Serum/plasma rate of change in [unspecified analyte] concentration (e.g., electrolytes, glucose, or other solutes)
This test measures how quickly your body’s level of a specific substance in your blood changes over time. It helps doctors track conditions affecting fluid balance, metabolism, or other processes.
["Assesses dynamic changes in your blood chemistry over a monitored period."]
Key facts at a glance
- LOINC
- 45367-0
- Short code
- LPT 20 ug CA Bld-nRate
- Synonyms
- LPT 20 ug CA Bld-nRate
- Category
- chemistry
- Sample
- whole-blood
- Container
- Lavender-top (EDTA)
- Units
- N/A
- Ref low
- 0.8
- Ref high
- 1.2
- Critical range
- — – 5 N/A
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 18–65 years
- CPT
- 85610
- SNOMED
- 396252006
- Specimen volume
- 3 mL
- Stability
- Room temperature: 4h, Refrigerated: 24h
- Hemolysis max
- 0
- Lipemia max
- 0
- Icterus max
- 0
- TAT
- 4–24 hours
- Order
- routine
Why This Test Is Done
Your doctor may order this test if they suspect conditions like kidney disease, diabetes, or fluid imbalances. It helps monitor how your body handles substances like electrolytes, glucose, or other solutes over time, especially if you’re on medications that affect these levels.
What to Expect Before the Test
No special preparation is usually needed. You’ll provide a blood sample (serum or plasma) or, in some cases, urine. If you’re taking certain medications, let your doctor know to avoid interfering with results.
What the Results Mean
Results show how fast your substance levels rise or fall. For example, a rapid increase might indicate dehydration or overproduction of a substance, while a slow change could suggest a steady metabolic process or slower clearance.
Common Conditions Monitored
This test helps diagnose or manage conditions like electrolyte imbalances, kidney function, or metabolic disorders. It may also guide treatment adjustments for patients on IV fluids, diuretics, or medications that alter blood chemistry.
Reference range
INR: 0.8-1.2 (warfarin: 2.0-3.0)N/A
Inform your healthcare provider if you are taking blood thinners. No special preparation required.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
Clinical significance: This test provides a time-based snapshot of how quickly your body’s substance levels shift. It’s particularly useful for identifying trends (e.g., rapid fluctuations) that standard single-point measurements might miss, aiding in early detection of complications or treatment efficacy.
Short name
Rate of change test
Frequently asked questions
What does a ‘rate of change’ test measure exactly?
Can this test replace other blood tests?
How often should I get this test?
Sources
- 1
- 2Lab Tests OnlineSource
- 3
Click any link to access the full source. PubMed Central (PMC) links provide free full-text access.
This information is for educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment.
This content is for general informational and educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the guidance of a qualified healthcare provider with any questions you have about a medical condition, and never disregard professional medical advice or delay seeking it because of something you read here.
If you think you may have a medical emergency, call your local emergency number or go to the nearest emergency department immediately.
Medically reviewed by WellAlly Editorial Team Last reviewed August 16, 2026. · Read our editorial policy