Editorial Note on: Spinal Cord advance online publication, 11 September 2012; doi:10.1038/sc.2012.107

Urodynamic investigations are the most important diagnostic tool for neurogenic lower urinary tract dysfunction in patients with spinal cord injury (SCI). However, the examination is invasive, as insertion of a catheter is required. The authors therefore investigate a relevant problem: do we need prophylactic antibiotics in patients undergoing urodynamic testing?

It is difficult to understand why the authors chose inpatients for the study, as the risk for urinary tract infections (UTIs) is generally higher for hospitalized patients. For example, in acute SCI patients, intermittent catheterization has not always been firmly established, making handling errors probable. This is reflected by the fact that UTI were less frequent in patients catheterized by attendants than in those performing self-catheterization.

The authors conclude that prophylactic antibiotics are not needed, as 15.8% of the patients undergoing urodynamics develop UTI. I draw a different conclusion. One should bear in mind that UTIs are associated with a high morbidity and even mortality, and that complete eradication of bacteriuria, once acquired, is a difficult task. If you can prevent UTI in 9–16% of patients by antibiotic prophylaxis, this is in my eyes a good risk-benefit ratio, better than for most other preventive measures commonly used in medicine.

Furthermore, the authors propose that certain subgroups, namely patients with reflex voiding and patients with significant bacteriuria may be at a higher risk to acquire UTI than others. Unfortunately, the study population was too small to allow any significant subgroup analyses.

In conclusion, the study underlines that the question if to use antibiotic prophylaxis prior to urodynamics can only be settled by a large, randomized prospective study. Until then, unfortunately, the quotation from Bertold Brechts famous play, The good person of Szechwan, still applies: ‘The curtain closed and all the questions open.’