Administration Of Butorphanol Research Articles

Population pharmacokinetics of butorphanol following intramuscular administration to exercised thoroughbred horses.

Butorphanol is commonly administered, both by the intravenous and intramuscular routes, to racehorses to facilitate handling for diagnostic procedures. As the administration of butorphanol for therapeutic purposes is considered appropriate, in order to avoid inadvertent positive drug tests, a thorough understanding of the pharmacokinetics of this drug is necessary. In the current study, 12, exercised Thoroughbred horses were administered a single intramuscular dose of 0.1 mg/kg butorphanol, and serum and urine samples were collected at various times post drug administration for determination of butorphanol concentrations using a highly sensitive liquid chromatography tandem mass spectrometry method. Serum data were modeled using a nonlinear mixed effect population PK model. The maximum concentration (Cmax) and time to maximum concentration (Tmax) were 139.9 ± 72.8 ng/mL and 0.43 ± 0.44 h (mean ± SD), respectively. Although likely not clinically relevant, but important for drug testing purposes, a prolonged terminal phase was observed, yielding a terminal half-life of 7.67 ± 1.86 h. Using the blood screening limits proposed by the Horseracing Integrity and Welfare Unit, the detection time for intramuscular administration of butorphanol was estimated to be 96 h.

Effects of Butorphanol on Respiration in White Rhinoceros (Ceratotherium simum) Immobilized with Etorphine-Azaperone.

This article reports on respiratory function in white rhinoceros (Ceratotherium simum) immobilized with etorphine-azaperone and the changes induced by butorphanol administration as part of a multifaceted crossover study that also investigated the effects of etorphine or etorphine-butorphanol treatments. Six male white rhinoceros underwent two immobilizations by using 1) etorphine-azaperone and 2) etorphine-azaperone-butorphanol. Starting 10 min after recumbency, arterial blood gases, limb muscle tremors, expired minute ventilation, and respiratory rate were evaluated at 5-min intervals for 25 min. Alveolar to arterial oxygen gradient, expected respiratory minute volume, oxygen consumption, and carbon dioxide production were calculated. Etorphine-azaperone administration resulted in hypoxemia and hypercapnia, with increases in alveolar to arterial oxygen gradient, oxygen consumption, and carbon dioxide production, and a decrease in expired minute ventilation. Muscle tremors were also observed. Intravenous butorphanol administration in etorphine-azaperone-immobilized white rhinoceros resulted in less hypoxemia and hypercapnia; a decrease in oxygen consumption, carbon dioxide production, and expired minute ventilation; and no change in the alveolar to arterial oxygen gradient and rate of breathing. We show that the immobilization of white rhinoceros with etorphine-azaperone results in hypoxemia and hypercapnia and that the subsequent intravenous administration of butorphanol improves both arterial blood oxygen and carbon dioxide partial pressures.

The effects of selected sedatives on basal and stimulated serum cortisol concentrations in healthy dogs.

