Forty-five-year follow-up on the renal function after spinal cord injury.

STUDY DESIGN: Retrospective chart review. OBJECTIVES: To investigate the extent of renal deterioration in patients with spinal cord injury (SCI) and to identify risk indicators associated with renal deterioration. SETTING: Clinic for Spinal Cord Injuries, Rigshospitalet, Hornbæk, Denmark. METHODS: This study included 116 patients admitted to our clinic with a traumatic SCI sustained between 1956 and 1975. Results from renography and (51)Cr-EDTA plasma clearance were collected from medical records from time of injury until 2012, and the occurrence of renal deterioration was analysed by cumulative incidence curves. The impact of demographics, neurological level and completeness of SCI, urinary tract stones, dilatation of the upper urinary tract (UUT) and bladder-emptying methods were analysed with Cox proportional hazard ratios. RESULTS: The bladder-emptying methods used for the longest period were reflex triggering (63%), bladder expression (22%), indwelling catheter (5%), normal voiding (4%), ileal conduit (3%) and clean intermittent catheterisation (2%). The cumulative risk of moderate renal deterioration (functional distribution outside 40-60% on renography or relative glomerular filtration rate (GFR) ⩽75% of expected according to age and gender) was 58%. The cumulative risk of severe renal deterioration (functional distribution outside 30-70% on renography or relative GFR⩽51%) was 29% after 45 years postinjury. Only dilatation of UUT and renal/ureter stone requiring removal significantly increased the risk of moderate and severe renal deterioration. CONCLUSION: Renal deterioration occurs at any time after injury, suggesting that lifelong follow-up examinations of the renal function are important, especially in patients with dilatation of UUT and/or renal/ureter stones.

50 years follow-up on plasma creatinine levels after spinal cord injury.

STUDY DESIGN: Retrospective chart review. OBJECTIVES: To investigate the role of plasma creatinine (p-creatinine) in monitoring renal deterioration in patients up to 50 years after spinal cord injury (SCI). SETTING: The Clinic for Spinal Cord Injuries, Rigshospitalet, Denmark. METHODS: A total of 119 patients with a traumatic SCI during the years 1944-1975 were included in the study. P-creatinine measurements, results from renography and glomerular filtration rate (GFR) measured with 51Cr-EDTA clearance were obtained from medical records and analyzed using a linear mixed model and linear regression analyses. RESULTS: When compared with median p-creatinine level in the first 5-year period after injury, the level of p-creatinine was stable throughout the first 30 years and decreased significantly after the 30th until 45th year post injury. Only patients with a functional distribution outside the 30-70% limits on renography or a relative GFR < or =51% of that expected had a significantly elevated level of p-creatinine. Significance was not found for patients with a distribution outside the 40-60% limits on renography or relative GFR < or =75%. By comparing Cr-EDTA clearance and p-creatinine in terms of exceeding the upper reference level, p-creatinine revealed 17% sensitivity, 100% specificity, 100% positive predictive value and 73% negative predictive value as a diagnostic test for renal deterioration defined as GFR < or =75%. CONCLUSION: P-creatinine decreases over time in patients with SCI with a level below the upper reference limit and is a poor detector of early renal deterioration in patients with SCI.