Risk factors for moderate-to-severe postoperative pain after percutaneous nephrolithotomy: a retrospective cohort study

Percutaneous nephrolithotomy (PCNL) is a minimally invasive procedure for removing renal calculi, while a large number of patients experience acute moderate-to-severe pain despite the analgesia provided. This study aimed to explore the risk factors for postoperative pain after PCNL, which may provide a novel perspective to refine the enhanced recovery after surgery (ERAS) program and to improve clinical outcomes. The clinical data of 331 patients who underwent PCNL in our hospital from September 2020 to February 2021 were retrospectively analyzed. The pain intensity was assessed every 4 h until 24 h post-surgery. According to the visual analog scale (VAS) score, patients were divided into two groups: mild or no pain group (VAS score, 0–3) and moderate-to-severe pain group (VAS score, 4–10). The pre-, peri-, and post-operative data were collected and analyzed. The indicators with statistically significant differences were selected, and multivariate logistic regression analysis was employed to determine the risk factors for postoperative pain after PCNL. Among 331 patients, 221 patients had moderate-to-severe pain and the incidence rate was 66.77%. Multivariate logistic regression analysis showed that the independent risk factors for moderate-to-severe pain after PCNL were the diameter of the renal calculus (odds ratio (OR) = 6.23, 95% confidence interval (CI) 2.50–15.56, P = 0.001), the number of renal calculi (OR = 15.892, 95% CI 7.721–32.711, P < 0.01), the presence of residual calculi (OR = 1.780, 95% CI 0.897–3.533, P = 0.01), and operation time (OR = 1.033, 95% CI 1.020–1.046, P < 0.01). The diameter of the renal calculus, the number of renal calculi, the presence of residual calculi, and operation time were significant predictors of postoperative pain after PCNL.