Perirenal Bupivacaine Infiltration for Post-Procedure Pain Control in Percutaneous Nephrostomy Tube Insertion

Purpose

To determine whether use of a long-acting local anesthetic (bupivacaine), compared with lidocaine, improves early post-procedure pain control when used for perinephric local anesthesia.

Hypothesis

We hypothesize that patients undergoing percutaneous nephrostomy tube placement will report lower pain scores during immediate post-procedure recovery when bupivacaine, rather than lidocaine, is used for perinephric local anesthesia.

Justification

Lidocaine alone remains the standard local anesthetic for perinephric infiltration during percutaneous nephrostomy tube placement, but its analgesic effects are relatively short-lived. Bupivacaine offers longer-lasting analgesia, with local infiltration typically providing 4-8 hours of relief compared with 0.5-2 hours for lidocaine. (1,2)

Several randomized controlled trials (RCTs) in percutaneous nephrolithotomy have evaluated infiltration of 20 mL of 0.25% bupivacaine along the nephrostomy tract, from the renal capsule to the skin. These studies reported lower postoperative pain scores and reduced analgesic requirements, including a longer time to first opioid request, lower total opioid consumption over 48 hours, and lower visual analogue scale (VAS) pain scores at multiple postoperative time points. (3,4,5)

Evidence from laparoscopic surgery also supports the analgesic benefits of local bupivacaine infiltration. A meta-analysis of 20 RCTs in gynecologic laparoscopy (n = 1,861) found reduced pain at 4 and 6 hours following port-site local anesthetic infiltration. (6) A multicenter, double-blind RCT of laparoscopic hysterectomy (n = 108) found that subcutaneous port-site infiltration with 0.5% bupivacaine reduced pain scores through 48 hours and decreased rescue analgesic use. (7) Similarly, combined cystic plate and port-site injection of 0.25% bupivacaine reduced early postoperative pain following laparoscopic cholecystectomy. (8)

In the Edmonton Zone, interventional radiologists who have used bupivacaine for perinephric infiltration during nephrostomy tube placement report improved postprocedural pain control compared with lidocaine. To our knowledge, no study has specifically evaluated perirenal bupivacaine infiltration for pain control following percutaneous nephrostomy tube insertion. A prospective, randomized controlled study with blinded outcome assessment is therefore warranted to determine whether bupivacaine provides significantly better postprocedural pain control than lidocaine. The findings may guide local anesthetic selection and ultimately improve patient comfort during recovery from nephrostomy tube placement.

Objectives

The primary objective is to determine whether perinephric infiltration of bupivacaine, compared with lidocaine, improves early post-procedure pain control in patients undergoing percutaneous nephrostomy tube placement, as measured by pain scores during immediate recovery.

Research Methods

This will be a prospective, randomized, controlled study with single-blinded outcome assessment within the Edmonton Zone Interventional Radiology service.

Patients referred to the interventional radiology service who meet the established clinical indications for percutaneous nephrostomy tube placement will be considered for enrollment. Upon arrival in the pre-procedural area, patients will first undergo the standard clinical consent process for the medically indicated nephrostomy procedure. Clinical consent will be documented in the patient's health record in accordance with local institutional policy. This clinical consent is distinct from, and does not constitute, consent to participate in research. After the clinical indication for nephrostomy placement has been established and clinical consent for the procedure has been obtained-or, where clinically appropriate, during the same pre-procedural encounter but as a clearly separate discussion-the patient will be approached about participating in this research study.

A member of the research team will review the REB-approved research informed consent form with the patient. The discussion will explain that the patient is being invited to participate in a research study comparing early post-procedure pain after clinically indicated percutaneous nephrostomy tube placement using standard lidocaine perirenal anesthesia versus bupivacaine perirenal anesthesia. It will also explain that the nephrostomy insertion remains clinically indicated; the study compares the local-anesthetic approach, and the patient will be asked to rate pain on a 0-10 Visual Analog Scale during routine recovery-room assessments over approximately four hours. The discussion will cover the possible benefit of improved immediate pain control (which is not guaranteed), potential local-anesthetic risks, including systemic toxicity, and planned dose limits and monitoring. Confidentiality, data-handling procedures, and the voluntary nature of participation will also be discussed. Patients willing to participate will be asked to provide written, signed informed consent.

