Accurate measurement of surgical blood loss and replacement is crucial in the prevention of hypovolemia and excessive blood replacement with circulatory overload. Since every method of estimating blood loss is subject to inherent error or human fallibility, we have found it useful to check the patient's weight change during operation against calculated loss and replacement. This report illustrates a simplified weighing technique which can be performed without expensive or cumbersome apparatus and which does not add significantly to the time or work of the operating room staff.
A standard, commercial, wall-mounted, double-beamed, balanced meat scale * (which costs approximately $350) is modified so that it has 10 kg. notches on the upper arm and 100 gm. divisions on the lower arm which can be read to 20 gm. with reasonable accuracy (Fig. 1). A needle pointer indicates "under" and "over" positions for precise balancing.†
The scale is mounted high on the