Critical Laboratory Value in DKA

A 30-year-old female patient is admitted to the hospital for diabetic ketoacidosis (DKA). During her stay, she undergoes various laboratory tests to monitor her metabolic status.

Upon reviewing her lab results, the nurse notes the following electrolyte abnormalities:

- Sodium: 134 mEq/L (normal: 135-145 mEq/L)

- Potassium: 6.5 mEq/L (normal: 3.5-5.0 mEq/L)

- Chloride: 100 mEq/L (normal: 97-107 mEq/L)

- Bicarbonate: 15 mEq/L (normal: 22-29 mEq/L)

Which laboratory value is of greatest concern for this patient due to the risk of life-threatening complications?