Page 23 - Delaware Medical Journal - November 2015
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CASE REPORT
TABLE 1: some of the symptoms which should raise clinical suspicion for elevated serotonergic activity
Mental Status Change
Anxiety, agitation, delirium, restlessness, disorientation
Autonomic manifestations
Diaphoresis, tachycardia, hyper- thermia, hypertension, vomiting, diarrhea, pupillary dilatation
Neuromuscular Hyperactivity
Tremor, muscle rigidity, myoclonus, ocular clonus, deep tendon hyperreflexia, bilateral Babinski sign
CASE PRESENTATION
A 41-year-old Caucasian female with known chronic Hepatitis C virus infection, hypertension, and bipolar disorder presented to the Emergency Department with worsening shortness of breath, malaise, and cough that were gradually worsening over ten days. She recently had been hospitalized for atypical pneumonia.
She smoked one pack or cigarettes per day and abused heroin. Her outpatient medications included Fluoxetine, Perphenazine, Amlodipine, Metoprolol, and Omeprazole.
In the emergency room, patient was noted to be in distress
with tachypnea and tachycardia. Her labs showed leukocytosis. She was admitted with a diagnosis of possible pneumonia
and was started on antibiotics. Within 24 hours of admission, patient went into respiratory distress with severe agitation and confusion. She developed acute hypoxic respiratory failure. She failed Bilevel Positive Airway Pressure (BiPAP) treatment and was intubated and placed on mechanical ventilation in ICU. showed bilateral basilar ground-glass opacities and interlobular septal thickening. Patient underwent bronchoscopy with bronchoalveolar lavage was positive for yeast and neutrophilia but negative for acid-fast bacilli or malignant cells. Mycoplasma blood antigen came back positive. The possibility of pulmonary fungal infection vs. mycoplasma pneumonia complicated with Acute Respiratory Distress Syndrome (ARDS) was considered. Despite being on appropriate measures including antibiotics and antifungals she continued to deteriorate. Patient developed muscular rigidity followed by malignant hyperthermia with a temperature of 106°F. At this time, the possibility of serotonin syndrome was entertained and Cyproheptadine was initiated. Patient was successfully extubated and transferred to general rehabilitative services.
DISCUSSION
This case displays a very typical presentation of serotonin
(5-HT) syndrome (SS). The key learning point is the high index of suspicion to diagnose and treat this condition before it becomes fatal. SS is classically described by a triad of symptoms: mental status change, autonomic hyperactivity, and neuromuscular abnormality.1 Selective Serotonin Reuptake Inhibitors (SSRIs)
are likely the most common associated drug class that can
lead to serotonin syndrome.2 The combination of SSRIs with MOI inhibitors, antidepressants, anticonvulsants, antibiotics
like linezolid, and typical/atypical antipsychotics increases the likelihood of developing the symptoms.2,3 The true incidence of this syndrome is largely under-represented and, many times the symptoms are attributed to other causes including but not limited to: neuroleptic malignant syndrome, anti-cholinergic toxicity, malignant hyperthermia, meningitis, or encephalitis.1
Serotonin syndrome is most often a clinical diagnosis. The
key step towards diagnosis is a thorough history and physical examination. The most common clinical manifestations are neurological, autonomic, and neuro-muscular changes. Multiple research studies on mice consistently show that elevated blood pressure and temperature are the two most common symptoms caused by serotonin toxicity.4,5 Table 1 lists some of the symptoms which should raise clinical suspicion for elevated serotonergic activity.6 Sternbach Criteria was developed to assess risk for Serotonin Syndrome by physical examination (Table 2)2,6
In our case, the patient was taking Fluoxetine, the prototypical SSRI medication, and Perphenazine, a medium-potency typical
TABLE 2: Sternbach/Hunter Criteria
Criteria is met if patient has taken a serotonergic agent and one of the following:
Spontaneous clonus
Inducible clonus and agitation or diaphoresis
Ocular clonus and agitation or diaphoresis
Tremor and hyperreflexia
Hypertonia
Temperature above 38°C and ocular clonus or inducible clonus
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