1. Assessment of the Nutritional Status of Children with End-stage Renal Disease

2. Malnutrition is a common and serious complication of chronic kidney disease (CKD), and is associated with increased morbidity and mortality.
Contributing factors to this malnutrition include poor appetite, various co-morbidities, dietary restrictions, inflammation, infection, metabolic acidosis and oxidative stress.

3. Nutritional status is particularly important in children as it influences growth and sexual and neuro-cognitive development. Thus, its accurate and regular assessment is highly recommended in patients on regular hemodialysis (HD).
Growth failure is one of the commonest and a profound clinical manifestation of CKD in infants, children and adolescents.
Early recognition of growth delay in infancy is crucial because growth failure in this critical period is extremely difficult to catch up later.

4. Height age is usually more retarded than bone age.
Children with height SD scores less than -2.5 at dialysis initiation were found to have 2.07 times the risk of death and to spend 0.22 more days per month in the hospital compared to those with height SD scores
More than -2.5.
Body mass index (BMI) has been suggested as a more appropriate method of standardization in renal disease.

5. No single measure adequately reflects nutritional status.
The recommended measures for evaluation of protein- energy nutritional status for children on HD;
Dietary intake
Serum albumin
Pre-albumin
Height SDS
Estimated dry weight
BMI
Head circumference (<3yrs)
Skin fold thickness
Mid-arm anthropometric measures

6. The NKF-K/DOQI (2000) recommended that children on dialysis should have their initial dietary protein intake based on the RDA for chronological age, with an additional increment of 0.4 g/kg/day for patients on HD.
It also recommended that diet should consist of protein of high biological value.

7. Hypo-albuminemia is frequently seen in patients with CKD and has been consistently shown to be associated with increased mortality in children (each 1- g/dl decrease in serum albumin is associated with a 54% higher risk of death).
Pre-albumin is not recommended for the nutritional assessment of pediatric patients with CKD.
Protein catabolic rates of less than 1 g/kg/day are indicative of low protein intake and protein malnutrition and should lead to institution of corrective steps (e.g. a.a. infusion during HD results in short term improvement in protein metabolism, however its cost limit its wider use).

8. Kidney disease wasting (KDW) in chronic dialysis patients affects approximately one third of HD patients. Serum levels of inflammatory markers are increased and numerous causes of chronic inflammation may be present.

9. Causes of KDW:
Decreased nutrition intake
-Dietary restrictions
-Delayed gastric empting and diarrhea
-Intercurrent illness and hospitalization
-Decrease in food intake on hemodialysis day
-Medication causing dyspepsia (phosphate binder, iron preparations)
-Depression
-Altered sense of taste
Increased losses
-Gastrointestinal blood loss
-Intradialytic nitrogen losses
Increase in protein catabolism
-Metabolic acidosis
-Dysfunction of the growth hormone-insulin growth factor axis
-Catabolic effect of other hormone (parathyroid hormone, cortisol, glucagon)

10. The sequelae of KDW are numerous, including malaise, fatigue, poor rehabilitation, impaired wound healing, increase susceptibility to infection, increased rate of hospitalization and mortality.
Consequently, assessment of the nutritional status for children receiving maintenance dialysis is extremely important.

11. Two methods of obtaining dietary information may be used; prospectively, by means of a 3-day diary, or retrospectively, by interview with recall of intake over the previous 24 hrs.
The estimated dry weight, in combination with stature, remains the usual central component of the nutritional evaluation.

12. Measures of growth and nutritional status are often expressed as SD scores or Z scores.
An SD score is the difference, in SD units, between an individual’s measure and the mean for children with the same characteristics.
SD score = observed - mean for age and sex/SD for age and sex.

13. SDS allows comparison of data irrespective of age and sex, and measurements were referred to reference data derived from Egyptian Growth Charts.
The Z score of the anthropometric measurements are calculated for each case according to the following formula:
Z score = Individual measurement – Mean population value for age and gender
Standard deviation of mean population value for age and gender

14. Measurements: The skin fold thickness (in mm):
This is taken by using a Holtain skin fold thickness caliper, an instrument that has been designed to give a constant pressure of 10 g/m2 over its entire operating range. Its dial is marked in divisions of 0.2 mm, but the reading of 0.1 mm can be easily estimated.

15. Triceps skin fold (TSF) thickness: The measure is taken on both the right and the left arms and then the mean is taken.
The child is standing with his back to the measurer and his arm relaxed, with the palm facing the lateral thigh, the tips of the acromion process and olecranon are placed and a mark is made on the skin (a point midway between them and parallel to the long axis of the arm). Then, the skin fold is picked up between the index finger and the thumb of the left hand, over the posterior surface of the triceps muscle, 1 cm above the mark. Care is taken not to include the underlying muscle. The caliper jaws are applied at the marked level.

16. Subscapular skin fold thickness: The subject’s shoulder are erect and the arm beside the body. The skin fold is picked up at the inferior angle of the scapula and the caliper jaws are applied.
Mid-arm circumference (MAC), mid-arm muscle circumference (MAMC) and mid-arm muscle circumference area (MAMA) are measures used as indices of total muscle mass.
MAC is measured in the upper arm, midway between the acromion and the olecranon process, with a flexible measuring tape.
MAMC and MAMA were estimated by using equations that incorporate MAC and the TSF thickness measure.
MAMC = MAC × TSF
MAMA = [(MAC × TSF)2 / 4 × 3.14] - 10 in boys
MAMA = [(MAC × TSF)2 / 4 × 3.14] in girls.

17. Head circumference:
-in children <3 yr.
-Poor head growth is well documented in children with CKD.

18. All measurements are taken after dialysis to exclude the effect of edema that was present in some patients before dialysis due to volume overload and disappears at the end of dialysis.
Frequency of assessment: at a minimum of every 6 months in children with CKD stages 2 to 3. For children with more advanced CKD, more frequent evaluation is required.

19. Other nutritional assessment techniques: 1-Dual energy x-ray absorptometry (DEXA) 2-Bio-electrical impedance analysis 3-Densitometry 4-Total-body potassium counting 5-In-vivo neutron activation analysis 6-Isotope dilution

20. Attempts to improve growth include adequate dialysis, improved nutrition, renal osteodystrophy management, correction of metabolic acidosis and administration of recombinant human growth hormone (rhGH).