Propofol–medetomidine–ketamine total intravenous anaesthesia in thiafentanil–medetomidine-immobilized impala (Aepyceros melampus)

Objective

To characterize a propofol–medetomidine-ketamine total intravenous anaesthetic in impala (Aepyceros melampus).

Effects of fentanyl–lidocaine–ketamine versus sufentanil–lidocaine–ketamine on the isoflurane requirements in dogs undergoing total ear canal ablation and lateral bulla osteotomy

ObjectiveTo compare the isoflurane-sparing effects of sufentanil–lidocaine–ketamine (SLK) and fentanyl–lidocaine–ketamine (FLK) infusions in dogs undergoing total ear canal ablation and lateral bulla osteotomy (TECA–LBO).Study designRandomized blinded clinical study.AnimalsA group of 20 client-owned dogs undergoing TECA–LBO.MethodsIntravenous (IV) administration of lidocaine (3 mg kg^–1) and ketamine (0.6 mg kg^–1) with fentanyl (5.4 μg kg^–1; n = 10; FLK group) or sufentanil (0.72 μg kg^–1; n = 10; SLK group) was immediately followed by the corresponding constant rate infusion (CRI) (lidocaine 3 mg kg^–1 hour^–1; ketamine 0.6 mg kg^–1 hour^–1; either fentanyl 5.4 μg kg^–1 hour^–1 or sufentanil 0.72 μg kg^–1 hour^–1). Anaesthesia was induced with propofol 3–5 mg kg^–1 IV and was maintained with isoflurane. End-tidal isoflurane concentration (Fe′Iso) was decreased in 0.2% steps every 15 minutes until spontaneous movements were observed (treated with propofol 1 mg kg^–1 IV) or an increase of > 30% in heart rate or mean arterial pressure from baseline occurred (treated with rescue fentanyl or sufentanil). Quality of recovery and pain were assessed at extubation using the short-form Glasgow Composite Pain Scale (SF-GCPS), Colorado State University Canine Acute Pain scale (CSU-CAP), and visual analogue scale (VAS). Data were analysed with analysis of variance, t tests, Fisher test and Spearman coefficient (p < 0.05).ResultsFe′Iso decreased significantly in SLK group (45%; p = 0.0006) but not in FLK (15%; p = 0.1135) (p = 0.0136). SLK group had lower scores for recovery quality (p = 0.0204), SF-GCPS (p = 0.0071) and CSU-CAP (p = 0.0273) than FLK at extubation. Intraoperative rescue analgesia and VAS were not significantly different between groups.Conclusions and clinical relevanceCompared with FLK infusion, CRI of SLK at these doses decreased isoflurane requirements, decreased pain scores and improved recovery quality at extubation in dogs undergoing TECA–LBO.     

The impact of vatinoxan on medetomidine–ketamine–midazolam immobilization in Patagonian maras (Dolichotis patagonum)

ObjectiveTo compare cardiovascular and ventilatory effects, immobilization quality and effects on tissue perfusion of a medetomidine–ketamine–midazolam combination with or without vatinoxan (MK-467), a peripherally acting α₂-adrenoceptor antagonist.Study designRandomized, blinded, crossover study.AnimalsA group of nine healthy Patagonian maras (Dolichotis patagonum).MethodsMaras were immobilized twice with: 1) medetomidine hydrochloride (0.1 mg kg^–1) + ketamine (5 mg kg^–1) + midazolam (0.1 mg kg^–1) (MKM) + saline or 2) MKM + vatinoxan hydrochloride (0.8 mg kg^–1), administered intramuscularly. Drugs were mixed in the same syringe. At 20, 30 and 40 minutes after injection, invasive blood pressure, heart rate, respiration rate, end-tidal CO₂, haemoglobin oxygen saturation, and muscle oxygenation were measured, arteriovenous oxygen content difference was calculated. Muscle tone, jaw tone, spontaneous blinking and palpebral reflex were evaluated. Times to initial effect, recumbency, initial arousal and control of the head were recorded. Paired t test, Wilcoxon matched-pairs signed rank test and analysis of variance were used to compare protocols; (p < 0.05).ResultsVatinoxan significantly reduced systolic (p = 0.0002), mean (MAP; p < 0.0001) and diastolic (p < 0.0001) arterial blood pressures between 20 and 40 minutes. MAPs at 30 minutes (mean ± standard deviation) with MKM and MKM + vatinoxan were 105 ± 12 and 71 ± 14 mmHg, respectively. Without vatinoxan, four animals were hypertensive (MAP > 120 mmHg), whereas with vatinoxan, four animals were hypotensive (MAP < 60 mmHg). Muscle and jaw tone were significantly more frequently present with MKM (both p = 0.039). Other measurements did not significantly differ between protocols.Conclusions and clinical relevanceIn Patagonian maras, vatinoxan attenuated the increase in blood pressure induced by medetomidine. Muscle and jaw tone were more frequently present with MKM, indicating that quality of immobilization with vatinoxan was more profound.     

