Journal: J Clin Anesth 20(2):143-145, 2008.
Reprint: Dept of Anesthesiology and Reanimation, School of Medicine, Dokuz Eylul University, 35340 Izmir, Turkey (M Akan, MD)
Faculty Disclosure: Abstracted by R. Klotz, who has nothing to disclose.
Serotonin syndrome is a group of signs and symptoms caused by excessive activation of the serotonergic receptors. It is usually a drug-related complication, from drugs that increase serotonin release, inhibit serotonin reuptake, or change the serotonin response. These drugs include ergot alkaloids, opioids, selective serotonin reuptake inhibitors, monoamine oxidase inhibitors, sumatriptan and lithium. It is usually seen with the combined use of these agents, but overdose of any single agent can precipitate the syndrome. Multiple serotonin receptors may be involved in the development of the serotonin syndrome, but it occurs mostly due to overstimulation of 5-hydroxytriptamine (HT) 1A and 5-HT2A receptors. Its clinical presentation consists of autonomic dysfunction, alterations in mental status, and neuromuscular disorder. Serotonin syndrome is a potentially lethal syndrome.
The authors present a case of possible serotonin syndrome that was caused by intrathecal fentanyl in a patient taking ergot alkaloids and multiple illicit drugs. A 25-yr-old man was admitted with acute appendicitis. The patient had a history of migraines treated with ergot alkaloids. He had a history of illicit drug use, including 3,4-methylenedioxy-N-methyl-amphetamine (MDMA) (2 pills taken 3 wks earlier), and marijuana, and ephedrine. The patient also was a long-time smoker and social drinker of coffee and beer. Previous anesthetics were uneventful. In the operating room, body temperature was 37.3º C, heart rate 120 beats/min, blood pressure 116/62 mmHg, and respiratory rate 16 breaths/min.
Spinal anesthesia was performed due to concerns over airway edema associated with general anesthesia in patients who smoke marijuana. Spinal anesthesia, with a T5 sensory dermatome, was achieved with bupivacaine 0.5% 16 mg and fentanyl 120 mcg. In the first 10 minutes after spinal anesthesia, the patient became agitated and had excessive shivering, with rigidity of the upper extremities. A resting pill-rolling tremor was noted in the right arm. The patient developed auditory and visual hallucinations. As the surgery progressed, he developed extensive muscle rigidity, pain, gradual increase in body temperature along with upper body flushing, and increase in heart rate and end-tidal carbon dioxide. These conditions were managed successfully and he was transferred to the surgical ward.
The clinical manifestations of serotonin syndrome are alterations in the conscious state—agitation, confusion, coma; autonomic dysfunction—hyperthermia, diaphoresis, diarrhea, and shivering; and neuromuscular changes—hyperreflexia, uncoordination, tremor and myoclonus. There must be at least three symptoms present, and diagnosis is one of exclusion.
Fentanyl is a synthetic opioid analgesic widely used in anesthesia. Because of its affinity for the 5-HT1A receptor, it also influences 5-HT efflux. Fentanyl does not precipitate serotonin syndrome when used alone, but it is associated with serotonin syndrome, especially when used in combination with other drugs.
Dihydroergotamine (DHE) is a 5-HT agonist used to treat migraines. Despite DHE being reported as safe and without potential side effects, three cases of neurologic symptoms such as serotonin syndrome have been reported in patients using DHE with other medications for chronic migraine therapy.
The authors conclude that the serotonin syndrome in the patient presented was caused by the administration of intrathecal fentanyl in a patient taking DHE. In addition, MDMA and ephedrine possibly exaggerated the clinical symptoms. |
