Objective: To determine the association between symptomatic central venous line-related deep venous thrombosis and a mortality-adjusted measure of duration of mechanical ventilation in critically ill children with central venous lines.
Design: Retrospective matched cohort study.
Setting: Eleven pediatric intensive care units across the United States.
Patients: Twenty-nine index critically ill children with central venous line-related deep vein thrombosis from a previous prospective observational study on symptomatic venous thromboembolism were compared with 116 control children with central venous lines without venous thrombosis. Each index patient was matched to four control patients based on age group, disease category, severity of illness score, and number of days in the intensive care unit before central venous line insertion.
Measurements and Main Results: Index patients were appropriately matched to control patients with similar characteristics between the two groups. Index patients had fewer ventilator-free days (ie, days alive and breathing unassisted within 28 days after central venous line insertion) compared with matched control patients (16.8 ± 11.5 days vs. 22.3 ± 4.9 days, p = .040). Index patients also had less intensive care unit-free days (ie, days alive and discharged from the intensive care unit within 28 days after central venous line insertion) (9.8 ± 9.9 days vs. 17.9 ± 5.7 days, p < .001). Durations of mechanical ventilation (17.6 ± 40.6 days vs. 5.2 ± 5.5 days, p = .236) and intensive care unit stay (38.1 ± 61.7 days vs. 11.9 ± 10.9 days, p = .011) were longer in index patients. The mortality rate was statistically similar between the two groups.
Conclusions: The presence of symptomatic central venous line-related deep vein thrombosis is associated with worse outcomes, particularly fewer ventilator-free days, in critically ill children. The causal relationship that deep venous thrombosis leads to impairment in lung function and delays weaning from mechanical ventilation and discharge from the intensive care unit needs to be proven prospectively. Ventilator-free days is a possible alternative outcome measure for future deep venous thrombosis studies.