On Day 6 of hospitalization, Mr. O continues to be tachycardic and obtunded with nuchal rigidity. The team decides to transfer Mr. O to another hospital for a higher level of care and continued workup of his persistent AMS.
Immediately upon arrival at the second hospital, infectious disease and neurology teams are consulted for further evaluation. Mr. O’s AMS continues despite no clear signs of infection or other neurologic insults.
The authors’ observations
Based on Mr. O’s psychiatric history and laboratory results, the first medical team concluded his initial AMS was likely secondary to DKA; however, the AMS continued after the DKA resolved. At the second hospital, Mr. O’s treatment team continued to dig for answers.
EVALUATION Exploring the differential diagnosis
At the second hospital, Mr. O is admitted to the ICU with fever (37.8°C), tachycardia (120 bpm), tachypnea, withdrawal from painful stimuli, decreased reflexes, and muscle rigidity, including clenched jaw. The differential diagnoses include meningitis, sepsis from aspiration pneumonia, severe metabolic encephalopathy with prolonged recovery, central pontine myelinolysis, anoxic brain injury, and subclinical seizures.
Empiric vancomycin, 1.75 g every 12 hours; ceftriaxone, 2 g/d; and acyclovir, 900 mg every 8 hours are started for meningoencephalitis, and all psychotropic medications are discontinued. Case reports have documented a relationship between hyperglycemic hyperosmolar syndrome (HHS) and malignant hyperthermia in rare cases1; however, HHS is ruled out based on Mr. O’s laboratory results.A lumbar puncture and imaging rules out CNS infection. Antibiotic treatment is narrowed to ampicillin-sulbactam due to Mr. O’s prior CT chest showing concern for aspiration pneumonia. An MRI of the brain rules out central pontine myelinolysis, acute stroke, and anoxic brain injury, and an EEG shows nonspecific encephalopathy. On Day 10 of hospitalization, a neurologic exam shows flaccid paralysis and bilateral clonus, and Mr. O is mute. On Day 14 of hospitalization, his fever resolves, and his blood cultures are negative. On Day 15 of hospitalization, Mr. O’s creatine kinase (CK) level is elevated at 1,308 U/L (reference range 26 to 192 U/L), suggesting rhabdomyolysis.
Continue to: Given the neurologic exam findings...