Clinical question: What is the incidence of hospital-acquired venous thromboembolism (HA-VTE), and which children are at the highest risk?
Background: The incidence of HA-VTE in adults is well documented and has led to extensive efforts to implement a risk-stratified approach to mechanical and pharmacologic prophylaxis. Studies of HA-VTE incidence in children have shown variability in observed incidence depending on the setting (community vs. tertiary care), rate of central venous catheter (CVC) use, and rate of underlying chronic conditions. Overall, as the incidence of HA-VTE has risen dramatically over the past decade, hospitalized children have become increasingly complex and have been subjected to increasing CVC placement. As in adults, pediatric VTE is associated with increased in-hospital mortality and can be associated with post-thrombotic syndrome.
Study design: Single-center, retrospective chart review.
Setting: 205-bed urban tertiary-care children’s hospital.
Synopsis: Using ICD-9 codes associated with deep vein thrombosis and pulmonary embolism, researchers identified potential cases of VTE over a 15-year period. Chart review confirmed the diagnosis of VTE if positive findings were found on compression ultrasound with duplex Doppler, CT angiography, MR venography, or conventional venography, or if the risk of PE was high probability on ventilation-perfusion scans. VTE was defined as hospital acquired if signs, symptoms, and diagnosis of VTE occurred after two days of hospitalization or if VTE was diagnosed ≤90 days after hospital discharge. ICD-9 codes were also used to identify complex chronic conditions (CCCs) and trauma.
Among the 90,485 patient admissions over this time period, 238 patients and 270 episodes of HA-VTE were identified in patients who were ≤21 years old. This yielded a composite rate of 0.3%, but only a 0.2% rate for patients diagnosed during hospitalization. Certain populations manifested a higher rate of HA-VTE. Compared to children two to nine years old, eight-fold higher rates were observed in older adolescents (14-17 years) and young adults (18-21 years), primarily due to non-CVC-associated VTE.
Bottom line: Despite an overall low incidence of hospital-acquired VTE in children under 21 years of age, certain CCCs, such as renal and cardiac diagnoses, were associated with much higher rates. Increasing age, medical complexity, and CVCs were also associated with a higher rate of VTE in the hospital.
Citation: Takemoto CM, Sohi S, Desai K, et al. Hospital-associated venous thromboembolism in children: incidence and clinical characteristics. J Pediatr. 2014;164(2):332-338.
Reviewed by Pediatric Editor Weijen Chang, MD, SFHM, FAAP, associate clinical professor of medicine and pediatrics at the University of California at San Diego School of Medicine, and a hospitalist at both UCSD Medical Center and Rady Children’s Hospital.