Feasibility of short-term supine rehabilitation for pediatric orthostatic intolerance: a case series.

[Purpose] This pilot feasibility case series examined the safety, tolerability, and implementability of a short-term inpatient supine exercise program using a low-load bicycle ergometer in pediatric patients with orthostatic intolerance (OI). [Participants and Methods] Four adolescents with OI who had difficulty attending school participated in a 10-13-day inpatient rehabilitation program. The intervention consisted of daily supine ergometer exercise (5-min warm-up, 15-min active pedaling, 5-min cool-down). Feasibility outcomes included completion rate, adherence, and adverse events. Exploratory clinical outcomes included heart rate (HR) response during standing tests, perceived exertion using a 100-mm visual analog scale (VAS), and school attendance two weeks after discharge. [Results] All participants completed the program without adverse events, demonstrating good feasibility and safety. Adherence to supervised sessions was high, and all patients performed self-training. Improvements in perceived exertion were observed in all cases, whereas changes in HR responses were variable. School attendance improved in three patients, although only two were able to attend more than three days per week. [Conclusion] A short-term supine ergometer program appears feasible, safe, and well tolerated in pediatric patients with OI. Given the small sample size, lack of controls, and reliance on subjective outcomes, these findings should be interpreted cautiously.