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Objectives: We evaluated a potential association between the administration of high-dose buprenorphine and perpetuation of hyperthermia in cats following ovariohysterectomy (OVH). We hypothesized that buprenorphine 0.24 mg/kg subcutaneously (SC) would result in longer-lasting postoperative hyperthermia in cats vs a group receiving morphine 0.1 mg/kg SC., Methods: Anesthetic records from cats admitted for OVH as part of surgical exercises for second year veterinary medicine students in 2018 and 2019 were collected. All cats were sedated with dexmedetomidine 20 µg/kg and morphine 0.1 mg/kg intramuscularly. Anesthesia was induced with propofol and maintained with isoflurane in oxygen. At extubation, cats received morphine 0.1 mg/kg SC in 2018 and buprenorphine 0.24 mg/kg SC in 2019. Temperature was measured rectally prior to sedation, esophageally during anesthesia and rectally at 1, 4 and 16-20 h after extubation. Demographic data and temperature prior to administration of postoperative opioids were compared with t -tests. The effects of treatment (opioids) and time on postoperative rectal temperature and on the incidence of hyperthermia (temperature >39.2°C) were evaluated with mixed and generalized linear mixed-effect models. Significance was set at P <0.05., Results: There were no differences in demographic characteristics between treatment groups (all P  ⩾0.2). Intraoperative esophageal temperature was lower in cats scheduled to receive morphine (mean ± SD 36.6 ± 0.2) than in those receiving buprenorphine (36.9 ± 1.0) ( P <0.0001). Postoperative temperature was higher for cats receiving buprenorphine than for those receiving morphine ( P <0.0001). The incidence of hyperthermia 16-20 h after opioid administration was 56% for morphine and 73% for buprenorphine ( P  = 0.03)., Conclusions and Relevance: Buprenorphine 0.24 mg/kg SC for postoperative analgesia in cats was associated with hyperthermia that persisted for 16-20 h after administration, and the incidence of hyperthermia for this group was higher than in the cats that received morphine 0.1 mg/kg SC.

Objective: To analyze practice habits associated with the use, reversal and monitoring of nondepolarizing neuromuscular blocking agents (NMBAs) in dogs by different groups of veterinarians., Study Design: Online anonymous survey to veterinarians., Population: Data from 390 answered surveys., Methods: A questionnaire was sent to e-mail list servers of the American College of Veterinary Anesthesia and Analgesia (ACVAA-list), Sociedad Española de Anestesia y Analgesia Veterinaria (SEEAV-list), Colégio Brasileiro de Anestesiologia Veterinária (Brazilian College of Veterinary Anesthesiology; CBAV-list) and American College of Veterinary Ophthalmologists (ACVO-list) to elicit information regarding use of NMBAs and reversal agents, monitoring techniques, criteria for redosing, reversing and assessing adequacy of recovery of neuromuscular function. Binomial logistic regression was used to test for association between responses and group of veterinarians in selected questions., Results: Veterinarians of the ACVO-list use NMBAs on a higher fraction of their caseload than other groups (all p < 0.0001). Subjective assessment (observation) of spontaneous movement, including spontaneous breathing, is the most common method for assessing neuromuscular function (43% of pooled responses); 18% of participants always reverse NMBAs, whereas 16% never reverse them. Restoration of neuromuscular function is assessed subjectively by 35% of respondents. Residual neuromuscular block is the most common concern regarding the use of NMBAs for all groups of veterinarians. Side effects of reversal agents (anticholinesterases) were of least concern for all groups., Conclusions and Clinical Relevance: While most veterinarians are concerned about residual neuromuscular block, relatively few steps are implemented to reduce the risks of this complication, such as routine use of quantitative neuromuscular monitoring or routine reversal of NMBAs. These results suggest a limitation in transferring information among groups of veterinarians, or in implementing techniques suggested by scientific research., (Copyright © 2018 Association of Veterinary Anaesthetists and American College of Veterinary Anesthesia and Analgesia. Published by Elsevier Ltd. All rights reserved.)

