Hospital-acquired venous thromboembolism during invasive mechanical ventilation in children: a single-center, retrospective cohort study

Background Invasive mechanical ventilation (IMV) has been independently associated with hospital-acquired venous thromboembolism (HA-VTE) among critically ill children, including extremity deep venous thrombosis and pulmonary embolism. Objectives We aimed to characterize the frequency and timing of HA-VTE following IMV exposure. Methods This was a single-center, retrospective cohort study including children aged <18 years, hospitalized in a pediatric intensive care unit, undergoing mechanical ventilation for >24 hours from October 2020 through April 2022. Encounters with an existing tracheostomy or receiving treatment for HA-VTE prior to endotracheal intubation were excluded. The primary outcomes characterized clinically-relevant HA-VTE, including timing after intubation, location, and the presence of known hypercoagulability risk factors. Secondary outcomes were IMV exposure magnitude, defined by IMV duration and ventilator parameters (ie, volumetric, barometric, and oxygenation indices). Results Of 170 consecutive, eligible encounters, 18 (10.6%) experienced HA-VTE at a median of 4 days (IQR, 1.4-6.4) following endotracheal intubation. Those with HA-VTE had an increased frequency of a prior venous thromboembolism (27.8% vs 8.6%, P = .027). No differences in frequency of other HA-VTE risk factors (ie, acute immobility, hematologic malignancy, sepsis, and COVID-19–related illness), presence of a concurrent central venous catheter, or the magnitude of IMV exposure were noted. Conclusion Children undergoing IMV experience HA-VTE at markedly higher rates than previously estimated in the general pediatric intensive care unit population after endotracheal intubation. While prospective validation is needed, these findings are an important step toward informing the development of risk-stratified thromboprophylaxis trials in critically ill children.