Abstract ID: A28
Abstract Title: Efficacy of continuous wound catheters delivering local anesthetic for postoperative analgesia: A quantitative and qualitative systematic review of randomized controlled trials
Authors: Lee J1, Liu S2, Thirlby R3, Wu C4
The Johns Hopkins University Baltimore MD 1, Virginia Mason Medical Center Seattle WA 2, Virginia Mason Medical Center Seattle WA 3, The Johns Hopkins University Baltimore MD 4
Poster Type: Poster
ABSTRACT BODY
Introduction:
Although more “advanced” analgesic techniques such as epidural analgesia may provide superior analgesia, many of these analgesic modalities are labor intensive and expensive, and may not be readily available for all surgical procedures. However, a relatively simple technique of the surgeon directly placing catheters to infuse local anesthetics into wound can be widely used, is technically efficient, may be used for several days, and may now be used on an ambulatory basis with the introduction of new portable pumps. Although there are multiple reports and small randomized controlled trials (RCTs) examining use of continuous wound catheters in multiple surgical procedures, there have been conflicting reports of overall efficacy and no single large RCT has been performed to definitively assess risk benefit of this modality. We conducted this systematic review of randomized trials to determine efficacy of this modality.
Materials and Methods:
The National Library of Medicine's Medline database and the Cochrane Central Register of Controlled Trials were searched for the time period 1966 to April 2005. Since our intent was to compare efficacy of continuous wound catheters placed by the surgeon into the operative field that delivered local anesthetics vs. placebo or no catheters for postoperative analgesia, only prospective RCTs were included. Exclusion criteria include RCTs that used continuous peripheral nerve block and central neuraxial techniques, did not identify a placebo or no catheter control group, or did not use an intra-operatively placed wound catheter. The reference list of each of the analyzed articles was checked for any additional studies. Studies were further subdivided into the following clinical surgical groups for sub-analysis: abdominal, cardiothoracic, gynecologic, minor, and orthopedic. Meta-analysis (RevMan 4.2; The Cochrane Collaboration’s Information Management System; Copenhagen, Denmark) was performed using random effects model for the quantitative systematic review, and qualitative review was performed by displaying data in table format.
Results:
45 studies with 2,031 patients were included for analysis. Meta-analysis associated significant multiple benefits for continuous wound catheters including decreased pain scores at rest and with activity (32% reduction, P<0.001), decreased need for opioids (25 % reduction, p<0.001), decreased risk of nausea and vomiting (16% reduction, p=0.001), and increased patient satisfaction (30% increase, p=0.007). Limited data also associated decreased length of stay in hospitalized patients (1 day, p=0.01). No increases in adverse effects were noted. Sub-analysis of surgical groups confirmed these general findings, but quantitative values are dubious as studies were uniformly small and clinically heterogeneous. Nonetheless, qualitative systematic review of studies supported the same benefits.
Discussion:
Both quantitative and qualitative systematic review identified efficacy of continuous wound catheters with improved analgesia, reduced opioid use and side effects, increased patient satisfaction, and perhaps reduced hospital stay. Potential complications could not be assessed due to small sample size. Future large, homogenous RCTs will be valuable to confirm these findings. Because of its ease of placement and mobility, use of continuous wound catheters for postoperative pain management may be an attractive option in situations where more “advanced” modalities may be difficult to administer.
ATTACHED FILES
Reg Anesth Pain Med 2005; 30(3):A28