Nutritional screening tools for CAPD patients: are computers the way forward?

The aim of this study was to develop a computer programme (CP) to identify CAPD patients at risk of malnutrition as well as screen monthly biochemical results of transplant (tx), haemodialysis (HD), CAPD and nephrology (Ne) patients for abnormal levels such as hyperkalaemia.

The CP was designed using the programme Proton. Proton can automatically download biochemical results from pathology making it possible to generate a list of patients with results outside a desired biochemical range in accordance with national renal standards for adult patients. Biochemical measures of nutritional status were used to define malnutrition as 2 or more results outside of these parameters (see Table 1): 10% weight loss, Kt/V < 1.9, normalised protein catabolic rate (nPCR) < 1.2: predialysis urea < 15 mmol/L, phosphate (PO4) < 0.75 mmol/L, potassium (K), < 3.3 mmol/L. The CP was compared with standardised dietetic assessments (SDA) for validity. An SDA includes a review of medical, social history, biochemistry (blood and urine), dialysis prescriptions, treatment plans, medications, weight changes, BMI, dietary intake compared to therapeutic guidelines with documented aims. The therapeutic guidelines used to complete dietary assessment include: protein 1.2-1.5 g/kg Ideal Body Weight (IBW), energy: aim for BMI of 20-25 kg/m2, sodium: 100-120 mmol/L, K: 1 mmol/kg IBW, fluid: urine output + medical advice, PO4: 175-200 mg of PO4/10 g of protein. 3005 patients from Richard Bright Renal Unit in Bristol, England, including 4 Satellite HD units, had blood results screened for abnormal levels using CP (see Table 1). In the clinic setting, the length of time taken to review biochemical results was measured before and after implementation.

The CP identified 88% of CAPD patients at risk of malnutrition compared with 67% by SDA. The time taken to look up biochemical results of patients attending the outpatient clinics was reduced by approximately 30 minutes leaving only the diet history computer screen to review for each patient.

The CP should be compared with subjective global assessment (SGA) for validity in the identification of malnutrition. Serum cholesterol, prealbumin, protein equivalent of total nitrogen appearance (nPNA), C reactive protein (CRP) and bicarbonate should be incorporated into the CP in order to improve its specificity.

Using the present parameters, the CP over diagnosed the number of CAPD patients at risk of malnutrition. However, the CP improves time management and rationalisation of dietetic activity by screening abnormal biochemistry.