Specimen Name Result Units Range
Plasma Sodium 131 mmol/L (135-145)
Potassium 2.2 mmol/L (3.5-5.5)
Chloride 72 mmol/L (100-109)
Bicarbonate 47 mmol/L (22-32)
Urea 15.3 mmol/L (2.7-7.2)
ABG pH 7.43 (7.36-7.44)
PaO2 61 mmHg (70-100)
PaCO2 75 mmHg (35-45)
HCO3- 48 mmol/L (21-26)

82yo mal with CCF and CAL

What is the acid-base disorder?
Mixed Metabolic Alkalosis & Respiratory Acidosis
  • pH : alkalaemia
  • HCO3- : metabolic
  • PCO2 : should be 40-45 mmHg, therefore respiratory component
  • PO2 + 1.25*PCO2 > 150 : on supplemental O2

Metabolic Alkalosis:

  • chronic diuretic use
  • renal compensation for hypercarbia

 

ABG Correction Factors

  • Metabolic Alkalosis:
    • PCO2 : last 2 digits of pH ≤ 7.60
    • HCO3- : for each 10 mmol/L rise → ↑ PCO2 ≈ 7 mmHg
    • *least well compensated due to hypoxaemia 2° hypoventilation
  • Respiratory Acidosis:
    • Acute : for each PCO2 10 mmHg rise → ↑ HCO3- ≈ 1-2 mmol/L
    • Chronic : for each PCO2 10 mmHg rise → ↑ HCO3- ≈ 4 mmol/L