How to read a basic metabolic panel
Other platforms explain it with text and video. In VMS you practice it on the patient.
The basic metabolic panel is one of the most ordered blood tests. It shows fluid balance, kidney function, acid-base status and blood sugar in one look.
Step by step
Check the sample
Confirm the patient, time and whether the sample was hemolyzed, which can falsely raise potassium. [1]
Compare with prior results
Look at the trend. A small change can matter more than a single value just outside the range. [1]
Sodium and potassium
Sodium reflects water balance. Potassium affects the heart rhythm, so very high or low values need an ECG. [2]
Bicarbonate and anion gap
Low bicarbonate suggests metabolic acidosis. Calculate the anion gap: sodium minus (chloride plus bicarbonate). A high gap suggests ketoacidosis, lactic acidosis, kidney failure or toxins. [2]
Kidney function
A rising creatinine signals reduced kidney function. A BUN to creatinine ratio over 20 suggests dehydration or poor kidney blood flow. [2]
Glucose and calcium
Check glucose against meals and insulin. Correct calcium for low albumin, or check ionized calcium. [2]
Act on critical values
Report critical results to the responsible clinician quickly and document who was told and when. [3]
Common errors
- Treating high potassium from a hemolyzed sample without repeating it.
- Forgetting to calculate the anion gap.
- Reading one value without looking at the trend.
Typical adult ranges; use your lab's ranges [2]
| Test | Typical range | Common meaning of a change |
|---|---|---|
| Sodium | 135 to 145 mEq/L | Water balance |
| Potassium | 3.5 to 5.0 mEq/L | Heart rhythm risk when abnormal |
| Chloride | 98 to 106 mEq/L | Follows sodium and acid-base |
| Bicarbonate (CO2) | 22 to 29 mEq/L | Low in metabolic acidosis, high in alkalosis |
| Anion gap | About 8 to 12 mEq/L | High in many acidoses |
| BUN | 7 to 20 mg/dL | High with dehydration, kidney injury, GI bleeding |
| Creatinine | About 0.6 to 1.2 mg/dL | High with reduced kidney function |
| Glucose (fasting) | 70 to 99 mg/dL | High in diabetes or stress, low with insulin excess |
| Calcium | 8.5 to 10.2 mg/dL | Correct for albumin |
Practice it in VMS
In VMS you do this on the patient, not on paper: every step goes on the checklist with a score, and in Teach mode Blocky tells you what comes next.
VMS cases that train this skill
Sources
- AAMC Core Entrustable Professional Activities (Core EPAs)
- NCCPA PANCE Content Blueprint
- The Joint Commission, National Patient Safety Goals
Facts and steps follow AAMC Core Entrustable Professional Activities (Core EPAs); NCCPA PANCE Content Blueprint. VMS is not affiliated with these organizations. Updated: 2026-10-11.