Serotonin Syndrome Flashcards
Pathophys of serotonin syndrome
Increased serotonergic activity in CNS
Serotonin is NT in GI tract, platelets and in CNS (well-being, attention, behavior, thermoregulation, clotting)
Overactivation of serotonin at postsynaptic receptors
Cause of serotonin syndrome
Simultaneous administration of 2 (or more) serotonergic agents
Can even be with initiation of 1 serotonergic drug or after increased dosing
Serotonergic agents
Increase release of serotonin (meth, cocaine, E, levodopa)
Impairing reuptake (cocaine, E, meperidine, SSRIs, tramodol, SNRIs, TCAs, antiemetics, dextromethorphan, cyclbenzaprine)
Inhibit metabolism (MAOis)
Agonist (busprione, triptans, ergots, fentanyl)
Lithium (sensitivity of postsynaptic receptor)
Triad of serotonin syndrome
AMS
Neuromuscular abnormalities
Autonomic hyperactivity
(within mins to hours of agent)
AMS changes in serotonin syndrome
Agitation Anxiety Disorientation Restlessness Excitement Startle easily
Neuromuscular abnormalities in serotonin syndrome
Tremors Clonus Hyperreflexia Muscle rigidity \+bilteral Babinski Akasthisia (needs to be in motion)
Autonomic hyperactivity of serotonin syndrome
HTN, tachycardia/pnea, hyperthermia, shivering, vomiting, diarrhea, diaphoresis, dry mucous, flushed, hyperactive BS, mydriasis, arrhythmias
Labs or imaging in serotonin syndrome
No lab to confirm
Serum levels don’t predict if have it
Labs: cBC, CMP, culture, UA, CSF, TSH, tox screen
May see elevated CPK or myoglobin (nonspecific)
Hunter toxicity criteria
Pt must have taken a serotonergic agent AND have 1:
Spontaneous clonus
Inducible clonus PLUS agitation or diaphoresis
Ocular clonus PLUS agitation or diaphoresis
Tremor PLUS hyperrefelxia
Hypertonia PLUS temp >38 C PLUS ocular clonus or inducible clonus
What is neuroleptic malignant syndrome associated with?
Antipsychotics (Haldol, Risperdal, Reglan, Phenergan)
Anti-emetics
Tetrad of neuroleptic malignant syndrome
FARM Fever Autonomic instability Rigidity Mental status changes
Things to differentiate NMS from serotonin syndrome
Hyporeflexia and bradyreflexia
Slower onset and slower resolution (Days to weeks)
Use bromocriptine for tx
When do you see malignant hyperthermia?
Genetic ppl (inherited autosomal dominant disorder) with exposure to anesthesia and succinylcholine (during or right after)
Why does malignant hyperthermia happen?
Uncontrolled release of large quantities of Ca from muscle leading to hypermetabolic state
Most reliable sign of malignant hyperthermia
Rapid rise in CO2 resistant to increased ventilation
Presentation of malignant hyperthermia
Muscle rigidity
Tachycardia
Hyperthermia
(can become DIC and organ failure)
Tx of malignant hyperthermia
Discontinue agent
Administer dantrolene to block Ca release
How to differentiate anticholinergic toxidrome from serotonin syndrome
Anticholinergic does not affect muscle tone or reflexes! (red as a beet, dry as a bone, blind as a bat, hot as a hare, mad as a hatter)
Management of seretonin syndrome
Discontinue all agents
Support to normalize vitals (O2, fluids, cardiac monitor, no restraints)
Sedate with benzos (control agitation and correct BP/ HR)
Antipyretics for serotonin syndrome?
No b/c elevated temp is due to increase in muscular activity rather than hypothalamic temp set point
Mild management of serotonin syndrome
Observe 4-6 hrs
Eliminate agent
If mental status, VS normal and no clonus or increase in DTRs, may d/c and f/u in 24 hrs
Moderate/severe management of serotonin syndrome
Hospital (ICU with intubation)
Management for pts with temp >41.1 C (105.9 F)
Critically ill so immediate sedation, paralysis and intubation
What is cyproheptadine and when use?
Serotonin antagonist/ Histamine 1 receptor antagonist
Use if combo of supportive care and benzos don’t improve sxs (adjunct!!)
