Case Presentation: A 66-year-old female became noncompliant with home medications presented to the emergency room with altered mental status. She had an established diagnosis of decompensated cirrhosis on a recent discharge from hospital leading to metabolic encephalopathy. Five days into her hospital stay, the patient refused medications and nutrition leading to an IV saline treatment. Two days after initially refusing nutrition a lactulose enema was administered. The patient’s sodium levels changed from 148 to 172 overnight and she was admitted to the ICU. Sodium was corrected carefully between 7-8 meq/day but damage had already been done by rapid development of hyprenatremia.

Discussion: Osmotic demyelination syndrome is difficult to diagnose and is seen on MRI after tissue destruction has taken place. Although it is a known risk in the rapid fluctuation of sodium and patients receiving both IV saline and a lactulose enema should have their sodium levels carefully monitored to avoid hypernatremia and critically damaging cerebral edema. Only a few such cases have been reported to the best of our knowledge and this case provides a great teaching point, which otherwise can be easily overlooked and prove fatal to the patient. The unusual presentation of this patient began with the refusal to comply with medications or nutrition which was treated with a lactulose enema. However, the patient was already being treated with normal saline for hydration. This combination led to severe hypernatremia in this patient which eventaully led to osmotic demyelination syndrome which was later diagnosed on MRI after the destruction had occurred. Monitoring the patient’s sodium levels aggressively in these patients and careful administation of lactulose enema should be a standard of care. Especially, a combination of normal saline and lactulose enema can prove fatal in patients. The proposed mechanism is the hyperosmolar nature of lactulose pulling fluids in the gut leading to increase concentration of sodium in blood causing fatal hyprenatremia.

Conclusions: Patients who initially present with metabolic encephalopathy can be at risk for osmotic demyelination syndrome when treated with saline and lactulose enema. Monitoring the patient’s sodium levels is a critically important step in avoiding demyelination.