Metabolic Acidosis : Wheeless' Textbook of Orthopaedics

- See ABG
- See Diff Dx: Anion Gap / Non Anion Gap

- By definition: primary decrease HCO3 concentration.
- Simple Met acidosis, Stimulates Ventilation, Decreasing pCO2
- Base Deficit:
         - indicator of blood loss, resuscitation,and mortality in trauma patients, and it is a more sensitivemarker of hypovolemia than vital signs;
         - base deficit and base excess are the same term;
         - normal base deficit is 0 to 3 mmol/L

- Must distinguish from compensatory decr in HCO3 due to Resp Alk.
- Predicted pCO2 Decrease (vs. HCO3) after Full Resp. Compensation.
- HCO3: 10 12 14 16 18 20 22 24
- pCO2: 21-25 24-28 27-31 30-34 33-37 36-40 39-43 42-46 * if pCO2 = approx predicted value, then Respiratory Compensation. * if pCO2 > than predicted, then concomitant Resp. Acidosis * if pCO2 < than predicted, then concomitant Met. Alkalosis
- Respiratory compensation (pCO2) for Metabolic acidosis will not be < 10.
- After Full Compensation: pCO2 = 1.5(HCO3) + 8 (+/- 2)
- Hypervent, lethargy, HTN/Hypoten, Arrhythmia, HyperCa
- See Diff Dx for Management: Anion Gap / Non Anion Gap
- Order: toxin screen, serum lactate, and serum ketone levels.

Base Deficit Stratifies Mortality and Determines Therapy.

Effect of normal saline infusion on the diagnostic utility of base deficit in identifying major injury in trauma patients.