Distal renal tubular acidosis

    Definition

    Distal renal tubular acidosis is a disease that occurs when the kidneys don't remove acid properly into the urine, leaving the blood too acidic (called acidosis).

    Alternative Names

    Renal tubular acidosis - distal; Renal tubular acidosis type I; Type I RTA; RTA - distal; Classical RTA

    Causes

    Your kidneys normally regulate your body's pH by removing acids from the blood and discarding them 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 bloodstream.

    Type I RTA is caused by a variety of conditions, including:

    • Amyloidosis
    • Fabry disease
    • Sickle cell disease
    • Sjogren syndrome
    • Systemic lupus erythematosus
    • Wilson disease
    • Use of certain drugs such as amphotericin B, lithium, and analgesics

    Symptoms

    Other symptoms can include:

    Exams and Tests

    Arterial blood gas and blood chemistries may suggest metabolic acidosis or electrolyte imbalances, most often low levels of potassium or bicarbonate.

    Other tests that may be done include:

    • Urine pH, usually greater than 5.0 in patients with this condition
    • Urinalysis may show increased levels of calcium and potassium

    Treatment

    The goal is to restore the normal pH (acid-base level) and electrolyte balance. This will indirectly correct bone disorders and reduce the risk of calcium buildup in the kidneys (nephrocalcinosis) and kidney stones. The underlying cause should be corrected if it can be identified.

    Alkaline medications such as potassium citrate and sodium bicarbonate correct the acidic condition of the body. Sodium bicarbonate may correct the loss of potassium and calcium.

    Vitamin D and calcium supplements are usually not given because there may be calcium deposits in the kidneys, even after bicarbonate therapy.

    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

    When to Contact a Medical Professional

    Call your health care provider if you have symptoms of distal renal tubular acidosis.

    Get help immediately if you develop emergency symptoms, such as:

    Prevention

    There is no prevention for this disorder.

    References

    Seifter JL. Acid-base disorders. In: Goldman L, Ausiello D, eds. Cecil Medicine. 23rd ed. Philadelphia, Pa: Saunders Elsevier; 2007:chap 119.


    Review Date: 11/30/2009
    Reviewed By: David C. Dugdale, III, MD, Professor of Medicine, Division of General Medicine, Department of Medicine, University of Washington School of Medicine; Herbert Y. Lin, MD, PHD, Nephrologist, Massachusetts General Hospital; Associate Professor of Medicine, Harvard Medical School. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M., Inc.
    The information provided herein should not be used during any medical emergency or for the diagnosis or treatment of any medical condition. A licensed medical professional should be consulted for diagnosis and treatment of any and all medical conditions. Call 911 for all medical emergencies. Links to other sites are provided for information only -- they do not constitute endorsements of those other sites. © 1997- A.D.A.M., Inc. Any duplication or distribution of the information contained herein is strictly prohibited.
    adam.com