Obeng EA, Harney KM, Moniz T, Arnold A, Neufeld EJ, Trenor CC. Pediatric heparin-induced thrombocytopenia: prevalence, thrombotic risk, and application of the 4Ts scoring system.
J Pediatr 2015;
166:144-50. [PMID:
25444534 PMCID:
PMC4274245 DOI:
10.1016/j.jpeds.2014.09.017]
[Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/10/2013] [Revised: 08/05/2014] [Accepted: 09/09/2014] [Indexed: 01/19/2023]
Abstract
OBJECTIVE
To characterize heparin-induced thrombocytopenia (HIT) at a single pediatric center including the prevalence and the accuracy of the 4Ts scoring system as a predictor of HIT.
STUDY DESIGN
In this retrospective cohort study, we identified 155 consecutive patients <21 years old with sufficient data for 4Ts scoring. The 4Ts scoring system is a validated pretest tool in adults that predicts the likelihood of HIT using clinical features. Hospital-wide exposure to unfractionated and low molecular weight heparin was determined by querying the hospital pharmacy database.
RESULTS
The majority of patients with suspected HIT (61.2%) were on surgical services. Prediction of HIT risk using initial 4Ts scoring found 3 (2%) had high risk 4Ts scores, 114 (73%) had intermediate risk 4Ts scores, and the remaining 38 (25%) had low risk 4Ts scores. HIT was confirmed in 0/38 patients with low risk 4Ts scores, 2/114 patients with intermediate-risk 4Ts scores, and all 3 patients with high-risk 4Ts scores presented with HIT with thrombosis. Of 12 positive HIT screening tests, results were falsely positive in 66.6% of patients with intermediate risk 4Ts scores and 100% of patients with low risk 4Ts scores. The prevalence of HIT was 0.058% and HIT with thrombosis was 0.046% in pediatric patients on unfractionated heparin.
CONCLUSIONS
The prevalence of HIT appears significantly lower in pediatric patients compared with adults. Application of the 4Ts system as a pretest tool may reduce laboratory evaluation for HIT in heparin-exposed children with low risk 4Ts scores, decreasing unnecessary further testing, intervention, and cost.
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