OBJECTIVE To evaluate the effects of 2 fractions of inspired oxygen (Fio 2 s) during anesthesia on postanesthesia Pao 2 and other measures of oxygen exchange. ANIMALS 22 healthy adult sexually intact female dogs undergoing ovariohysterectomy by ventral midline celiotomy. PROCEDURES Dogs were randomly assigned to receive either oxygen (Fio 2 > 0.9 [100% oxygen]; n = 11; control group) or a mixture of nitrogen and oxygen (Fio 2 = 0.4; 11; 40% oxygen group) as the carrier gas for isoflurane while anesthetized. All dogs were allowed to breathe spontaneously while anesthetized. For each dog, the Pao 2 , Paco 2 , other indices of oxygenation, and extent of sedation were monitored at predetermined times during and for 1 hour after anesthesia. Measured variables were compared between the 2 treatment groups and over time within each treatment group. RESULTS None of the measured variables differed significantly between the control and 40% oxygen groups at any time during the postanesthesia period. Within each treatment group, the Paco 2 and extent of sedation decreased over time during the postanesthesia period. CONCLUSIONS AND CLINICAL RELEVANCE Results indicated that indices of oxygenation did not differ significantly between healthy dogs in which the Fio 2 was maintained at > 0.9 and those in which the Fio 2 was maintained at 0.4 while anesthetized for ovariohysterectomy. Thus, the addition of nitrogen to the carrier gas for an inhalant anesthetic conferred neither an advantage nor disadvantage in regard to oxygenation during the first hour of anesthesia recovery.

A positive staircase effect is well documented during neuromuscular monitoring. However, the increase in twitch amplitude may not remain stable over time. We compared the staircase phenomenon and twitch stability during single twitch (ST) or train-of-four (TOF) stimulation in anesthetized dogs. Force of contraction was measured in ten dogs. Each thoracic limb was stimulated with ST 0.1 Hz or TOF q 12 s for 25 min (random order). No neuromuscular blockers were administered. Every 5 min, ST and T1 amplitudes were compared within and between groups. Stability of twitch amplitude (<5 % change in 5 min) was also evaluated. ST and T1 amplitude increased over time without significant differences between groups. After 10 min of ST stimulation, the average ST amplitude had increased significantly to 107 %, and remained unchanged thereafter. T1 amplitude was significantly greater than baseline only at 5 (111 %) and 10 min (109 %); a decline towards baseline occurred thereafter. Stability was reached after 15 min for all dogs in the ST group, however, three dogs continued to have changes >5 % with TOF. An initial increase in ST amplitude remained stable over the observation period, but the increase in T1 amplitude during TOF was frequently followed by a decay. A stable twitch amplitude (variation <5 % in 5 min) was observed in all dogs with ST after 15 min of stimulation, which was not the case during TOF stimulation. Therefore, it appears at least in dogs, that ST might offer some advantages over T1 for measuring twitch amplitude.

Objective: To compare the quality of anesthesia and analgesia from femoral and sciatic nerve blocks (FS) with bupivacaine and dexmedetomidine with that from an epidural injection (EPI) with bupivacaine and buprenorphine in dogs undergoing unilateral stifle arthroplasty., Study Design: Prospective, blinded, randomized, clinical comparison., Animals: Twenty-six dogs weighing 36 ± 10 kg and aged 5 (1-11) years., Methods: Dogs were randomly assigned to either FS [n = 13; bupivacaine 0.5% (0.5 mg kg(-1) ) plus dexmedetomidine (0.1 μg kg(-1) ) for each nerve] or EPI [n = 13; bupivacaine 0.5% (1 mg kg(-1) ) plus buprenorphine (4 μg kg(-1) )]. Data collected included intraoperative cardiopulmonary variables and postoperative pain scores (Glasgow Composite Pain Scale), sedation scores, opioid consumption, time to urination and time to return of various behaviors. Rescue analgesia (hydromorphone 0.05 mg kg(-1) ) was administered intravenously whenever pain scores were ≥ 6/24. Subsequent data from rescued dogs were excluded from further analysis., Results: No differences were found for any of the variables evaluated during and after anesthesia. Over 60% (nine dogs in FS, eight dogs in EPI) of patients from either group did not need additional analgesia within the 24 hour observational period. Three and four patients in FS and EPI, respectively, that required rescue analgesia did so within the first 30 minutes after extubation; only one patient in EPI required supplemental analgesia more than 4 hours after extubation. One patient in each group did not urinate spontaneously for 24 hours., Conclusions and Clinical Relevance: Both techniques have the potential to provide sufficient analgesia for up to 24 hours in approximately two-thirds of dogs. Careful observation for signs of pain and preparedness to intervene is still recommended. The incidence of urinary retention was low in both groups. These techniques show promise for providing high-quality analgesia for stifle arthroplasty., (© 2015 Association of Veterinary Anaesthetists and the American College of Veterinary Anesthesia and Analgesia.)

