Bladder stones in catheterized spinal cord-injured patients in Nigeria

Objective: The objective was to determine the incidence of bladder stones in patients with spinal cord injury (SCI) and to assess if catheter encrustation or positive urinary culture of Proteus mirabilis is predictive of bladder stones. Background: Bladder stones are common urological complication in those with SCI managed with indwelling urinary catheter. Detection and removal of bladder stones are important to prevent possible further complications. Design: This was a prospective cohort study. Materials and Methods: Ultrasound scan was performed in persons with SCI seen from 1st January to 31st December 2009 who had indwelling urethral catheter for at least 3-month post-injury. Indwelling urethral catheters were examined for encrustation at the time of removal, urine culture taken specifically for P. mirabilis and ultrasound scan done to detect bladder stones. Results: There were 89 patients with spinal cord injury and 68 (76.4%) patients were evaluated during the review period. Twenty-nine (42.6%) patients had bladder stones and 22 (32.3%) patients had catheter encrustation. Of the 22 patients with catheter encrustation, 19 (86.3%) also had bladder stones. Forty-six (67.6%) patients had no catheter encrustation. Of these, 7 (14.7%) were found to have bladder stones. Thirty-seven (38.2%) urine cultures were positive for P. mirabilis. Of these 37 (54.4%) patients, 27 also had bladder stones. Catheter encrustation (P = 0.004) and a positive urine culture of P. mirabilis (P = 0.007) in patients with indwelling urinary catheter is highly predictive of the presence of bladder stone. Conclusions: This study shows that a large number of SCI patients have an indwelling urethral catheter and suggests that ultrasound scan for the presence of stone should be schedule in a catheterized SCI patient if catheter encrustation or a positive urine culture of P. mirabilis is noted.