Hormone assessment is typically recommended for awake, unsedated dogs. However, one of the most commonly asked questions from veterinary practitioners to the endocrinology laboratory is how sedation impacts cortisol concentrations and the adrenocorticotropic hormone (ACTH) stimulation test. Butorphanol, dexmedetomidine, and trazodone are common sedatives for dogs, but their impact on the hypothalamic-pituitary-adrenal axis (HPA) is unknown. The objective of this study was to evaluate the effects of butorphanol, dexmedetomidine, and trazodone on serum cortisol concentrations. Twelve healthy beagles were included in a prospective, randomized, four-period crossover design study with a 7-day washout. ACTH stimulation test results were determined after saline (0.5 mL IV), butorphanol (0.3 mg/kg IV), dexmedetomidine (4 µg/kg IV), and trazodone (3-5 mg/kg PO) administration. Compared to saline, butorphanol increased basal (median 11.75 µg/dL (range 2.50-23.00) (324.13 nmol/L; range 68.97-634.48) vs 1.27 µg/dL (0.74-2.10) (35.03 nmol/L; 20.41-57.93); P < 0.0001) and post-ACTH cortisol concentrations (17.05 µg/dL (12.40-26.00) (470.34 nmol/L; 342.07-717.24) vs 13.75 µg/dL (10.00-18.90) (379.31 nmol/L; 275.96-521.38); P ≤ 0.0001). Dexmedetomidine and trazodone did not significantly affect basal (1.55 µg/dL (range 0.75-1.55) (42.76 nmol/L; 20.69-42.76); P = 0.33 and 0.79 µg/dL (range 0.69-1.89) (21.79 nmol/L; 19.03-52.14); P = 0.13, respectively, vs saline 1.27 (0.74-2.10) (35.03 nmol/L; 20.41-57.93)) or post-ACTH cortisol concentrations (14.35 µg/dL (range 10.70-18.00) (395.86 nmol/L; 295.17-496.55); (P = 0.98 and 12.90 µg/dL (range 8.94-17.40) (355.86 nmol/L; 246.62-480); P = 0.65), respectively, vs saline 13.75 µg/dL (10.00-18.60) (379.31 nmol/L; 275.86-513.10). Butorphanol administration should be avoided prior to ACTH stimulation testing in dogs. Further evaluation of dexmedetomidine and trazodone's effects on adrenocortical hormone testing in dogs suspected of HPA derangements is warranted to confirm they do not impact clinical diagnosis.

The impact of opioid administration on the incidence of postanaesthetic colic in horses.

Effective management of postoperative pain is essential to ensure patient welfare, reduce morbidity and optimize recovery. Opioids are effective in managing moderate to severe pain in horses but concerns over their adverse effects on gastrointestinal (GI) motility and associated increased colic risk limit their widespread use. Studies investigating the impact of systemic opioids on both GI motility and colic incidence in horses have yielded inconclusive outcomes. Therefore, this retrospective study aims to assess the influence of systemic administration of butorphanol, morphine, and methadone on post-anaesthetic colic (PAC) incidence. Horses undergoing general anaesthesia for non-gastrointestinal procedures that were hospitalized for at least 72 h post-anaesthesia were included in this study. Anaesthetised horses were stratified by procedure type into horses undergoing diagnostic imaging without surgical intervention, emergency or elective surgery. In addition, patients were grouped by opioid treatment regime into horses receiving no opioids, intraanaesthetic, short- (<24 h) or long-term (>24 h) postoperative opioids. Administered opioids encompassed butorphanol, morphine and methadone. The number of horses showing signs of colic in the 72 h after anaesthesia was assessed for each group. A total of 782 horses were included, comprising 659 undergoing surgical procedures and 123 undergoing diagnostic imaging. The overall PAC incidence was 15.1%. Notably, horses undergoing diagnostic imaging without surgery had a significantly lower PAC rate of 6.5% compared to those undergoing surgery (16.7%, p = 0.0146). Emergency surgeries had a significantly lower PAC rate of 5.8% compared to elective procedures (18%, p = 0.0113). Of the 782 horses, 740 received intraoperative opioids and 204 postoperative opioids, 102 of which long-term (≥24 h). Neither intraoperative (p = 0.4243) nor short-term postoperative opioids (p = 0.5744) increased PAC rates. Notably, only the long-term (≥24 h) administration of morphine significantly increased PAC incidence to 34% (p = 0.0038). In contrast, long-term butorphanol (5.3% PAC, p = 0.8482) and methadone (18.4% PAC, p = 0.6161) did not affect PAC rates. In summary, extended morphine administration was the only opioid treatment associated with a significantly increased risk of PAC.

Effects of Intratesticular Lidocaine in Pet Rabbits Undergoing Orchiectomy.

