Nephrology is a subspecialty of internal medicine that specializes in the diagnosis and treatment of kidney diseases and electrolyte disorders. The kidneys are two organs located on each side of the loin. They function as filters of blood to remove metabolic wastes (e.g. urea, creatinine, uric acid etc) and excessive fluid from the body; help regulate the electrolytes (e.g. sodium, potassium, calcium and phosphate), and secret hormones to stimulate the production of red blood cells and activate vitamin D. If the kidney fails, unwanted substances will build up in our blood and can cause dysfunction or damages to other organs or tissues. Acute or chronic kidney failure may be reversible with prompt identification and treatment of the underlying cause. If kidney function becomes irreversible and progresses to end-stage kidney disease, patients will need dialysis or kidney transplant to sustain their lives.

• Nocturia or reduced urine output, blood in urine (haematuria – visible/non-visible haematuria), foamy or bubbly urine (proteinuria), smoky urine
• Pain in the loin
• Oedema (around the eyes, in the lower limbs and abdomen), short of breath and hypertension
• Loss of appetite, nausea and vomiting
• Fatigue or (anaemia symptom)

• Diabetic nephropathy
• Hypertension
• - Glomerulonephritis e.g. IgA nephropathy, focal segmental glomerulonephritis, lupus nephritis
• Kidney stone
• Inherited disease including polycystic kidney disease
• Nephrectomy

• Urinalysis
• Blood test
• Renal biopsy
• Diagnostic imaging

Patients with chronic kidney disease may progressively and irreversibly lose their kidney function if they fail to receive prompt and specific treatment. The objectives of managing chronic kidney disease are to slow down the progression of kidney damage by treating the primary cause and to minimize the effect of electrolyte disturbance, fluid overload and anaemia. However, in end-stage kidney failure, patients will need to receive continuous renal replacement therapy, which includes haemodialysis, peritoneal dialysis or kidney transplant.

Medical treatments includespecific treatment of the underlying cause of renal failure to slow down the disease progression, hence a delay in the need for dialysis or kidney transplant. Medical treatment also adress symptoms like oedema and anaemia.

Haemodialysis

Haemodialysis is a process of cleaning blood outside the body with the use of a filtering machine known as dialyzer, which is also referred to as an “artificial kidney”. During haemodialysis, blood is taken from the vessels and passed to a dialyzer to remove the uremic toxins and excessive water before returning to the patient. Haemodialysis takes around 3-5 hours and needs to be performed twice or three times per week in a dialysis facility or a hospital.

Before starting haemodialysis, your doctor would need to make a vascular access into the blood vessels to take blood in and out of your body. One of the options available is tunnel cuffed haemodialysis catheter, which is a double tube that goes from the surface of the skin to a major vein in the neck. With the catheter, the procedure of dialysis will not be painful. Another option is to create an arteriovenous fistula (made by joining an artery and a vein), or an arteriovenous graft (made by joining an artery and a vein using a soft tube) in the forearm. At the beginning of each dialysis, two needles will be placed into the arteriovenous fistula or graft to take blood out and return to the body. This could cause a mild level of pain to the patient, but many get used to the needles in time.

Peritoneal Dialysis

Peritoneal dialysis is a common mode of dialysis in public hospitals in Hong Kong. A permanent catheter needs to be inserted into the peritoneal cavity before performing peritoneal dialysis. Peritoneal fluid is indwelled into the peritoneal cavity and stays there for few hours before taking out again. It makes use of the large surface area of the peritoneal cavity to remove metabolic wastes and excessive fluid. Peritoneal dialysis can be performed at home after training, which means patients need not visit the hospital or other dialysis facility to perform the treatment.

There are two types of peritoneal dialysis. With continuous ambulant peritoneal dialysis (CAPD), patients need to do the exchange by hand. Approximately 1.5-2.5 litres of solution is instilled into the peritoneal cavity and stay there for a prescribed period of time (dwell time). After a few hours of dwell time, patients need to drain the solution out and refill a new bag to their abdomen. Each exchange takes around 45-60 minutes, and the process needs to be repeated 3-4 times per day. For those who are treated with automated peritoneal dialysis (APD), they could rely on a machine, often known as a cycler, to drain the solution in and out of their body automatically. The treatment takes approximately 8-10 hours and is usually performed at night time while the patient sleeps.

Kidney Transplant

According to the statistics released by the United States Renal Data System in 2016, the mortality rate of patients with kidney failure receiving kidney transplant is significantly lower than those receiving either type of dialysis, indicating a significant advantage of transplantation in treating kidney failure.

In most cases, the patient’s own (native) kidneys would not be removed. Instead, a new kidney would be placed in the front of the lower abdomen. Patients could receive donation either from a cadaveric donor or a living donor. After a successful kidney transplant, dialysis is no longer required. However, medication is needed to suppress the immune system and prevent rejection.

Virtus Nephrology specialists

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