Risk factors for hospital-associated venous thromboembolism in critically ill children following cardiothoracic surgery or therapeutic cardiac catheterisation.

BACKGROUND: Paediatric hospital-associated venous thromboembolism is a leading quality and safety concern at children's hospitals. OBJECTIVE: The aim of this study was to determine risk factors for hospital-associated venous thromboembolism in critically ill children following cardiothoracic surgery or therapeutic cardiac catheterisation. METHODS: We conducted a retrospective, case-control study of children admitted to the cardiovascular intensive care unit at Johns Hopkins All Children's Hospital (St. Petersburg, Florida, United States of America) from 2006 to 2013. Hospital-associated venous thromboembolism cases were identified based on ICD-9 discharge codes and validated using radiological record review. We randomly selected two contemporaneous cardiovascular intensive care unit controls without hospital-associated venous thromboembolism for each hospital-associated venous thromboembolism case, and limited the study population to patients who had undergone cardiothoracic surgery or therapeutic cardiac catheterisation. Odds ratios and 95% confidence intervals for associations between putative risk factors and hospital-associated venous thromboembolism were determined using univariate and multivariate logistic regression. RESULTS: Among 2718 admissions to the cardiovascular intensive care unit during the study period, 65 met the criteria for hospital-associated venous thromboembolism (occurrence rate, 2%). Restriction to cases and controls having undergone the procedures of interest yielded a final study population of 57 hospital-associated venous thromboembolism cases and 76 controls. In a multiple logistic regression model, major infection (odds ratio=5.77, 95% confidence interval=1.06-31.4), age ⩽1 year (odds ratio=6.75, 95% confidence interval=1.13-160), and central venous catheterisation (odds ratio=7.36, 95% confidence interval=1.13-47.8) were found to be statistically significant independent risk factors for hospital-associated venous thromboembolism in these children. Patients with all three factors had a markedly increased post-test probability of having hospital-associated venous thromboembolism. CONCLUSION: Major infection, infancy, and central venous catheterisation are independent risk factors for hospital-associated venous thromboembolism in critically ill children following cardiothoracic surgery or cardiac catheter-based intervention, which, in combination, define a high-risk group for hospital-associated venous thromboembolism.

Development of a new risk score for hospital-associated venous thromboembolism in noncritically ill children: findings from a large single-institutional case-control study.

OBJECTIVE: To determine risk factors for pediatric hospital-associated venous thromboembolism (HA-VTE) in noncritically ill children to derive a novel HA-VTE risk model for this population. STUDY DESIGN: Patients with HA-VTE were identified retrospectively via the electronic health record at All Children's Hospital Johns Hopkins Medicine from April 10, 2013 through January 1, 2006. Seven contemporaneous, noncritically ill control children were randomly selected for each case of HA-VTE. The association between putative risk factors and HA-VTE was estimated with ORs and 95% CIs, which were calculated using the Wald method. A P-value threshold ≤.2 was used in univariate analysis for inclusion into a multivariate (adjusted) model. RESULTS: Fifty cases of HA-VTE occurred in noncritically ill children. The presence of a central venous catheter (OR 27.67, 95% CI, 8.40-91.22), infection (OR 10.40, 95% CI, 3.46-31.25), and length of stay ≥4 days (OR 5.26, 95% CI, 1.74-15.88) were found to be statistically significant risk factors for HA-VTE. An 8-point risk score was derived in which scores of 8 points, 7 points, and ≤6 points corresponded to venous thromboembolism risks of 12.5%, 1.1%, and 0.1%, respectively. CONCLUSION: The presence of a central venous catheter, infection, and length of stay ≥4 days are significant risk factors for HA-VTE in noncritically ill children, forming the basis for a new risk score that could inform venous thromboembolism prophylaxis decision-making. These findings warrant prospective validation.

Development of a new risk score for hospital-associated venous thromboembolism in critically-ill children not undergoing cardiothoracic surgery.