The use of local anesthetics for castration is both simple and cost-effective, and it may contribute to reducing the anesthetic requirements. Despite its common use in clinical practice, the literature regarding the effects of intratesticular lidocaine in rabbits is limited. In this study, nine rabbits per group were assigned to intratesticularly receive either 2% lidocaine (0.05 mL/kg into each testicle) or an equivalent volume of saline prior to elective orchiectomy. Anesthesia was induced by intranasal administration of ketamine, medetomidine, and butorphanol. During intraoperative assessment, no significant differences in vital parameters (heart rate, respiratory rate, and peripheral saturation of oxygen) were observed between the groups. However, rabbits receiving intratesticular saline displayed a higher incidence of responses to surgical stimuli. Postoperative pain was evaluated using the composite Centro Animali Non Convenzionali Rabbit Scale (CANCRS), revealing a significantly lower score at the initial post-surgery assessment in rabbits treated with intratesticular lidocaine. All subjects exhibited rapid resumption of food intake and fecal output. While all rabbits demonstrated satisfactory perioperative performances, the use of intratesticular lidocaine was associated with a diminished response to surgical stimuli. Consequently, this practice has the potential to reduce the requirement for additional anesthetics or analgesics, promoting faster recovery.

Effects of intranasal and intramuscular administration of butorphanol and zolazepam-tiletamine combination on intraocular pressure and tear secretion in New Zealand White rabbits.

This study aimed to compare the effect of intranasal (IN) and intramuscular (IM) administration of butorphanol and zolazepam-tiletamine (ZT) combination on intraocular pressure (IOP) and tear secretion (TS) in rabbits. Fourteen healthy male New Zealand White rabbits weighing 3.05 ± 0.72 kg, aged between 1 and 2 years old, were included in the study. Animals randomly received 0.5 mg/kg butorphanol and 15 mg/kg ZT combination either with IN or IM administration. IOP and TS were measured at baseline (T0), and followed by 5, 15, 30, 45, and 60 min after drug administration. The sedation variables, the time to onset of sedation, duration of sedation, and sedation scores were also recorded. The route of administration for the butorphanol and ZT combination had no significant effect on the mean IOP (p = .301) and TS (p = .445). Furthermore, there were no significant changes observed in the IOP (p = .472) and TS (p = .348) over time. The time to onset of sedation was earlier in the IN group (4.57 ± 0.79 min) than in the IM group (5.86 ± 0.9 min; p = .0004). The duration of sedation was significantly longer for IM (57.43 ± 3.41 min) compared with IN (45.0 ± 1.91 min; p < .0001). No significant difference in the sedation score was observed between groups at all time points. In conclusion, both IN and IM administration of the butorphanol and ZT combination in rabbits had similar effects on IOP and TS.

Effect of Butorphanol with and without Medetomidine on Intraocular Pressure in Cats

This study aimed to determine the effects of intramuscular administration of butorphanol with and without medetomidine on intraocular pressure (IOP) in cats. Sixteen clinically normal cats were used. Cats were randomly received two-treatment regimen. The first regimen was 0.2mg/kg butorphanol, and the second regimen was a mixture of 0.1mg/kg butorphanol and 0.05mg/kg medetomidine. IOP values were recorded before treatment (T0) and following the treatment at 10 (T10), 20 (T20), 30 (T30), and 40 min (T40) in both groups. Administration of butorphanol with and without medetomidine did not cause a statistically significant change in IOP values. The IOP did not change over time (p = 0.41). The mean values of IOP in butorphanol, and butorphanol-medetomidine groups were 20.00 ± 2.29 and 20.38 ± 2.35 mm Hg, respectively. In conclusion, intramuscular administration of butorphanol with or without medetomidine had no significant effect on IOP in cats.

Sedation Quality and Cardiorespiratory, Echocardiographic, Radiographic and Electrocardiographic Effects of Intramuscular Alfaxalone and Butorphanol in Spanish Greyhound Dogs.

