BIOCHEMICAL EVALUATION OF CALCIUM STONE PATIENTS: HOW SOON CAN IT BE DONE AFTER STONE SURGERY/PASSAGE? MORTON URIVETZKY, PH.D. ROSE RAVALLI, R.N., C.U.R.N. JERRY WEINBERG, M.D. ARTHUR D. SMITH, M.D. From the Department of Urology, Long Island Jewish Medical Center, New Hyde Park, New York
ABSTRACT--Biochemical evaluations were done two times for 29 outpatients with calcium stone i!i disease, the first time within one month after surgical extraction or passage of stones and the second ,i time two months or more later. Classification of the etiologic basis for the stone disease was the same after both tests in 27 patients. In the other 2 patients the diagnosis was changed from renal t o absorptive hypercalciuria. Both of these patients had creatinine clearance rates less than 60 percent of normal during the first test. One also had multiple residual stones during both evaluations, and!. the second had a urinary tract infection during the first test that resolved with a normal creatinine !~ clearance by the second test period. When nephrogenous cyclic adenosine monophosphate (cAMPn) !~ assays were done on fasting specimens in these patients, the results were consistent with absorptiv~ ~ hypercalciuria. Almost all patients can be evaluated and placed in management programs within ~ !:~ yew weeks after surgery. If cAMPn assays are not done, patients with decreased renal secondary to residual stones or infection can be tested at a later time.
Patients who form calcium stones often suffer recurrent attacks of renal colic and require multiple hospitalizations for calculous disease•l To reduce the frequency of such episodes, urology stone clinics at many medical centers seek the etiology of each patient's disease in order to prescribe an appropriate maintenance program. In our clinic, this evaluation includes review of the patient's medical and dietary histories and a biochemical profile of blood and urine specimens during customary and restricted diets. ~4 Based on the results of the tests the patients are prescribed a management program, with follow-up care. It has been recommended that patients who had stones, no matter how they were rendered stone-free (passage or surgery), be evaluated medically and placed on appropriate management regimens. 5
410
Many clinicians believe the biocherr ing should be done several weeks or J lowing renal colic or discharge from t tal to allow patients to r e t u r n customary environment and diet to more adequate assessment of the facto1 sible for these stone-forming propensi delay is supported by a recent publication i!~i:i!~ which, on the basis of analysis of twenty-fou~J! ::~ hour urine specimens collected during ad-lihii~ diets, Norman and associates 6 concluded that:j; ~ stone risk factors are not maximally expresse.: :i:l ~ until three months after episodes of cohc o~ stone extractions. In today's medical econo Y, ::~,~ however, it is difficult to obtain patient c o ~ ~ pliance with a workup protocol requ peated office visits and tests extend: several months.
UROLOGY
/
NOVEMBER 1990
/
VOLUME XXXVI,
Criteriafor classification of idiopathic hypercalciuria
TABLE I.
Type Renal Absorptive Type I Type II Type III Normal
--Serum-Ca P
Restricted Diet (rng/24 hr)
Calcium ExcretionFasting (mg/dL Post-Load Glomerular (mg/rng Filtrate) Creatinine)
N1
N1
>200
>0.11
>0.2
N1 N1 N1 N1
N1 N1 Low N1
>200
ABSTRACT--Biochemical evaluations were done two times for 29 outpatients with calcium stone i!i disease, the first time within one month after surgical extraction or passage of stones and the second ,i time two months or more later. Classification of the etiologic basis for the stone disease was the same after both tests in 27 patients. In the other 2 patients the diagnosis was changed from renal t o absorptive hypercalciuria. Both of these patients had creatinine clearance rates less than 60 percent of normal during the first test. One also had multiple residual stones during both evaluations, and!. the second had a urinary tract infection during the first test that resolved with a normal creatinine !~ clearance by the second test period. When nephrogenous cyclic adenosine monophosphate (cAMPn) !~ assays were done on fasting specimens in these patients, the results were consistent with absorptiv~ ~ hypercalciuria. Almost all patients can be evaluated and placed in management programs within ~ !:~ yew weeks after surgery. If cAMPn assays are not done, patients with decreased renal secondary to residual stones or infection can be tested at a later time.
Patients who form calcium stones often suffer recurrent attacks of renal colic and require multiple hospitalizations for calculous disease•l To reduce the frequency of such episodes, urology stone clinics at many medical centers seek the etiology of each patient's disease in order to prescribe an appropriate maintenance program. In our clinic, this evaluation includes review of the patient's medical and dietary histories and a biochemical profile of blood and urine specimens during customary and restricted diets. ~4 Based on the results of the tests the patients are prescribed a management program, with follow-up care. It has been recommended that patients who had stones, no matter how they were rendered stone-free (passage or surgery), be evaluated medically and placed on appropriate management regimens. 5
410
Many clinicians believe the biocherr ing should be done several weeks or J lowing renal colic or discharge from t tal to allow patients to r e t u r n customary environment and diet to more adequate assessment of the facto1 sible for these stone-forming propensi delay is supported by a recent publication i!~i:i!~ which, on the basis of analysis of twenty-fou~J! ::~ hour urine specimens collected during ad-lihii~ diets, Norman and associates 6 concluded that:j; ~ stone risk factors are not maximally expresse.: :i:l ~ until three months after episodes of cohc o~ stone extractions. In today's medical econo Y, ::~,~ however, it is difficult to obtain patient c o ~ ~ pliance with a workup protocol requ peated office visits and tests extend: several months.
UROLOGY
/
NOVEMBER 1990
/
VOLUME XXXVI,
Criteriafor classification of idiopathic hypercalciuria
TABLE I.
Type Renal Absorptive Type I Type II Type III Normal
--Serum-Ca P
Restricted Diet (rng/24 hr)
Calcium ExcretionFasting (mg/dL Post-Load Glomerular (mg/rng Filtrate) Creatinine)
N1
N1
>200
>0.11
>0.2
N1 N1 N1 N1
N1 N1 Low N1
>200