Evaluation of the analgesic effect of fentanyl–ketamine and fentanyl–lidocaine constant rate infusions in isoflurane-anesthetized dogs undergoing thoracolumbar hemilaminectomy

ObjectiveTo evaluate anesthetic conditions and postoperative analgesia with the use of intraoperative constant rate infusions (CRIs) of fentanyl–lidocaine or fentanyl–ketamine in dogs undergoing thoracolumbar hemilaminectomy.Study designProspective, randomized, blinded, clinical study.AnimalsA total of 32 client-owned dogs.MethodsDogs were premedicated with fentanyl (5 μg kg^–1) administered intravenously (IV), anesthesia was induced with IV alfaxalone and maintained with isoflurane. Fentanyl (0.083 μg kg^–1 minute^–1) was infused IV with either ketamine (0.5 mg kg^–1; then 40 μg kg^–1 minute^–1; group KF) or lidocaine (2 mg kg^–1; then 200 μg kg^–1 minute^–1; group LF) assigned randomly. Heart rate, noninvasive arterial pressures, respiratory rate, esophageal temperature, end-tidal partial pressure of carbon dioxide and isoflurane concentration were recorded throughout anesthesia. Maintenance of anesthesia, recovery and postoperative pain (Glasgow Composite Pain Scale) were scored. Cardiopulmonary data were analyzed using a two-way anova with repeated measures, demographics of the two groups with a t test, and scores with Mann–Whitney U test, with p < 0.05.ResultsAll dogs recovered from anesthesia without complications. No significant difference was found between groups for cardiopulmonary variables, total anesthesia time, sedation score and requirement for postoperative sedation or for rescue analgesia. Anesthetic maintenance score was of lower quality in KF than in LF [median (interquartile range): 0 (0–0.5) versus 0 (0–0); p = 0.032)], but still considered ideal. Recovery score was higher and indicative of less sedation in LF than in KF [1 (1–1.5) versus 0.5 (0–1); p < 0.0001]. Pain score was higher in KF than in LF [2 (1–3) versus 1 (1–2); p = 0.0009].Conclusions and clinical relevanceBoth CRIs of KF and LF provided adequate anesthetic conditions in dogs undergoing thoracolumbar hemilaminectomy. Based on requirement for rescue analgesia, postoperative analgesia was adequate in both groups.     

Clinical evaluation of intranasal medetomidine–ketamine and medetomidine–S(+)-ketamine for induction of anaesthesia in rabbits in two centres with two different administration techniques

Objective

The aim was to compare efficacy and side effects of induction with medetomidine–ketamine or medetomidine–S(+)-ketamine by intranasal (IN) instillation in rabbits and to evaluate both protocols during subsequent isoflurane anaesthesia.

Evaluation of a dexmedetomidine–midazolam–ketamine combination administered intramuscularly in captive ornate box turtles (Terrapene ornata ornata)

