A 31-year-old female with a history of Type 1 Diabetes presents via EMS after being found unresponsive by family. You assess the patient and are concerned about DKA. Let's interpret her acid-base status. 

Data:

• pH = < 6.8
• pCO2 = 26
• HCO3 = 4
• Na = 113, Cl = 84

1. Acidemia or Alkalosis: Our patient has significant ACIDOSIS

2. Metabolic or Respiratory: our HCO3 is less than 24, thus METABOLIC

3. Anion Gap or Non-Anion Gap Metabolic Acidosis: Anion Gap = [113 - (84 + 4)] = 25 thus ANION GAP METABOLIC ACIDOSIS

4. Compensated? Assess via Winter's Formula. calculated pCO2 = [1.5(HCO3) + 8] +/- 2 = [1.5*(4) + 8] +/- 2 = 12 to 16

• Measured pCO2 > Calculated pCO2, thus RESPIRATORY ACIDOSIS 

5. Delta Ratio:

• calculate Delta Gap: 
• Delta Gap = Anion Gap - 12
• 25 -12 = 13
• use Delta Gap to calculate Corrected HCO3 
  
• Corrected HCO3 = Delta Gap + 4 
• 13 + 4 = 17
• Interpret:
• if corrected HCO3 > 24, Metabolic Alkalosis
  
• if corrected HCO3 < 24, NON-ANION GAP METABOLIC ACIDOSIS 
  

6. Interpret in context of the patient

• Our patient has a triple acid-base disorder with an Anion Gap Metabolic Acidosis, Respiratory Acidosis and Non-Anion Gap Metabolic Acidosis 
• Anion Gap Metabolic Acidosis: likely from severe DKA
• Respiratory Acidosis: this is an ominous finding that likely indicates respiratory muscle fatigue in a patient who shoud be hyperventilating from severe acidosis. 
• Non-Anion Gap Metabolic Acidosis: unclear in this patient but consider etiologies related to loss of bicarbonate
• could be from the Normal Saline bolus patient received during resuscitation prior to blood draw which results in lost bicarbonate being replaced with Chloride
• could be from diarrhea leading to loss of bicarbonate
• diabetics are prone to Renal Tubular Acidosis