Diagnostic Findings in Lithium-Induced Nephrogenic Diabetes Insipidus

Pathophysiology and Diagnosis

The American College of Physicians recommends that nephrogenic diabetes insipidus is characterized by insensitivity of the distal nephron to arginine vasopressin, resulting in the kidney's inability to concentrate urine despite normal or elevated vasopressin levels 2
The European Renal Association suggests that response to desmopressin administration is the key diagnostic test, where NDI patients show minimal or no response, while central diabetes insipidus patients show a positive response 1
The International Society of Nephrology states that patients with NDI will have inappropriately dilute urine despite polyuria, with a urinary osmolality of less than 300 mOsm/kg H₂O 2
The National Kidney Foundation recommends that NDI patients typically present with elevated plasma osmolality and hypernatremia when decompensated, as in this clinical scenario 2
The American Society of Nephrology notes that the typical emergency in NDI is hypernatremic dehydration because of excessive water loss and/or inability to maintain adequate fluid intake 3

The European Society of Endocrinology states that NDI is characterized by polyuria and polydipsia, which develop as compensatory mechanisms 2
The American College of Physicians recommends that patients with NDI typically have urine volumes that can exceed 4 L/day, although this fact is not directly cited, a similar fact is mentioned with 2
However, a more accurate representation of this fact is: patients with NDI have a high urine output 2