Immediate Initiation of Renal Replacement Therapy in Acute‑on‑Chronic Kidney Injury with Right‑Heart Failure

Indications for Dialysis

A rise in serum creatinine > 30 % from baseline during diuretic therapy signals worsening cardiorenal syndrome and mandates escalation to renal replacement therapy 1.
When the creatinine increase occurs together with persistent congestion (e.g., ongoing respiratory distress and volume overload), it reflects decompensated heart failure rather than volume depletion and further supports urgent dialysis 1.
Failure of ≥48 h of continuous intravenous loop diuretic (furosemide) infusion with concurrent creatinine worsening meets criteria for diuretic resistance and indicates that medical decongestion has failed 1.

Slow continuous venovenous ultrafiltration (CVVH) is the modality of choice for patients with severe renal insufficiency and volume overload in the setting of right‑heart failure, because it allows controlled fluid removal (≈ 200–500 mL/h) while minimizing hemodynamic instability 1.
Intermittent hemodialysis can be used as an alternative but carries a higher risk of hypotension in right‑heart failure patients 2.
Peritoneal dialysis may be considered for longer‑term management after stabilization, as it avoids large hemodynamic swings and helps preserve residual kidney function 4.

Ultrafiltration must be performed under direct nephrology supervision in an intensive‑care or intermediate‑care setting, with the nephrologist determining the ultrafiltration rate, duration, and anticoagulation strategy 1.

Continue nitroglycerin infusion unless systolic blood pressure falls below 90 mmHg; the vasodilator reduces preload and afterload, benefiting right‑heart failure 1.
Temporarily reduce or hold loop diuretics once ultrafiltration begins, because mechanical fluid removal replaces diuretic‑induced natriuresis 1.
Resume low‑dose loop diuretics only after achieving clinical euvolemia and if residual renal function permits 1.
Monitor electrolytes (potassium, sodium, magnesium, phosphate) every 6–12 hours during ultrafiltration; aggressive repletion of potassium and magnesium is required to counteract deficiencies that worsen diuretic resistance 1.
Target systolic blood pressure 110–140 mmHg during ultrafiltration to maintain adequate renal perfusion pressure and avoid hypotension 1.

Sequential nephron blockade with thiazide‑type diuretics (e.g., metolazone) or aldosterone antagonists is appropriate only when estimated GFR > 20 mL/min; in patients with GFR < 15 mL/min the efficacy of thiazides is minimal 1.
Hypertonic saline combined with furosemide requires expert supervision and is contraindicated in accelerated hypertension and severe CKD because of the risk of further sodium overload 1.
Inotropic agents (e.g., dobutamine, milrinone) improve renal perfusion in low‑output heart failure but are not indicated for right‑dominant volume‑overload states, where they may increase tachycardia and myocardial oxygen demand without addressing congestion 1.

Immediate (every 1–4 h): record hourly fluid removal rate and cumulative volume removed; monitor vital signs (BP, HR, RR, SpO₂); assess clinical congestion (jugular venous pressure, lung crackles, peripheral edema) 1.
Daily: obtain body weight at the same time each day; measure serum creatinine, BUN, electrolytes (K⁺, Na⁺, Mg²⁺, PO₄³⁻); check hemoglobin and transfuse if < 90 g/L to improve oxygen delivery 1.
Therapeutic goals: achieve complete resolution of respiratory distress and clinical congestion before transitioning to oral diuretics; aim for stabilization or improvement of creatinine toward baseline values; maintain systolic BP 110–140 mmHg and avoid hypotension (SBP < 90 mmHg) 1.