Parathyroid conditions and calcium imbalance: Clinical

There are a number of ways you can measure calcium in the blood.

First, there’s total calcium levels and this is made up of three fractions.

About 40 percent of the calcium is bound to albumin and about 15 percent is bound to minerals and the remaining 45 percent freely circulates the body and it’s called ionized calcium.

Total calcium levels range between 8.5 to 10.5 milligrams per deciliter, while ionized calcium ranges between 4.8 and 5.7 milligrams per deciliter.

When total calcium levels fall below 8.5 milligrams per deciliter, it’s considered hypocalcemia and when total calcium levels rise above 10.5 milligrams per deciliter, it’s considered hypercalcemia.

Okay, let’s start with hypocalcemia.

Individuals with hypocalcemia can be asymptomatic or have symptoms like tetany - which are intermittent muscular spasms - and perioral tingling.

On clinical examination, there may be a positive Chvostek’s sign. That’s when the facial muscles contract in response to tapping the skin over the facial nerve, just 2 centimeters anterior to the ear.

Another sign is the Trousseau sign. That’s where a blood pressure cuff is placed over the individual’s arm and is inflated to a pressure above the systolic blood pressure and is held like that for 3 minutes.

A positive Trousseau sign is when there’s a muscle spasm in the arm and forearm.

Now, the first thing to do in hypocalcemia is redo the lab work to make sure that the reading is accurate.

If hypocalcemia is confirmed, then the next thing is to check albumin levels.

Since most of the total calcium is bound to albumin, any rise or fall in the albumin will affect total calcium levels, leading to pseudohypocalcemia.

Normal albumin levels are 4 milligrams per deciliter and normal total calcium levels are 10 milligrams per deciliter.

For every 1 milligram per deciliter drop in albumin, calcium levels lower by 0.8 milligrams per deciliter. So, based on this, the corrected calcium levels can be calculated.