Nephrology

Nephrology is the medical specialty, branch of internal medicine, which deals with the study of the structure and function of the kidney, both in health and disease, including prevention and treatment of kidney diseases. The word nephrology derives from the Greek word νεφρός (nephrós), which means kidney, and from the suffix -logy (study, treatise).

Definition

Nephrology can be defined as the clinical specialty that deals with the study of anatomy, physiology, pathology, health promotion, prevention, clinical, therapeutic and rehabilitation of diseases of the urinary system in its entirety, including the urinary tract that affect the renal parenchyma. Unlike urology, this is not a surgical specialty.

A doctor who specializes in nephrology is called a nephrologist. Nephrology should not be confused with urology, which is the surgical specialty of the urinary tract and the male genital tract.

Scope of specialty

Nephrology is concerned with the diagnosis of kidney disease and its treatment, both with drugs and with renal replacement therapy (including monitoring of kidney transplant patients). Additionally, nephrologists as experts in the care of electrolyte disorders and hypertension. Most kidney conditions are chronic.

Diseases dealt with by nephrology

Patients are referred to nephrology specialists for a variety of reasons, including the following.

• Kidney failure is the condition in which the kidneys stop working properly:
  • Acute kidney failure, sudden loss of kidney function.
  • Chronic renal insufficiency, another doctor has detected symptoms of kidney declination, often a rise in creatinine, which persists more than 3 months.
• Hematuria, blood loss through the urine.
• Proteinuria, protein loss, especially albumin, in the urine.
• Stones in the kidney.
• Kidney cancer, especially renal carcinoma, but this is usually the domain of the urologist.
• Chronic or recurrent urinary tract infections.
• Hypertension that has failed to respond to multiple forms of antihypertensive medication or may have a secondary cause.
• Hydroelectrolytic alterations or acid-base imbalance.
• People who need to initiate substitute renal therapy such as kidney transplant, hemodialysis and peritoneal dialysis.
• Glomerulonefritis. A direct effect on the glomérulo, a fundamental part of the Nephrene which is responsible for preventing certain substances from excreting abnormally from the urine.
• Nephrotic syndrome. Nephrologic syndrome characterized by protein loss in urine in a range less than 3.5 g/24 h, macro or microscopic hematuria and arterial hypertension.
• Nephrotic syndrome. Nephrologic syndrome characterized by protein loss in urine in a range greater than 3.5 g/24 h, edema, hypoalbuminemia, dyslipidemia, lipiduria.
• Patients in renal replacement therapy such as:
  • Peritoneal dialysis: Start, placement of Tenckhoff catheter percutaneously, patient follow-up in dialysis, handling complications mainly peritonitis.
  • Hemodialysis: Start, management and placement of temporary and definitive vascular access, patient follow-up in hemodialysis, as well as diagnosis and treatment of its complications.
• Renal transplant: Beginning of the protocol, both of the living donor and the cadaveric, follow-up, surveillance of the surgical event, follow-up to the immediate, mediate and late postoperative, management of immunosuppression.

Diagnosis

As with all medicine, important clues as to the cause of any symptoms come from the patient's history and physical examination.

Laboratory tests are almost always directed at: urea, creatinine, electrolytes, blood count, and urinalysis, which is often the dominant test in suggesting a diagnosis.

Specialized tests may be ordered to detect or link certain systemic diseases to kidney failure, such as serologies for hepatitis B or hepatitis C, or lupus, paraproteinemias such as amyloidosis, multiple myeloma, or other systemic diseases leading to kidney failure. Collection of a 24-hour urine sample can give valuable information about the filtering capacity of the kidney and the amount of protein loss in some forms of kidney disease. However, in the chronic kidney disease scene, 24-hour urine samples have recently been superseded by urine point ratio of protein to creatinine.

Other tests often performed by nephrologists include:

• Kidney biopsy, to get a diagnosis of disorder tissue when nature or the exact stage is still uncertain.
• Ultrasound exploration of the urinary tract and from time to time examine the renal blood vessels.
• Computed axial tomography when mass injuries are suspected or to help diagnose nefrolitiasis.
• The gammagraphy (nuclear medicine) for the exact measurement of renal function (made rarely), the diagnosis of kidney artery disease, or 'dividential function' of each kidney.
• Nuclear MRI scan when blood vessels may be affected.

Treatments in nephrology

Many kidney diseases are treated simply with medication, such as diuretics, corticosteroids, immunosuppressants, antihypertensive]s and others. Frequently, treatment with erythropoietin and vitamin D is required to replace these two hormones, whose production is decreased in chronic kidney disease.

When the symptoms of renal failure become too severe, renal replacement therapy is required. The technique of choice is renal transplantation. This is carried out by the urologist, and in some cases by the general surgeon. However, the nephrologist is in charge of the selection of the recipient of the transplant as well as his follow-up and the treatment of his complications (especially rejection and infections derived from immunosuppressive treatment).

In cases in which transplantation is not indicated or possible, there are other techniques, generically called renal dialysis. Among these, it is worth highlighting hemodialysis, hemofiltration, hemodiafiltration and peritoneal dialysis.

Other medical specialties

In cases with CKD, it is important to control and prevent dehydration-acidosis: if an adequate fluid intake is not possible in these patients, they can rapidly lead to dehydration, decreased renal perfusion and progressive deterioration of function renal.

In chronic kidney disease, metabolic acidosis results from the inability of the kidneys to excrete enough hydrogen ions and to reabsorb bicarbonate. The consumption of diets high in protein can contribute to acidosis, and this in turn to a series of adverse effects: anorexia, nausea, vomiting, lethargy, weakness, muscle wasting, and weight loss.