Respiratory

Base Excess (BE)

Normal Range
-2 to +2 mEq/L
Sample Type
Standard
Fasting
No
Unit
mEq/L

Base Excess (BE) measures the deviation of the actual bicarbonate concentration from the normal range under standard conditions. It is a critical parameter in Arterial Blood Gas (ABG) analysis to determine the metabolic component of an acid-base imbalance. A positive value indicates a surplus of base (alkalosis), while a negative value (base deficit) indicates a shortage of base or an excess of acid (acidosis). This helps clinicians differentiate between respiratory-driven pH changes and primary metabolic derangements.

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Interactive
mEq/L

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Why Context Matters

BE interpretation is complex when mixed acid-base disorders occur (e.g., combined respiratory and metabolic acidosis). It can also be influenced by abnormal hemoglobin levels or administration of exogenous buffers during resuscitation, requiring expert clinical correlation.

Lab ranges are statistical averages, not biological laws. "Normal" for a 20-year-old male isn't normal for a 60-year-old female.

Clinical References

Source-of-truth databases and clinical guidelines for Base Excess (BE):

Research & Guidelines

Related Indicators

Pulmonary Function Test

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Forced Vital Capacity (FVC)

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Forced Expiratory Volume (1s) (FEV1)

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DR

Medically Reviewed by Dr. Binoy Babu, MBBS

Board Certified Doctor • 10+ Years Clinical Experience

Dr. Babu is a practicing physician dedicated to empowering patients with clear, actionable medical information. He founded 2opi to bridge the gap between complex lab reports and patient understanding, ensuring everyone has access to a reliable second opinion.

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