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Blood Gas Interpretation

Uncompensated Metabolic Acidosis [SIG002US]

This is the blood gas result for Deepak Patel for scenario SIG002US

Clinical Picture

  • 64-year-old male presenting with severe abdominal pain
  • Patient is alert and responds appropriately, but is in visible discomfort
  • Known history of diverticular disease
  • Tachycardic, tachypneic, hypotensive, and febrile



  • Sample type: Arterial
  • FiO2: 21%
  • pH: 7.30
  • paCO2: 38 mmHg
  • paO2: 90 mmHg
  • HCO3: 18
  • Base excess: -8
  • Acid-base balance: Abnormal
  • Other parameters: Elevated lactate



  • pH, HCO3, and base excess are not within normal limits on this blood gas. Lactate is not within normal limits (acidotic).
  • The acidotic bicarbonate (HCO3) and base excess match with the acidotic pH, consistent with a metabolic acidosis. The normal PaCO2 indicates compensation has not yet occurred; therefore, this is an uncompensated metabolic acidosis, such as that commonly found in acute sepsis or lactic acidosis.


Further reading