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

OBJECTIVE: To 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 DESIGN: Prospective blinded crossover experimental study. ANIMALS: A total of 10 healthy adult female Beagle dogs. METHODS: Dogs 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. RESULTS: Propofol 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 RELEVANCE: When 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.

Management of a severe peripartum hemorrhage following cesarean section in a dog.

This report describes the intensive blood pressure management and transfusion of a peripartum intrauterine hemorrhage following a cesarean section in a dog. The impact of pregnancy-associated physiologic changes and anesthesia on hemodynamic parameters along with potential alternate management techniques are discussed.

Gestion d'une hémorragie péri-partum sévère à la suite d'une césarienne chez une chienne. Ce rapport décrit la gestion intensive de la pression sanguine et des transfusions lors d'une hémorragie intra-utérine péri-partum à la suite d'une césarienne chez une chienne. L'impact des changements physiologiques associés à la gestation et à l'anesthésie sur les paramètres hémodynamiques ainsi que des techniques de gestion alternatives sont discutés.(Traduit par Dr Serge Messier).

Anesthetic and analgesic effects of an opioid-free, injectable protocol in cats undergoing ovariohysterectomy: A prospective, blinded, randomized clinical trial.

This study evaluated the effects of ketamine-dexmedetomidine-midazolam as part of an opioid-free, multimodal protocol in cats undergoing ovariohysterectomy. In a prospective, blinded, randomized clinical trial, cats received either 1 of 2 doses of ketamine [5 mg/kg body weight (BW), n = 10, K5 or 7 mg/kg BW, n = 13, K7] with midazolam (0.25 mg/kg BW) and dexmedetomidine (40 µg/kg BW) intramuscularly, intraperitoneal bupivacaine (2 mg/kg BW) and subcutaneous meloxicam (0.2 mg/kg BW) after surgery. Buprenorphine (0.02 mg/kg BW, intravenously) was administered if pain scores exceeded intervention scores with 2 pain scoring systems. Similar prevalence of rescue analgesia was observed (K5 = 6/10; K7 = 7/13) with significantly lower requirements in kittens (2/8) than adults (11/15). Tachypnea (K5 = 7/10 and K7 = 9/13) and desaturation (K5 = 3/10 and K7 = 4/13) were the 2 most common complications. Age influenced the prevalence of rescue analgesia. Most adult cats required opioids for postoperative pain relief.

Effets anesthésiants et analgésiques d'un protocole injectable sans opioïde chez des chats soumis à une ovario-hystérectomie : essai clinique prospectif, randomisé, à l'aveugle. Lors de la présente étude nous avons évalué les effets de la combinaison kétamine-dexmedetomidine-midazolam comme élément d'un protocole multimodal sans opioïde chez des chats soumis à une ovario-hystérectomie. Dans un essai clinique prospectif, randomisé, à l'aveugle, des chats reçurent une des deux doses de kétamine [5 mg/kg poids corporel (BW), n = 10, K5 ou 7 mg/kg BW, n = 13, K7] avec du midazolam (0,25 mg/kg BW) et du dexmedetomidine (40 µg/kg BW) par voie intramusculaire, de la bupivacaine par voie intrapéritonéale (2 mg/kg BW) et du meloxicam sous-cutané (0,2 mg/kg BW) après la chirurgie. De la buprenorphine (0,02 mg/kg BW, par voie intraveineuse) fut administrée si les pointages de douleur excédaient les pointages d'intervention avec deux systèmes de pointage de la douleur. Une prévalence similaire d'analgésie de secours fut observée (K5 = 6/10; K7 = 7/13) avec des demandes significativement moindres chez les chatons (2/8) que chez les adultes (11/15). De la tachypnée (K5 = 7/10 et K7 = 9/13) et de la désaturation (K5 = 3/10 et K7 = 4/13) étaient les deux complications les plus fréquentes. L'âge influençait la prévalence de l'analgésie de secours. La plupart des chats adultes ont requis des opioïdes pour soulager la douleur post-opératoire.(Traduit par Dr Serge Messier).

Thermal antinociception following oral administration of tapentadol in conscious cats.

