Nephrolithiasis: treatment, causes, and prevention.

Factors that promote stone formation include low daily urine volumes; saturation of the urine with calcium, oxalate, calcium phosphate, uric acid, or cystine; acidic urine; and bacterial infection. The author identifies the mechanisms of stone formation and outlines management aimed at preventing recurrences.

Performance of the Cockcroft-Gault and modification of diet in renal disease equations in estimating GFR in ill hospitalized patients.

Background: Estimating glomerular filtration rate (GFR) in severely ill inpatients is clinically important for therapeutic interventions and prognosis, but notoriously difficult to do accurately. The Modification of Diet in Renal Disease (MDRD) equation and Cockcroft-Gault (CG) formula are widely used to estimate renal function in sick hospitalized patients; however, neither method has been validated in this setting.

Methods: Iodine 125-iothalamate clearances (iGFR) performed in 107 sick inpatients with renal dysfunction were compared with estimated GFRs (eGFRs) from the 6- and 4-variable MDRD (MDRD eGFR) and CG (CG eGFR) equations.

Performance of the modification of diet in renal disease and Cockcroft-Gault equations in the estimation of GFR in health and in chronic kidney disease.

The performance of the Modification of Diet in Renal Disease (MDRD) and the Cockcroft-Gault (CG) equations as compared with measured (125)I-iothalamate GFR (iGFR) was analyzed in patients with chronic kidney disease (CKD) and in potential kidney donors. All outpatients (n = 1285) who underwent an iGFR between 1996 and 2003 were considered for analysis. Of these, 828 patients had CKD and 457 were potential kidney donors.

Evaluation of hyponatremia: a little physiology goes a long way.

Hyponatremia is common in hospitalized patients. By taking a careful and logical approach, one can promptly recognize the causative factor or factors in nearly all cases. Most cases of hyponatremia are due to impaired renal water excretion, and recognizing the cause and pathophysiologic process makes it possible to provide focused individualized care and avoid mistreatment.

Preventing kidney stones: calcium restriction not warranted.

The traditional wisdom on preventing calcium stones, the most common form of kidney stone, has been to advise patients to limit dietary calcium. Research has proved this wrong, however. Normal dietary calcium intake, along with reduced salt and protein, is now advised.