Diuretics will be administered to reverse sodium and water retention, relieve peripheral edema or ascites, and reduce right atrial pressure. However, if diuretic-induced hypovolemia decreases right ventricular preload too much, the result will be reduced cardiac output, hypotension, and prerenal azotemia. Mr. K.'s serum electrolytes and renal function will be closely monitored. His serum potassium and magnesium levels will be kept within normal limits to ensure optimum ventricular contractility. For details on these drugs, see Table 1 .
Some patients show little or no response to vasodilators initially, yet benefit from long-term use.
Other patients may show an initial response that diminishes over time. In some patients, they may actually worsen the condition because their negative inotropic effects increase pulmonary artery pressure. Patients receiving calcium channel blockers should be monitored closely for an increase in pulmonary capillary wedge pressure. The nurse will also tell him to dress warmly in cool weather to avoid vasoconstriction of the extremities and to avoid extreme cold or heat. Before his discharge, he will be encouraged to take control of as many aspects of his care as possible.