Laura Fresno

Comparison of subcutaneous and transdermal administration of buprenorphine for pre-emptive analgesia in dogs undergoing elective ovariohysterectomy.

The clinical efficacy of a 70 microg/h transdermal buprenorphine patch and of 20 microg/kg of buprenorphine administered subcutaneously (SC) for the relief of post-operative pain was determined in 24 healthy female dogs undergoing elective ovariohysterectomy (OHE). Dogs were randomly assigned to three groups: (1) a control group that received no analgesics, (2) a BSC group that received buprenorphine SC (20 microg/kg), and (3) a BP group that received buprenorphine by a 70 microg/h transdermal patch. Dogs were scored for signs of pain at 0, 2, 4, 6, 8, 10, 14, 20, 26, 32 and 38 h after extubation using the Numerical Rating Scale (NRS) and a modified University of Melbourne Pain Scale (UMPS). Mean NRS and UMPS scores for dogs in the BSC group (2.56 ± 0.23 and 3.05 ± 0.27, respectively) and the BP group (2.02 ± 0.24 and 2.67 ± 0.23, respectively) were significantly lower (P<0.05) compared with dogs in the control group (5.42 ± 0.38 and 7.89 ± 0.44, respectively), whereas differences between the two buprenorphine treatment groups were not significant. The results indicated that the analgesia produced by the 70 microg/h patch was similar to that induced by SC administration of 20 microg/kg of buprenorphine in dogs undergoing OHE, suggesting that the transdermal buprenorphine patch may be a useful alternative for pain management in dogs.

Effects of platelet-rich plasma on intestinal wound healing in pigs

Anastomotic dehiscence and leakage remain a major problem in gastrointestinal surgery. Recently, attention has been focused on cellular acceleration of the wound healing process using platelet-rich plasma (PRP) and this study reports the effects of PRP on intestinal wound healing in pigs. Autologous PRP was obtained from 35 pigs that were then subjected to two intestinal anastomosis procedures. Activated PRP was applied at one of the anastomosis sites, while the other site served as control. After 24, 48, 72 and 96 h and then at 7 days, histology was performed and wound breaking strength was measured at 72 h and 7 days. PRP application appeared to increase granulation tissue and fibrosis, but did not influence anastomotic breaking strength.

Fetoscopic coverage of experimental myelomeningocele in sheep using a patch with surgical sealant

OBJECTIVE Assess the feasibility of a fetoscopic patch coverage method for myelomeningocele repair in a sheep model. STUDY DESIGN Experimental study. A myelomeningocele-like defect was created in 15 fetal sheep on day 75 of gestation. Six remained untreated, whereas 9 underwent fetoscopic coverage of the defect on day 95 of gestation using an inert patch secured with surgical sealant. Clinical and histological examinations were performed after delivery. RESULTS Four valid newborn lambs were obtained in each group. Mean fetoscopic surgical time was 26.9 (SD=7.4)min. All untreated animals had an open lumbar defect with cerebrospinal fluid leakage, paraplegia, urinary incontinence, and Chiari malformation. All treated animals had a closed defect and were able to walk; one had weak bladder control, and another mild Chiari malformation. CONCLUSION In a chronic myelomeningocele model in fetal sheep, fetoscopic repair using a sealed patch results in simple, fast, satisfactory neural tube closure and averts neurological damage and Chiari malformation.

Inert patch with bioadhesive for gentle foetal surgery of myelomeningocele in a sheep model

OBJECTIVE Current techniques used in foetal myelomeningocele repair can require considerable manipulation of fragile foetal tissues to obtain tension-free closure. The aim of this study was to assess the feasibility of a simple foetal coverage method without foetal tissue manipulation to provide closure of the neural tube defect in myelomeningocele. STUDY DESIGN This is an experimental study performed in 15 foetal sheep with lumbar myelomeningocele, surgically created on day 75 of gestation. Five foetuses remained untreated. Ten underwent coverage with inert sheeting (5 Silastic; 5 Silastic+Marlex) secured by surgical tissue adhesive without suturing on day 95; none of them underwent foetal muscle or skin manipulation. Clinical and subsequent histological examinations were performed at 48h after birth. The Chi-square, Fisher exact, and Mann-Whitney U tests, when appropriate, were used for the comparisons. RESULTS The mean operating time for foetal coverage was 7.1 (SD=1.6)min. All untreated animals were unable to walk, had sphincter incontinence, showed an open defect, histological spinal cord damage, and a large Chiari malformation. All covered animals were able to walk, had sphincter continence, showed almost complete closure of the defect with regeneration of several soft tissue layers, and minimum Chiari malformation. CONCLUSION In a surgical myelomeningocele model in sheep, a simple, fast and gentle coverage method using a sealed patch avoids foetal tissue manipulation and enables adequate closure of the neural tube defect, providing regeneration of several tissue layers that protect the spinal cord, and significantly reducing Chiari II malformation.

