Abstract
Pulmonary congestion due to fluid retention is a major cause of pulmonary edema in dialysis patients. However, congestive heart failure that is not associated with marked fluid retention has recently been designated as Clinical Scenario 1 (CS1). We report four dialysis patients who suffered from pulmonary congestion that occurred in accordance with CS1. The patients were transferred to the ER because of dyspnea, which had developed during the night within a week prior to the first dialysis day. Peripheral blood hypoxemia was recognized and chest X-ray demonstrated pulmonary edema. Marked hypertension and elevation of serum BNP were shown, despite a moderate degree of body weight gain (3.8-9.2% above the dry weight). All of the patients were treated by infusing nitroglycerin and nicardipine intravenously. Non-invasive positive pressure ventilation (NPPV) was applied for two patients. Since hypertension and hypoxemia improved sufficiently by performing these therapies, emergency dialysis was carried out only for two patients while removing a fluid volume that corresponded to the interdialytic weight gain plus 0.5-0.8 kg. At 9-18 hours after admission, all of the patients became supported only by nasal oxygen inhalation because of the improvement of oxygenation induced by NPPV and vasodilator therapy. Increased afterload, which was caused by rapidly elevated blood pressure following arterial vasoconstriction (afterload mismatch), and a shift of circulating blood from the venous reservoir to the heart and the lungs (central volume shift) are considered to be the background mechanisms of CS1. By carefully evaluating the reason for congestive heart failure in dialysis patients, an attempt should be made to redistribute circulating blood from the cardiopulmonary compartment to peripheral vessels by using vasodilator agents rather than removing a large volume of fluid by emergency hemodialysis in cases of CS1.
