Feasibility and safety of passive orthostatic positioning in mechanically ventilated ICU patients: A prospective observational study

Early mobilization strategies are essential for preventing intensive care unit (ICU) - acquired complications. However, the feasibility of passive orthostatism in mechanically ventilated patients remains underexplored. This study evaluates the safety and acute physiological effects of passive orthostatic positioning using an orthostatic board in critically ill patients undergoing invasive mechanical ventilation. A single-group exploratory study was conducted in an ICU setting with 13 adult patients. Each patient underwent a single passive orthostatic session using a motorized orthostatic board. Physiological (hemodynamics and ventilatory mechanics) and neurological (glasgow coma scale [GCS]) parameters were measured at 3 time points: pre-intervention, immediately post-intervention, and 20 minutes after upright positioning. A repeated-measures linear mixed model with Kenward-Roger correction and permutation testing was used for analysis. The study included 13 ICU patients (mean age 60.92 ± 14.53 years; 53.8% male). Significant improvements were observed in the tidal volume (VT), driving pressure, and GCS scores across the 3 time points. Driving pressure decreased markedly (P <.001), whereas GCS score increased significantly (P <.001). The heart rate also showed a significant increase at 20 minutes (P = .019). No significant changes were noted in mean arterial pressure, SpO2, or respiratory rate. No adverse events occurred during the study. Passive orthostatism using an orthostatic board is a safe and feasible early mobilization strategy for mechanically ventilated ICU patients. This resulted in improved ventilatory mechanics and level of consciousness, without hemodynamic instability or complications. These findings support further investigations of orthostatic positioning as a complementary tool for ICU rehabilitation.