Abstract: SA-PO989

Double Trouble: Severe Hypernatremia Secondary to Central Diabetes Insipidus (DI) Complicated by Hypercalcemic Nephrogenic DI: A Case Report

Session Information

Category: Nephrology Education

  • 1302 Fellows and Residents Case Reports

Authors

  • Siddiqui, Waqas Javed, Drexel University College of Medicine, Levittown, Pennsylvania, United States
  • Yousaf, Muhammad abdullah, Rawalpindi Medical University, LANSDALE, Pennsylvania, United States
  • Tauqir, Zehra, Rawalpindi Medical University, LANSDALE, Pennsylvania, United States
  • Aggarwal, Sandeep, Drexel University College of Medicine, Levittown, Pennsylvania, United States
Background

Patients with advanced malignancies often have electrolyte abnormalities. We present a case of patient with central DI secondary to metastatic pituitary invasion complicated by hypercalcemic nephrogenic DI.

Methods

40 year old female with history of stage IV Breast Ca including skeletal and leptomeningeal metastasis with compression of optic chiasm and pituitary with central DI, baseline labs shown in table 1, was admitted with confusion. Patient's husband stated that she had been constantly thirsty, drinking “gallons” of water in the recent past and making a lot of urine. Pertinent vitals and physical exam showed: BP = 134/76 mmHg and heart rate = 130/minute, patient was confused, sunken eyes, flat neck veins, and tachycardia and reduced skin turgor. Patient was found to have severe hypercalcemia and profound hypernatremia (Electrolytes and urine output are summarized in table 1). Other relevant labs: PTH = 24 pg/mL, PTH-rp = 2.4 pmol/L and 25-OH Vitamin D = 25.9ng/mL. Patient received 5% dextrose for rehydration, one dose of Intravenous (IV) Pamidronate 90 mg, one dose of IV Desmopressin 2mcg and 4 days of subcutaneous Calcitonin 200 International Units Q12H was given.Initially Patient’s urine output in the hospital was in the range of 350 – 400 mL/hour which responded well to one dose of DDAVP. In the subsequent days, patient’s serum sodium and calcium normalized but she died because of the extensive malignancy.

Conclusion

Our case emphasizes the importance of identification of causes and complications of electrolyte abnormalities associated with metastatic cancers. These electrolyte abnormalities can be primary or paraneoplastic and should be actively pursued and treated in such cases.

Table 1: Urine and serum electrolyte and Urine output trends
Timeline/TrendsSerum Na
meq/L
Serum Osmolality
msom/kg
Urine Na
mmol/L
Urine Osmolality
msom/kg
Serum Ca mg/dLUrine output ml/hour
Baseline - Prior to admission151334201158.8N/A
At admission – Day 01673477218516.5350 - 450
Day 1
(DDAVP + Calcitonin + Pamidtronate)
158N/A18945112.2100 - 150
Day 2158N/AN/AN/A11.550 - 150
Day 31483031514559.375 - 150
Na = Sodium; Ca = Calcium; N/A = Not available; DDAVP = Desmopressin; msom = milliosmoles; kg= Kilogram; mmol = millimoles; mg = milligrams; dL = deciliter; L = liters; mL = milliliters