The quality of sedation and changes in cardiorespiratory variables after the intramuscular administration of alfaxalone and butorphanol in Spanish greyhound dogs were evaluated. Twenty-one adult dogs were included. The dogs received alfaxalone (2 mg/kg) and butorphanol (0.2 mg/kg) intramuscularly. Sedation scoring, cardiorespiratory parameters (including blood gas analysis), echocardiography, thoracic radiography and electrocardiography were performed before sedation and 30 min after drug administration. Moderate sedation was observed, and side effects, such as tremors, nystagmus and auditory hyperesthesia, were noticed. Statistically significant changes in heart rate, invasive blood pressure, pH, arterial saturation of O2 and partial pressure of O2 and CO2 were found. Echocardiographic variables, including end-diastolic volume, left ventricular diameter in diastole, aortic and pulmonic flow, diastolic transmitral flow and left atrial/aortic ratio, and electrocardiography parameters, including PQ interval and QT interval, showed statistically significant changes. In conclusion, the intramuscular administration of alfaxalone and butorphanol to healthy dogs produced moderate sedation with mild cardiorespiratory, echocardiographic and electrocardiographic changes, without alterations in cardiac size on radiographic images.

Use of midazolam and butorphanol to sedate harbor seal pups (Phoca vitulina) undergoing rehabilitation

AbstractBetween 2012 and 2022, the Vancouver Aquarium Marine Mammal Rescue Centre sedated 110 harbor seal pups for physical examinations, diagnostic procedures, or treatment. A sedation protocol of butorphanol and midazolam (0.1–0.2 mg/kg each) was administered via a single i.v. injection in 171 procedures. Of these, 21 pups were anesthetized only with the injectables, while supplemental isoflurane inhalation anesthesia by mask was provided during 58 procedures; 92 other animals required intubation for respiratory support due to apnea or to achieve a deeper plane of anesthesia to facilitate more invasive procedures. Of the 171 sedations, five were euthanized due to poor prognosis and six failed to recover. Maximum sedation, sufficient for intended procedure or anesthesia induction, was achieved within a mean of 8.5 ± 5.8 min for i.v. injection (n = 133). Sedation duration (drug administration to full recovery) without supplemental inhalation anesthesia had a mean of 30.2 min and ranged from 14 to 52 min (n = 13). When used in stabilized young harbor seals, administration of injectable butorphanol and midazolam proved to be an effective protocol to obtain safe and reliable sedation for physical examination, minimally invasive diagnostic procedures, or as a premedication for general anesthesia.

Evaluation of Three Methods of Sensory Function Testing for the Assessment of Successful Maxillary Nerve Blockade in Horses.

Maxillary nerve blocks (MNBs) commonly facilitate dental surgeries in standing horses. The goal of this prospective, blinded, cross-over design trial including 15 client-owned horses was to evaluate 3 methods of sensory function testing for confirming a successful MNB. Testing was performed bilaterally before sedation, 5 min after sedation, and 15 and 30 min after MNB with 0.5% bupivacaine and involved a needle prick dorsal to each naris, hemostat clamping of each nostril, and gingival algometry (measuring sensitivity to pain). Responses to stimulation were numerically scored and scores were summed up to a total score. Total score increases on the blocked side by ≥ 2 between baseline and 30 min Post MNB recordings signified a successful MNB. Sedation in the preceding 6 h, presence of sino-nasal disease, side of dental pathology, age, butorphanol administration, and detomidine dosing (µg/kg/min) throughout the tooth extraction procedure were recorded. In 73% of horses, MNB was successful. Sedation in the preceding 6 h (P = .732), age (P = .936), side of pathology (P = .516), and sino-nasal disease (P = .769) were not associated with total scores. Detomidine dosage and butorphanol use did not differ between horses in which the MNB was considered successful and for those in which it was not (P = .967 and P = .538, respectively). Scores obtained with gingival algometry were less closely associated with total scores (rho = .649) than those obtained with needle prick and nostril clamping (rho = .819 and .892, respectively). Therefore, needle prick and nostril clamping are considered the more reliable methods for use in clinical practice to determine the success of an MNB.

Pharmacokinetics of intravenous propofol in southern white rhinoceros (Ceratotherium simum simum) after intramuscular etorphine-butorphanol-medetomidine-azaperone.