The effects on cardio-respiratory and acid-base variables of the anaesthetic alfaxalone in a 2-hydroxypropyl-β-cyclodextrin (HPCD) formulation in sheep

The objective of this study was to determine the pharmacodynamic effects in sheep of the anaesthetic alfaxalone in a 2-hydroxypropyl-β-cyclodextrin formulation. Seven Ripollesa sheep, weighing 43.0±6.6 kg, were used in the study. Twenty-four hours after instrumentation, the sheep were anesthetised with alfaxalone (2 mg/kg bodyweight IV) in cyclodextrin. Heart rate, arterial blood pressure, respiratory rate and arterial blood gases were recorded. Alfaxalone administration resulted in minimal cardio-respiratory depression. Time to standing from anaesthesia was 22.0±10.6 min. Apnoea was not observed in any of the sheep. Significant differences from baseline were not observed in respiratory rate or arterial blood pressure. Heart rate increased significantly (P<0.05) immediately after administration, returning to control values at 20 min. The calculated haemoglobin saturation (SO2) decreased significantly during the first 15 min after alfaxalone administration. The arterial pH decreased significantly during the first 30 min of the study, although no significant differences from basal values were observed in the arterial partial pressure of carbon dioxide (PaCO2). The results showed that alfaxalone in 2-hydroxypropyl-β-cyclodextrin administered as an IV bolus at 2 mg/kg produced minimal adverse effects and an uneventful recovery from anaesthesia in sheep.

Pharmacokinetics of buprenorphine after intravenous administration of clinical doses to dogs.

The purpose of this study was to evaluate plasma concentrations and pharmacokinetic parameters of buprenorphine in dogs following intravenous (IV) administration of clinical doses of the opioid. An IV bolus of 0.02mg/kg buprenorphine was administered to six healthy Beagles and blood samples were collected through a jugular catheter before and at 1, 5, 10, 15, 20, 30 and 45 min, and 1, 2, 4, 6, 8 and 12h after administration. Plasma buprenorphine concentrations, measured using a commercial radioimmunoassay (RIA), decreased following a three-exponential curve. The two distribution and the elimination half-lives were 2.9+/-1.8min, 16.5+/-3.7min, and 266.6+/-82.0min, respectively; the clearance was 329.6+/-62.2mL/min, and the steady state volume of distribution was 83.7+/-26.5L. The results demonstrated the feasibility of the RIA assay to analyse buprenorphine in dog plasma samples. Following IV administration buprenorphine showed a three-compartment kinetic profile, as has been described previously in humans, rabbits and cats. The relationship between plasma concentrations and dynamic effects in dogs remains to be established.

Plasma iron, C-reactive protein, albumin, and plasma fibrinogen concentrations in dogs with systemic inflammatory response syndrome.

OBJECTIVE To investigate the diagnostic and prognostic value over time of plasma iron compared with the inflammatory markers albumin, C-reactive protein (CRP), and fibrinogen in dogs with systemic inflammatory response syndrome (SIRS). DESIGN Prospective observational study of sequentially enrolled dogs. SETTING ICU of a veterinary teaching hospital. ANIMALS One hundred and sixteen client-owned dogs: 54 dogs with SIRS or sepsis, 42 with focal inflammation, and 20 clinically healthy dogs. MEASUREMENTS AND MAIN RESULTS Blood samples were obtained on admission in all study groups, and then on alternate days until discharge or death in both inflammation groups. On admission, dogs with SIRS had significantly lower plasma iron (65 ± 5.8 μg/dL, P = 0.001) concentrations than dogs with focal inflammation (89.5 ± 6.2 μg/dL, P = 0.001). Plasma iron, albumin, and CRP effectively discriminated the SIRS/sepsis group from those presenting with focal inflammation with areas under the curve for the receiver operating curves of 0.679, 0.834, and 0.704, respectively. The admission values for these variables did not discriminate survivors from nonsurvivors within the SIRS/sepsis group. However, the magnitude of increase in iron concentration and the decrease in CRP concentration from admission to hospital discharge was higher in survivors than in nonsurvivors within the SIRS/septic group (22.8 vs. 2.51 μg/dL, respectively, P = 0.021 for iron; -67.1 vs. -4.1 mg/L, respectively, P = 0.002 for CRP), resulting in iron and CRP concentrations at hospital discharge for survivors similar to those in the focal inflammation group. CONCLUSION Hypoferremia is a sensitive marker of systemic inflammation in dogs. In this study, the increase in iron concentrations during the hospitalization period of SIRS/septic dogs was associated with a better prognosis, suggesting that plasma iron in combination with CRP and albumin concentrations might be used to monitor dogs with inflammatory disease processes.Objective To investigate the diagnostic and prognostic value over time of plasma iron compared with the inflammatory markers albumin, C-reactive protein (CRP), and fibrinogen in dogs with systemic inflammatory response syndrome (SIRS). Design Prospective observational study of sequentially enrolled dogs. Setting ICU of a veterinary teaching hospital. Animals One hundred and sixteen client-owned dogs: 54 dogs with SIRS or sepsis, 42 with focal inflammation, and 20 clinically healthy dogs. Measurements and Main Results Blood samples were obtained on admission in all study groups, and then on alternate days until discharge or death in both inflammation groups. On admission, dogs with SIRS had significantly lower plasma iron (65 ± 5.8 μg/dL, P = 0.001) concentrations than dogs with focal inflammation (89.5 ± 6.2 μg/dL, P = 0.001). Plasma iron, albumin, and CRP effectively discriminated the SIRS/sepsis group from those presenting with focal inflammation with areas under the curve for the receiver operating curves of 0.679, 0.834, and 0.704, respectively. The admission values for these variables did not discriminate survivors from nonsurvivors within the SIRS/sepsis group. However, the magnitude of increase in iron concentration and the decrease in CRP concentration from admission to hospital discharge was higher in survivors than in nonsurvivors within the SIRS/septic group (22.8 vs. 2.51 μg/dL, respectively, P = 0.021 for iron; −67.1 vs. −4.1 mg/L, respectively, P = 0.002 for CRP), resulting in iron and CRP concentrations at hospital discharge for survivors similar to those in the focal inflammation group. Conclusion Hypoferremia is a sensitive marker of systemic inflammation in dogs. In this study, the increase in iron concentrations during the hospitalization period of SIRS/septic dogs was associated with a better prognosis, suggesting that plasma iron in combination with CRP and albumin concentrations might be used to monitor dogs with inflammatory disease processes.