All patients will be de-identified and assigned an ID code. Outcome data for each patient will be entered into a database and linked to the corresponding de-identified ID code. All de-identified data will be stored in an encrypted file on a password-protected laptop. All subsequent analyses will use the de-identified data. Participants will include adult inpatients and outpatients presenting to a tertiary hospital for percutaneous nephrostomy tube placement. Exclusion criteria will include a contraindication to bupivacaine, an inability to complete protocolized pain scoring, or evere hepatic impairment, defined as Child-Pugh Class C (total score 10-15).

After providing informed consent, each participant will be randomized in a 1:1 ratio to the lidocaine or bupivacaine group using a computer-generated allocation sequence managed by the research coordinator. For each participant, the coordinator will retrieve the next assignment and communicate it before the procedure. The interventional radiologists performing the procedure will not have access to the allocation sequence or know upcoming assignments in advance.

The comparator will be standard lidocaine peri-renal anesthesia, consistent with usual practice, including tract infiltration to the level of the renal capsule. The intervention will be infiltration of 0.5% bupivacaine hydrochloride (Sensorcaine; Aspen Pharmacare Canada Inc., Oakville, ON, Canada) along the nephrostomy tract and adjacent to the renal capsule under image guidance.

Safety measures will ensure that the amount of local anesthetic used remains below the maximum dose. Specifically, participants assigned to the bupivacaine group will receive 0.5% bupivacaine (5 mg/mL) along the nephrostomy tract and around the renal capsule. The maximum planned volume for 0.5% bupivacaine peri-renal infiltration will be 10 mL per side (50 mg per side), with a maximum of 20 mL (100 mg) for bilateral procedures. Participants assigned to the lidocaine group will receive 1.0% lidocaine (10 mg/mL) in a similar manner along the nephrostomy tract and around the renal capsule. The maximum planned volume for 1.0% lidocaine peri-renal infiltration will be 10 mL per side (100 mg per side), with a maximum of 20 mL (200 mg) for bilateral procedures. The actual volume will be adjusted for the participant's weight, clinical factors, and any lower applicable dose limit; the maximum dose permitted by the applicable product monograph and institutional guidance will not be exceeded. Patients with severe hepatic impairment, defined as Child-Pugh Class C (total score 10-15) will be excluded from the study. The administered concentrations, volumes, and total doses will be documented, and participants will receive routine clinical monitoring for adverse effects.

Outcomes and data collection will include pain scores collected in the diagnostic imaging recovery room according to the site's standard schedule (e.g., q15 min × 4, q30 min × 2, q1 h × 2 over a 4-hour recovery period) using the Visual Analog Scale (VAS). Before the procedure, patients will be educated about the importance of self-reported pain assessment and how to use the VAS, which ranges from 0 ("no pain") to 10 ("worst possible pain"). Pain assessments will be performed by the site's nurse coordinator, who will be blinded to the local anesthetic technique used for each patient. Patient and procedural variables (e.g., inpatient vs outpatient status, sedation, laterality, and procedure duration/complexity) will be captured where available to describe comparability and explore potential confounding variables.

In summary, participants will be asked to provide written informed consent and report their pain using a standardized pain scale (VAS) at routine post-procedure recovery time points over approximately four hours. No procedures beyond standard nephrostomy tube placement will be required. Clinical teams will provide local anesthetic according to the assigned protocol and record standard procedural variables. Recovery nursing staff will document pain scores and analgesic administration as part of usual care, with study-specific data extracted under a coded study ID.

