Chapter 32. Neurocritical Care in the Surgical Intensive Care Unit
A 50-year-old man with history of anxiety, depression, alcohol abuse, chronic pain, and hyperthyroidism presents with altered mental status and fever. His medications are sertraline, propylthiouracil, acetaminophen, clonazepam, and tramadol. Exam reveals a combative male mumbling incoherently. He appears diaphoretic. His vital signs are temperature of 105°F, pulse of 130 bpm, blood pressure of 190/80 mm Hg, respiratory rate of 35 breaths/min, and oxygen saturation of 89%. He is treated with intravenous (IV) haloperidol for his agitation. He subsequently has a seizure and is intubated for airway protection. Which of the following is the most appropriate treatment for this patient?
C. Administer IV methylprednisolone
D. Administer fentanyl pain control
E. Start broad-spectrum antibiotics
B. This patient likely has serotonin syndrome (SS). SS is clinical entity characterized by the triad of altered mental status, neuromuscular abnormalities, and autonomic hyperactivity. Patients with SS can present with a spectrum of clinical signs and symptoms ranging from mild tremors and gastrointestinal upset to muscle rigidity, seizures, and severe hyperthermia. The mechanism is thought to be due to excess levels of serotonin generally brought on by combinations of medications with pro-serotonergic effects. Multiple drugs have been associated with the development of SS, usually in combination, including selective serotonin reuptake inhibitors, methylene blue, fentanyl (and other phenylpiperidine narcotics), linezolid, trazodone, and tramadol. The differential diagnosis for patients presenting with SS-like signs and symptoms includes thyroid storm, neuroleptic malignant syndrome, malignant hyperthermia, catatonia, and central fever. Administration of dantrolene does not treat SS, and neuroleptic malignant syndrome is unlikely since haloperidol administration followed symptom development. Methylprednisolone could be part of a treatment for thyroid storm to reduce thyroxine (T4) to triiodothyronine (T3) conversion, but the symptoms are more consistent with SS. As fentanyl is a causal agent for SS, it is not an ideal analgesic for this patient. Infection is unlikely given the clinical presentation, and therefore, antibiotics are not indicated.
A 72-year-old man with a history of coronary artery disease, diabetes, chronic obstructive pulmonary disease, and depression presents with confusion, productive cough, fever, gastrointestinal upset, and diffuse infiltrates on chest x-ray. Several other people who live in his building presented with similar symptoms. Vital signs are oxygen saturation of 93% on 2 L/min nasal cannula, heart rate of 95 bpm, blood pressure of 115/40 mm Hg, respiratory rate of 25 breaths/min, and temperature of 103°F. His urine Legionella antigen is positive. Which laboratory values would be most helpful in the workup of his altered mental status?