PREVENTING AND MANAGING HYPOTENSION

Simple maneuvers to prevent dialysis hypotension include measures to help maintain blood volume and to limit interdialytic weight gain. After several years of development, the use of hematocrit sensors and intelligent feedback regulation of the ultrafiltration rate based on blood volume, on-line measurement of cardiac output, or blood pressure, will soon be a reality. The use of acetate is fast becoming obsolete in the United States, because acetate has a number of adverse effects on the cardiovascular system. A preliminary report that acetate dialysis is associated with better solute removal from the body needs to be confirmed. Wider use of cool temperature dialysis is limited by frequent patient discomfort (feeling cold, shivering), and cool dialysis may adversely affect urea removal during dialysis, though this needs to be studied. In patients who experience sudden episodes of hypotension during dialysis, the mechanism may be sudden withdrawal of sympathetic tone. This may be related to generation of adenosine due to tissue ischemia. A rational approach to this type of patient would be to minimize tissue ischemia by increasing the baseline hematocrit if low, and by giving nasal oxygen during the treatment. Predialysis nasal administration of lysine vasopressin may help some patients with refractory dialysis hypotension.