Long-Term Pulmonary Function Post-Spinal Cord Injury.

OBJECTIVE: To investigate mean values of pulmonary function tests at specific time points to assess long-term progression in patients with spinal cord injury (SCI). DESIGN: Retrospective cohort study from 1997 to 2022. SETTING: National rehabilitation hospital, providing scheduled admission for potential SCI-related issues. Follow-up assessments are recommended annually, guiding the observation period into consecutive one-year intervals. PARTICIPANTS: This study included 1,394 adult patients who were admitted at least twice to the National Rehabilitation Center between 1997 and 2022, selected from an initial pool of 1,510. Overall, 116 patients were excluded due to the absence of any pulmonary function test (PFT) results. INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURE(S): Changes in PFT values over time, specifically assessing for a potential two-phase pattern post-injury. The hypothesis that PFT values would initially improve before declining was formulated based on existing literature. RESULTS: Significant changes in pulmonary function were noted among 1,394 adults with SCI. FVC and FEV1 initially increased within the first 1-2 years post-injury but declined to below baseline levels after 6 years. Pronounced changes occurred between <1 year and 1-2 years post-injury (FVC: Δ = 4.89, SE = 0.87, p < 0.001; FEV1: Δ = 4.28, SE = 1.09, p = 0.002) and 1-2 years to >6 years (FVC: Δ = -5.83, SE = 0.94, p < 0.001; FEV1: Δ = -6.49, SE = 1.18, p < 0.001). No significant changes in the FEV1/FVC ratio. Motor completeness was significantly associated with the increase and decline phase, showing a steeper increase and less decline compared to the motor-incomplete group. CONCLUSIONS: Pulmonary function in SCI initially increases but declines over time, falling below initial levels by 6 years. Further evaluation with more complete datasets is warranted to elucidate factors influencing these changes.