A technique to collect and measure surgical wound biochemical mediators at specific time points.
We describe a methodology by which we are able to collect and measure inflammatory and nociceptive biochemical mediators at the surgical wound site. Collecting site-specific biochemical markers allows us to evaluate the relationship between surgical wound and serum levels; determine any associations between mediator release, pain and analgesic consumption; and evaluate the effect of systemic and peripheral drug administration on surgical wound biochemistry.
This methodology has been applied to healthy women undergoing elective cesarean delivery with spinal anesthesia. Wound exudate and serum mediators, in conjunction with pain scores and analgesics consumption were measured at 1, 6, 24, and 48 hours post-cesarean delivery. Biochemical mediators that were detected included IL-1β, IL-2, IL-4, IL-6, IL-7, IL-8, IL-10, IL-12, IL-13, IL-17, TNFα, INFγ, G-CSF, GM-CSF, MCP-1 and MIP-1β, nerve growth factor (NGF), prostaglandin E2 (PG-E2) and substance P. We found no correlations between wound and serum cytokines concentrations or time-release profiles (J Pain. 2008 Jul 9(7):650-7). This article describes and demonstrates the feasibility of collecting and assaying nociceptive and inflammatory mediators in surgical wounds at specific time points. The lack of significant correlations between serum and wound levels shows the importance of determining site-specific release if surgical wounds and localized pathologies are to be studied.
Nociceptive and inflammatory biochemical mediator collection
Assay analysis
The On-Q® PainBuster® Pain Relief System should be inserted across the entire incision in subcutaneous layer just prior to wound closure. This facilitates aspiration via the three-way stopcock at the specified time intervals. The On-Q® system continuously delivers normal saline subcutaneously into the wound at a rate of 2 ml/h. This prevents the catheter clotting and improves the reliability of the system to produce exudate samples. If aspiration of exudate is difficult (approximately 5% of cases), consider changing the subject’s position (e.g., sitting the patient up or lying them flat), pushing gently above the wound, using a 0.5-1ml normal saline flush or withdrawing the catheter 1-2 cm.
The authors have nothing to disclose.
Dr. Carvalho’s work is supported by a Building Interdisciplinary Careers in Women’s Health research grant from the Office of Research on Women’s Health and National Institute of Child Health and Human Development of the National Institutes of Health (5K12 HD043452). Dr Angst received supplies (the On-Q® PainBuster® Post-Op Pain Relief System) and funding for the conducting the biochemical assays from I-Flow (Lake Forest, CA).
Material Name | Tipo | Company | Catalogue Number | Comment |
---|---|---|---|---|
On-Q® PainBuster® Post-Op Pain Relief System | I-Flow, Lake Forest, CA | |||
Complete proteinase inhibitor | Roche Bioscience, Palo Alto, CA | |||
17-multiplex bead immunoassay Bio-PlexTM plate | BioRad, Hercules, CA | |||
Bio-Plex amine coupling kit | BioRad, Hercules, CA | |||
The NGF antibody DY256 | R&D Systems, Minneapolis, MN | |||
Prostaglandin E2 and substance P ELISA Kits | Assay Designs, Inc., Ann Arbor, Michigan |