BACKGROUND: Although risk of hospital-associated venous thromboembolism (HA-VTE) differs between critically and non-critically ill children, studies to date have not led to distinct, pragmatic risk scores. OBJECTIVE: To determine risk factors for HA-VTE in critically ill children not undergoing cardiothoracic surgery, in order to derive a novel HA-VTE risk score for this population. METHODS: We conducted a retrospective analysis from January 2006 through April 2013 at All Children's Hospital Johns Hopkins Medicine. HA-VTE cases were identified using ICD-9 discharge diagnosis codes, with subsequent validation via radiologic record review. Cases were restricted to Pediatric Intensive Care Unit (PICU) admissions. Patients who underwent cardiothoracic surgery were excluded; cardiac catheterization per se was not exclusionary. For each case, three non-HA-VTE PICU controls were randomly selected. Data were abstracted on putative risk factors, and associations between risk factors and HA-VTE were estimated using odds ratios (ORs) and 95% confidence intervals (95%CIs). RESULTS: There were 57 HA-VTE cases and 171 controls. HA-VTE occurrence was 3 per 1000 PICU admissions (0.3%). Central venous catheter (CVC) (OR:26.64; 95%CI:7.46-95.13), length of stay (LOS) ≥4days (OR:20.22; 95%CI:2.27-180.07), and significant infection (OR:3.41; 95%CI:1.13-10.29) were independent, statistically-significant risk factors for HA-VTE in a multivariate model. A risk score was derived in which HA-VTE risk exceeded 2% (threshold for anticoagulant thromboprophylaxis in hospitalized adults) with a score of 15, and was >1% but <2% (risk zone for mechanical thromboprophylaxis in hospitalized adults) with scores of 7-14. CONCLUSION: The presence of a CVC, LOS≥4days and infection are significant risk factors for HA-VTE in critically ill children not undergoing cardiothoracic surgery, forming the basis for a new risk score that warrants prospective validation.

Risk factors for hospital-sssociated venous thromboembolism in the neonatal intensive care unit.

OBJECTIVE: To determine hospital-associated venous thromboembolism (HA-VTE) risk factors in critically ill neonates. METHODS: We conducted a case-control study in the neonatal intensive care unit (NICU) of All Children's Hospital Johns Hopkins Medicine (St. Petersburg, FL), from January 1, 2006 - April 10, 2013. We identified HA-VTE cases using electronic health record. Four NICU controls were randomly selected for each HA-VTE case. Associations between putative risk factors and HA-VTE were estimated using odds ratios (ORs) and ninety-five percent confidence intervals (95%CIs) from univariate and multivariate regression analyses. RESULTS: Twenty-three HA-VTE cases and 92 controls were included. The annual HA-VTE incidence was approximately 1.4 HA-VTE cases per 1,000 NICU admissions. In univariate analyses, mechanical ventilation (OR=7.27, 95%CI=2.02-26.17, P=0.002), central venous catheter (CVC; OR=52.95, 95%CI=6.80-412.71, P<0.001), infection (OR=7.24, 95%CI=2.66-19.72, P<0.001), major surgery (OR=5.60, 95%CI=1.82-17.22, P=0.003) and length of stay ≥15days (OR=6.67, 95%CI=1.85-23.99, P=0.004) were associated with HA-VTE. Only CVC (OR=29.04, 95%CI=3.18-265.26, P=0.003) remained an independent risk factor in the multivariate analysis. Based on this result, the estimated risk of HA-VTE in NICU patients with a CVC was 0.9%. CONCLUSION: This study identifies CVC as an independent risk factor for HA-VTE in critically ill neonates. However, the level of risk associated with CVC is below the conventional threshold for primary anticoagulation thromboprophylaxis. Larger studies are needed to substantiate these findings and identify novel putative risk factors to further distinguish NICU patients at highest HA-VTE risk.