Oral 5-aminolevulinic acid induced photodynamic diagnostic ureterorenoscopy - does the blood pressure require monitoring?

Background: Photodynamic Diagnosis has been proven to improve detection of superficial bladder cancer and improve visualisation of resection margins. The use of 5-aminolevulinic acid as the photosensitising agent has been associated with side effects, specifically hypotension. We aimed to evaluate the effect of oral 5-ALA on the blood pressure in a group of patient who underwent Photodynamic Diagnostic Ureterorenoscopy. Methods: We carried out an observational study on all patients who underwent PDD-Ureterorenoscopy with oral 5-ALA between July 2009 and September 2011. Pre-administration, hourly post-administration and hourly post-operative blood pressures were noted. Mean arterial blood pressure and the threshold for cerebral ischaemia were calculated as well. Results: The study includes thirty-eight procedures which involved twenty-four patients with a mean age of 74 (SD ± 16.95). Hypotension was defined as