Objective: Quantitative neuromuscular monitoring is essential for studies of potency and duration of neuromuscular blocking agents, and for detecting residual paralysis in anesthetized patients. This investigation evaluates whether there are systematic differences between acceleromyography (AMG) and electromyography (EMG); two quantitative methods for monitoring neuromuscular block., Study Design: Prospective., Animals: Ten healthy Beagle dogs., Methods: Dogs were anesthetized with isoflurane and dexmedetomidine. Both ulnar nerves were stimulated with a train-of-four (TOF) pattern every 15 seconds. The magnitude of the first twitch (T1) and the TOF ratio (magnitude of T4/T1; TOFR) were quantified simultaneously with AMG and EMG, applied randomly to each extremity. The extent of maximal block (T1 depression) and onset time were measured by AMG and EMG during TOF monitoring after the administration of cisatracurium (0.05 mg kg(-1)). In addition, recovery of T1 to 25% and 75%, the recovery index (time between T1 of 25% and 75%), and recovery of the TOFR to 0.9 were used to characterize recovery from cisatracurium and were compared between monitors. Regression and Bland-Altman plots for T1 and TOFR were also created., Results: Maximal block and onset time were not different between monitors. Time to recovery of T1 to 25% and 75%, and time to TOF ratio 0.9 was significantly shorter with AMG. The recovery index was not different between monitors. When the TOFR returned to 0.9 with AMG, EMG still measured considerable residual block (TOFR 0.47)., Conclusions and Clinical Relevance: Electromyography consistently detected residual NMB when recovery from NMB was complete as assessed by AMG., (© 2014 Association of Veterinary Anaesthetists and the American College of Veterinary Anesthesia and Analgesia.)

Objective: To determine whether dogs that received eyedrops containing phenylephrine and scopolamine would have a higher mean arterial blood pressure (MAP) when anesthetized than would dogs that did not receive the eyedrops., Animals: 37 nondiabetic and 29 diabetic dogs anesthetized for phacoemulsification and 15 nondiabetic dogs anesthetized for corneal ulcer repair (control dogs)., Procedures: Medical records were reviewed to identify study dogs. Dogs undergoing phacoemulsification received 2 types of eyedrops (10% phenylephrine hydrochloride and 0.3% scopolamine hydrobromide) 4 times during a 2-hour period prior to the procedure. Control dogs did not receive these eyedrops. Heart rate and MAP were measured before surgery in all dogs 10 and 5 minutes before, at the time of (t0), and 5 (t5) and 10 (t10) minutes after atracurium administration., Results: MAP was greater in the 2 groups that received the eyedrops than in the control group at t0 and t5; at t10, it was greater only for the nondiabetic dogs that received eyedrops. Nine nondiabetic dogs and 1 diabetic dog anesthetized for phacoemulsification had at least 1 MAP value>131 mm Hg; 73% of MAP values>131 mm Hg were detected within 10 minutes after atracurium administration. At no time did a control dog have an MAP value>131 mm Hg., Conclusions and Clinical Relevance: Anesthetized dogs pretreated with eyedrops containing phenylephrine and scopolamine had higher MAP values than dogs that did not receive the eyedrops, suggesting the drops caused hypertension. Atracurium may interact with the eyedrops and contribute to the hypertension.

