The Distribution of Body Fluids In Congestive Heart Failure

The Usefulness of Bioelectrical Impedance as a Marker of Fluid Status in Patients With Congestive Heart Failure: A Systematic Review and Meta-Analysis

Bioelectrical impedance analysis (BIA) is a method that measures electrical currents conducted through water, which assesses fluid status by measuring extracellular water (ECW), total body water (TBW), and resistance (R). Limited studies are done to evaluate the utility of BIA in patients with congestive heart failure (CHF), and therefore, we performed a systematic review and meta-analysis to evaluate this. A comprehensive literature search was performed at Medline and Embase until March 2022. Our primary outcome was a comparison of TBW and ECW between patients with CHF and controls. Our secondary outcome was to compare R between the groups. All analysis was conducted using RevMan 5.4 software. Six studies with 1,046 patients met our inclusion criteria. Out of 1,046 patients, 526 had CHF and 538 had no CHF. Among patients with CHF, all 526 had decompensated CHF. There was no significant difference in TBW between patients with heart failure and the control group (mean deviation (MD) = 1.42 (-0.44-3.27), percent of variation (I2) = 0%, p = 0.13). ECW was significantly higher with an assessment of BIA in heart failure patients compared to patients in the control group (MD = 1.62 (0.82-2.42), I2 = 0%, p < 0.0001). Resistance of extracellular fluid was significantly lower in the heart failure group (MD = -45.64 (-72.88--18.41), I2 = 83%, p = 0.001). Publication bias was deferred as the number of included studies was less than 10. BIA can be helpful in ambulatory and inpatient setting to identify patients' fluid status, which can improve outcomes. However, larger prospective studies are needed to further evaluate the usefulness of BIA in the CHF population.

The distribution of body fluids in congestive heart failure. III. Exchanges in patients during diuresis

The balance technic was applied in six studies of patients with congestive heart failure during the diuresis of their edema fluid. From the data so obtained changes in the extra- and intracellular phases of the body fluids were calculated, as well as transfers of sodium and potassium between the several phases and between the body and external environment. The results indicate that abnormalities of intracellular fluid exist in this condition.

Protein content in lymph and edema fluid in congestive heart failure

Protein content of tissue fluid and lymph is not uniform and depends upon regional differences in capillary permeability modified by changes in capillary filtration pressure. Whereas increased pressure in freely permeable liver sinusoids promotes formation of excess liver and thoracic duct lymph and ascitic fluid high in protein, increased venous pressure in less permeable beds promotes formation of excess lymph and edema fluid progressively lower in protein content. To ascertain the influence of colloid osmotic (oncotic) and hydrostatic pressure on excess lymph and edema formation in congestive heart failure, a disorder characterized by generalized venous hypertension, protein content of lymph (thoracic duct, liver, and small intestine), intracavitary and peripheral edema fluid, and plasma were measured in 42 patients with cardiac failure. In "acute" heart failure, thoracic duct lymph and ascitic fluid have high protein content (85% and 68% of plasma protein respectively) and are derived primarily from the liver, but in "chronic" heart failure protein content of thoracic duct lymph and ascitic fluid are lowered (46% and 40% of plasma protein respectively) by lymph from extrahepatic sites. In both stages, pleural and leg edema fluid are comparatively low in protein content (26 to 44% and 3 to 8% of plasma protein respectively). In congestive heart failure, edema and intracavitary fluid form primarily in response to increased venous pressure which outside the liver is partially counterbalanced by increased effective plasma oncotic pressure.