OBJECTIVE: To evaluate the onset, magnitude and duration of thermal antinociception after oral administration of two doses of tapentadol in cats. STUDY DESIGN: Prospective, randomized, blinded, experimental study. ANIMALS: Six healthy adult cats weighing 4.4 ± 0.4 kg. METHODS: Skin temperature (ST) and thermal threshold (TT) were evaluated using a wireless TT device up to 12 hours after treatment. Treatments included placebo (PBO, 50 mg dextrose anhydrase orally), buprenorphine (BUP, 0.02 mg kg-1) administered intramuscularly, low-dose tapentadol (LowTAP, 25 mg orally; mean 5.7 mg kg-1) and high-dose tapentadol (HighTAP, 50 mg orally; mean 11.4 mg kg-1) in a blinded crossover design with 7 day intervals. Statistical analysis was performed using anova with appropriate post hoc test (p ≤ 0.05). RESULTS: Salivation was observed immediately following 11 out of 12 treatments with tapentadol. The ST was significantly increased at various time points in the opioid treatments. Hyperthermia (≥ 39.5 °C) was not observed. Baseline TT was 45.4 ± 1.4 °C for all treatments. Maximum TT values were 48.8 ± 4.8 °C at 1 hour in LowTAP, 48.5 ± 3.0 °C at 2 hours in HighTAP and 50.2 ± 5.3 °C at 1 hour in BUP. TT significantly increased after LowTAP at 1 hour, after HighTAP at 1-2 hours, and after BUP at 1-2 hours compared with baseline values. TTs were significantly increased in BUP at 1-2 hours compared with PBO. CONCLUSION AND CLINICAL RELEVANCE: Oral administration of tapentadol increased ST and TT in cats. The durations of thermal antinociception were similar between HighTAP and BUP, both of which were twice as long as that in LowTAP. Studies of different formulations may be necessary before tapentadol can be accepted into feline practice.

Agreement among undergraduate and graduate veterinary students and veterinary anesthesiologists on pain assessment in cats and dogs: A preliminary study.

This study investigated agreement among undergraduate and graduate veterinary students and veterinary anesthesiologists on video pain assessment at the University of Montreal. Pain assessment in dogs and cats appeared to be affected by gender, previous experience, and degree of training despite a small population of observers.

Accord entre étudiants de premier cycle, diplômés en médicine vétérinaire et anesthésistes pour l'évaluation de la douleur chez les chats et les chiens : étude préliminaire. Cette étude a évalué l'accord entre les étudiants de premier cycle, les étudiants diplômés en médicine vétérinaire et les anesthésiologistes vétérinaires pour l'évaluation de la douleur sur vidéo, à l'Université de Montréal. L'évaluation de la douleur chez les chiens et les chats était influencée par le sexe, l'expérience antérieure et le niveau de formation, malgré une population d'observateurs limitée.(Traduit par les auteurs).

Clinical applicability of the Feline Grimace Scale: real-time versus image scoring and the influence of sedation and surgery.

BACKGROUND: The Feline Grimace Scale (FGS) is a facial expression-based scoring system for acute pain assessment in cats with reported validity using image assessment. The aims of this study were to investigate the clinical applicability of the FGS in real-time when compared with image assessment, and to evaluate the influence of sedation and surgery on FGS scores in cats. METHODS: Sixty-five female cats (age: 1.37 ± 0.9 years and body weight: 2.85 ± 0.76 kg) were included in a prospective, randomized, clinical trial. Cats were sedated with intramuscular acepromazine and buprenorphine. Following induction with propofol, anesthesia was maintained with isoflurane and cats underwent ovariohysterectomy (OVH). Pain was evaluated at baseline, 15 min after sedation, and at 0.5, 1, 2, 3, 4, 6, 8, 12 and 24 h after extubation using the FGS in real-time (FGS-RT). Cats were video-recorded simultaneously at baseline, 15 min after sedation, and at 2, 6, 12, and 24 h after extubation for subsequent image assessment (FGS-IMG), which was performed six months later by the same observer. The agreement between FGS-RT and FGS-IMG scores was calculated using the Bland & Altman method for repeated measures. The effects of sedation (baseline versus 15 min) and OVH (baseline versus 24 h) were assessed using linear mixed models. Responsiveness to the administration of rescue analgesia (FGS scores before versus one hour after) was assessed using paired t-tests. RESULTS: Minimal bias (-0.057) and narrow limits of agreement (-0.351 to 0.237) were observed between the FGS-IMG and FGS-RT. Scores at baseline (FGS-RT: 0.16 ± 0.13 and FGS-IMG: 0.14 ± 0.13) were not different after sedation (FGS-RT: 0.2 ± 0.15, p = 0.39 and FGS-IMG: 0.16 ± 0.15, p = 0.99) nor at 24 h after extubation (FGS-RT: 0.16 ± 0.12, p = 0.99 and FGS-IMG: 0.12 ± 0.12, p = 0.96). Thirteen cats required rescue analgesia; their FGS scores were lower one hour after analgesic administration (FGS-RT: 0.21 ± 0.18 and FGS-IMG: 0.18 ± 0.17) than before (FGS-RT: 0.47 ± 0.24, p = 0.0005 and FGS-IMG: 0.45 ± 0.19, p = 0.015). CONCLUSIONS: Real-time assessment slightly overestimates image scoring; however, with minimal clinical impact. Sedation with acepromazine-buprenorphine and ovariohysterectomy using a balanced anesthetic protocol did not influence the FGS scores. Responsiveness to analgesic administration was observed with both the FGS-RT and FGS-IMG.

