Abstract: PUB105
The Thirst Is Real: A Case of Severe Hypernatremia and Azotemia
Session Information
Category: Fluid, Electrolytes, and Acid-Base Disorders
- 1102 Fluid, Electrolyte, and Acid-Base Disorders: Clinical
Authors
- Lopez, Jacqueline, University of Utah Health, Salt Lake City, Utah, United States
- Ramkumar, Nirupama, University of Utah Health, Salt Lake City, Utah, United States
- Gilligan, Sarah, University of Utah Health, Salt Lake City, Utah, United States
Introduction
Hypernatremia is defined as a serum sodium concentration >145 mmol/L and reflects a relative deficit of free water. Tomkins et al. found it occurs in 1% of hospitalized patients and up to 10% of ICU patients. Hypernatremia is associated with higher mortality rates than any other electrolyte abnormality, though often attributed to the comorbidities of affected patients. It is also highly associated with prerenal azotemia, the result of reduced blood flow, often seen in dehydration. Decreased free water intake and increased free water loss occur when thirst or access to water is impaired, making the highest-risk groups patients with altered mental status, intubated patients, and elderly individuals.
Case Description
A 91-year-old female with a history of HFrEF, infrarenal AAA, HTN, CKD III, and cirrhosis presented with 1 week of poor oral intake with severe hypernatremia, AKI, and azotemia. Upon presentation sodium level was 168 mmol/L, Cr 3.72, BUN 224 mg/dL, and eGFR 10. Physical exam and vitals showed dry mucous membranes and drowsiness but was otherwise unremarkable. Her free water deficit was around 3 L. Given her fraility, numerous comorbidities and poor functional status, dialysis was unlikely to improve quality of life or functional status. She was treated with intravenous 5% dextrose in water and sodium bicarbonate. Over the course of eight days her sodium levels decreased by about 2 mmol/L per day until it reached 142 mmol/L and stayed within a normal range. BUN level decreased to 99 mg/dL with just fluid restoration. Goals of care were discussed and she was ultimately discharged on hospice. She passed away within one month of discharge.
Discussion
Elderly populations are highly vulnerable to hypernatremia due to decreased thirst drive, impaired urinary concentrating ability, and decreased free water. While the risk of azotemia, specifically prerenal, is inherently increased because of that. Kathpal et al. found severe hypernatremia to have mortality in hospital of 38% and nearly 65% in the month after discharge. This case showcases the resolution of azotemia without the need for dialysis which not only supports hypovolemia as the cause and but also exemplifies the benefit of adequate volume correction in these patients. This case displays the need for fluid correction in the setting of azotemia as well as more dedicated efforts in hypernatremia prevention and treatment in vulnerable populations.