Plan for Data Analysis

Sample size was estimated using a power analysis informed by a prior study evaluating bupivacaine for postoperative pain control after percutaneous nephrolithotomy. (4) In that study, the mean pain score at 4 hours was 4.4 (SD 2.3). Assuming a two-sided α of 0.05, detecting a 1.5-point reduction in pain score with 80% power requires a minimum of 16 participants per group. (9)

Primary analyses will compare post-procedure pain between groups 4-hour recovery period. Categorical variables will be compared using chi-square testing or Fisher's exact test, as appropriate. Continuous outcomes will be assessed for normality and summarized accordingly: normally distributed data will be compared using a two-sample t-test and reported as mean ± SD, whereas non-normally distributed data will be compared using the Wilcoxon rank-sum test and reported as median (range). All tests will be two-sided, and p < 0.05 will be considered statistically significant.

References

1. Bupivacaine Hydrochloride. FDA Drug Label. Food and Drug Administration. Updated date: 2026-04-23.
2. Henkel ED, Haller CN, Diaz LZ, Ricles V, Wong Grossman AV, Nemergut ME, Krakowski AC. Optimizing pediatric periprocedural pain management part II-Adjunct therapies to support the use of infiltrative anesthetics. Pediatr Dermatol. 2024 Jul-Aug;41(4):588-598. doi: 10.1111/pde.15677. Epub 2024 Jul 4. PMID: 38965874.
3. Kirac M, Tepeler A, Bozkurt OF, Elbir F, Ozluk C, Armagan A, Unsal A, Biri H. The efficacy of bupivacaine infiltration on the nephrostomy tract in tubeless and standard percutaneous nephrolithotomy: a prospective, randomized, multicenter study. Urology. 2013 Sep;82(3):526-31. doi: 10.1016/j.urology.2013.02.083. Epub 2013 Jul 4. PMID: 23831069.
4. Al Demour SH, Halalsheh OM, Al-Azab RS, Al-Zubi MT, Al-Rawashdah SF, Ibrahim MM, Abubaker AK, Aloweidi AS, Almustafa MM. The efficacy of bupivacaine infiltration along nephrostomy tract on postoperative pain control and opioid consumption after PCNL: a prospective randomized controlled trial. Eur Rev Med Pharmacol Sci. 2023 Jun;27(11):4951-4959. doi: 10.26355/eurrev_202306_32612. PMID: 37318469.
5. Shah HN, Shah RH, Sodha HS, Khandkar AA, Gokhale A. A randomized control trial evaluating efficacy of nephrostomy tract infiltration with bupivacaine after tubeless percutaneous nephrolithotomy. J Endourol. 2012 May;26(5):478-83. doi: 10.1089/end.2011.0465. Epub 2011 Dec 22. PMID: 22191494.
6. Hirsch M, Tariq L, Duffy JM. Effect of Local Anesthetics on Postoperative Pain in Patients Undergoing Gynecologic Laparoscopy: A Systematic Review and Meta-analysis of Randomized Trials. J Minim Invasive Gynecol. 2021 Oct;28(10):1689-1698. doi: 10.1016/j.jmig.2021.04.024. Epub 2021 May 12. PMID: 33991671.
7. Hortu I, Turkay U, Terzi H, Kale A, Yılmaz M, Balcı C, Aydın U, Laganà AS. Impact of bupivacaine injection to trocar sites on postoperative pain following laparoscopic hysterectomy: Results from a prospective, multicentre, double-blind randomized controlled trial. Eur J Obstet Gynecol Reprod Biol. 2020 Sep;252:317-322. doi: 10.1016/j.ejogrb.2020.07.007. Epub 2020 Jul 7. PMID: 32653604.
8. Protic M, Veljkovic R, Bilchik AJ, Popovic A, Kresoja M, Nissan A, Avital I, Stojadinovic A. Prospective randomized controlled trial comparing standard analgesia with combined intra-operative cystic plate and port-site local anesthesia for post-operative pain management in elective laparoscopic cholecystectomy. Surg Endosc. 2017 Feb;31(2):704-713. doi: 10.1007/s00464-016-5024-5. Epub 2016 Jun 20. PMID: 27324337.
9. Herambourg, C. Power Analysis Calculator. Available at: https://www.omnicalculator.com/statistics/power-analysis. Accessed: June 21, 2026.