Heparin-induced thrombocytopenia type II in a surgical intensive care unit

The aim of this study was to investigate the epidemiology of and outcome from heparin-induced thrombocytopenia type II (HIT) in surgical intensive care unit (ICU) patients.

All 13,948 patients admitted to a university hospital surgical ICU between January 2004 and March 2008 were included in this retrospective cohort study.

Of 349 patients with a clinical suspicion of HIT, 88 patients had platelet factor 4/heparin antibodies using enzyme-linked immunosorbent assay. The prevalence and incidence of HIT were 0.82% and 0.63%, respectively. The complication rate was 43.5%, and the ICU and hospital mortality rates were 23.9% and 33%, respectively. In a multivariable analysis, the nadir platelet count (odds ratio, 1.03; 95% confidence interval, 1.01-1.05; P = .048) was the only factor independently associated with risk of death in these patients. In a nested matched case-control analysis, mortality rates were similar in patients with HIT and in the matched controls. However, complication rates were higher, and ICU and hospital lengths of stay were longer in patients with HIT compared with those of the control group.

In this cohort of surgical ICU patients, HIT was associated with increased morbidity but not mortality rates compared with a nested matched control group. The nadir platelet count was independently associated with a higher risk of in hospital death in these patients.