injuries poisoning
Serotonin Syndrome
Diagnosis of Serotonin Syndrome
Clinical criteria Diagnosis of serotonin syndrome is clinical. Various explicit criteria have been proposed. TheHunter criteriaare currently preferred because of ease of use and high accuracy (almost 85% sensitivity and>95% specificity compared with diagnosis by a toxicologist). These criteria require that patients have taken a serotonergic drug and have one of the following: Muscle hypertonia Spontaneous clonus Tremor plus hyperreflexia Ocular or inducible clonus, plus either agitation, diaphoresis, or temperature>38° C Systemic infections, drug or alcohol withdrawal syndromes, and toxicity caused by sympathomimetic or anticholinergic drugs should also be considered in the differential diagnosis. Differentiation of serotonin syndrome from Neuroleptic Malignant Syndrome may be difficult because symptoms (eg, muscle rigidity, hyperthermia, autonomic hyperactivity, altered mental status) overlap. Clues to serotonin syndrome include use of serotonergic drugs, rapid onset (eg, within 24 hours), and hyperreflexia, in contrast to the often decreased reflex responses in neuroleptic malignant syndrome. There are no confirmatory tests, but patients should have testing to exclude other disorders (eg, cerebrospinal fluid analysis for possible central nervous system infection, urine testing for drugs of abuse). Also, some tests (eg, serum electrolytes, platelet count, renal function tests, creatine kinase, prothrombin time, testing for urine myoglobin) may be necessary to identify complications in severe serotonin syndrome. Among patients with hyperthermia, altered mental status, autonomic hyperactivity, and muscular rigidity factors that favor serotonin syndrome over neuroleptic malignant syndrome include use of serotonergic drugs, onset within 24 hours, and hyperreflexia 