← Chapter 2
Medical-Surgical Nursing II · Chapter 2

The Calcium Bench: Correct It, Pair It With PTH, Read the QT

A calcium number on its own can lie twice — once because 40 percent of it is bound to albumin, and again because it means nothing until you see the PTH sitting beside it. Type in a panel, or tap a case, and the bench corrects the calcium, names the parathyroid pattern, redraws the QT interval and hands you the emergency plan in the order it must be done.

1 · The panel

mg/dL · reference 8.5–10.5
g/dL · correction anchor 4.0
pg/mL · reference 10–65
mg/dL · reference 2.5–4.5

2 · Cases from the chapter

Two reciprocals worth owning. PTH drives calcium up and phosphate down. And calcium runs opposite to the QT: high calcium shortens it, low calcium lengthens it — and the long QT of hypocalcaemia is the one that becomes torsades on your shift.

3 · Corrected calcium

7.2mg/dL correctedlow
QT

4 · Read the pair, then act

What the nurse does, in order