Paucis Verbis: Serotonin syndrome

What exactly IS serotonin syndrome? 

It's caused by the excess of serotonin and presents classically as:

• Altered mental status
• Autonomic instability
• Neuromuscular hyperactivity

Fortunately, there's a nice algorithm (Hunter's decision rule) which helps you decide whether it is serotonin syndrome or not. I also include a table, which I adapted from the New England Journal of Medicine review article on Serotonin Syndrome, which helps you to differentiate it from its mimickers, such as anticholinergic syndrome, neuroleptic malignant syndrome, and malignant hyperthermia.

(click to zoom in)

A video to remind you what clonus looks like:

You can download this PV card:  [MS Word] [PDF]

See other Paucis Verbis cards.

Thanks to Dr. Steve MacDade (Univ of Florida, Jacksonville EM resident) for the idea!

Reference

Ables AZ, Nagubilli R. Prevention, recognition, and management of serotonin syndrome. Am Fam Physician. 2010 May 1;81(9):1139-42. Free AFP text.


Boyer EW, Shannon M. The serotonin syndrome. N Engl J Med. 2005 Mar 17;352(11):1112-20. .