Guidelines for the rate of volume replacement in hypovolemia
In the absence of hypotension or shock, gradual volume repletion is preferred. The goal of therapy is to achieve positive fluid balance, not merely to administer a large volume of intravenous fluid. For example, a patient may have an ostomy output of 3 L/day. The patient’s insensible losses are approximately 1 L/day. When one takes urine output into account, one can see that well more than 4 L of fluid must be administered per day if positive fluid balance is to be achieved and volume contraction is to be corrected.
• In cases of hypovolemic shock, rapid volume repletion is preferred to restore tissue perfusion and to prevent shock from becoming irreversible. At least 1 to 2 L of isotonic saline should be given in the first hour. Blood should be given in cases of hemorrhagic shock. Blood pressure and mental status may be used to guide subsequent intravenous fluid administration. Central venous pressure measurement may be needed in patients who fail to respond to initial therapy, especially if there is substantial ongoing fluid loss.
