ABG INTERPRETATION GUIDE
The 3-Step Mastery Method
Step 1: Determine pH Status
Normal: 7.35 – 7.45
• < 7.35: Acidosis
• > 7.45: Alkalosis
Step 2: Check Respiratory Component (PaCO2)
• High PaCO2 (>45) + Low pH: Respiratory Acidosis
• Low PaCO2 (<35) + High pH: Respiratory Alkalosis
Step 3: Check Metabolic Component (HCO3)
• Low HCO3 (<22) + Low pH: Metabolic Acidosis
• High HCO3 (>26) + High pH: Metabolic Alkalosis
Winters' Formula (Metabolic Acidosis Compensation):
Expected PaCO2 = (1.5 x HCO3) + 8 ± 2
Verified by Dr. Medical Expert | Graduate of Taiz University
Reference: WHO & KDIGO Guidelines 2026
The 3-Step Mastery Method
Step 1: Determine pH Status
Normal: 7.35 – 7.45
• < 7.35: Acidosis
• > 7.45: Alkalosis
Step 2: Check Respiratory Component (PaCO2)
• High PaCO2 (>45) + Low pH: Respiratory Acidosis
• Low PaCO2 (<35) + High pH: Respiratory Alkalosis
Step 3: Check Metabolic Component (HCO3)
• Low HCO3 (<22) + Low pH: Metabolic Acidosis
• High HCO3 (>26) + High pH: Metabolic Alkalosis
Winters' Formula (Metabolic Acidosis Compensation):
Expected PaCO2 = (1.5 x HCO3) + 8 ± 2
Verified by Dr. Medical Expert | Graduate of Taiz University
Reference: WHO & KDIGO Guidelines 2026
