ICU Conference 3/28/12 Follow-Up: Serotonin Syndrome and NMS
Pt on “multiple psychiatric medications” presents to the ER “acting strangely”… after doing a physical exam and excluding other potential causes, your primary differential includes…
Serotonin Syndrome
Epidemiology: Occurs in 15% of patients who overdose on SSRI’s
Pathophys: Excess serotonergic activity due to inhibition of reuptake and metabolism of serotonin
Most common causes: SSRI’s/ SNRI’s, TCA’s, MAO-I’s, MDMA, Lithium, anti-emetics
Presentation: Clinical Triad – AMS, autonomic instability/ hyperactivity, neuromuscular rigidity. “Wet dog shakes”
Making the Diagnosis: Primarily clinical; Can also use Hunter criteria
Treatment: Benzodiazepines and cooling if necessary! Also consider: Cyproheptadine and Chlorpromazine (serotonin antagonist). Consider paralyitcs for severe cases.
NMS
Epidemiology: Typically occurs in the first month of treatment with anti-psychotics; Approximately .02% incidence in all pts on anti-psychotics. Highest risk with high doses and high potency medications and parenteral administration.
Pathophys: Dopamine antagonism
Symptoms: Altered mental status, muscle rigidity, hyperthermia, autonomic instability. Typically develop over hours to days
Treatment: Treat the hyperthermia aggressively – cooling blankets, ice packs, cooled saline, ice bath. Dantrolene (muscle relaxant), Bromocriptine, and Benzodiazepines for agitation.
Serotonin Syndrome | NMS |
Hyperkinetic | Bradykinetic |
Lower extremities primarily | All muscle groups involved |
Clonus, Hyperreflexia | Rigidity |
Excess serotonin | Dopamine antagonism |
<12 hrs onset after agents | 1-2 days onset |
Primary treatments for both: Withdraw offending agensts, supportive care with benzodiazepines and cooling! (Always call the tox center)
References:
(You will need your Downstate library passwords to access some of these articles)
Boyer et al. The Serotonin Syndrome. NEJM 352;11. March 17, 2005.
Hoffman RJ. Chapter 41. The Critically Ill Poisoned Patient. In: Farcy DA, Flaxman A, Marshall JP, Chiu WC, eds. Critical Care Emergency Medicine. New York: McGraw-Hill; 2012.
Juurlink DN. Chapter 69. Antipsychotics. In: Hoffman RS, Nelson LS, Goldfrank LR, et al, eds. Goldfrank’s Toxicologic Emergencies. 9th ed. New York: McGraw-Hill; 2011.
Emedicine – Neuroleptic Malignant Syndrome
Emedicine – Serotonin Syndrome
zinas
Latest posts by zinas (see all)
- EBM: 4/2/2012 - April 2, 2012
- Wednesday Wrap-up: ICU Conference 3/28/2012 - March 29, 2012