Let’s break down typical lab values for mixed primary acid-base disorders:

1. Mixed Metabolic Acidosis + Respiratory Alkalosis:
   pH: Decreased (acidic) or near normal
   PaCO2: Decreased (<35 mmHg)
   HCO3- (Bicarb): Decreased (<22 mmol/L)
   Example: Diabetic ketoacidosis with hyperventilation.
2. Mixed Metabolic Acidosis + Metabolic Alkalosis:
   pH: Near normal or slightly increased (alkaline)
   PaCO2: Normal or slightly decreased
   HCO3- (Bicarb): Variable (depending on dominant disorder)
   Example: Vomiting (metabolic alkalosis) with diabetic ketoacidosis.
3. Mixed Respiratory Acidosis + Metabolic Alkalosis:
   pH: Near normal or slightly increased (alkaline)
   PaCO2: Increased (>45 mmHg)
   HCO3- (Bicarb): Increased (>28 mmol/L)
   Example: COPD with gastric suctioning.
4. Mixed Respiratory Acidosis + Respiratory Alkalosis (rare):
   pH: Variable
   PaCO2: Variable
   HCO3- (Bicarb): Normal or slightly decreased
   Example: Acute respiratory failure with mixed ventilatory drive disorders.