Effects of tourniquet number and exsanguination on amikacin concentrations in the radiocarpal and distal interphalangeal joints after low volume intravenous regional limb perfusion in horses

Abstract

Low volume (10 mL) cephalic IVRLP should be combined with the placement of 2 tourniquets (proximal and distal to the carpus) to achieve therapeutic amikacin concentrations in the RCJ. Exsanguination prior to low volume IVRLP does not alter synovial fluid amikacin concentrations.

Subtourniquet pressures generated by application of wide‐rubber tourniquets in standing, sedated horses

“…In another study, Kilcoyne et al performed consecutive synovial fluid amikacin concentration measurements during a 30‐minute cephalic IVRLP (pneumatic tourniquet; 450 mm Hg) at 5‐minute intervals and found that the maximum concentration occurred between 10 and 20 minutes. These 3 reports would suggest a minimum 20‐minute tourniquet time for equine IVRLP. Results of the current study support the potential for WRTs to maintain STP for at least 30 minutes when applied at the AB, GK, and MC; however, less limb movement was noted within 0‐20‐minutes than within 0‐30‐minutes.…”

“…Therefore, consecutive synovial fluid measurements within the same IVRLP trial may be more valuable than those of different trials, even if a cross‐over design is employed. Moser et al and Schoonover et al reported higher synovial fluid amikacin concentrations at a 30‐minute tourniquet application time compared with 15 minutes during the same cephalic IVRLP (pneumatic tourniquet; 420 mm Hg). In another study, Kilcoyne et al performed consecutive synovial fluid amikacin concentration measurements during a 30‐minute cephalic IVRLP (pneumatic tourniquet; 450 mm Hg) at 5‐minute intervals and found that the maximum concentration occurred between 10 and 20 minutes.…”

“…In both reports, synovial fluid measurements were not obtained consecutively within the same IVRLP trial, but, rather, samples were measured during separate tourniquet trials. Wide variability in synovial fluid amikacin concentrations is commonly reported in IVRLP studies . Reasons for this variability are unknown but are likely due to minor patient differences or procedure‐related variables.…”

Synovial butorphanol concentrations and mechanical nociceptive thresholds after intravenous regional limb perfusion in standing sedated horses

“…Little consensus exists regarding how IVRLP should be performed, which limits direct comparisons between studies and the ability to identify sources of variability. There is debate concerning the ideal technical aspects of the procedure (eg, tourniquet type and number, perfusate volume, perfusion time), and the available data are equivocal . The IVRLP performed here was intended to reproduce that easily performed by the general practitioner, and attempts were made to ensure consistency of the procedure and sample collection.…”

“…There is debate concerning the ideal technical aspects of the procedure (eg, tourniquet type and number, perfusate volume, perfusion time), and the available data are equivocal. 33,34,[36][37][38] The IVRLP performed here was intended to reproduce that easily performed by the general practitioner, and attempts were made to ensure consistency of the procedure and sample collection. A different methodology could have reduced the variability of the results, but the literature suggests variability is likely regardless of the procedure used.…”