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Chapter 036. Edema (Part 4)

Sequence of events leading to the formation and retention of salt and water and the development of edema. ANP, atrial natriuretic peptide; RPF, renal plasma flow; GFR, glomerular filtration rate; ADH, antidiuretic hormone. Inhibitory influences are shown by broken lines. Incomplete ventricular emptying (systolic heart failure) and/or inadequate ventricular relaxation (diastolic heart failure) both lead to an elevation of ventricular diastolic pressure. If the impairment of cardiac function primarily involves the right ventricle, pressures in the systemic veins and capillaries rise, augmenting the transudation of fluid into the interstitial space and enhancing the likelihood of peripheral edema. The elevated systemic. | Chapter 036. Edema Part 4 Sequence of events leading to the formation and retention of salt and water and the development of edema. ANP atrial natriuretic peptide RPF renal plasma flow GFR glomerular filtration rate ADH antidiuretic hormone. Inhibitory influences are shown by broken lines. Incomplete ventricular emptying systolic heart failure and or inadequate ventricular relaxation diastolic heart failure both lead to an elevation of ventricular diastolic pressure. If the impairment of cardiac function primarily involves the right ventricle pressures in the systemic veins and capillaries rise augmenting the transudation of fluid into the interstitial space and enhancing the likelihood of peripheral edema. The elevated systemic venous pressure is transmitted to the thoracic duct with consequent reduction of lymph drainage further increasing the accumulation of edema. If the impairment of cardiac function incomplete ventricular emptying and or inadequate relaxation involves the left ventricle primarily then pulmonary venous and capillary pressures rise. Pulmonary artery pressure rises and this in turn interferes with the emptying of the right ventricle leading to an elevation of right ventricular diastolic and of central and systemic venous pressures thereby enhancing the likelihood of the formation of peripheral edema. The elevation of pulmonary capillary pressure may cause pulmonary edema which impairs gas exchange. The resultant hypoxemia may impair cardiac function further sometimes causing a vicious circle. Nephrotic Syndrome and Other Hypoalbuminemic States See also Chap. 277 The primary alteration in this disorder is a diminished colloid oncotic pressure due to losses of large quantities of protein into the urine. With severe hypoalbuminemia and the consequent reduced colloid osmotic pressure the NaCl and H2O that are retained cannot be restrained within the vascular compartment and total and effective arterial blood volumes decline. This process initiates .