Impact of age, body mass index, and renal function for severe hypotension caused by oral 5-aminolevulinic acid administration in patients undergoing transurethral resection of bladder tumor

Background: Severe hypotension is a notable adverse event caused by administration of 5-aminolevulinic acid (5-ALA) during photodynamic diagnosis-assisted transurethral resection of bladder tumor (PDD-TURBT). Hypotension can be prolonged following induction of anesthesia and may require continuous administration of a vasopressor. Here, we investigated the risk factors for severe hypotension caused by oral administration of 5-ALA. Methods: A total of 128 patients with bladder tumors who underwent PDD-TURBT using 5-ALA were included in this study. Clinicopathological data were collected retrospectively and the correlations between the incidence of severe hypotension and clinicopathological factors were analyzed. Results: Severe hypotension developed in 8 cases (6.3 %). Age >= 80 years, body mass index (BMI) >= 25 (kg/m(2)), and estimated glomerular filtration rate (eGFR) < 45 (mL/min/1.73 m(2)) were significantly correlated with severe hypotension (P = 0.003, 0.017, and 0.027, respectively). Severe hypotension developed in 1 of 89 cases (1.1 %) which have 0 or 1 risk factor, and in 3 of 31 cases (9.7 %) which have 2 risk factors, whereas it developed in 4 of 8 cases (50 %) which have all risk factors. Patients with all risk factors developed severe hypotension significantly more frequently compared with patients with 1 or fewer risk factors (P < 0.001). Conclusion: Age >= 80 years, BMI >= 25, and eGFR < 45 are risk factors for severe hypotension in PDD-TURBT using 5-ALA. The risk of developing severe hypotension is extremely high in patients who have all factors. Adjustment of the 5-ALA dose may be desirable in those patients.