How to read kidney function (creatinine and eGFR)
Other platforms explain it with text and video. In VMS you practice it on the patient.
Kidney function affects fluids, electrolytes and the safe dose of many drugs. Creatinine and eGFR are read differently in sudden and long-term kidney disease.
Step by step
Start with creatinine
Creatinine comes from muscle and is cleared by the kidneys. A rising value means filtration is falling. [1]
Compare with the baseline
Acute kidney injury is a rise of 0.3 mg/dL or more within 48 hours, a rise to 1.5 times baseline within 7 days, or urine under 0.5 mL/kg per hour for 6 hours. [1]
Use eGFR in stable patients
eGFR is calculated from creatinine, age and sex. It is not accurate while creatinine is changing quickly. [1]
Stage chronic disease
Chronic kidney disease means low eGFR or kidney damage lasting more than 3 months. Check urine albumin to creatinine ratio too. [1]
Look for the cause
Think of low blood flow (dehydration, bleeding), kidney damage (drugs, contrast, infection) and blockage (enlarged prostate, stones). [1]
Adjust drugs
Review drugs that need dose changes or should be stopped, such as NSAIDs, metformin and some antibiotics and anticoagulants. [2]
Remember body size
Very low or very high muscle mass makes creatinine misleading. Cystatin C can help. [1]
Common errors
- Using eGFR to judge a patient whose creatinine is rising quickly.
- Not checking the patient's baseline creatinine.
- Forgetting to adjust drug doses for kidney function.
CKD stages by eGFR (mL/min/1.73 m2) [1]
| Stage | eGFR | Meaning |
|---|---|---|
| G1 | 90 or more | Normal filtration; CKD only if damage markers present |
| G2 | 60 to 89 | Mildly reduced |
| G3a | 45 to 59 | Mild to moderately reduced |
| G3b | 30 to 44 | Moderately to severely reduced |
| G4 | 15 to 29 | Severely reduced |
| G5 | Under 15 | Kidney failure |
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
- NCCPA PANCE Content Blueprint
- Open RN, Nursing Pharmacology 2e (CC BY 4.0)
- AAMC Core Entrustable Professional Activities (Core EPAs)
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.