Incidence and risk factors associated with venous thrombotic events in pediatric intensive care unit patients

Objective: To evaluate the incidence and risk factors associated with venous thromboembolism (VTE) in children admitted to pediatric intensive care units (PICUs). Design: Prospective observational study. Setting: Eleven tertiary care PICUs in the United States. Patients: Children who were admitted to PICUs and had radiographically confirmed VTE over a rolling 6-month period were enrolled in the study. Demographic, patient-related, and outcomes data were collected and compared with all children admitted during the same period. Interventions: None. Results: Sixty-six symptomatic VTE were documented in sixty-two patients among 6653 patients admitted to 11 PICUs. Thirteen (19.7%) of the thrombi were present on admission. The incidence rate was 0.74% (range, 0-2.7% per PICU) with a point prevalence of 0.93%. Doppler ultrasound was most frequently used to diagnose or confirm a suspected VTE. Variables associated with unadjusted risk for VTE include: younger age (3.8 months for patients with VTE vs. 51 months for non-VTE patients, p < .001), cardiac diagnosis (41% in VTE cases vs. 15% in non-VTE, p < .001), pre-/post-operative status (63% in VTE cases vs. 40% in non-VTE, p = .001), presence of central venous catheter (88% in VTE case vs. 17% in non-VTE, p < .001), or mechanical ventilation (85% in VTE cases vs. 30% non-VTE, p < .001). Multivariate analysis showed increased risk of VTE with CVC (odds ratio 6.9; confidence interval 2.7-17.5) and mechanical ventilation (odds ratio 2.8; confidence interval 0.98-7.93). Children with VTE were sicker (Pediatric Index of Mortality 2 score risk of mortality of 3.0% vs. 0.9%; p<0.0001), stayed longer in the ICU (21.2 days vs. 1.6 days; p < .0001) and had increased mortality (10.2% vs. 2.6; p < .0001). Conclusions: Children admitted to the PICU have an increased risk of VTE. The presence of a CVC is the strongest risk factor for VTE in this PICU population. Children with VTE were younger, sicker, stayed longer in PICU, and had a higher mortality rate. (Pediatr Crit Care Med 2011; 12:628-634)