[A multicenter retrospective study of secondary transport on extracorporeal membrane oxygenation in critically ill children].

<b>Objective:</b> To evaluate the safety and efficacy of secondary transport on extracorporeal membrane oxygenation (ECMO) for critically ill children. <b>Methods:</b> This was a retrospective cohort study. Data from 222 pediatric patients who underwent ECMO transport from May 2019 to May 2024 at 5 ECMO centers and Chinese Database of Pediatric Extracorporeal Life Support Organization were collected. The cases were divided into primary and secondary transport groups by nature of transport. The clinical data, including demographics, ECMO indications, transport distance, pre-transport lab results, prognosis and complications were analyzed. Two independent samples <i>t</i>-test, Wilcoxon test, and <i>χ</i>² test or Fisher's exact probability method were used to compare the differences between 2 groups and evaluate the safety and efficacy of secondary transport. <b>Results:</b> Among the 222 children transported with ECMO, there were 135 males and 87 females, with an age of 3.0 (0.2, 7.0) years. There were 202 cases in the primary transport group and 20 cases in the secondary transport group. All secondary transport patients had failed attempts at weaning ECMO before transfer. The patients in the secondary transport group were older, had higher rates of surgical cannulation, circulatory support, and pre-ECMO lactate levels compared to the primary transport group (7.0 (2.8, 10.0) <i>vs.</i> 3.0 (0.2, 6.0) years old, 55.0% (11/20) <i>vs.</i> 3.6% (7/202), 80.0% (16/20) <i>vs.</i> 41.6% (84/202), (10±4) <i>vs.</i> (7±6) mmol/L, <i>Z=</i>3.41, <i>χ²</i>=66.31, 10.99, <i>t=</i>2.24, all <i>P<</i>0.05). In the secondary transport group, the vasoactive-inotropic scores of patients on circulatory support and the oxygenation index for patients requiring respiratory support were higher than those in the primary transport group (83±33 <i>vs.</i> 82±68, 51.0±1.8 <i>vs.</i> 37.4±10.2, <i>t=</i>2.36, 2.63, respectively; both <i>P<</i>0.05). There were no statistically significant differences between the 2 groups in sex, transport distance, pre-ECMO creatinine, arterial blood gas BE values, and ECMO duration (all <i>P></i>0.05). No life-threatening complications occurred during the transport in either group. Two patients in the secondary transport group underwent heart transplantation, and 1 patient underwent radiofrequency ablation. The overall survival rate between the 2 groups showed no statistically significant difference (45.0% (9/20) <i>vs.</i> 55.4% (112/202), <i>χ</i>²=1.15, <i>P</i>>0.05). <b>Conclusions:</b> Secondary ECMO transport for critically ill children don't increase mortality or life-threatening complications during transport. ECMO patients who cannot receive effective treatment locally can benefit from secondary transport to an advanced ECMO center provides further treatment opportunities.