Bead size has a greater effect on in vitro elution from antimicrobial-impregnated calcium sulfate beads than drug concentration.

OBJECTIVE: To compare the elution characteristics of amikacin-impregnated calcium sulfate (CaSO4) beads based on different drug concentrations and bead size configurations. SAMPLE: Six groups of amikacin-impregnated CaSO4 beads and one negative control group. PROCEDURES: Amikacin-impregnated CaSO4 beads were formed with either 500 mg (low-concentration) or 1 g (high-concentration) of amikacin per 15 g CaSO4 hemihydrate powder. The number of beads necessary to approximate 150 mg of amikacin for each of the 3 bead sizes (3 mm, 5 mm, and 7 mm) at both low and high concentrations were placed in 6 mL of phosphate-buffered saline. The saline was sampled at 14 time points over 28 days. Amikacin concentrations were determined using liquid chromatography-mass spectrometry. RESULTS: Smaller beads reached higher mean peak concentrations than larger beads (P < .0006). Peak concentrations for the low- and high-concentration groups were 20.5 mg/mL and 27.4 mg/mL, 13.1 mg/mL and 14.0 mg/mL, and 8.85 mg/mL and 6.75 mg/mL for the 3 mm, 5 mm, and 7 mm beads, respectively. Bead size also affected the length of therapeutic duration, lasting 6 days for the 3 mm and 5 mm beads and 9 days for the 7 mm beads. However, this was only statistically evident among the high-concentration beads (P < .044). Antimicrobial concentration within the same bead sizes did not affect elution. CLINICAL RELEVANCE: Amikacin-impregnated CaSO4 beads achieved extreme supratherapeutic eluent concentrations. While additional studies are needed, bead size significantly affected elution with smaller beads reaching higher peak concentrations and 7 mm, high-concentration beads demonstrating a longer therapeutic duration than smaller beads.

Intestinal dehiscence and mortality in cats undergoing gastrointestinal surgery.

OBJECTIVES: The aim of this study was to determine the incidence of and risk factors for both gastrointestinal (GI) incisional dehiscence and mortality in a large cohort of cats undergoing GI surgery. We hypothesized that cats with preoperative septic peritonitis (PSP), systemic inflammatory response syndrome (SIRS) or sepsis would have higher GI dehiscence and mortality rates than unaffected cats. METHODS: A medical records search identified cats with surgically created, full-thickness incisions into their stomach, small intestines or large intestines. Preoperative data, including signalment, clinical signs, comorbidities, surgical history, current medications, presenting physical examination findings, complete blood counts and serum biochemistry values, were collected. It was determined whether or not cats had PSP, SIRS or sepsis at admission. Intraoperative data, final diagnosis and postoperative variables such as vital parameters, bloodwork and (if applicable) the development of GI dehiscence or mortality were noted. Postoperative follow-up of at least 10 days was obtained in survivors. RESULTS: In total, 126 cats were included. One cat developed GI dehiscence following complete resection of a jejunal adenocarcinoma. Twenty-three cats (18.2%) died within 10 days of surgery. Cats with PSP (P = 0.0462) or that developed hypothermia 25-72 h postoperatively (P = 0.0055) had higher odds of mortality in multivariate analysis. Cats with PSP had 6.7-times higher odds of mortality than cats not diagnosed with PSP. CONCLUSIONS AND RELEVANCE: In cats receiving GI surgery, the incidence of GI incisional dehiscence was <1%. Cats with PSP had a higher likelihood of mortality. SIRS was a common finding in cats with septic peritonitis, but was not associated with mortality. Postoperative mortality during the home recovery period might be significant in cats. Future studies evaluating postoperative mortality in cats should consider extending the research period beyond the date of discharge.

Titanium-Alloy Anchoring System as a Suitable Method of Extracapsular Repair.

Objective: To characterize the effect of a titanium-alloy anchoring system (TAS) on the motion of the cranial cruciate ligament (CrCL) deficient stifle. To compare the motion with the TAS to that of the CrCL-intact and CrCL-deficient stifle. Study Design: Each canine pelvic limb was mounted in a loading jig under 30% body weight. Motion data was collected using an electromagnetic tracking system at stifle angles of 125°, 135°, and 145° with the CrCL-intact, CrCL-deficient and the TAS applied. Results: Total translation of the CrCL-deficient stifle following the TAS was reduced, but remained greater than the CrCL-intact stifle at angles of 125°, 135°, and 145°. Internal rotation of the TAS groups was greater than the CrCL-intact group at 145°, but not 125° and 135°. Varus motion of the TAS group was decreased compared to the CrCL-deficient group, but increased compared to the CrCL-intact group at angles of 125°, 135°, and 145°. Conclusion: Total translation and internal rotation of the CrCL-deficient stifle following the TAS differed from that of the CrCL-intact stifle. However, the TAS reduced total translation and internal rotation of the tibia relative to the femur in the CrCL-deficient stifle to levels that may yield clinically acceptable results.

Cytokine and Growth Factor Concentrations in Canine Autologous Conditioned Serum.

OBJECTIVE: To compare cytokine and growth factor concentrations in canine autologous conditioned serum (ACS) to canine plasma. STUDY DESIGN: Experimental in vivo study. ANIMALS: Client-owned, adult dogs (n=22). METHODS: Blood collected from 16 medium to large breed dogs was used to produce ACS (Orthokine(®) vet irap 10 syringes) and citrated plasma (control). Canine-specific ELISA assays were run per manufacturers' instructions for interleukin (IL)-10, IL-4, tumor necrosis factor (TNF)-α, insulin-like growth factor (IGF)-1, fibroblast growth factor (FGF)-2, transforming growth factor (TGF)-ß1, IL-1ß, and interleukin-1 receptor antagonist (IL-1ra). Serum, in addition to plasma and ACS, was collected from an additional 6 dogs for TNF-α, IL-1ß, and IL-1ra analysis (total of 22 dogs). Data were analyzed for differences in each cytokine concentration using pairwise comparisons between ACS, plasma, and serum using Wilcoxon signed-rank tests. Significance was set at P<.05. RESULTS: There was a large variability in growth factor and cytokine concentrations in ACS and plasma for individual dogs. There were no significant differences in IL-10, TNF-α, IGF-1, FGF-2, and TGF-ß1 concentrations between ACS, plasma, and serum. The IL-1ß concentrations in ACS (median, range 46.3 pg/mL, 0-828.8) and IL-4 (0.0 pg/mL, 0-244.1) were significantly higher than plasma (36.6 pg/mL, 0-657.1 and 0.0 pg/mL, 0-0, respectively). The IL-1ra concentration in ACS (median, range 3,458.9 pg/mL, 1,243.1-12,089.0) was significantly higher than plasma (692.3 pg/mL, 422.5-1,475.6). The IL-1ra:IL-1ß ratio in ACS was significantly higher than plasma (39.9 vs. 7.2). CONCLUSION: IL-1ra concentrations in canine ACS were comparable to those published for people and horses and pro-inflammatory cytokines remained low in canine ACS.