Routine laboratory studies are common in the intensive care unit; abnormalities are even more common. Typically these studies include a chemistry panel (Chem 10). The differential diagnoses of the most frequent and clinically relevant electrolyte abnormalities are detailed below.

Differential Diagnosis and Evaluation of Hyponatremia

Differential Diagnosis and Evaluation of Hypernatremia

Differential Diagnosis and Evaluation of Hypokalemia

Differential Diagnosis of Hyperkalemia

Differential Diagnosis of Hypo and Hypercalcemia

Differential Diagnosis of Hypo and Hypermagnesemia

Differential Diagnosis of Hypo and Hyperphosphatemia

References:

1. Marino, P. (2014). Marino’s the ICU book. Philadelphia: Wolters Kluwer Health/Lippincott Williams & Wilkins.
2. Fulop, M. (1998). Algorithms for diagnosing some electrolyte disorders. American Journal of Emergency Medicine, 16(1), 76–84.
3. WikEM: Hypokalemia
4. WikEM: Hyponatremia