Nephrology



Editors-In-Chief: C. Michael Gibson, M.S., M.D. [mailto:mgibson@perfuse.org], Vijay Lapsia, M.D. Assistant professor of Medicine/Nephrology, Medical Director, Mount Sinai Kidney Center. [mailto:vijay.lapsia@mssm.edu], and Stephanie Fernandez, M.D. [mailto:etepfernandez@yahoo.com]

Nephrology is the branch of internal medicine dealing with the study of the function and diseases of the kidney. The word nephrology is derived from the Greek word nephros, which means "kidney," and the suffix -ology, signifying "study of."

Scope of the specialty
Nephrology concerns itself with the diagnosis and treatment of kidney diseases including electrolyte disturbances and hypertension, and the care of those requiring renal replacement therapy, including dialysis and renal transplant patients. Many diseases affecting the kidney are not limited to the organ itself, but are systemic disorders, and may require not only a whole patient approach, but also special treatment, such as systemic vasculitides or other autoimmune diseases, such as lupus.

Who sees a nephrologist?
Patients are referred to nephrology specialists for various reasons, such as:
 * Acute renal failure, a sudden loss of renal function
 * Chronic kidney disease, declining renal function, usually with an inexorable rise in creatinine.
 * Hematuria, blood loss in the urine
 * Proteinuria, the loss of protein especially albumin in the urine
 * Kidney stones, usually only recurrent stone formers.
 * Chronic or recurrent urinary tract infections
 * Hypertension that has failed to respond to multiple forms of anti-hypertensive medication or could have a secondary cause
 * Electrolyte disorders or acid/base imbalance

Urologists are surgical specialists of the urinary tract - see Urology. They are involved in renal diseases that might be amenable to surgery:
 * Diseases of the Bladder and prostate such as malignancy, stones, or obstruction of the urinary tract.

Diagnosis
As with the rest of medicine, important clues as to the cause of any symptom are gained in the history and physical examination.

Laboratory tests are almost always aimed at: urea, creatinine, electrolytes, and urinalysis-- which is frequently the key test in suggesting a diagnosis.

More specialized tests can be ordered to discover or link certain systemic diseases to kidney failure such as hepatitis B or hepatitis C, lupus serologies, paraproteinemias such as amyloidosis or multiple myeloma or various other systemic diseases that lead to kidney failure. Collection of a 24-hour sample of urine can give valuable information on the filtering capacity of the kidney and the amount of protein loss in some forms of kidney disease. However, 24-hour urine samples have recently, in the setting of chronic renal disease, been replaced by spot urine ratio of protein and creatinine.

Other tests often performed by nephrologists are:
 * Renal biopsy, to obtain a tissue diagnosis of a disorder when the exact nature or stage remains uncertain.;
 * Ultrasound scanning of the urinary tract and occasionally examining the renal blood vessels;
 * CT scanning when mass lesions are suspected or to help diagnosis nephrolithiasis;
 * Scintigraphy (nuclear medicine) for accurate measurement of renal function (rarely done), diagnosis of renal artery disease, or 'split function' of each kidney;
 * Angiography or Magnetic resonance imaging angiography when the blood vessels might be affected

Therapy
Many kidney diseases are treated with medication, such as steroids, DMARDs (disease-modifying antirheumatic drugs), antihypertensives (many kidney diseases feature hypertension). Often erythropoietin and vitamin D treatment is required to replace these two hormones, the production of which stagnates in chronic renal disease.

When symptoms of renal failure become too severe, dialysis might be required. Please refer to dialysis for a comprehensive account of this treatment.

If patients proceed to renal transplant, nephrologists often monitor the immunosuppressive regimen and the infections that can occur at this stage.

Pioneers in Nephrology

 * Dr. Joseph W. Eschbach, nephrologist whose research lead to the treatment of anemia.
 * Dr. Georg Haas, preformed the first human hemodialysis treatment.
 * Dr. Willem Johan Kolff, is a pioneer in the development of the hemodialysis machine as well as in the field of other artificial organs.
 * Dr. Arthur Arnold Osman, was the first nephrologist.
 * Dr. Belding H. Scribner, one of the pioneers of kidney dialysis.