Labs in SS

 Q: Which of the following lab best correlates with Serotonin Syndrome (SS)? (select one)

A) Leukocytosis 

B) Creatine phosphokinase (CPK) 

C) Serum bicarbonate 

D) Serum Serotonin level

E) None of the above

Answer: E

The objective of this question is to highlight the fact that serotonin syndrome (SS) is purely a clinical diagnosis and in most cases a diagnosis of exclusion. Diagnosis of SS should be established in conjunction with history, clinical presentation, patient's medications, and physical exam. Serum serotonin level does not correlate with disease severity. 'Hunter's decision rules' is a reliable algorithm for the diagnosis of serotonin toxicity. 

DIC, rhabdomyolysis, lactic acidosis, acute kidney failure, and ARDS are all secondary complications.

#clinical-diagnosis

#neurology

References:

1. Dunkley EJ, Isbister GK, Sibbritt D, Dawson AH, Whyte IM. The Hunter Serotonin Toxicity Criteria; simple and accurate diagnositc decision rules for serotonin toxicity. QJM. 2003;96(9):639. 

2. Scotton WJ, Hill LJ, Williams AC, Barnes NM. Serotonin Syndrome: Pathophysiology, Clinical Features, Management, and Potential Future Directions. Int J Tryptophan Res. 2019;12:1178646919873925. Published 2019 Sep 9. doi:10.1177/1178646919873925 

3. Frank C. Recognition and treatment of serotonin syndrome. Can Fam Physician. 2008;54(7):988-992.