Plasma buprenorphine concentrations after the application of a 70 μg/h transdermal patch in dogs. Preliminary report

The objective of the present study was to evaluate the plasma concentrations and pharmacokinetics of buprenorphine after transdermal application in dogs (n = 4). A 70 microg/h transdermal buprenorphine patch was applied to the ventral abdomen of four healthy beagles. Blood samples were collected through a preplaced jugular catheter before and at 1, 2, 4, 8, 12, 24, 36, 48 and every 6 h until 108 h after the patch application. Plasma buprenorphine concentrations were measured using a (125)I-labelled radioimmunoassay (RIA) assay. No adverse effects were observed in any of the dogs. Concentrations of buprenorphine were detected in plasma after the application of the transdermal buprenorphine patch on the four experimental animals. Buprenorphine plasma concentrations increased during the first 36 h and then remained in the 0.7-1.0 ng/mL range during the study period. A decrease in plasma buprenorphine concentration was not observed during the study. Although analgesia could not be demonstrated the present study shows the ability of buprenorphine transdermal delivery systems developed for human use to deliver measurable concetrations of buprenorphine in dogs.

Effects of an intravenous bolus of alfaxalone versus propofol on intraocular pressure in sheep.

The objective of this prospective study was to determine the effects of a single intravenous bolus of alfaxalone in 2-hydroxypropyl-β-cyclodextrin and propofol on the intraocular pressure (IOP) in sheep. Ten Ripollesa sheep with a bodyweight of 48.5 (6.8) kg (mean [sd]) were used in the study. Twenty-four hours before the experimental procedure, a complete ophthalmic examination was performed in all animals. The day of the study, intravenous alfaxalone (2 mg/kg) or propofol (6 mg/kg) was randomly administered in a cross-over design, with a washout period of two weeks. Measurements of IOP, globe position and pupil size were obtained at basal time, before induction (time 0) and at two, five, 10, 15, 20, 30, 45, 60, 90 and 120 minutes after drug administration. Occasional side effects and time to standing were also noted. Intravenous administration of alfaxalone and propofol in sheep resulted in no alteration of IOP. Nevertheless, a decrease in the pupil size was observed in both groups. This present study shows that alfaxalone and propofol, administrated as a single intravenous bolus, are good options for maintaining IOP during anaesthesia in sheep, although marked miosis was observed after administration.

Modulation of the biochemical composition of amniotic and allantoic fluids as a control mechanism of feline foetal development

Amniotic fluid exerts a protective function and is an essential component for foetal development and maturation during pregnancy. However, little is known about the exact physiological functions of foetal fluids in this process as well as their biochemical composition in cats. In the present study, the biochemical composition of amniotic and allantoic fluids and maternal serum in pregnant queens was compared after performing an ovariohysterectomy. Fifteen queens were included in the study and distributed in four different groups, D(30), D(40), D(50) and D(60), according to their gestational age. Foetal fluids showed thoroughly greater concentrations of dissociate and total bilirubin, bile acids and gamma-glutamyl transferase than those of maternal serum, whereas albumin, total protein, alanine-transferase, creatine-kinase, amylase, lipase, triglycerides, cholesterol, HDL-cholesterol, and LDL-cholesterol were significantly lower, as compared to maternal serum. Other parameters like alkaline phosphatase, uric acid, creatinine, and electrolytes showed significant differences at specific stages of pregnancy, when compared to maternal serum. Lactate and cortisol significantly increased at the end of the pregnancy in foetal fluids, when compared with maternal serum. No significant differences between foetal fluids and maternal serum were observed for aspartate aminotransferase, lactate dehydrogenase, urea, phosphorus and glucose. According to our results, foetal fluids composition is not a result of simple filtration from maternal blood, the fetus being an active element involved in the production of the same and reflecting organ development and maturation.