1974 Volume 65 Issue 10 Pages 633-636
Urolithiasis of the upper urinary tract, especially recurrent and bilateral renal stones including nephrocalcinosis, is common and important but still obscures the causes in urological field.
Hyperparathyroidism which is one of the causes of urolithiasis has been diagnosed with abnormal serum and urinary calcium and phosphate. It is, however, difficult to make a diagnosis with total serum calcium in cases of borderline hypercalcemia.
Ionized serum calcium level was measured in 10 patients with hyperparathyroidism by a flowthrough electrode. On the determination of ionized calcium in those patients, only 3.3% showed in normal range of 3.6mg/dl to 4.8mg/dl while 20% of the determination of total calcium in the same patients showed a normal range of 9mg/dl to 11mg/dl.
It is suggested that serum ionized calcium should be measured in patients with borderline hypercalcemia.
Another interesting aspect is that ionized calcium recovers in advance of total calcium after parathyroidectomy. It might be suggested that rate of calcium ionization is increased at this point.
