Bicarbonate Test

Bicarbonate test helps in detection of an imbalance of acid and base in the body. Kidneys and lungs are primarily involved in pH regulation in the body by eliminating the excess bicarbonate. Lungs remove excess CO₂ along with exhalation while kidneys help flush out excess acids in urine. Raising or lowering the respiratory rate can thus affect acid-base balance within minutes. Medical conditions effecting lung and kidney function also leads to acid-base imbalance. Some conditions, in which, bicarbonate test is advised include heart failure, blood pressure fluctuations, and liver and kidney disease.

A bicarbonate test is typically recommended in individuals experiencing the following symptoms:

• Weakness
• Fatigue
• Confusion
• Prolonged vomiting
• Prolonged diarrhoea
• Difficulty in breathing

This test may also be recommended at specific intervals when the individual has some disease or is taking some medication that has a tendency to affect the acid-base balance in body. Another blood test that measures carbon dioxide is blood bases.

Although bicarbonate test does not need any special preparation, a doctor may recommend stopping certain medicines before the test as these medicines may interfere with test results. Do not stop or change the course of any medication without consulting a doctor.

Eating fruits with high acid content can also affect bicarbonate test results. Inform the doctor about any medicines, vitamins, herbs and supplements that you take.

Medicines that lead to an increase in bicarbonate levels include steroids, bicarbonates, barbiturates, loop diuretics, fludrocortisone and hydrocortisone.

Medications that lower bicarbonate levels include tetracycline, methicillin, nitrofurantoin, thiazide diuretics and triamterene.

Blood is withdrawn from a vein in the arm (on the back of the hand or the inside of the elbow) by inserting a needle.

Though it is a completely safe and harmless procedure, some risks of blood collection with a needle include bleeding, bruising, infection and lightheadedness. Also, slight pain is felt at the site of needle insertion, and throbbing and mild soreness is experienced at the site after withdrawing blood.

The normal range of bicarbonate in blood is 23 to 29 millimoles per litre (mmol/L) or milliequivalents per litre (mEq/L). This range may slightly vary in different laboratories due to the type of instruments used.

Bicarbonate levels that are higher or lower than normal indicate the presence of an underlying condition that disrupts the maintenance of acid-base balance in body. Some conditions that may lead to a reduction in bicarbonate levels are:

• Chronic diarrhoea
• Kidney disease
• Shock
• Addison disease, an adrenal gland condition
• Metabolic acidosis (decreased bicarbonate level in the blood)
• Aspirin overdose
• Methanol poisoning
• Diabetic ketoacidosis (high levels of acids called ketones in the blood)
• Ethylene glycol poisoning

Some conditions that cause a rise in bicarbonate levels are:

• Breathing disorders and lung diseases such as chronic pulmonary obstructive disorder
• Metabolic alkalosis (increased bicarbonate in the blood due to certain kidney diseases)
• Prolonged vomiting and/or diarrhoea
• Conn syndrome
• Cushing syndrome

Regardless of what the results say, it is important to contact a  doctor for correct interpretation and diagnosis of the health condition.

Disclaimer: All results must be clinically correlated with the patient’s complaints to make a complete and accurate diagnosis. This information is provided from a purely educational point of view and is in no way a substitute for medical advice by a qualified doctor.