Oral 5-aminolevulinic acid administration prior to transurethral resection of bladder tumor causes intraoperative hypotension: Propensity score analysis.

BACKGROUND

Transurethral resection of bladder tumor (TUR-BT) using 5-aminolevulinic acid (5-ALA) is common; however, intraoperative hypotension is frequent. This study aimed to investigate the impact of preoperative oral 5-ALA taking on hypotension and vasopressors dose during general anesthesia, and postoperative nausea and vomiting.

METHODS

This retrospective study included patients aged ≥ 20 years who had undergone elective TUR-BT for bladder tumors under general anesthesia. An inverse probability of treatment weighted using stabilized inverse propensity scores was adopted to minimize bias. After adjustment based on patient data, outcomes of interest in patients with and without preoperative administration of 5-ALA were compared using a generalized estimating equation. Primary outcomes were hypotension incidence during anesthesia, which was defined as a mean arterial pressure < 60 mmHg, and the impact of 5-ALA administration on hypotension.

RESULTS

Of 324 patients considered, 153 (47.2 %) received 5-ALA preoperatively. The weighted incidence of hypotension was 23.3 % in patients taking 5-ALA, with an odds ratio of 4.21 (95 % confidence interval 2.07-8.55). Odds ratios (ORs) and 95 % confidence intervals for oral 5-ALA administration were 1.55 (1.23-1.96) for ephedrine, 1.18 (0.66-2.11) for phenylephrine, and 12.3 (5.73-26.5) for postoperative nausea and vomiting.

CONCLUSIONS

Preoperative oral 5-ALA administration was associated with hypotension during general anesthesia in patients who underwent TUR-BT despite receiving higher doses of ephedrine. Postoperative nausea and vomiting were also more common in these patients.