Intra-hospital transport (IHT) of critically ill patients remains a high-risk procedure, particularly in intubated and mechanically ventilated intensive care unit (ICU) patients requiring multiple invasive devices. Data from prospective multicentre studies using standardized definitions of adverse events (AEs) remain limited. This study aimed to determine the prevalence of AEs during IHT and to identify factors associated with their occurrence.

We conducted a prospective multicentre observational study in nine French ICUs. All consecutive IHTs involving intubated and mechanically ventilated adult patients were included. AEs were defined according to the 2011 SFAR recommendations and recorded across five predefined transport phases, from preparation to patient reinstallation. Logistic regression was used to identify factors associated with AE occurrence.

Among 160 analysed transports, at least one AE occurred in 56.4% of IHTs (95% CI 48.6–64.2). Most events were clinical (47.5%); serious AEs were rare (0.6%). The procedural phase accounted for the highest proportion of events (66.7%). In multivariable analysis, AE occurrence was independently associated with neuromuscular blocking agent use (OR 4.0 [1.2–13.5]), ≥4 invasive devices (OR 2.6 [1.1–6.1]), and ≥3 accompanying staff members (OR 2.7 [1.4–5.5]). Emergency status and transport indication were not significantly associated with AE occurrence.

IHT of mechanically ventilated ICU patients is associated with a high rate of AEs, driven primarily by patient severity and procedural complexity. These findings support the need for structured transport protocols and larger multicentre studies to evaluate targeted safety strategies.