Inter-Rater Reliability of the Feline Grimace Scale in Cats Undergoing Dental Extractions.

This study aimed to evaluate the inter-rater reliability of the Feline Grimace Scale (FGS) in cats undergoing dental extractions and the effects of the caregiver's presence on the FGS scores. Twenty-four cats (6 ± 3.3 years old; 4.9 ± 1.7 kg) undergoing oral treatment were included in a prospective, blinded, randomized, clinical study. They underwent treatment under general anesthesia (acepromazine-hydromorphone-propofol-isoflurane-meloxicam-local anesthetic blocks) at day 1 and were discharged at day 6. Images of cat faces were captured from video recordings with or without the caregiver's presence at 6 h postoperatively (day 1), day 6, and before and after rescue analgesia. Images were randomized and independently evaluated by four raters using the FGS [five action units (AU): ear position, orbital tightening, muzzle tension, whiskers change, and head position; score 0-2 for each]. Inter-rater reliability and the effects of the caregiver's presence were analyzed with intraclass correlation coefficient [single measures (95% confidence interval)] and the Wilcoxon signed-rank test, respectively (p < 0.05). A total of 91 images were scored. Total FGS scores showed good inter-rater reliability [0.84 (0.77-0.89)]. Reliability for each AU was: ears [0.68 (0.55-0.78)], orbital tightening [0.76 (0.65-0.84)], muzzle [0.56 (0.43-0.69)], whiskers [0.64 (0.50-0.76)], and head position [0.74 (0.63-0.82)]. The FGS scores were not different with [0.075 (0-0.325)] or without [0.088 (0-0.525)] the caregivers' presence (p = 0.12). The FGS is a reliable tool for pain assessment in cats undergoing dental extractions. The caregiver's presence did not affect FGS scores.

Analgesic Efficacy of Bupivacaine or Bupivacaine-Dexmedetomidine After Intraperitoneal Administration in Cats: A Randomized, Blinded, Clinical Trial.

The aim of this study was to compare the analgesic efficacy of intraperitoneal bupivacaine vs. bupivacaine-dexmedetomidine in combination with intramuscular buprenorphine in cats undergoing ovariohysterectomy. Sixty healthy adult cats (2.8 ± 0.7 kg; n = 30/group) were included in a randomized, prospective, blinded, clinical trial after owners' written consent. After premedication with acepromazine (0.02 mg/kg) and buprenorphine (0.02 mg/kg) intramuscularly, anesthesia was induced with propofol to effect (6.2 ± 1.4 mg/kg) and maintained with isoflurane. Bupivacaine 0.25% alone (BG; 2 mg/kg) or bupivacaine (same dose) with dexmedetomidine (BDG; 1 µg/kg) were instilled/splashed over the ovarian pedicles and caudal aspect of uterus before ovariohysterectomy. Final injectate volume was standardized between groups. Sedation was evaluated using a five-point simple descriptive scale. Pain was evaluated using the short-form UNESP-Botucatu composite pain scale (SF-CPS) before, and at 0.5, 1, 2, 3, 4, 6, 8, 12, and 24 h after surgery. Rescue analgesia was provided with buprenorphine (0.02 mg/kg intravenously) and meloxicam (0.2 mg/kg subcutaneously) when SF-CPS ≥ 4. The Mantel-Haenszel chi-square test was used for analyzing ordinal variables (e.g., SF-CPS pain scores). The effect of time in SF-CPS scores was assessed with the Cochran-Mantel-Haenszel test for repeated measures. The alpha level for each contrast was adjusted downward with the sequential Benjamini-Hochberg procedure. The number of cats receiving rescue analgesia was analyzed using χ2 test (p < 0.05). The prevalence of rescue analgesia was the same for the two treatments (p = 1.000) [BG, n = 6, 20%; BDG, n = 6, 20%] and similar for timing of rescue analgesia (p = 0.16). The SF-CPS scores were significantly increased between 1 and 12 h in BG, and between 0.5 and 8 h in BDG when compared with baseline values. Median (interquartile range) pain scores were higher in BG [1 (1-2)] than BDG [1 (0-1)] at 12 h (p = 0.023). Sedation scores were not significantly different between groups throughout the study. In terms of prevalence of rescue analgesia, but not duration of action, the analgesic efficacy of bupivacaine-dexmedetomidine was similar to bupivacaine alone after intraperitoneal administration in cats receiving buprenorphine.

