How to Use Continuous-Rate Infusion Catheters for Treatment of Synovial Sepsis

Intrasynovial sepsis in horses results in severe lameness and can potentially be careerand/or life threatening. In foals, infectious arthritis secondary to the hematogenous spread of bacteria is the most common form of intrasynovial infections encountered, whereas traumatically induced septic tenosynovitis and infectious arthritis seem to be more common in adults. Successfully treating an infected synovial structure requires rapidly eliminating the infecting organisms from the synovial structure before irreversible damage occurs. Recommended treatments include systemic antimicrobials and antiinflammatories, synovial and endoscopic lavages, and arthrotomies. Local antimicrobial administration has also been used to improve drug delivery to the site of infection in the form of intra-articular injections, intraosseous perfusion, regional limb perfusion, antimicrobial-impregnated polymethyl methacrylate beads, antimicrobial-impregnated collagen sponges, and continuous-rate infusion (CRI) via indwelling synovial catheters. Direct intra-articular antimicrobial injections can deliver concentrations greater than 100 times the minimum inhibitory concentration (MIC) of commonly isolated bacterial pathogens. To continuously deliver and maintain high intrasynovial antimicrobial MICs, a commercially available continuous-rate infusion system is available to treat a multitude of joints, tendon sheaths, and bursas (Fig. 1).