Alkalosis

Definition

Alkalosis is a condition in which the body fluids have excess base (alkali). This is the opposite of excess acid (acidosis).

Causes, incidence, and risk factors

The kidneys and lungs maintain the proper balance of chemicals, called acids and bases, in the body. Decreased carbon dioxide (an acid) or increased bicarbonate (a base) levels make the body too alkaline, a condition called alkalosis.

Respiratory alkalosis is caused by low carbon dioxide levels in the blood. This can be due to:

• Fever
• Being at a high altitude
• Lack of oxygen
• Liver disease
• Lung disease, which causes you to breathe faster (hyperventilate)
• Salicylate poisoning

Metabolic alkalosis is caused by too much bicarbonate in the blood.

Hypochloremic alkalosis is caused by an extreme lack or loss of chloride, which can occur with prolonged vomiting.

Hypokalemic alkalosis is caused by the kidneys' response to an extreme lack or loss of potassium, which can occur when people take certain diuretic medications.

Compensated alkalosis occurs when the body returns the acid/base balance to normal in cases of alkalosis, but bicarbonate and carbon dioxide levels remain abnormal.

Symptoms

• Confusion (can progress to stupor or coma)
• Hand tremor
• Light-headedness
• Muscle twitching
• Nausea, vomiting
• Numbness or tingling in the face or extremities
• Prolonged muscle spasms (tetany)

Signs and tests

An arterial blood gas analysis or basic metabolic panel will confirm alkalosis and determine if it is a respiratory alkalosis or a metabolic alkalosis. Other tests may be needed to determine the cause of the alkalosis. These may include:

• Litmus paper (urine dipstick tests)
• Urinalysis
• Urine pH

Treatment

Treatment of alkalosis depends on finding the specific cause.

For alkalosis caused by hyperventilation, breathing into a paper bag causes you to retain more carbon dioxide and improves the alkalosis. If your oxygen level is low, you may receive oxygen to help the alkalosis.

Some people need medications to correct chemical loss (such as chloride and potassium). Your health care provider will monitor your vital signs (temperature, pulse, rate of breathing, blood pressure).

Expectations (prognosis)

Most cases of alkalosis respond well to treatment.

Complications

• Arrhythmias
• Coma
• Electrolyte imbalance (such as hypokalemia)

Calling your health care provider

Call your health care provider if you become confused, unable to concentrate, or unable to "catch your breath."

A visit to the emergency room or call to the local emergency number (such as 911) is warranted for:

• Loss of consciousness
• Rapidly worsening symptoms of alkalosis
• Seizures
• Severe breathing difficulties

Prevention

Prevention depends on the cause of the alkalosis. Normally, people with healthy kidneys and lungs do not have significant alkalosis.

References

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