Analgesic effects of gabapentin and buprenorphine in cats undergoing ovariohysterectomy using two pain-scoring systems: a randomized clinical trial.

Objectives The aim of the study was to evaluate the analgesic efficacy of gabapentin-buprenorphine in comparison with meloxicam-buprenorphine or buprenorphine alone, and the correlation between two pain-scoring systems in cats. Methods Fifty-two adult cats were included in a randomized, controlled, blinded study. Anesthetic protocol included acepromazine-buprenorphine-propofol-isoflurane. The gabapentin-buprenorphine group (GBG, n = 19) received gabapentin capsules (50 mg PO) and buprenorphine (0.02 mg/kg IM). The meloxicam-buprenorphine group (MBG, n = 15) received meloxicam (0.2 mg/kg SC), buprenorphine and placebo capsules (PO). The buprenorphine group (BG, n = 18) received buprenorphine and placebo capsules (PO). Gabapentin (GBG) and placebo (MBG and BG) capsules were administered 12 h and 1 h before surgery. Postoperative pain was evaluated up to 8 h after ovariohysterectomy using a multidimensional composite pain scale (MCPS) and the Glasgow pain scale (rCMPS-F). A dynamic interactive visual analog scale (DIVAS) was used to evaluate sedation. Rescue analgesia included buprenorphine and/or meloxicam if the MCPS ⩾6. A repeated measures linear model was used for statistical analysis ( P <0.05). Spearman's rank correlation between the MCPS and rCMPS-F was evaluated. Results The prevalence of rescue analgesia with a MCPS was not different ( P = 0.08; GBG, n = 5 [26%]; MBG, n = 2 [13%]; BG, n = 9 [50%]), but it would have been significantly higher in the BG (n = 14 [78%]) than GBG ( P = 0.003; n = 5 [26%]) and MBG ( P = 0.005; n = 4 [27%]) if intervention was based on the rCMPS-F. DIVAS and MCPS/rCMPS-F scores were not different among treatments. A strong correlation was observed between scoring systems ( P <0.0001). Conclusions and relevance Analgesia was not significantly different among treatments using an MCPS. Despite a strong correlation between scoring systems, GBG/MBG would have been superior to the BG with the rCMPS-F demonstrating a potential type II error with an MCPS due to small sample size.

Paravertebral brachial plexus blockade in cats: a cadaver study.

Objectives The aims of this study were to describe the paravertebral brachial plexus (PBP) blockade in cats, and compare the spread of bupivacaine-methylene blue solution (BMS) using two volumes of injection into the PBP. Methods Six cadavers (4.4 ± 1.8 kg) randomly received 0.15 ml/kg (LOW) or 0.2 ml/kg (HIGH) per injection of BMS into the PBP. The first injection was made ventral to the transverse process of the sixth cervical vertebra (nerves C6 and C7) at the emergence of nerve roots. A second injection was performed at the edge of the cranial border of the scapula and directed ventrally towards the first rib (C8 and T1). Cadavers were dissected and the presence of BMS in contact with the nerves (success rate) and length of staining were evaluated for each nerve (C6/C7/C8/T1). Length of target nerves in contact with BMS was measured and <15 mm was considered fair, ⩾15 mm sufficient and >40 mm excessive. Complications (aspiration of blood, staining of pleural space and/or spinal cord) were recorded. Paired t-test, Mann-Whitney U-test and χ2 test were used for statistical analysis when appropriate ( P <0.05). Results Eleven hemilateral brachial plexuses were injected. Aspiration of blood occurred during one injection. Inadvertent pleural or spinal staining was not observed. Success rates (positive nerve staining) in the LOW and HIGH groups, respectively, were as follows: C6: 83% and 80%; C7: 66% and 100%; C8: 66% and 100%; T1: 50% and 60% ( P >0.05). Median (range) length of nerve staining was 22 mm (15-39 mm) for LOW and 21 mm (13-35 mm) for HIGH ( P >0.05). Excessive nerve staining was not recorded. Conclusions and relevance This study describes the PBP blockade in cats with acceptable nerve staining and minimal complications. Success rate and length of nerve staining were not significantly different between the LOW and HIGH groups.

