Jie Zhou, Xiaoyan Yu, Shangshang Wang
To develop a "nutrition-volume-electrolyte" Trinity nursing protocol for elderly patients with diabetic nephropathy (DN), centered on precise nutritional protein regulation, and to evaluate its clinical and economic value. This single-center retrospective cohort study included 66 elderly patients with DN admitted between January 2022 and November 2025. Based on the implementation of the updated nursing protocol in January 2024, 31 patients who received routine nursing care were assigned to the historical control group, and 35 patients who received Trinity integrated nursing based on stratified nutritional protein management combined with volume and electrolyte regulation were assigned to the observation group. Interventions were delivered during hospitalization and continued for three months after discharge. Outcomes included nutritional indicators, volume load, electrolyte target attainment, renal function, adverse events, quality of life, and health economic measures. After three months, albumin, prealbumin, hemoglobin, and transferrin were significantly higher in the observation group than in the control group (all P < 0.01). At all assessed time points, the 24-h intake-output difference, B-type natriuretic peptide (BNP) level, and edema severity score were lower in the observation group (all P < 0.001). Target attainment rates for serum potassium, sodium, calcium, and phosphorus were higher (all P < 0.05), and changes in eGFR, serum creatinine, and 24-h urinary total protein were more favorable (all P < 0.05). Adverse events were less frequent in the observation group than in the control group (25.71% vs. 51.61%, P = 0.030). 36-Item Short Form Health Survey (SF-36) scores were higher, whereas hospital stay, total medical cost per capita, and cost per unit effect were lower (all P. < 0.001). In conclusion, the Trinity integrated nursing protocol improved nutritional status, volume, and electrolyte balance, renal outcomes, quality of life, and economic performance in elderly patients with DN, supporting its value in clinical nursing management.