Bicarbonate Deficit Calculator

Bicarbonate can be present in the body in two chemical forms — HCO₃ and CO₂. Carbon dioxide is the main by-product of metabolism and is circulated in the blood. Bicarbonate is a common form that it takes when present in the blood.

Below, you will find key information regarding bicarbonates:

• It is a negatively charged ion which is excreted and reabsorbed by the kidneys;
• It is also transported to the lungs and then exhaled as carbon dioxide;
• It helps to maintain the acid-base balance in the blood;
• It works with the other electrolytes, including sodium, potassium, and chloride, to maintain electrical neutrality at the cellular level; and
• Knowing the bicarbonate level might be useful when investigating the acid-base status.

Find out more about the acid-base status of a human in:

• Venous blood gas calculator; and
• Arterial blood gas calculator.

Bicarb deficit can occur in:

• Metabolic acidosis (e.g. diabetic ketoacidosis);
• Compensated respiratory alkalosis;
• Kidney disease;
• Liver failure;
• Diarrhea; and
• Other conditions related to our metabolism.

Low bicarbonate levels in the blood is a sign of metabolic acidosis, which might be associated with the following symptoms:

• Long and deep breaths;
• Fast heartbeat;
• Headache, confusion, and weakness;
• Tiredness;
• Vomiting and/or nausea; and
• Loss of appetite.

Bicarbonate deficit formula can be presented as follows:

bicarb deficit = 0.5 × weight × (desired bicarb – bicarb level)

where:

• bicarb deficit — bicarbonate deficit;

• weight — is expressed in kilograms (don't worry if you want to use different units — our bicarbonate deficit calculator will convert them for you);

• desired bicarb — desired bicarbonate level expressed in mmol/L, the reference values for bicarbonate ranges from 22 to 29 mmol/L; and

• bicarb level — actual bicarbonate level expressed in mmol/L.

Depending on the result, the deficit can be treated with sodium bicarbonate. However, the dosage of the medication depends on the patient's health and the cause of the bicarbonate deficit. Bicarbonate replacement therapy remains controversial in some patients, e.g., those with severe metabolic acidosis.

Let's use an example to show how bicarbonate deficit calculator works.

1. First of all, you need to enter the patient's weight. Let's assume that it is 72 kilograms (159 lbs).

2. You need to enter the patient's bicarbonate level. Let's assume that it is 19 mmol/L.

3. Choose desired bicarbonate level. The default value in our bicarbonate deficit calculator is set to be 24 mmol/L, but feel free to change it.

The calculations look as follows:

bicarb deficit = 0.5 × weight × (desired bicarb – bicarb level)

bicarb deficit = 0.5 × 72 kg × (24 mmol/L – 19 mmol/L)

bicarb deficit = 0.5 × 72 × 5

bicarb deficit = 180 mmol/L

The bicarbonate deficit of this patient equals 180 mmol/L.