Background: We aimed to determine with this randomized, triple-masked, placebo-controlled study if benefits are afforded by adding a multiple-day, ambulatory, continuous ropivacaine paravertebral nerve block to a single-injection ropivacaine paravertebral block after mastectomy.
Methods: Preoperatively, 60 subjects undergoing unilateral (n = 24) or bilateral (n = 36) mastectomy received either unilateral or bilateral paravertebral perineural catheter(s), respectively, inserted between the third and fourth thoracic transverse process(es). All subjects received an initial bolus of ropivacaine 0.5% (15 mL) via the catheter(s). Subjects were randomized to receive either perineural ropivacaine 0.4% or normal saline using portable infusion pump(s) [5 mL/h basal; 300 mL reservoir(s)]. Subjects remained hospitalized for at least 1 night and were subsequently discharged home where the catheter(s) were removed on postoperative day (POD) 3. Subjects were contacted by telephone on PODs 1, 4, 8, and 28. The primary end point was average pain (scale, 0–10) queried on POD 1.
Results: Average pain queried on POD 1 for subjects receiving perineural ropivacaine (n = 30) was a median (interquartile) of 2 (0–3), compared with 4 (1–5) for subjects receiving saline (n = 30; 95% confidence interval difference in medians, −4.0 to −0.3; P = 0.021]. During this same period, subjects receiving ropivacaine experienced a lower severity of breakthrough pain (5 [3–6] vs 7 [5–8]; P = 0.046) as well. As a result, subjects receiving perineural ropivacaine experienced less pain-induced physical and emotional dysfunction, as measured with the Brief Pain Inventory (lower score = less dysfunction): 14 (4–37) versus 57 (8–67) for subjects receiving perineural saline (P = 0.012). For the subscale that measures the degree of interference of pain on 7 domains, such as general activity and relationships, subjects receiving perineural saline reported a median score 10 times higher (more dysfunction) than those receiving ropivacaine (3 [0–24] vs 33 [0–44]; P = 0.035). In contrast, after infusion discontinuation, there were no statistically significant differences detected between treatment groups.
Conclusions: After mastectomy, adding a multiple-day, ambulatory, continuous ropivacaine infusion to a single-injection ropivacaine paravertebral nerve block results in improved analgesia and less functional deficit during the infusion. However, no benefits were identified after infusion discontinuation.
From the *Department of Anesthesiology, †Clinical Translational Research Institute, ‡Department of Ophthalmology, and §Department of Surgery, University of California San Diego, San Diego, CA.
Accepted for publication October 16, 2013.
Address correspondence to: Brian M. Ilfeld, MD, MS, Department of Anesthesiology, University of California San Diego, 200 West Arbor Dr, MC 8770, San Diego, CA 92103-8770 (e-mail: firstname.lastname@example.org).
The authors declare no conflict of interest.
Funding for this project provided by the National Institutes of Health grant GM077026 (PI: Dr Ilfeld) from the National Institute of General Medical Sciences (Bethesda, MD); the Clinical and Translational Research Institute, University of California, San Diego (San Diego, CA), with funding provided by the National Institutes of Health National Center for Research Resources grant UL1RR031980; the Department of Anesthesiology, University of California San Diego (San Diego, CA); and Baxter Healthcare International (Deerfield, IL). This company also provided the portable infusion pumps used in this investigation, and had no input into any aspect of study conceptualization, design, and implementation; data collection, analysis, and interpretation; or manuscript preparation. The contents of this article are solely the responsibility of the authors and do not necessarily represent the official views of the funding entities.
Presented, in part, as a scientific abstract at the Annual Meeting of the American Society of Anesthesiologists in San Francisco, CA, October 14, 2013.
Most of the study contributions of Dr Loland occurred while working at the University of California San Diego, San Diego, CA. Dr Loland subsequently moved to the University of Washington, Seattle, WA.