Presented by: Horacio Sanguinetti MD,PhD
Clinica San Camilo

Introduction

Shock wave lithotripsy (SWL) is a primary procedure utilized for the treatment of renal lithiasis measuring less than 2 cm. Unlike alternative lithiasis treatment methods, SWL is typically performed on an outpatient basis, without the need for anesthesia. The Pain Catastrophizing Scale (PCS) is a validated questionnaire that assesses the extent to which patients catastrophize pain based on their prior experiences. The objective of this study is to evaluate the predictive capacity of the pain catastrophizing scale in determining the outcomes of shock wave lithotripsy.

Materials

Prospective enrollment of patients scheduled for SWL occurred between October 1, 2022, and January 31, 2023. The patients' gender and the size of the largest lithiasis in millimeters were documented. On the day of the procedure, patients completed the PCS, consisting of 13 questions with 5 response options, each assigned a value ranging from 0 to 4 points. A single dose of Ketorolac 10 mg was administered to patients, after which the procedure was performed without anesthesia. Following the procedure, patients provided a pain score using a Visual Analog Scale (VAS) ranging from 1 to 10 points. At the 4-week mark, all patients underwent a Computed Tomography evaluation to assess the presence of residual lithiasis, considering fragments larger than 3 mm. The patients were divided into two groups based on their PCS scores: Non-catastrophizers with PCS scores ≤ 14 points and catastrophizers with PCS scores > 14 points. The results were subsequently evaluated using chi-square analysis.

Results

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A total of 46 patients (15 women and 31 men) were evaluated, all presenting kidney stones with an average lithiasis size of 7.15 mm (ranging from 5 to 11 mm). The average PCS score was 13.95 points. Residual lithiasis was detected in 11 patients (23.9%). The non-catastrophizer group (PCS ≤ 14) comprised 35 patients, with an average initial lithiasis size of 7.11 mm and an average VAS score of 4.7 points. Among these patients, 5 were found to have residual lithiasis (17.1%). The catastrophizer group (PCS > 14) consisted of 11 patients, with an average initial lithiasis size of 7.27 mm and an average VAS score of 6.3 points. Within this group, 6 patients exhibited residual lithiasis (45.5%) (p < 0.001).

Conclusion

Our study indicates that patients who exhibit a higher degree of pain catastrophization (PCS > 14) are more likely to experience residual lithiasis following shock wave lithotripsy.

Funding

None

Lead Authors

Guido Angeloni,
Clinica San Camilo

Co-Authors

Maximiliano Lopez Silva,
Clinica San Camilo

Esteban Mauricio Colicigno,
Clinica San Camilo

Norberto Bernardo,
Clinica San Camilo