From the Guidelines
In heart failure, fluid overload is typically most evident in the dependent areas of the body, particularly the lower extremities (legs, ankles, and feet) and the lungs. Patients commonly present with peripheral edema, which manifests as swelling in the ankles and legs that worsens throughout the day and improves with elevation 1. Pulmonary edema is another significant manifestation, causing shortness of breath, orthopnea (difficulty breathing when lying flat), and paroxysmal nocturnal dyspnea (waking up at night gasping for air). Fluid can also accumulate in the abdomen (ascites), especially in right-sided heart failure, and in the sacral region in bedridden patients. This fluid accumulation occurs because the failing heart cannot pump blood efficiently, leading to increased pressure in the venous system. As venous pressure rises, fluid is forced out of the blood vessels into surrounding tissues. In left-sided heart failure, fluid backs up into the lungs, while right-sided heart failure typically causes peripheral edema and abdominal fluid accumulation.
Key Areas of Fluid Overload
- Lower extremities (legs, ankles, and feet)
- Lungs
- Abdomen (ascites)
- Sacral region in bedridden patients
Management focuses on reducing this fluid overload through diuretics, sodium restriction, and treating the underlying heart condition, as recommended by the 2022 AHA/ACC/HFSA guideline for the management of heart failure 1. Patients with HF admitted with evidence of significant fluid overload should be promptly treated with intravenous loop diuretics to improve symptoms and reduce morbidity. The initial intravenous dose should equal or exceed their chronic oral daily dose and should be given as either intermittent boluses or continuous infusion, with serial assessment of urine output and signs and symptoms of congestion to adjust the diuretic dose accordingly 1.
From the Research
Areas Affected by Fluid Overload in Heart Failure
- Fluid overload in heart failure is typically most evident in areas such as the lungs, leading to pulmonary congestion, and the peripheral tissues, resulting in peripheral edema 2, 3.
- The condition can also cause vascular congestion and elevated jugular venous pressures, indicating fluid accumulation in the vascular system 2.
- Additionally, fluid overload can lead to congestion in other parts of the body, including the liver and the gastrointestinal system, due to the redistribution of fluid from the venous splanchnic beds to the central pulmonary circulation 3, 4.
Pathophysiological Mechanisms
- The pathophysiology of fluid overload in heart failure is complex and involves not only fluid accumulation but also fluid redistribution from the venous system to the lungs, leading to pulmonary congestion 3, 4.
- Other mechanisms, such as neurohormonal or inflammatory activation, can also contribute to fluid overload in heart failure 3.
- The assessment of volume overload status is crucial in managing heart failure, and it requires consideration of the interactions between interstitial and intravascular fluid compartments 4.
Clinical Implications
- The management of fluid overload in heart failure often involves the use of diuretics to relieve congestive symptoms and achieve a state of euvolaemia 2, 5, 6.
- However, the appropriate use of diuretics can be challenging due to potential complications, such as electrolyte abnormalities, worsening renal function, and diuretic resistance 2, 5.
- A thorough understanding of the pathophysiology of fluid overload and its assessment is essential for guiding individualized therapy and improving outcomes in patients with heart failure 4.