Marije Risselada

Objective To compare antimicrobial activity as demonstrated by the zone of inhibition (ZOI) produced by antibiotic‐impregnated calcium sulfate (CaSO 4 ) beads after storage for 0, 3, 6, 9, and 12 months. Study design Controlled laboratory study. Sample population Three‐millimeter diameter CaSO 4 beads impregnated with vancomycin (125 mg/mL), or amikacin (250 mg/mL), or without antibiotic (control). Methods Calcium sulfate beads were created at the onset of the study. Individual beads were separated in sterile containers and stored in a closed cabinet at room temperature and humidity for 0, 3, 6, 9, or 12 months until testing. The ZOI against methicillin‐resistant Staphylococcus pseudintermedius, methicillin‐resistant Staphylococcus aureus, and Pseudomonas aeruginosa was recorded with serial replating on a fresh lawn of bacteria every 24 h until beads failed to produce a ZOI. The ZOIs and their changes were compared with mixed‐effects linear models. Eluted concentrations of vancomycin measured with high‐performance liquid chromatography were reported. Results At 24 h, ZOIs were comparable regardless of time since formulation, except vancomycin against P. aeruginosa, which failed to generate a ZOI. The daily changes of ZOI and duration of activity of antibiotics did not vary between storage length ( p > .05). There was no consistent change in eluted drug concentration between storage length of beads. Conclusion Light protected storage at room temperature for up to 12 months did not impair the in vitro activity of antibiotic‐impregnated CaSO 4 beads, as demonstrated through ZOIs. Clinical significance When stored correctly, antibiotic‐impregnated CaSO 4 beads can be used at least up to 12 months after formulation.

Objective To compare postoperative analgesic use and postoperative complications between dogs that received liposomal bupivacaine (LB) during surgical gastrointestinal foreign body (GIFB) removal and those that did not. Study design Retrospective study. Animals Two hundred five dogs. Methods Medical records for all dogs with GIFB removal at the Purdue University Veterinary Hospital between May 2017 and August 2021 were searched. Incomplete records and dogs with less than 2 weeks’ veterinary follow up were excluded. Data collected included: patient information, time until surgery, intraoperative findings, surgical data (including perforation at time of surgery, linear vs. solid, enterotomy vs. enterectomy), use of LB (including time and manner of administration), time to extubation after surgery, in‐hospital postoperative analgesic use and duration, and postoperative complications. Fentanyl was noted as used/not used, quantified as mean hourly rate over 12 h intervals. All analyses were performed using commercial statistical software with p < .05 as the significance level. Results Dogs that received LB were heavier ( n = 65, median 28.5 kg) than those that did not ( n = 140, median 24.4 kg) ( p = .005). Postoperative fentanyl use ( p < .05 between 13 and 72 h) and hourly rates ( p < .05 between 13 and 48 h) were less, and postoperative time in the intensive care unit (ICU) ( p < .001) and hospital were shorter ( p < .001) in dogs receiving LB. Postoperative wound complications were seen in 7/65 dogs (10.8%, 95% CI = 4.4–21.0%) with LB and 4/140 (2.9%, 95% CI = 0.8–7.2%) without LB ( p = .039). Conclusion Use of LB was associated with reduced postoperative analgesic use, and shortened ICU and hospital stay but also with wound complications. Clinical significance Caution should be used when using LB in (clean) contaminated surgeries.