Osmol Gap Calculator for suspected exogenous osmoles in intoxication - The Anesthesia Guide

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Osmol Gap

Sodium (Na⁺) (mmol/L)

Urea (mmol/L)

Glucose (mmol/L)

Measured osmolality (mOsm/kg)

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Calculated osmolality

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Osmol gap

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Interpretation

Formula: -

Clinical note: -

Details

Calculated osmolality = 2 x Na + glucose + urea
Osmol gap = measured osmolality - calculated osmolality
An osmol gap above 10 mOsm/kg is commonly considered pathological
Tip: subtract S-ethanol to help assess for other alcohols such as ethylene glycol

This calculator is a clinical aid and does not replace medical judgment.

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