URINARY CHLORIDE DETERMINATIONS IN THE ESTIMATION OF THE SALT REQUIREMENTS IN SURGICAL PATIENTS

IT HAS been demonstrated in patients with normal kidney function that urinary chloride values usually demonstrate a lack of salt before serum chloride levels fall below normal limits.¹ For this reason, there has been renewed interest in the use of urinary chlorides for computing the salt requirements of the surgical patient. Van Slyke and Evans¹ have reintroduced the Fantus method² of determining urinary chloride concentrations as a bedside test and propose that the estimation be made on urine obtained before each infusion. More recently, Evans³ has suggested that the first morning specimen is a more reliable guide to therapy. This clinic has noted a similar inaccuracy in the implications of the chloride content of random urine specimens when compared with the total daily urinary chloride output. The concentration of single voided specimens was frequently below the desirable level of 3 gm. per liter recommended by Van