Intubation following high-dose rocuronium in a cat with protracted laryngospasm.

CASE SUMMARY: An 11-year-old spayed female domestic shorthair cat with a history of laryngospasm at induction of general anesthesia presented for dental evaluation and treatment. The cat was premedicated with hydromorphone (0.05 mg/kg) and alfaxalone (0.5 mg/kg) intravenously, pre-oxygenated for 5 mins (3 l/min, face mask) and anesthesia was induced with alfaxalone (to effect) intravenously. Lidocaine (0.1 ml, 2%) was applied topically to the arytenoid cartilages following loss of jaw tone. Laryngospasm was not noted during or immediately following lidocaine application. However, after waiting 60 s for the onset of effect of the topical lidocaine, laryngospasm was apparent. Orotracheal intubation by direct visualization was unsuccessful after four attempts by three anesthetists (with increasing levels of experience). At this point, a failed intubation was declared and the non-depolarising neuromuscular blocking agent rocuronium (1 mg/kg IV) given, resulting in arytenoid abduction and appropriate conditions for intubation. Successful intubation occurred 9 mins after induction of anesthesia. Oxygen was continuously supplemented throughout and arterial hemoglobin saturation with oxygen was never <94%. RELEVANCE AND NOVEL INFORMATION: To the authors' knowledge, this is the first report of the use of high-dose rocuronium to successfully resolve prolonged laryngospasm at induction of general anesthesia in a cat. Despite laryngospasm and a delay in achieving orotracheal intubation, low values for arterial hemoglobin saturation with oxygen (indicative of hypoxemia) were not observed, highlighting the benefits of pre-oxygenation and apneic oxygenation. The principles of the Difficult Airway Society 2015 guidelines were followed in managing this difficult intubation.

Accidental knotting and subsequent removal of a catheter from the epidural space in an adult cow: a case report.

This is the first reported case in the veterinary literature of a knot in an epidural catheter. The report reviews this very rare complication and describes options for investigation and retrieval of catheters entrapped in the epidural space of any species.

Pharmacokinetic and pharmacodynamic modelling after subcutaneous, intravenous and buccal administration of a high-concentration formulation of buprenorphine in conscious cats.

BACKGROUND: The aim of this study was to describe the joint pharmacokinetic-pharmacodynamic model and evaluate thermal antinociception of a high-concentration formulation of buprenorphine (Simbadol™) in cats. METHODS: Six healthy cats (4.9 ± 0.7 kg) were included in a prospective, randomized, blinded, crossover study. Simbadol™ (1.8 mg mL-1) was administered by the subcutaneous (SC; 0.24 mg kg-1), intravenous (IV; 0.12 mg kg-1) or buccal (OTM; 0.12 mg kg-1) route of administration and thermal thresholds (TT) were compared with a saline group (SAL). Thermal threshold testing and blood sampling were performed at predetermined time points up to 72 hours including a placebo group. Plasma buprenorphine and norbuprenorphine concentrations were measured using liquid chromatography mass spectrometry. A bespoke bicompartmental pharmacokinetic model simultaneously fitted data from two analytes/three routes of administration. Temporal changes in TT were analyzed using one-way ANOVA followed by Dunnett's test and treatment comparisons using two-way ANOVA with Bonferroni's correction (P < 0.05). RESULTS: Thermal thresholds were significantly increased after SC, IV and OTM from 1-24 hours (except 2 hours), 0.5-8 hours (except 6 hours), and 1-8 hours (except 6 hours), respectively, when compared with baseline. Thermal thresholds were significantly increased after SC (1-30 hours), IV (1-8 hours) and OTM (1-12 hours) when compared with SAL, but not different among buprenorphine-treated cats. The absolute buprenorphine clearance was 0.98 L kg-1 hour-1, volume of distribution at steady state was 7.9 L kg-1 and the elimination-half-life was 12.3 hours. Bioavailability for SC and OTM was 94% and 24%, respectively. Subcutaneous absorption was biphasic. An initial peak (0.08 hours) was followed by a slow (half-life 11.2 hours) and progressive (peak acceleration at 2.8 hours) uptake. CONCLUSION: The SC administration of Simbadol™ was characterized by prolonged absorption half-life and sustained plasma concentrations yielding long-lasting antinociception (≥ 24 hours) when compared with the IV and OTM routes.