ObjectiveTo characterize the effects of a combination protocol of dexmedetomidine–midazolam–ketamine (DMK) administered intramuscularly (IM) in ornate box turtles (Terrapene ornata ornata).Study designProspective experimental trial.AnimalsA total of 16 apparently clinically healthy adult ornate box turtles (eight male, eight female).MethodsEach turtle was treated with dexmedetomidine (0.1 mg kg⁻¹), midazolam (1 mg kg⁻¹) and ketamine (10 mg kg⁻¹) administered IM. Time to first response, time to maximal effect, the plateau phase and time to recovery from reversal administration were recorded. Physiologic variables, muscle tone, reflexes and the ability to perform endotracheal intubation were recorded at 5 minute intervals. Movement in response to an IM injection of 0.1 mL sterile 0.9% NaCl administered in the left pelvic limb, using a 25 gauge needle to a depth of just past the bevel of the needle, was assessed every 15 minutes. Atipamezole (0.5 mg kg⁻¹) IM and flumazenil (0.05 mg kg⁻¹) SC were administered 60 minutes after the initial DMK injections.ResultsThe mean time to first response, time to maximal effect, the plateau phase and time to recovery were 2.1, 14.9, 38.7 and 7.8 minutes, respectively. A respiratory rate was not observed in most turtles. The body temperature significantly increased over time. The palpebral reflex was persistent in 43% of turtles and the tail pinch reflex remained intact in 13% of turtles. All turtles recovered with no observed adverse effects.Conclusions and clinical relevanceIn this study, this DMK protocol administered to ornate box turtles resulted in a rapid-onset, light anesthesia lasting approximately 40 minutes and a smooth recovery with no adverse effects noted.     

Comparison of anesthetic effects of tiletamine–zolazepam–medetomidine or ketamine–medetomidine in captive Amur leopard cats (Prionailurus bengalensis euptailurus)

ObjectiveTo evaluate the effects and utility of tiletamine–zolazepam–medetomidine (TZM) and ketamine–medetomidine (KM) for anesthesia of Amur leopard cats (Prionailurus bengalensis euptailurus).Study designProspective, randomized experimental trial.AnimalsA total of six female (3.70 ± 0.49 kg) and six male (5.03 ± 0.44 kg; mean ± standard deviation) Amur leopard cats aged 2–6 years.MethodsEach animal was administered four protocols separated by ≥3 weeks. Each protocol included medetomidine (0.05 mg kg^–1) combined with tiletamine–zolazepam (1 mg kg^–1; protocol MTZ_LO); tiletamine–zolazepam (2 mg kg^–1; protocol MTZ_HI); ketamine (2 mg kg^–1; protocol MK_LO); or ketamine (4 mg kg^–1; MK_HI) administered intramuscularly. At time 0 (onset of lateral recumbency) and 30 minutes, heart rate (HR), respiratory rate (f_R), rectal temperature, noninvasive mean arterial pressure (MAP) and hemoglobin oxygen saturation (SpO₂) were recorded. Times to onset of lateral recumbency, duration of anesthesia and time to standing were recorded.ResultsOverall, animals were anesthetized with all protocols within 10 minutes, anesthesia was maintained ≥57 minutes, and recovery (time from the first head lift to standing) was completed within 5 minutes. During anesthesia with all protocols, HR, f_R, rectal temperature, SpO₂ and MAP were 99–125 beats minute^–1, 33–44 breaths minute^–1, 37.6–39.4 °C, 90–95% and 152–177 mmHg, respectively. No adverse event was observed.Conclusions and clinical relevanceTZM and KM at various dosages resulted in rapid onset of anesthesia, duration of >57 minutes and rapid recovery without administration of an antagonist. Accordingly, all these combinations are useful for anesthetizing Amur leopard cats and for performing simple procedures. However, the low doses of the anesthetic agents are recommended because there was no difference in duration of anesthesia between the dose rates studied.     

Immobilization,cardiopulmonary and blood gas effects of ketamine–butorphanol–medetomidine versus butorphanol–midazolam–medetomidine in free-ranging serval (Leptailurus serval)

