Intraoperative hypotension caused by oral administration of 5-aminolevulinic acid for photodynamic diagnosis in patients with bladder cancer

Objective: To analyze perioperative blood pressure in patients undergoing transurethral resection of bladder tumor with photodynamic diagnosis.

Methods: A total of 109 consecutive patients who underwent photodynamic diagnosis-assisted transurethral resection of bladder tumor at Kanazawa University, Kanazawa, Ishikawa, Japan, were included in this study and considered as the photodynamic diagnosis group. Clinical data were collected, and perioperative systolic bladder pressure and vasopressor usage were analyzed. In contrast, consecutive patients who previously underwent conventional transurethral resection of bladder tumor (without the use of oral 5-aminolevulinic acid) were used as the control group.

Results: The systolic blood pressure before anesthesia, lowest systolic blood pressure from the anesthesia induction to the start of operation and lowest systolic blood pressure during operation were significantly lower in the photodynamic diagnosis group. The rate of vasopressor use was significantly higher in the photodynamic diagnosis group. On multivariate analysis, we found that general anesthesia and regular use of renin-angiotensin system inhibitor were associated with an increased risk of hypotension (lowest systolic blood pressure from the anesthesia induction to the start of operation <80 mmHg).

Conclusions: Oral intake of 5-aminolevulinic acid can obviously cause a drop in intraoperative blood pressure in patients undergoing transurethral resection of bladder tumor. Therefore, urologists and anesthesiologists should consider withdrawal of renin-angiotensin system inhibitors and monitor the blood pressure during photodynamic diagnosis-assisted transurethral resection of bladder tumor.