An evaluation of renal inpatient meals against Renal Nutrition Group standards.

BACKGROUND: The Renal Nutrition Group (RNG) of the British Dietetic Association has developed standards for the nutritional composition of meals provided to renal patients in hospital. However, no data are available as to whether these are achievable. The purpose of this study was to determine whether renal inpatient meals can meet the standards set by the RNG. METHOD: A prospective 10-day weighed food analysis of hospital meals provided to renal patients was undertaken. Two sample meals were analysed at each mealtime to include (1) the most energy dense choice and (2) the most frequent patient choice (FPC). RESULTS: Energy dense choice meals achieved the standard for protein provision on 90% of days, but provided too little energy on 100% of days (for men) and on 30% of days (for women). Although daily standards for potassium were met on 70% of days, those for sodium and phosphate were exceeded. FPC meals met the daily standards for potassium, sodium and phosphate on at least 80% of days, but provided too little protein on 40% of days and too little energy on 100% of days (for men and women). CONCLUSION: The majority of hospital meals fail to meet the RNG standards. Problems exist in providing sufficient energy and protein whilst restricting sodium, potassium and phosphate.

Is decreased treatment time in hemodialysis patients harmful if solute clearance is maintained?

An association between decreased duration of hemodialysis and increased morbidity and mortality in patients has been suggested. Whether this is due only to decreased solute clearance is unclear. In this prospective randomised study the effect of reducing treatment time whilst maintaining constant solute clearance was examined in fourteen patients. The study lasted for a period of 36 weeks (3x12 week study periods) and used a crossover design. The patients dialysis prescription (KW) was not changed on entering the study and was maintained during short (150 minutes) and long dialysis (240 minutes) by varying blood flow, dialysate flow and dialyzer surface area. The delivered KW was kinetically assessed. Fractional urea clearance was also measured during each treatment period by measurement of urea concentration in spent dialysate and total body water using 3H2O. At the end of each treatment period a full biochemical and hematological profile, nutritional intake and status, 24 h ambulatory blood pressure, nerve conduction studies, and quality of life questionnaire were performed. Within patients the delivered single pool KW was uniform throughout the 3 treatment periods and fractional urea clearance did not vary. However, Kt/W assessed using equilibrated models (Daugardis and Smye) was significantly lower in the short dialysis period. No differences between short and long dialysis sessions were noted in any of the measured variables. Thus, over a 36 week period there is no evidence to suggest that hemodialysis patients are adversely affected by decreased duration of treatment provided that solute clearance is maintained.

Nutritional status, delaying progression and risks associated with protein restriction.

Low protein diets (LPD), providing < or = 0.6 g protein/kg body weight daily, have traditionally been used in the nutritional management of chronic renal failure (CRF). Initially they were advocated when dialysis availability was limited. More recently LPD have been proposed as a means of delaying the rate of CRF progression. Despite much research in this area, the value of protein restriction remains contentious. A major concern over their use is that they may induce malnutrition. This is of critical importance since mortality rates are significantly increased in individuals who are malnourished when dialysis is initiated. Other approaches to the nutritional management of CRF may be more appropriate. The primary goal of any nutritional therapy should be to optimise the patient's nutritional status. In the UK LPD are used in a minority of units. An alternative approach to the use of these diets is to view the prevention of malnutrition as being of paramount importance. For uraemic patients, dialysis is the best treatment.

Effect of a high protein diet in patients with the nephrotic syndrome.

1. Twelve patients with the nephrotic syndrome were prescribed for 4 week periods a normal protein diet (NPD) containing 1 g of protein/kg ideal body weight. They were then prescribed for further 4 week periods in random order diets with high (HPD) and low (LPD) protein contents, respectively 2.0 and 0.5 g/kg ideal body weight. 2. Compliance was confirmed by dietary history and measurement of urinary excretion. 3. Serum albumin was the same on all diets. Twenty-four hour urinary protein excretion increased progressively with increasing dietary protein (LPD 6.1 g. NPD 8.2 g. HPD 9.2 g). Recumbent plasma renin activity and serum phosphate were significantly increased on HPD (plasma renin activity: LPD 5.7, NPD 4.6, HPD 8.2 pmol of angiotensin I min-1 1(-1); serum phosphate: LPD 1.27, NPD 1.26, HPD 1.41 mmol/l). 4. There was no evidence of protein-induced hyperfiltration or hyperperfusion: 51Cr-ethylenediaminetetra-acetate and [125I]iodohippurate clearances were similar on all three diets. 5. Since proteinuria, increased plasma renin levels and hyperphosphataemia may contribute to progression of renal failure and because HPD did not improve hypoalbuminaemia, the use of HPD in the nephrotic syndrome should be abandoned. 6. Until it can be established that LPD, which is accompanied by the least proteinuria, does not, with long-term feeding, lead to malnutrition, NPD should be used in the treatment of the nephrotic syndrome.