Diagnosis and Management of Fluid Overload in Heart Failure and Cardio-Renal Syndrome: The "5B" Approach

Semin Nephrol. 2012 Jan;32(1):129-41. doi: 10.1016/j.semnephrol.2011.11.016.


Cardio-Renal syndrome may occur as a result of either primarily renal or cardiac dysfunction. This complex interaction requires a tailored approach to manage the underlying pathophysiology while optimizing the patient's symptoms and thus providing the best outcomes. Patients often are admitted to the hospital for signs and symptoms of congestion and fluid overload is the most frequent cause of subsequent re-admission. Fluid management is of paramount importance in the strategy of treatment for heart failure patients. Adequate fluid status should be obtained but a target value should be set according to objective indicators and biomarkers. Once the fluid excess is identified, a careful prescription of fluid removal by diuretics or extracorporeal therapies must be made. While delivering these therapies, adequate monitoring should be performed to prevent unwanted effects such as worsening of renal function or other complications. There is a very narrow window of optimal hydration for heart failure patients. Overhydration can result in myocardial stretching and potential decompensation. Inappropriate dehydration or relative reduction of circulating blood volume may result in distant organ damage caused by inadequate perfusion. We suggest consideration of the "5B" approach. This stands for balance of fluids (reflected by body weight), blood pressure, biomarkers, bioimpedance vector analysis, and blood volume. Addressing these parameters ensures that the most important issues affecting symptoms and outcomes are addressed. Furthermore, the patient is receiving the best possible care while avoiding unwanted side effects of the treatment.

MeSH terms

  • Acute-Phase Proteins
  • Biomarkers
  • Blood Pressure
  • Blood Volume
  • Body Composition*
  • Cardio-Renal Syndrome* / diagnosis
  • Cardio-Renal Syndrome* / physiopathology
  • Cardio-Renal Syndrome* / therapy
  • Electric Impedance
  • Fluid Therapy*
  • Heart Failure* / diagnosis
  • Heart Failure* / physiopathology
  • Heart Failure* / therapy
  • Humans
  • Lipocalin-2
  • Lipocalins / blood
  • Natriuretic Peptide, Brain / blood*
  • Proto-Oncogene Proteins / blood
  • Water-Electrolyte Balance
  • Water-Electrolyte Imbalance* / diagnosis
  • Water-Electrolyte Imbalance* / physiopathology
  • Water-Electrolyte Imbalance* / therapy


  • Acute-Phase Proteins
  • Biomarkers
  • LCN2 protein, human
  • Lipocalin-2
  • Lipocalins
  • Proto-Oncogene Proteins
  • Natriuretic Peptide, Brain