Effect of Intrathecal Amikacin Administration and Repeated Centesis on Digital Flexor Tendon Sheath Synovial Fluid in Horses

• Published in: Veterinary surgery 2007, Vol.36 (1), p.57-63
• Main Authors: DYKGRAAF, SUSANNE, DECHANT, JULIE E, JOHNS, JENNIFER L, CHRISTOPHER, MARY M, BOLT, DAVID M, SNYDER, JACK R
• Format: Article
• Language: English
• Subjects: amikacin; Amikacin - administration & dosage; Amikacin - therapeutic use; Animals; Anti-Bacterial Agents - administration & dosage; Anti-Bacterial Agents - therapeutic use; Antibiotics; Area Under Curve; biomarkers; Body fluids; Clinical outcomes; Cross-Over Studies; digital flexor tendon sheath; drug evaluation; drug injection; Drug therapy; Female; Horse Diseases - drug therapy; Horses; inflammation; intrathecal injection; Intubation, Intratracheal - veterinary; Lameness, Animal - drug therapy; Male; musculoskeletal system; musculoskeletal system physiology; Neutrophils; physiological response; postoperative complications; Proteins - analysis; randomized clinical trials; surgery; synovial fluid; Synovial Fluid - chemistry; Synovial Fluid - cytology; Tendon Injuries; Tendons; Tenosynovitis - drug therapy; Tenosynovitis - veterinary; tenovaginocentesis; Time Factors; Treatment Outcome; veterinary drugs; Veterinary services
• ISSN: 0161-3499; 1532-950X
• DOI: 10.1111/j.1532-950X.2007.00235.x

To determine the effect of intrathecal amikacin administration and repeated tenovaginocentesis on the total nucleated cell count (TNCC), total protein (TP) concentration and cytologic characteristics of synovial fluid of the equine digital flexor tendon sheath (DFTS). Randomized, cross-over experimental design. Adult horses (n=8). Synovial fluid was aseptically collected from the DFTS and either 1 mL amikacin sulfate (250 mg/mL) or lactated Ringer's solution (LRS) was injected into the DFTS. Serial synovial fluid samples were obtained at 0, 12, 24, 48, and 72 hours. The opposite treatment was administered to the contralateral DFTS after a washout period of 2 weeks. Treatment increased TP concentration, TNCC, percentage of neutrophils, and neutrophil counts from baseline levels. There was no difference between treatment of the DFTS with amikacin or LRS. Values peaked at 12-24 hours after the initial centesis and then declined toward baseline levels. Injection and repeat centesis of the normal DFTS with 250 mg amikacin or an equivalent volume of LRS resulted in mild increases in synovial fluid analytes from baseline. Synovial inflammation in this study was not accompanied by lameness at the walk and measured analytes returned toward baseline levels within 12-24 hours of first injection. The effect of tenovaginocentesis and intrathecal administration of amikacin or LRS on DFTS synovial fluid values are modest in most horses; however, some horses can develop marked increases in synovial fluid values that may be interpreted as sepsis.