Pain Control After Nephrectomy: Epidural & Continuous Surgical Site Analgesia
Many patients experience pain months after nephrectomy. Continuous surgical site analgesia may offer the best long-term pain control.
Continuous surgical site analgesia (CSSA) and epidural analgesia (EA) significantly improve postoperative analgesia, reduce postoperative morphine consumption, decrease the area of wound hyperalgesia, and accelerate patient rehabilitation after open nephrectomy, according to a study by Xavier Capdevila, MD, and colleagues in Anesthesia & Analgesia.1
The investigators found CSSA to be particularly effective in controlling chronic postoperative pain and improving health-related quality of life (HRQL) at 3 months. In the study, patients in the CSSA and EA groups received ropivacaine, whereas the control group received patient-controlled analgesic (PCA) morphine.
Open surgery remains common for patients requiring radical or partial nephrectomy and is associated with a high incidence of intense immediate postoperative pain and chronic pain in the months following surgery. Optimal pain management strategies for these patients have yet to be elucidated, making studies like Dr Cadevila and colleagues' essential.
"[Our] study is the first prospective randomized comparison among a PCA morphine control group, thoracic epidural, and continuous wound local anesthetic infusions within a multimodal analgesia regimen," the investigators wrote.
Dr Cadevila and colleagues' study randomly assigned 60 consecutive patients to EA, CSSA, or PCA morphine postoperatively for 72 hours, with each group having 20 patients. Those receiving EA and CSSA could also receive PCA morphine, if needed. Hyperalgesia was assessed on the postoperative days 1, 2, and 3, with chronic pain characteristics and quality of life analyzed at 1 and 3 months.
In the 72 hours following nephrectomy, patients receiving EA or CSSA had significantly less postoperative pain at rest and during coughing compared with those receiving only PCA morphine. Visual analog scale (VAS) pain scores during rest at 24 hours (mean ± standard deviation), the study's primary endpoint, was 2.4 ± 1.7 for EA, 2.2 ± 1.2 for CSSA, and 4.2 ± 1.2 for PCA morphine. Patients receiving EA had the lowest VAS pain scores at rest during the first 6 postoperative hours (P <.001) and throughout all postoperative 72 hours when coughing (P <.001).
EA and CSSA also led to improvements in secondary outcome measures compared with PCA morphine, including significantly less total morphine consumption (P <.001) and quicker improvement in rehabilitation measures. Median values of area of hyperalgesia almost reached statistical significance at 48 hours between the EA group and the PCA morphine group (36.4 cm2 vs 52 cm2, respectively; P =.01) and at 72 hours between the EA, CSSA, and PCA morphine groups (40 cm2, 39.5 cm2, and 59 cm2, respectively; P =.002).
No significant difference was observed between the EA group and the CSSA group throughout the first postoperative 72 hours; however, CSSA was associated with significant improvement in chronic postoperative pain measures, including reduced pain severity and hyperalgesia at 1 month and optimized quality of life 3 months after surgery (role physical scores, P =.005).
Summary & Clinical Applicability
"Our study is the first to analyze HRQL related to postoperative wound infusion," the authors wrote. "We report that CSSA resulted in improved scores for the physical and mental subscales of the SF-36 questionnaire compared with EA and PCA morphine 3 months after open nephrectomy."
Collectively, the study findings indicate that EA and CSSA both offer good pain control following nephrectomy, with CSSA potentially having greater impact on chronic postoperative pain control. Additional larger-scale studies are needed to confirm these findings.
Limitations & Disclosures
Dr Cadevila and colleagues reported no conflicts of interest but noted several limitations with their study, including determination of a sample size without use of a pilot study, which could have yielded valuable information (eg, success rate of different groups); small sample size, opening the possibility for a type II error; and lack of double-blinding, which was mandated by the ethics committee to ensure patient safety and an ethical study.
Capdevila X, Moulard S, Plasse C, et al. Effectiveness of epidural analgesia, continuous surgical site analgesia, and patient-controlled analgesic morphine for postoperative pain management and hyperalgesia, rehabilitation, and health-related quality of life after open nephrectomy: a prospective. Anesth Analg. 2017;124(1):336-345.