To determine the pharmacokinetics of a single bolus of intravenous (IV) propofol after intramuscular administration of etorphine, butorphanol, medetomidine, and azaperone in 5 southern white rhinoceros to facilitate reproductive evaluations. A specific consideration was whether propofol would facilitate timely orotracheal intubation. 5 adult, female, zoo-maintained southern white rhinoceros. Rhinoceros were administered etorphine (0.002 mg/kg), butorphanol (0.02 to 0.026 mg/kg), medetomidine (0.023 to 0.025 mg/kg), and azaperone (0.014 to 0.017 mg/kg) intramuscularly (IM) prior to an IV dose of propofol (0.5 mg/kg). Physiologic parameters (heart rate, blood pressure, respiratory rate, and capnography), timed parameters (eg, time to initial effects and intubation), and quality of induction and intubation were recorded following drug administration. Venous blood was collected for analysis of plasma propofol concentrations using liquid chromatography-tandem mass spectrometry at various time points after propofol administration. All animals were approachable following IM drug administration, and orotracheal intubation was achieved at 9.8 ± 2.0 minutes (mean ±SD) following propofol administration. The mean clearance for propofol was 14.2 ± 7.7 ml/min/kg, the mean terminal half-life was 82.4 ± 74.4 minutes, and the maximum concentration occurred at 2.8 ± 2.9 minutes. Two of 5 rhinoceros experienced apnea after propofol administration. Initial hypertension, which improved without intervention, was observed. This study provides pharmacokinetic data and insight into the effects of propofol in rhinoceros anesthetized using etorphine, butorphanol, medetomidine, and azaperone. While apnea was observed in 2 rhinoceros, propofol administration allowed for rapid control of the airway and facilitated oxygen administration and ventilatory support.

Epidural lidocaine, butorphanol, and butorphanol – lidocaine combination in dromedary camels

BackgroundThe use of general anesthesia in dromedary camels is constrained by risks related to decubitus. Caudal epidural analgesia is an alternative convenient technique providing loco-regional analgesia for numerous invasive and noninvasive painful conditions. Lidocaine is probably the most commonly used local anesthetic in clinical practice, but has a relatively short duration and may not provide significant long term analgesic benefits. Epidural administration of an opioid-local anesthetic mixture would improve the quality and length of analgesia and minimizes the adverse motor effects provoked by local anesthetics. Butorphanol (potent agonist–antagonist opioid) has been used to improve the duration of epidural analgesia in some animal species, but not in camels. Therefore, our purpose was to investigate the onset and duration of analgesia as well as the clinical and hemato-biochemical effects produced by the epidural administration of butorphanol (0.04 mg/kg), lidocaine (0.22 mg/ kg), and butorphanol-lidocaine (0.04 mg/kg—0.22 mg/ kg) mixture in nine adult dromedary camels in a crossover experimental study.ResultsThe onset of analgesia was not statistically different between lidocaine (6.5 ± 2.3 min) and butorphanol-lidocaine (7.3 ± 1.5 min) combination. Delayed onset of analgesia was reported after butorphanol administration (14.7 ± 3.5 min). Butorphanol-lidocaine combination produced marked longer duration (175 ± 8.7 min) than lidocaine (55 ± 6.8 min) and butorphanol (158 ± 5.3 min). Mild ataxia was observed in the butorphanol–lidocaine and lidocaine treated animals and slight sedation was reported after butorphanol and butorphanol-lidocaine administration. A transient significant increase in the glucose levels was recorded after all treatments.ConclusionsEpidural administration of butorphanol augments the analgesic effects and duration of lidocaine with minimal adverse effects.

Pre-operative administration of butorphanol mitigates emergence agitation in patients undergoing functional endoscopic sinus surgery: A randomized controlled clinical trial.

