Acid–Base Balance & acid base
disorders Nursing study guide – ABG
Interpretation 2026-27 latest version
,WHAT IS AN ABG?
The Components
• pH / PaCO2 / PaO2 / HCO3 / O2sat / BE
Desired Ranges
• pH - 7.35 - 7.45
• PaCO2 – 4.5 – 6 kPa
• PaO2 – 10.5 – 13.5 kPa
• HCO3 - 21-27
• O2sat - 95-100%
• Base Excess - +/-2 mEq/L
, ACID BASE BALANCE
The body produces acids daily
• 15,000 mmol CO2
• 50-100 mEq Nonvolatile acids
The lungs and kidneys attempt to maintain balance
Buffering also occurs in the liver through ammonia metabolism to
urea / glutamate
disorders Nursing study guide – ABG
Interpretation 2026-27 latest version
,WHAT IS AN ABG?
The Components
• pH / PaCO2 / PaO2 / HCO3 / O2sat / BE
Desired Ranges
• pH - 7.35 - 7.45
• PaCO2 – 4.5 – 6 kPa
• PaO2 – 10.5 – 13.5 kPa
• HCO3 - 21-27
• O2sat - 95-100%
• Base Excess - +/-2 mEq/L
, ACID BASE BALANCE
The body produces acids daily
• 15,000 mmol CO2
• 50-100 mEq Nonvolatile acids
The lungs and kidneys attempt to maintain balance
Buffering also occurs in the liver through ammonia metabolism to
urea / glutamate