ObjectiveTo compare ketamine–butorphanol–medetomidine (KBM) with butorphanol–midazolam–medetomidine (BMM) immobilization of serval.Study designBlinded, randomized trial.AnimalsA total of 23 captures [KBM: five females, six males; 10.7 kg (mean); BMM: 10 females, two males; 9.6 kg].MethodsServal were cage trapped and immobilized using the assigned drug combination delivered via a blow dart into gluteal muscles. Prior to darting, a stress score was assigned (0: calm; to 3: markedly stressed). Drug combinations were dosed based on estimated body weights: 8.0, 0.4 and 0.08 mg kg^–1 for KBM and 0.4, 0.3 and 0.08 mg kg^–1 for BMM, respectively. Time to first handling, duration of anaesthesia and recovery times were recorded. Physiological variables including blood glucose and body temperature were recorded at 5 minute intervals. Atipamezole (5 mg mg^–1 medetomidine) and naltrexone (2 mg mg^–1 butorphanol) were administered intramuscularly prior to recovery. Data, presented as mean values, were analysed using general linear mixed model and Spearman’s correlation (stress score, glucose, temperature); significance was p < 0.05.ResultsDoses based on actual body weights were 8.7, 0.4 and 0.09 mg kg^–1 for KBM and 0.5, 0.4 and 0.09 mg kg^–1 for BMM, respectively. Time to first handling was 10.2 and 13.3 minutes for KBM and BMM, respectively (p = 0.033). Both combinations provided cardiovascular stability during anaesthesia that lasted a minimum of 35 minutes. Recovery was rapid and calm overall, but ataxia was noted in KBM. Stress score was strongly correlated to blood glucose (r² = 0.788; p = 0.001) and temperature (r² = 0.634; p = 0.015).Conclusions and clinical relevanceBoth combinations produced similar effective immobilization that was cardiovascularly stable in serval. Overall, BMM is recommended because it is fully antagonizable. A calm, quiet environment before drug administration is essential to avoid capture-induced hyperglycaemia and hyperthermia.     

Comparison between three dosages of intramuscular alfaxalone and a ketamine–dexmedetomidine–midazolam–tramadol combination in golden-headed lion tamarins (Leontopithecus chrysomelas)

ObjectivesTo characterize the cardiopulmonary and anesthetic effects of alfaxalone at three dose rates in comparison with a ketamine–dexmedetomidine–midazolam–tramadol combination (KDMT) for immobilization of golden-headed lion tamarins (GHLTs) (Leontopithecus chrysomelas) undergoing vasectomy.Study designProspective clinical trial.AnimalsA total of 19 healthy, male, wild-caught GHLTs.MethodsTamarins were administered alfaxalone intramuscularly (IM) at 6, 12 or 15 mg kg^–1, or KDMT, ketamine (15 mg kg^–1), dexmedetomidine (0.015 mg kg^–1), midazolam (0.5 mg kg^–1) and tramadol (4 mg kg^–1) IM. Immediately after immobilization, lidocaine (8 mg kg^–1) was infiltrated subcutaneously (SC) at the incision site in all animals. Physiologic variables, anesthetic depth and quality of immobilization were assessed. At the end of the procedure, atipamezole (0.15 mg kg^–1) was administered IM to group KDMT and tramadol (4 mg kg^–1) SC to the other groups; all animals were injected with ketoprofen (2 mg kg^–1) SC.ResultsA dose-dependent increase in sedation, muscle relaxation and immobilization time was noted in the alfaxalone groups. Despite the administration of atipamezole, the recovery time was longer for KDMT than all other groups. Muscle tremors were noted in some animals during induction and recovery with alfaxalone. No significant differences were observed for cardiovascular variables among the alfaxalone groups, whereas an initial decrease in heart rate and systolic arterial blood pressure was recorded in KDMT, which increased after atipamezole administration.Conclusions and clinical relevanceAlfaxalone dose rates of 12 or 15 mg kg^–1 IM with local anesthesia provided good sedation and subjectively adequate pain control for vasectomies in GHLTs. KDMT induced a deeper plane of anesthesia and should be considered for more invasive or painful procedures. All study groups experienced mild to moderate hypothermia and hypoxemia; therefore, the use of more efficient heating devices and oxygen supplementation is strongly recommended when using these protocols.     

The effect of remifentanil infusion on sevoflurane minimum alveolar concentration–no movement (MACNM) and bispectral index in dogs