This study explored the effectiveness of pre-operative intravenous injection of butorphanol in the alleviation of emergence agitation (EA) in patients undergoing functional endoscopic sinus surgery (FESS). Patients (n = 708) were randomized into two groups. The butorphanol group (Group B, n = 358) received butorphanol infusion (20 ug/kg) before anesthesia induction, while the control group (Group C, n = 350) received an equal volume of normal saline infusion. General anesthesia was induced with sufentanil, propofol, and rocuronium, and was maintained with sevoflurane and remifentanil. Vasoactive drugs maintained the hemodynamic indices within 20% of the baseline. The incidence of EA was significantly lower in Group B than that in Group C (Group B vs. C: 24.3% vs. 31.4%, respectively; P = 0.034). The times to spontaneous breathing (26.5 min vs. 23.7 min, P = 0.011), verbal response (36.0 min vs. 33.4 min, P = 0.012), and extubation (31.0 min vs. 28.7 min, P = 0.025) were longer in Group B, and the grade of cough (0.33 vs. 0.43, P = 0.024) at extubation in Group B was lower than that in Group C (P = 0.024). The mean arterial pressure at the end of the operation (P = 0.004) and at 5 min after extubation (P = 0.008) was higher and hypotension was less prominent (0.6% vs. 2.6%, P = 0.030) in Group B. Pre-operative intravenous injection of butorphanol decreased the incidence of EA after FESS and provided smooth and hemodynamically stable emergence without extending the stay in post-anesthesia care unit. https://www.clinicaltrials.gov/, identifier NCT03398759.

Evaluation of intramuscular butorphanol, azaperone, and medetomidine in zoo-housed howler monkeys (Alouatta pigra)

Introduction: This study evaluated the efficacy and safety of sedation in zoo-housed howler monkeys (Alouatta pigra) after intramuscular (IM) administration of butorphanol, azaperone, and medetomidine (BAM).

A Comparative Study of Epidural Butorphanol and Epidural Fentanyl for Postoperative pain relief in Lower Limb Orthopaedic Surgeries.

Background: Epidural narcotic agonists like fentanyl, and morphine has been studied as an adjunct to Bupivacaine for intraoperative and to provide epidural postoperative analgesia. Side effects like pruritus, nausea, vomiting, respiratory depression, and urinary retention occur with their use. The search for an effective analgesic with no or low incidence of side effects is continuing. Aims and objective: To evaluate the onset of anaesthesia, duration of analgesia with epidural administration of Butorphanol and fentanyl in 2 groups. Observe and compare side effects between these groups during post-operative period. Material and Methods: We had done this study on 60 patients with Orthopaedic fractures (lowerlimb), which are treated with IM IL nailing femur and tibia distributed to two groups of 30 each. Surgery was done under CSE technique, with Group A receiving butorphanol and Group B Fentanyl as adjuvant. The onset, duration of analgesia and side effects were recorded in each group. Results: The onset of analgesia was rapid in Fentanyl group (3.26+/- 0.95) than Butorphanol group (6.54 +/-1.10). Duration of analgesia was longer in Butorphanol group (330 +/- 62 minutes) in comparison to Fentanyl group (210 +/- 32 minutes). Quality of analgesia is better in Butorphanol group (80%) than Fentanyl group (43 %). Side effects were more in Group B than Group A. Conclusion: Epidural Fentanyl has faster onset of analgesia. Epidural Butorphanol has longer duration of analgesia with better quality of analgesia. Epidural butorphanol has fewer side effects when compared to Fentanyl.

Pre-anesthetic use of butorphanol for the prevention of emergence agitation in thoracic surgery: A multicenter, randomized controlled trial.

