The Hunter Serotonin Toxicity Criteria: simple and accurate diagnostic decision rules for serotonin toxicity.
BACKGROUND
There are difficulties with the diagnosis of serotonin toxicity, particularly with the use of Sternbach's criteria.


OBJECTIVE
To improve the criteria for diagnosing clinically significant serotonin toxicity.


METHODS
Retrospective analysis of prospectively collected data


METHODS
We studied all patients admitted to the Hunter Area Toxicology Service (HATS) following an overdose of a serotonergic drug from January 1987 to November 2002 (n = 2222). Main outcomes were: diagnosis of serotonin toxicity by a clinical toxicologist, fulfillment of Sternbach's criteria and treatment with a serotonin receptor (5-HT(2A)) antagonist. A learning dataset of 473 selective serotonin reuptake inhibitor (SSRI)-alone overdoses was used to determine individual clinical features predictive of serotonin toxicity by univariate analysis. Decision rules using CART analysis were developed, and tested on the dataset of all serotonergic overdose admissions.


RESULTS
Numerous clinical features were associated with serotonin toxicity, but only clonus (inducible, spontaneous or ocular), agitation, diaphoresis, tremor and hyperreflexia were needed for accurate prediction of serotonin toxicity as diagnosed by a clinical toxicologist. Although the learning dataset did not include patients with life-threatening serotonin toxicity, hypertonicity and maximum temperature > 38 degrees C were universal in such patients; these features were therefore added. Using these seven clinical features, decision rules (the Hunter Serotonin Toxicity Criteria) were developed. These new criteria were simpler, more sensitive (84% vs. 75%) and more specific (97% vs. 96%) than Sternbach's criteria.


CONCLUSIONS
These redefined criteria for serotonin toxicity should be more sensitive to serotonin toxicity and less likely to yield false positives.
Dunkley
E J C
EJ
School of Medical Practice and Population Health, University of Newcastle, Newcastle, NSW, Australia.
Isbister
G K
GK
Sibbritt
D
D
Dawson
A H
AH
Whyte
I M
IM
D000704:Analysis of Variance; D001831:Body Temperature / Q000502:physiology; D003657:Decision Making; D003937:Diagnosis, Differential; D003955:Diagnostic Tests, Routine / Q000379:methods*; D006801:Humans; D009122:Muscle Hypertonia / Q000150:complications; D009207:Myoclonus / Q000150:complications; D011595:Psychomotor Agitation / Q000150:complications; D012021:Reflex, Abnormal / Q000502:physiology; D012189:Retrospective Studies; D012680:Sensitivity and Specificity; D012701:Serotonin / Q000506:poisoning*; D017367:Selective Serotonin Reuptake Inhibitors / Q000506:poisoning; D013546:Sweating / Q000502:physiology; D014202:Tremor / Q000150:complications
D012701:Serotonin; D017367:Selective Serotonin Reuptake Inhibitors