ObjectiveTo determine the effect of remifentanil infusion on the minimum alveolar concentration of sevoflurane preventing movement (SEVOMAC_NM) and bispectral index (BIS) in dogs.Study designProspective, unmasked study.AnimalsA total of 10 adult Beagle dogs weighing 9.0 ± 1.1 kg.MethodsDogs were anesthetized with sevoflurane and baseline SEVOMAC_NM was determined. Remifentanil was infused at 5, 10 and 20 μg kg^–1 hour^–1, in sequence, with 20 minutes washout between infusions. Variables monitored throughout anesthesia included heart rate (HR), oscillometric blood pressure, end-tidal partial pressure of carbon dioxide, end-tidal sevoflurane concentration (Fe′Sevo) and BIS. SEVOMAC_NM after remifentanil infusion (SEVOMAC_NM-REMI) determination started 20 minutes after the start of each infusion. Venous blood samples were collected for plasma remifentanil concentration determination at baseline, SEVOMAC_NM-REMI determination time points, and 20 minutes after each infusion was stopped. A mixed model analysis was used to determine the effect of remifentanil infusion on response variables. The relationships between BIS and Fe′Sevo, plasma remifentanil concentrations and the percentage decrease in baseline SEVOMAC_NM were evaluated (p < 0.05).ResultsThe overall SEVOMAC_NM at baseline was 2.47 ± 0.11%. Addition of remifentanil at all infusion rates significantly decreased SEVOMAC_NM, but the medium and high doses resulted in significantly greater decreases in SEVOMAC_NM than the lower dose. There was no difference in SEVOMAC_NM percentage change between infusions 10 and 20 μg kg^–1 hour^–1. Plasma remifentanil concentrations were significantly different in all infusion rates. Baseline BIS value was 70 ± 1 and was lower than the BIS values recorded during all remifentanil infusions. BIS values were not significantly different among infusion rates. HR was lower and mean arterial pressure was higher during remifentanil infusions than at baseline.Conclusions and clinical relevanceAll remifentanil infusions decreased SEVOMAC_NM in dogs. Remifentanil infusion at any rate studied did not reduce BIS values.     

Effects of perioperative saphenous and sciatic nerve blocks,lumbosacral epidural or morphine–lidocaine–ketamine infusion on postoperative pain and sedation in dogs undergoing tibial plateau leveling osteotomy

ObjectiveTo compare the quality of postoperative analgesia and sedation after preoperative saphenous and sciatic nerve blockade, preoperative lumbosacral epidural injection and perioperative intravenous (IV) morphine, lidocaine and ketamine infusions in dogs undergoing stifle arthroscopy and tibial plateau leveling osteotomy (TPLO) under general anesthesia.Study designProspective, blinded, randomized, clinical comparison study.AnimalsA total of 45 dogs weighing 33.9 (15.9–56.7) kg and aged 5.2 (1.0–12.0) years, mean (range), undergoing elective unilateral TPLO for spontaneous cranial cruciate ligament rupture.MethodsClient-owned dogs were enrolled. Dogs were randomly assigned to one of three groups: group MLK, perioperative IV morphine, lidocaine and ketamine infusion; group EPID, lumbosacral epidural with ropivacaine and morphine; or group SSNB, saphenous and sciatic nerve blockade with ropivacaine. Routine stifle arthroscopy followed by TPLO surgery was performed. Sedation and pain scores were assessed at 0, 2, 4, 8 and 24 hours following extubation. Rescue analgesia was administered as prescribed by Glasgow composite pain score–short form score >5.ResultsSedation scores for MLK were higher than EPID and SSNB. Pain scores for SSNB were lower than those for EPID and MLK. No significant differences were found in anesthesia duration or surgery duration among groups. No dogs required rescue analgesia.Conclusions and clinical relevanceAlthough analgesia was adequate in all groups, the best combination of analgesia without increased sedation was recorded for SSNB.     

Xylanase improves the intestinal barrier function of Nile tilapia(Oreochromis niloticus) fed with soybean(Glycine max) mealOA

Background Soybean(Glycine max) meal is one of the important protein sources for fish, but the non-starch polysaccharides(NSP) in soybean meal impair the intestinal barrier function. Here we aimed to investigate whether xylanase can alleviate the adverse effects on the gut barrier induced by soybean meal in Nile tilapia and to explore the possible mechanism.Results Nile tilapia(Oreochromis niloticus)(4.09 ± 0.02 g) were fed with two diets including SM(soybean meal) and SMC(soybean meal + 3,000 U...     

