Predicting procedural pain after ureteroscopy: does hydrodistention play a role?

Zeynep Gul, Kareem Alazem, Ina Li, Manoj Monga

To identify perioperative predictors of immediate pain after ureteroscopy, specifically evaluating the impact of hydrodistention from irrigation on pain. We retrospectively identified patients who underwent ureteroscopy for the treatment of calculi. Data recorded for these patients included their maximum pain score in the post-anesthesia care unit (PACU), average flow rate of irrigant used during the procedure, patient and stone characteristics, operative procedure, and details of patients' immediate, post-operative course. Spearman's rho was used to determine the relationship between non-parametric, continuous variables. Then, a linear regression was performed to assess which variables could predict the peak pain score. A total of 131 patients were included in the study. A non-parametric correlation analysis revealed that maximum pain score was negatively correlated with being male (r = -0.18, p=0.04), age (r = -0.34, p<0.001), and post-op foley placement (r = -0.20, p=0.02) but positively correlated with the preoperative pain score (r = 0.41, p<0.001), time in the PACU (r = 0.19, p = 0.03), and the morphine equivalent dose (MED) of narcotics administered in the PACU (r = 0.67, p<0.001). On linear regression, the significant variables were age, preoperative pain score, and stent placement. For every ten-year increase in age post-operative pain score decreased by 4/10 of a point (p = 0.03). For every 1 point increase in preoperative pain score there was a 3/10 of a point increase in the maximum pain score (p = 0.01), and leaving a stent in place post-operatively was associated with a 1.6 point increase in the maximum pain score. Hydrodistention does not play a role in post-ureteroscopy pain. Patients who are younger, have higher preoperative pain scores, or who are stented will experience more post-operative pain after ureteroscopy.