4- Serotonin Syndrome Flashcards
What is the serotonin syndrome triad?
- AMS
- Neuromuscular abns
- Autonomic hyperactivity
What is the typical onset for serotonin syndrome?
Rapid- minutes to hrs after initiation of causative agent
How is serotonin syndrome diagnosed?
Clinically- no lab to confirm dx, serotonin/ drug levels not predictive
Labs/ imaging helpful to r/o other causes
What nonspecific lab findings might be noted with serotonin syndrome?
Elevated CPK and myoglobin
What are the Hunter toxicity criteria?
Serotonergic agent AND 1+ of:
- spontaneous clonus
- inducible clonus PLUS agitation/ diaphoresis
- ocular clonus PLUS agitation/ diaphoresis
- tremor PLUS hyperreflexia
- hypertonia PLUS temp > 38C PLUS ocular/ inducible clonus
What is defined as a life threatening neurologic emergency a/w neuroleptic drugs and antiemetics?
Neuroleptic malignant syndrome
What is the classic tetrad a/w neuroleptic malignant syndrome?
FARM
Fever
Autonomic instability
Rigidity (“lead pipe rigidity”)
Mental status changes
What is defined as a potentially life threatening genetic disorder that occurs in susceptible individuals with exposure to anesthesia and succinylcholine?
Malignant hyperthermia
(occurs during/ immediately following anesthesia)
What is the most reliable initial sign of malignant hyperthermia (MH)?
Rapid rise in CO2 resistant to increased ventilation
Early detection/ tx of MH can lead to complete recovery. What is included in the tx?
D/c triggering agent
Dantrolene
How can you differentiate between serotonin syndrome and anticholinergic toxicity?
Anticholinergic toxicity does NOT affect muscle tone or reflexes
How will pupils appear for SS, ACT, NMS, and MH?
SS- mydriasis
ACT- mydriasis
NMS- normal
MH- normal
How will skin appear for SS, ACT, NMS, and MH?
SS- diaphoretic
ACT- red, hot, dry
NMS- diaphoretic
MH- diaphoretic
How will neuromuscular tone appear for SS, ACT, NMS, and MH?
SS- increased (esp LEs)
ACT- normal
NMS- “lead pipe” rigidity
MH- rigidity
How will reflexes appear for SS, ACT, NMS, and MH?
SS- hyperreflexia, clonus
ACT- normal
NMS- hyporeflexia, bradyreflexia (slower onset, slower resolution)
MH- variable
How will mental staus appear for SS, ACT, NMS, and MH?
SS- agitation
ACT- agitation
NMS- agitation, mutism, coma
MH- +/- agitation
What specific drugs have the potential to lead to NMS?
Haldol, Risperdal, Reglan, Phenergan
Pt presents with mydriasis, diaphoresis, increased NM tone especially in LEs, hyperreflexia, clonus, and agitation. What are you concerned for?
Serotonin syndrome
Hx of serotonin drug
Pt presents with mydriasis, red/ hot/ dry skin, normal NM tone, normal reflexes, and agitation. What are you concerned for?
ACT
Hx of anticholingergic drug
Pt presents with normal pupils, diaphoresis, “lead pipe” rigidity, hyporeflexia/ bradyreflexia, agitation, mutism, and coma. What are you concerned for?
NMS
Hx of dopamine antagonists (neuroleptics, anti-emetics)
Pt presents with normal pupils, diaphoresis, rigidity, variable reflexes, +/- agitation. What are you concerned for?
MH
Hx of anesthesia
What is included in the general management of serotonin syndrome?
D/c all serotonin agents
- *Supportive care/ normalize VS**
- no antipyretics agents
- no physical restraints
Sedation w/ benzos
What is the specific management for mild cases of serotonin syndrome?
Close obs x 4-6 hrs
IF mental status/ VS normal, no clonus/ increase in DTR- consider d/c and f/u in 24 hrs with edu for warning signs
What is the specific management for mod-severe serotonin syndrome?
Hospitalization +/- ICU w/ intubation
If temp > 105.9/ critically ill → immediate sedation, paralysis, intubation
What is the antidote for serotonin syndrome and how is it used?
Cyproheptadine (serotonin antagonist/ histamine-1 receptor antagonist)
Use if refractory to combo of supportive care/ benzos (considered adjunct)
