Introduction on Fluid Management in Patients with Chronic Heart Failure
Heart failure (HF) is one of the most common reasons for admission to hospital. It is associated with long in-patient stays, and has a high in-hospital and post-discharge morbidity and mortality, whether left ventricular ejection fraction (LVEF) is reduced (HFREF) or normal (HeFNEF).1,2 Congestion, or fluid overload, is a classic clinical feature of patients presenting with HF. In some patients, pulmonary congestion develops very rapidly because of a sudden increase in LV filling pressures, and a precipitating factor is often recognised, such as acute myocardial ischaemia, or uncontrolled hypertension. In this circumstance, the oedema is localised predominantly to the pulmonary airspaces (pulmonary oedema), while the total amount of fluid in the cardiovascular system remains unchanged.3 For most patients, however, congestion is a more generalised process that usually develops more gradually (peripheral oedema), and its management will be the focus of discussion in this review.
Chronic fluid accumulation is responsible for a substantial number of hospital admissions, and identifies patients with a worse prognosis than those admitted due to a sudden increase in LV filling pressures.4 Peripheral congestion in patients with heart failure usually develops over weeks or even months, and patients may present ‘acutely’ having gained over 20 litres of excess fluid, and hence over 20 kg of excess weight. The aim of management is to remove the excess fluid, so that the patient is no longer congested when they leave hospital, now transitioning to a diagnosis of ‘chronic HF (CHF)’. However, for many patients, some degree of congestion remains even with treatment,5,6 and it is not clear how many patients with CHF have subclinical congestion – that is, have an excess of body fluid falling short of the volume required to cause overt peripheral oedema.