Emergence agitation (EA) is common in patients after general anesthesia (GA) and is associated with poor outcomes. Patients with thoracic surgery have a higher incidence of EA compared with other surgery. This study aimed to investigate the impact of pre-anesthetic butorphanol infusion on the incidence of EA in patients undergoing thoracic surgery with GA. This prospective randomized controlled trial (RCT) was conducted in 20 tertiary hospitals in China. A total of 668 patients undergoing elective video-assisted thoracoscopic lobectomy/segmentectomy for lung cancer were assessed for eligibility, and 620 patients were enrolled. In total, 296 patients who received butorphanol and 306 control patients were included in the intention-to-treat analysis. Patients in the intervention group received butorphanol 0.02 mg/kg 15 min before induction of anesthesia. Patients in the control group received volume-matched normal saline in the same schedule. The primary outcome was the incidence of EA after 5 min of extubation, and EA was evaluated using the Riker Sedation-Agitation Scale (RSAS). The incidence of EA was determined by the chi-square test, with a significance of P < 0.05. In total, 296 patients who received butorphanol and 306 control patients were included in the intention-to-treat analysis. The incidence of EA 5 min after extubation was lower with butorphanol treatment: 9.8% (29 of 296) vs. 24.5% (75 of 306) in the control group (P = 0.0001). Patients who received butorphanol had a lower incidence of drug-related complications (including injecting propofol pain and coughing with sufentanil): 112 of 296 vs. 199 of 306 in the control group (P = 0.001) and 3 of 296 vs. 35 of 306 in the control group (P = 0.0001). The pre-anesthetic administration of butorphanol reduced the incidence of EA after thoracic surgery under GA. [http://www.chictr.org.cn/showproj.aspx?proj=42684], identifier [ChiCTR1900025705].

Preliminary investigation into change in packed cell volume (PCV) after administration of two premedication protocols followed by induction and maintenance of anaesthesia in goats

Administration of certain sedative and anaesthetic agents can cause a reduction in circulating packed cell volume (PCV) probably due to sequestration of red cells in the spleen, increasing its size. The effect on PCV after intravenous (IV) administration of butorphanol then diazepam, five minutes apart, or, these premedicants administered in reverse order, followed by propofol and isoflurane anaesthesia have not been investigated in goats. Two cohorts of Saanen goats, one for castration (males, 5 months, 13 goats) and one for experimental orthopaedic surgery for another study (females, 3 to 5 years, 12 goats) were included in this research. Goats were randomized to receive either butorphanol or diazepam first followed by the other agent IV five minutes apart prior to anaesthesia. Four blood samples to analyse PCV were taken per goat (baseline, after the first and second premedicant administration, and after propofol induction). A between and within-subjects design ANOVA was applied to determine the difference in PCV over time between treatment groups. Baseline PCV across all goats had a mean of 0.42 L/L (range 0.28 – 0.78 L/L). Both combinations of butorphanol and diazepam followed by induction of anaesthesia with propofol caused a clinically and statistically significant reduction in PCV (p < 0.001), with values dropping by 29.0% (diazepam-first) and 29.1% (butorphanol-first) from baseline values to the last sample (an overall decrease in PCV of 0.12 L/L for both groups). However, there was no statistical difference between groups (p = 0.696). Results demonstrate that clinicians need to be aware of the magnitude of reduction in PCV that can occur when butorphanol and diazepam are used as premedicants prior to propofol administration.

Intratesticular Versus Intrafunicular Lidocaine to Reduce Perioperative Nociception and Immunological Response in Ponies Undergoing Field Castration.

The aim of this study was to evaluate the impact of intratesticular or intrafunicular lidocaine to reduce perioperative nociception and cytokine release in ponies undergoing field castration under total intravenous anaesthesia. Before castration, one group was injected with intrafunicular (FL) lidocaine and the other received intratesticular (TL) lidocaine. All ponies were premedicated with acepromazine (0.05 mg/kg) intramuscularly. Twenty minutes after the administration of acepromazine, xylazine (1 mg/kg) and butorphanol (0.02 mg/kg) were administered intravenously. Lidocaine 2% was given 1 mL/100 kg intrafunicularly in the FL groups or 2 mL/100 kg intratesticularly on each testicular side for TL. Surgery was performed by the same team of two experienced surgeons using Serra's emasculator and an open technique was used for all ponies in order to promote postoperative drainage. In this study, we focused on the plasmatic levels of TNF-α and IL-6. The results from this study showed a significant difference in plasmatic concentrations of TNF-α and IL-6 between the two different locoregional anaesthetic protocols. Taken together, the results suggest that the intrafunicular lidocaine locoregional anaesthesia could be a useful technique in the anaesthesia protocol for field pony castration.

