Definition
Distal renal tubular acidosis is a disease that occurs when the kidneys do not properly remove acids from the blood into the urine. As a result, too much acid remains in the blood (called
Alternative Names
Renal tubular acidosis – distal; Renal tubular acidosis type I; Type I RTA; RTA – distal; Classical RTA
Causes
When the body performs its normal functions, it produces acid. If this acid is not removed or neutralized, the blood becomes too acidic. This can lead to electrolyte imbalances in the blood. It can also cause problems with normal function of some cells.
The kidneys help control the body’s acid level by removing acid from the blood and excreting it into the urine.
Distal renal tubular acidosis (Type I RTA) is caused by a defect in the kidney tubes that causes acid to build up in the blood.
Type I RTA is caused by a variety of conditions, including:
Amyloidosis - Fabry disease (abnormal buildup in the body of a certain type of fatty substance)
High blood calcium Sickle cell disease Sjogren syndrome Systemic lupus erythematosus Wilson disease - Use of certain medicines, such as amphotericin B, lithium, and analgesics
Symptoms
Symptoms of distal renal tubular acidosis include any of the following:
Confusion ordecreased alertness Fatigue - Impaired growth
Increased breathing rate Kidney stones Nephrocalcinosis Osteomalacia Rickets - Muscle weakness
Other symptoms can include:
-
Bone pain -
Decreased urine output -
Increased
heart rate orirregular heartbeat -
Muscle cramps -
Pain in the back, flank, or abdomen
-
Skeletal abnormalities
Exams and Tests
The doctor will perform a physical exam and ask about your symptoms.
Tests that may be ordered include:
Arterial blood gas Blood chemistry Urine pH Urinalysis
Treatment
The goal is to restore normal acid level and electrolyte balance in the body. This will help correct bone disorders and reduce calcium buildup in the kidneys (nephrocalcinosis) and kidney stones.
The underlying cause of distal renal tubular acidosis should be corrected if it can be identified.
Medicines that may be prescribed include potassium citrate and sodium bicarbonate. These are alkaline medicines that help correct the acidic condition of the body. Sodium bicarbonate may correct the loss of potassium and calcium.
Outlook (Prognosis)
The disorder must be treated to reduce its effects and complications, which can be permanent or life-threatening. Most cases get better with treatment.
Possible Complications
Untreated, distal renal tubular acidosis can lead to any of the following conditions:
- Osteomalacia
- Rickets
- Nephrocalcinosis
- Kidney stones
- Electrolyte imbalances, such as
low blood potassium level
When to Contact a Medical Professional
Call your health care provider if you have symptoms of distal renal tubular acidosis.
Get medical help right away if you develop emergency symptoms, such as:
-
Decreased consciousness -
Seizures -
Severe
decrease in alertness ororientation
Prevention
There is no prevention for this disorder.