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Kidney Week

Abstract: PO1167

Sleeping Beauty: Hypersomnolence and Hyperammonemia in a Patient with Multiple Myeloma

Session Information

Category: Fluid, Electrolyte, and Acid-Base Disorders

  • 902 Fluid, Electrolyte, and Acid-Base Disorders: Clinical


  • Regina, Stephen P., Methodist Health System, Dallas, Texas, United States
  • Collazo-Maldonado, Roberto L., Dallas Nephrology Associates, Dallas, Texas, United States
  • Qureshi, Muhammad Raza, Dallas Nephrology Associates, Dallas, Texas, United States

Metabolic encephalopathy in a patient with multiple myeloma is commonly reported in association with prevalent biochemical syndromes such as uremia, hypercalcemia, and or hyperviscosity due to immunoglobulin, but very rarely hyperammonemia has been described as another cause of encephalopathy.

Case Description

The patient is a 45 year old woman with a prior diagnosis of multiple myeloma in July 2020. A bone marrow biopsy confirmed plasma cell neoplasm with 90% plasma cells, and SPEP was positive for monoclonal IgA kappa. The patient was brought to the hospital again in August 2020, with the chief complaint of worsening confusion and hypersomnolence over two weeks. Labs included hemoglobin 7.3 g/dL, serum calcium 13.8 mg/dL, chloride 108 mEq/L, bicarbonate 16 mEq/L with anion gap of 19, lactate 1.4 mmol/L, albumin 3.2 g/dL, and a CT of the head showed numerous lytic skull lesions, including a 3.8 cm posterior skull lesion with extraosseous intracranial extension. ABG showed pH 7.56, pCO2 24.5 mmHg, pO2 63.3. Hypercalcemia was treated with medical therapies and improved. The nephrology service was called due to metabolic acidosis. Given the respiratory alkalosis, a plasma ammonia level was checked and noted to be elevated at 89 umol/L. Imaging of the liver was not compatible with cirrhosis. The patient was given oral lactulose for several days without improvement. To address the hyperammonemia, the patient was transferred to the ICU to begin CRRT and she also required intubation due to unsustainable respirations. The plasma ammonia level improved while on CRRT but the patient had a grim prognosis, was not a candidate for chemotherapy, and the family elected to pursue palliative care.


Hyperammonemia is a rare complication of multiple myeloma and is associated with high inpatient mortality. CRRT can treat hyperammonemia that is refractory to medical therapy (Gupta et al, CJASN 2016). However, hyperammonemia is a poor prognosticator in patients with multiple myeloma. Hyperammonemia should be included in the differential diagnosis of metabolic encephalopathy in patients with multiple myeloma.