{document}$$ K_{{\text{HF}}} = \frac{{Q_{\text{B}} \times Q_{{\text{UF}}} }} {{Q_{\text{B}} - Q_{{\text{UF}}} }} \times S $$\end{document} (predilution) K HD 
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\begin{document}$$ K_{{\text{HDF}}} = K_{{\text{HD}}} {\text{ }}\left( {{\text{1 - }}\;Q_{{\text{UF}}} \times S/Q_{\text{b}} } \right) + K_{{\text{HF}}} $$ \end{document}  Q UF S  K HF  Q b  K max  K HDF \documentclass[12pt]{minimal}
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\begin{document}$$ K_{{\text{HDF}}} = K_{{\text{HD}}} + K_{{\text{HF}}} - \frac{{K_{{\text{HD}}} \times K_{{\text{HF}}} }} {{K_{{\text{max}}} }} $$ \end{document}  K HDF  K max 29 30 31 3 24 25 23 2 32 23 Guideline 6: extracorporeal blood access and circulation fistula vascular access is preferred for long-term chronic hemodialysis in young children, less than 15 kg, the time needed to develop a fistula before it can be used could be some months the double-needle technique is the standard, but single needle with double pump system is an alternative a single lumen catheter with clamps offers for small children an acceptable compromise between a very low extracorporeal blood volume and valuable dialytic efficacy total extracorporeal blood volume (needles, tubing and dialyzer) should, approximately, be less than 10% of patient total blood volume anticoagulation in the extracorporeal circuit is achieved either with conventional heparin or with low-molecular-weight heparin Q B −1 −2 −1 −1 The success of chronic hemodialysis depends on good vascular access: internal arteriovenous fistulae (AVF), shunt (AVS), graft (AVG) or central venous catheter. The type of access used is variable depending on factors in different units and countries, for example surgical experience, patient age and size, the time available before dialysis must be started, and the presumed waiting time before transplantation. Patient choice plays a major part, especially with adolescents. 7 8 33 34 35 34 36 34 36 37 8 38 8 8 −1 −2 9 9 39 Q B −1 −2 −1 −1  Q B Q B −1 35 The total extracorporeal blood volume (needles, tubing, and dialyzer) should preferably be less than 10 % of patient total blood volume. This is essential for small children; however, the relative normal hemoglobin level obtained with erythropoïetin therapy enables this volume to be exceeded slightly without significant hypotension at the end of dialysis session when the patient reaches dry body weight. Nevertheless, it should be kept in mind that the higher the extracorporeal blood volume, the higher the volume of returned fluid, which will load the patient with fluid at the end of the dialysis session. (In very small children the substitution by air may be necessary to limit blood loss on one side and high substitution volume on the other side, but is very dangerous and should be strictly monitored.) System priming with saline, albumin, and sometimes blood should be applied in the first dialysis sessions with babies or small infants. −1 −1 −1 2 The venous blood line has a pediatric size air-trap chamber to limit extracorporeal blood volume. The dialysis membrane is protected by an arterial chamber of expansion which in small children is often not incorporated in the line to reduce the extracorporeal blood volume. Prevention or treatment of ethylene oxide allergy is possible by using steam sterilization of needles, lines, and membranes; this is becoming the preferred option throughout Europe. Guideline 7: which dialyzer membrane to “choose” synthetic membrane, low flux, capillary configuration high-flux membrane use requires use of ultrapure dialysate removal of urea and other uremic toxins dialytic should be considered, especially in chronic, long-term dialysis 32 4 Table 4  Dialyzer membranes: practical parameters of choice - Type of membrane: biocompatibility toward complement system - Initial blood volume needed, i.e. area-related, quality of restitution - Molecular permeability: