Effects of early acute in-bed leg cycling initiated from the intensive care unit following severe traumatic spinal cord injury: final results from the PROMPT-SCI trial

Background: Preclinical studies suggest that initiating activity-based therapy (ABT) within days of an acute spinal cord injury (SCI) best enhances recovery, but may also increase the risk of inducing spinal cord damage. This study assesses the effects of early ABT initiated within 48 h of spinal surgery (or 3 days of the SCI), while patients are in the intensive care unit (ICU) for hemodynamic management. Methods: This single-arm proof-of-concept trial included 45 adults with a severe traumatic SCI receiving daily 30-minute sessions of in-bed leg cycling for 14 consecutive days, in comparison to a matched historical control cohort that did not undergo ABT. Cycling was initiated in the ICU within 48 h of spinal surgery. The main patient outcome was the recovery of independent walking 6 months post-SCI. Secondary outcomes included the rates of complications and other neurofunctional assessments. Results: Recovery of independent walking occurred in 31% of PROMPT-SCI participants and 36% of controls (p = 0.3). Neurological recovery was similar between the two cohorts. The PROMPT-SCI cohort had decreased spontaneous spams (9% vs. 40%, p<10^{− 3}) and co-occurrence of pneumonia, pressure injury and urinary tract infection (P/UTI/PI) (2% vs. 13%, p = 0.03). Readiness for rehabilitation transfer was decreased by 7 days in the PROMPT-SCI cohort, approaching statistical significance (p = 0.051). When adjusting for baseline motor score, spontaneous spasms remained decreased with ABT (p = 0.001; odds ratio = 0.14 [95%CI: 0.04–0.45]), and rehabilitation transfer readiness was shorter (p = 0.03; β=-0.22 [95%CI: -0.41 – -0.04]). However, there was no significant association between concomitant P/UTI/PI and ABT (p = 0.08; Odds ratio = 0.14 [95%CI: 0.02–1.24]). Conclusions: Early acute ABT did not increase the risk for neurological deterioration when initiated in the ICU for patients requiring hemodynamic management. It can decrease the early occurrence of spontaneous spasms, and may potentially reduce the co-occurrence of P/UTI/PI and accelerate rehabilitation transfer readiness. Trial registration: ClinicalTrials.gov identifier NCT04699474 (Registration Date: January 5th 2021).