Physiology-guided volume optimization in patients with acute exacerbations of heart failure complicated by various comorbidities: two case reports

Background: Traditional volume management for acute decompensated heart failure emphasizes strict fluid restriction. However, this may be harmful in patients with relative hypovolemia (e.g., poor intake or sepsis). We report two cases managed with a physiology-guided, individualized maintenance fluid strategy (avoiding routine restriction) and present them as hypothesis-generating observations. Case presentation: Case 1: A 69-year-old man with dilated cardiomyopathy presented with acute exacerbation, hypotension, prerenal azotemia (urea/creatinine >20:1), and anorexia. We used maintenance fluids (approximately 35 mL/kg/day as an initial empirical target, adjusted clinically) while continuing guideline-directed medical therapy (GDMT). Symptoms improved; NT-proBNP fell from 20,470 to 2,669 pg/mL. Case 2: An 83-year-old woman with sepsis from an infected pressure ulcer developed acute heart failure. We used a similar maintenance fluid strategy (not aggressive resuscitation) plus antibiotics and gradual GDMT. Infection resolved, NT-proBNP fell from 14,995 to 365 pg/mL. Conclusion: In selected patients with ADHF and possible hypovolemic factors, a physiology-guided maintenance strategy may be considered as an alternative to strict restriction. This strategy may help interrupt the hypothesized vicious cycle of hypoperfusion and renal injury, and is compatible with the optimization of GDMT. However, causality cannot be inferred because multiple interventions were given simultaneously. These observations are hypothesis-generating and require prospective validation. Individualized management is essential.