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Serum Oxygen Saturation (via Intravenous Probe)

Published: August 9, 2026Updated: August 16, 2026

This test measures how much oxygen is bound to hemoglobin in your blood when taken from an intravenous line.

Quick summary

["Helps assess oxygen delivery in critical care settings."]

Medically reviewed by WellAlly Editorial TeamLast reviewed August 16, 2026Editorial policy

Key facts at a glance

LOINC
8850-0
Short code
SaO2 % IVC
Synonyms
SaO2 % IVC
Category
chemistry
Sample
serum
Container
Red-top tube (SST)
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Specimen volume
5 mL
Stability
Room temperature: 4h, Refrigerated: 24h, Frozen: 7d
Hemolysis max
500
Lipemia max
1000
Icterus max
500
TAT
4–24 hours
Order
routine

What Is This Test Measuring?

Oxygen saturation (O₂ sat) reflects the percentage of hemoglobin molecules carrying oxygen in your bloodstream. This test is taken directly from an intravenous catheter, providing real-time data on how efficiently your blood is transporting oxygen.

Why Might You Need This Test?

Doctors may order this test if you’re in a hospital setting with an IV line, especially during monitoring for conditions like severe anemia, respiratory failure, or during procedures requiring precise oxygen management.

How Is the Test Performed?

A small sample of blood is drawn from your IV line using a specialized probe. The probe measures oxygen saturation without removing blood for lab analysis, allowing for immediate results.

What Does the Result Mean?

Results are typically expressed as a percentage (e.g., 95% saturation). Lower values may indicate poor oxygen delivery, while higher values (above 100%) can suggest excess oxygen or technical issues.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

◆Associated findings1

Short name

O₂ Saturation (IV)

Frequently asked questions

Why is my oxygen saturation checked through an IV line instead of a finger probe?
Intravenous oxygen saturation probes are used in hospitals for continuous monitoring in critical care. Finger probes are more common for routine checks, but IV probes provide more stable readings in patients with unstable conditions or those receiving IV medications.
What does an abnormal oxygen saturation mean?
An abnormal result may signal issues like low blood oxygen levels (hypoxemia), which can be caused by lung problems, heart failure, or other medical conditions. Your doctor will discuss findings with you and may recommend further tests or treatments.
Can I eat or drink before this test?
No special preparation is needed for this test, as it involves a small blood sample from your IV line. However, always follow your healthcare provider’s instructions for any related procedures.
  1. 1
    MedlinePlus — Laboratory TestsSource
  2. 2
    Lab Tests OnlineSource
  3. 3
    Mayo Clinic — Tests & ProceduresSource

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.

Medical Disclaimer

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