Chemical immobilisation of free-ranging Pampas foxes (Pseudalopex gymnocercus): Assessment of ketamine–xylazine and tiletamine–zolazepam combinations

Two protocols to immobilise free-ranging Pampas foxes for ear-tagging or radio-collaring were evaluated. One hundred fifteen foxes were injected with ketamine–xylazine (K–X) and thirteen with tiletamine–zolazepam (T–Z). The use of both T–Z and K–X combinations typically resulted in a smooth induction and recovery. In 86% of the cases K–X protocol was judged effective (mean ± SD, K: 10.7 ± 3.3 mg/kg, X: 1.0 ± 1.0 mg/kg) while T–Z protocol was judged effective in 92% of the cases (T: 3.6 ± 1.05 mg/kg, Z: 3.6 ± 1.05 mg/kg). The primary differences between the two drug combinations were that the time necessary for the complete recovery was longer with T–Z, and thermic problems were found more frequently with K–X. Additionally, our results suggest that thermic stress may be a relatively frequent complication for Pampas foxes. This study provides baseline data on some physiologic variables in Pampas foxes captured with different methods and drugs in field conditions.     

A comparison of the pharmacodynamic effects of intravenous ketamine–xylazine with alfaxalone in mute swans (Cygnus olor) presenting at a wildlife veterinary hospital

ObjectiveTo compare effects of intravenous (IV) alfaxalone with ketamine–xylazine combination on anaesthetic induction, recovery and cardiopulmonary variables in mute swans.Study designRandomized, controlled, clinical study.AnimalsA group of 58 mute swans.MethodsSwans were given either alfaxalone (10 mg kg^–1; group A) or a combination of ketamine (12.5 mg kg^–1) and xylazine (0.28 mg kg^–1) (group KX) IV. Heart and respiratory rates, end-tidal carbon dioxide and peripheral haemoglobin oxygen saturation were recorded at 5 minute intervals during anaesthesia. Time from anaesthetic induction to intubation, from cessation of isoflurane to extubation, to lifting head, sternal recumbency and absence of head/neck ataxia were recorded. Anaesthetic and recovery quality were scored (1 = very poor; 5 = excellent). Data are presented as median (interquartile range). Significance was set at p < 0.05.ResultsIn group A, 44% (12/27) of swans required mechanical ventilation for 2–14 minutes versus 3.2% (1/31) of swans in group KX (p = 0.0002). Heart rate was higher in group A than in group KX [146 (127–168) versus 65.5 (56–78) beats minute^–1, respectively; p < 0.0001]. The isoflurane concentration required to maintain anaesthesia was higher in group A than in group KX [2.5% (2.0–3.0%) versus 1.5% (1.0–2.0%), respectively; p = 0.0001]. Time from cessation of isoflurane administration to lifting head was significantly longer in group A than in group KX [12 (9–17) versus 6 (4–7.75) minutes, respectively; p < 0.0001]. Anaesthesia quality scores were significantly better in group KX than in group A [4 (4–5) versus 4 (3–4), respectively; p = 0.0011], as were recovery scores [4 (3–5) versus 2 (2–3), respectively; p = 0.0005].Conclusions and clinical relevanceAlfaxalone is a suitable anaesthetic induction agent for use in mute swans. There is a greater incidence of postinduction apnoea and a higher incidence of agitation on recovery with alfaxalone than with ketamine–xylazine.     

Evaluation of BAM (butorphanol–azaperone–medetomidine) in captive African lion (Panthera leo) immobilization

Objective

The combination of butorphanol, azaperone and medetomidine (BAM) with subsequent antagonism by naltrexone–yohimbine or naltrexone–atipamezole was evaluated for reversible immobilization of captive African lions (Panthea leo).

Evaluation of butorphanol–azaperone–medetomidine (BAM) in captive blesbok immobilization (Damaliscus pygargus phillipsi)

Objective

The fixed-dose combination of butorphanol, azaperone and medetomidine (BAM; 30, 12 and 12 mg mL^?1, respectively) with subsequent antagonism by naltrexone–atipamezole was evaluated for reversible immobilization of captive blesbok (Damaliscus pygargus phillipsi).

West Nile virus and hemoparasites in captive snowy owls (Bubo scandiacus) — management strategies to optimize survival

In August 2005, 2 members of a group of 6 captive snowy owls (Bubo scandiacus) in central Saskatchewan died of West Nile virus infection. One of these owls and 3 of the remaining owls had significant numbers of circulating hemoparasites. Management strategies are suggested to reduce morbidity and mortality.