Effects of regional limb perfusion technique on concentrations of antibiotic achieved at the target site: A meta-analysis.
Authors: Redding Laurel E, Elzer Elizabeth J, Ortved Kyla F
Journal: PloS one
Summary
# Editorial Summary: Regional Limb Perfusion Technique and Antibiotic Delivery Intravenous regional limb perfusion (RLP) remains a cornerstone of treating equine distal limb and synovial infections, yet significant variation in technique persists across practitioners without clear evidence supporting one approach over another. Redding and colleagues conducted a meta-analysis of 36 studies (123 experimental arms) published between 1990 and 2021, extracting peak antibiotic concentrations (Cmax) and calculating the ratio of achieved concentration to minimum inhibitory concentration (Cmax:MIC)—the widely accepted benchmark being ≥10 for therapeutic efficacy. Whilst overall summary data were unreliable due to high heterogeneity across studies, meta-regression identified two modifiable technique variables associated with significantly higher antibiotic concentrations: use of a wide rubber tourniquet rather than alternatives, and concurrent administration of local analgesia alongside systemic perfusion. Most perfusion protocols achieved adequate Cmax:MIC ratios (≥10) against susceptible bacteria, but notably failed to do so against resistant organisms, which poses particular clinical concern for polymicrobial or gram-negative infections. For practitioners, these findings provide quantifiable support for standardising on wide rubber tourniquets and incorporating local analgesia into RLP protocols, though clinicians must remain cognisant that standard techniques may prove inadequate for resistant pathogens and warrant adjunctive antimicrobial strategies or culture-directed therapy.
Read the full abstract on PubMed
Practical Takeaways
- •Use a wide rubber tourniquet and add local analgesia to your regional limb perfusion technique to maximize antibiotic delivery to the target site
- •RLP is likely to be effective against susceptible bacteria but may fail against resistant pathogens—culture and sensitivity testing is critical before treatment
- •Many technique variables (tourniquet duration, location, perfusate volume, anesthesia type) do not significantly impact antibiotic concentration, so focus on tourniquet type and local analgesia rather than over-complicating your procedure
Key Findings
- •Wide rubber tourniquets and concurrent local analgesia were the only technique variables significantly associated with higher antibiotic concentrations at the target site
- •Mean antibiotic concentration achieved was 42.8× MIC for susceptible bacteria and 10.7× MIC for resistant bacteria across all studies
- •Majority of treatment arms achieved therapeutic threshold (Cmax:MIC ≥10) for susceptible pathogens but rarely for resistant pathogens
- •High heterogeneity among studies (I²=98.8%) limits reliability of summary values across different RLP techniques