Heart rate, arterial pressure and propofol-sparing effects of guaifenesin in dogs

ObjectiveTo evaluate the heart rate (HR) and systemic arterial pressure (sAP) effects, and propofol induction dose requirements in healthy dogs administered propofol with or without guaifenesin for the induction of anesthesia. Study designProspective blinded crossover experimental study. AnimalsA total of 10 healthy adult female Beagle dogs. MethodsDogs were premedicated with intravenous (IV) butorphanol (0.4 mg kg–1) and administered guaifenesin 5% at 50 mg kg–1 (treatment G50), 100 mg kg–1 (treatment G100) or saline (treatment saline) IV prior to anesthetic induction with propofol. HR, invasive sAP and respiratory rate (fR) were recorded after butorphanol administration, after guaifenesin administration and after propofol and endotracheal intubation. Propofol doses for intubation were recorded. Repeated measures analysis of variance (anova) was used to determine differences in propofol dose requirements among treatments, and differences in cardiopulmonary values over time and among treatments with p < 0.05 considered statistically significant. ResultsPropofol doses (mean ± standard deviation) for treatments saline, G50 and G100 were 3.3 ± 1.0, 2.7 ± 0.7 and 2.1 ± 0.8 mg kg–1, respectively. Propofol administered was significantly lower in treatment G100 than in treatment saline (p = 0.04). In treatments G50 and G100, HR increased following induction of anesthesia and intubation compared with baseline measurements. HR was higher in treatment G100 than in treatments G50 and saline following induction of anesthesia. In all treatments, sAP decreased following intubation compared with baseline values. There were no significant differences in sAP among treatments. fR was lower following intubation than baseline and post co-induction values and did not differ significantly among treatments. Conclusions and clinical relevanceWhen administered as a co-induction agent in dogs, guaifenesin reduced propofol requirements for tracheal intubation. HR increased and sAP and fR decreased, but mean values remained clinically acceptable.

Administration of butorphanol with ketamine/xylazine sedation reduces the negative responses to electroejaculation in rams

This study aimed to identify the possible advantages of administering butorphanol (BUT), associated with ketamine/xylazine (KX) sedation or not, for semen collection using electroejaculation (EE) in rams. Fifteen rams received four treatments in a cross-over design using a 2 × 2 factorial arrangement. The treatments were 1) control; 2) received KX; 3) received BUT; and 4) received both treatments. The responses to the procedures regarding heart rate, respiratory frequency, and rectal temperature were recorded, glucose and creatine kinase were measured, and semen quality was determined. More pulses were required when BUT was administered (P = 0.0067), but rams vocalized fewer times (P = 0.046). The administration of KX also tended to reduce the respiratory frequency (P = 0.068) and rectal temperature (P = 0.089), with no other effects. The administration of BUT reduced the heart rate (P < 0.0001), and there was an interactive effect between the administration of BUT and time on the heart rate (P < 0.0001), respiratory frequency (P = 0.01), and rectal temperature (P = 0.047). The administration of BUT reduced the heart rate increase immediately after EE (P < 0.0001). The respiratory frequency following EE was greater when BUT was administered (P < 0.0001), but the administration of BUT reduced the rectal temperature at the same time (P = 0.002). Glucose concentration was greater when BUT was administered (P < 0.0001). The only significant effect on the ejaculate characteristics was from the interaction between KX and BUT on sperm concentration (P = 0.004). The administration of KX alone increased sperm concentration (P = 0.035), but when BUT was added to KX, sperm concentration decreased (P = 0.002). Moreover, sperm concentration was greater when only BUT was administered than when KX and BUT were administered simultaneously (P = 0.037). The addition of BUT markedly decreased most negative responses more effectively than sedation with KX alone. In conclusion, BUT appears to be an interesting alternative to reduce the welfare concerns raised by the use of EE in rams; however, its possible effects on the ejaculate characteristics when associated with other anesthesia/sedation drugs require further study.