maximum clearance for urea and the other uremic toxins, e.g. phosphate, related to potential patient osmotic risk - Hydraulic permeability: possibility of use for HF or HDF procedure, but related to back filtration risk, high flux membranes need ultrapure dialysate - Adsorption capacity on to the membrane (a characteristic of synthetic membranes) - Cost the biocompatibility of the material towards leucocytes and complement activation the blood volume priming requirement, which is membrane area-related C UF  C UF −1 −1  C UF −1 −1 40 41 41 2 32 Reuse of the membrane is not applied in practice for children. Guideline 8: the dialysate bicarbonate buffered, −1 glucose concentration at physiological level, dialysate quality control (germs and endotoxins) is required 42 −1 2+ −1 −1 2+ 2 −2 2 −2 43 44 43 44 45 46 41 42 −1 −1 −1 42 −1 −1 47 48 49 −1 −1 3 28 Guideline 9: post-dialytic dry weight assessment and adjustment particularly difficult to define in growing children no “unique” optimum method, importance of a clinical “pediatric” experience need for regular assessment in a growing child close collaboration with pediatric renal dietician 47 48 50 9 26 51 52 53 54 55 −2 −2 52 53 54 55 55 56 9 56 9 56 Guideline 10: urea dialytic kinetic, dialysis dose, and protein intake assessment (nutrition) 11 11 11 41  Kt V K t V 57 58 59 60 Kie Kt V  Kt V  Kie −1 −1 −1 58 61 62 63 64 64 64 Kt V  Kt V 65 66  Kt V UF BW td 60 \documentclass[12pt]{minimal}
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\begin{document}$$ Kt/V = \log n\;\left[ {\frac{{C{\text{pre}}}} {{C{\text{eq}}}} - 0.008\;td\; - \frac{{UF}} {{BW}}} \right] $$ \end{document}  td  C  C  UF BW −1  C 67 68 69 67  Kt V  V  V 5 71 50 Table 5 67 Boys: Ht<132.7 cm V Ht>132.7 cm V Girls: Ht<110.8 cm V Ht>110.8 cm V Guideline 11: dialysis dose and outcome only “small solute urea clearance” prescription?  Kt V dialysis and residual renal small-solute clearance are not equivalent dialysis prescription should be adequate before being optimum, not only a “urea dialysis dose”  Kt V  Kt V 11  Kt V 1  Kt V 72 73 74 75 76 77 Fig. 1  Dialysis prescription balance  11 11 78 3 24 32 41 12 12 13 19 78 14 19 16 13 17 18 77 79 19 6 80 13 14 19 Table 6  Hemodialysis prescription for children: adequate, before optimum - Dialysis modality should enable achievement of blood pressure control (without antihypertensive medications for most children), normal myocardial morphology and function - Dialysis dose prescription should not only be an urea dialysis dose. Removal of the other uremic toxins should be considered, not only middle molecules but overall phosphate - Dialysis frequency and duration must be adjusted to the tolerance of ultrafiltration to reach the dry weight. Ultrafiltration rate should not exceed 1.5±0.5% of body weight per hour (in theory no more than 5% BW loss per whole session ). Blood volume (hematocrite) guided ultrafiltration secure  Kt V - Too fast ultrafiltration can induce hypotension and cramps during dialysis, usually during the second half time session, and fatigue and/or hang over after dialysis - A small solute, e.g. urea, clearance which is too high is a factor of disequilibrium syndrome occurring during dialysis, usually after the first half/or one hour session time with headache, even seizures, nausea, vomiting, sleepiness or a hypertensive tendency with a narrow range between systolic and diastolic pressure values. Symptoms usually disappear a few hours after the end of the dialysis Guideline 12: the dialysis session, prescription, and monitoring individual prescription is required: babies/infants/children specificities assessment and adjustment is needed regularly in small/growing children psychological preparation of the child and his family is needed, pain prevention is essential 39 22 −1 −2 −1 −1 −1 −1 −2  Kt V 11 3 80 −1 78 3 48 26 56 54 55 3 11 7 21 80 3 32 1 21 3 80 44 45 Conclusions 81 82 13 20 13 20 79 80 83 16 17 18 19 2 −2 43