Preventing blockage of long-term indwelling catheters in adults: are citric acid solutions effective?

Community health practitioners are frequently faced with the problem of indwelling catheters failing to drain. This mini-review examines the evidence regarding the effectiveness of citric acid-based bladder washout solutions (solution G, solution R), compared with saline for preventing blockage of long-term catheters in older adults. Although there is some evidence on the effect of citric acid solutions in laboratory conditions, the search yielded no evidence measuring catheter patency in humans. Only one randomized controlled trial addressing the use of citric acid solutions with human subjects was found. This provided some confirmation that solution G had immediate effect but gave no evidence of long-term benefit. No difference was apparent on examination of catheter tips. As the evidence is weak, practitioners should consider the use of citric acid maintenance solution as non-routine and only following formal evaluation in a one-off trial on appropriate patients.