Objective: To determine if horses before undergoing anesthesia for surgical correction of colic would have lower plasma arginine vasopressin (AVP) concentrations than healthy horses undergoing anesthesia for arthroscopic surgery, and would not increase their plasma AVP concentrations in response to anesthesia and surgery., Design: Prospective clinical study., Setting: University teaching hospital., Animals: Fourteen horses with colic and 8 healthy horses., Interventions: Horses with colic underwent anesthesia and surgery for alleviation of colic, and healthy horses underwent anesthesia and surgery for arthroscopy., Measurements and Main Results: Plasma AVP was measured perioperatively in horses with colic and in healthy horses. Before anesthesia, and 30 and 60 minutes after induction, horses with colic had greater median plasma AVP concentrations than control horses (P

The objective of this project was to evaluate the acid-base, blood gas, and physiologic parameters of white-tailed deer (Odocoileus virginianus) during laparoscopy in the head-down position. Eleven white-tailed does were captured and then immobilized with xylazine (6 mg/kg i.m.) and ketamine (7 mg/kg i.m.). The deer were intubated orotracheally and maintained with isoflurane in oxygen. The deer were positioned in dorsal recumbency and positive pressure ventilated. Heart rate (HR), arterial blood pressure, end-tidal carbon dioxide concentration (FE/CO2), and CO2 insufflation pressure were recorded every 5 min. Respiratory parameters, plasma electrolytes, and peak inspiratory pressure were measured immediately before tilting deer in the head-down position (45-55 degrees), 5 min after tilting, and immediately before the end of the procedure (while tilted). Butorphanol (0.05 mg/kg i.m.) was administered at the end of the procedure and yohimbine (0.2 mg/kg i.v.) administered before release. The deer weighed 52 kg (28-70 kg) [median (minimum-maximum)]. The peak inspiratory pressure in dorsal recumbency while still horizontal was 25 cm H2O (16-28 cm H2O), which increased to 29 cm H2O (18-46 cm H2O) after tilting (P = 0.02). PaO2, PaCO2, FE/CO2, and pH did not change after tilting in the head-down position or after insufflation. HR did not change during the anesthetic period. Mean arterial pressure did not change after tilting or abdominal insufflation, but decreased by the end of the anesthetic period (approximately 1 hr). Time from intubation to extubation was 117 min (72-170 min) (n = 5) and surgery time was 31 min (17-60 min; n = 10). We conclude that captured white-tailed deer have minimal derangements to acid-base, blood gas, or physiologic parameters during laparoscopy in the head-down position with abdominal insufflation, and thus this procedure may be performed safely in ventilated white-tailed deer.

Background Dynamic indicators such as pulse pressure and stroke volume variations can be measured to track changes in preload during hemorrhage, and evaluate fluid therapy. However, these dynamic indicators require mechanical ventilation, and might be affected by cardiac dysrhythmias and changes in vascular tone. Blood volume indicators may offer alternatives for assessing changes in volume status. Aims The aims of this study were to measure changes in blood volume indicators and dynamic indicators during removal of blood in two stages and subsequent blood replacement in anesthetized, mechanically ventilated, neonatal pigs. Methods In eight anesthetized, mechanically ventilated piglets (5-6 weeks old), cardiac index, stroke volume index, total end-diastolic volume, central blood volume, active circulating volume, pulse pressure variation, and stroke volume variation were measured during blood removal in two stages (15 mL kg−1 each stage) and blood replacement (30 mL kg−1). Values after each intervention were measured for each parameter. Results All indicators differed from baseline after removal of 15 mL kg−1 of blood, except for stroke volume variation. Differences between both stages of hemorrhage were only observed for indexed stroke volume, total end-diastolic volume, central blood volume, and pulse pressure variation. Conclusion Total end-diastolic volume and central blood volume changed during blood depletion and repletion, and differed between stages of hemorrhage. These indicators might be useful for assessing volume status instead of, or in addition to cardiac index and dynamic indicators. [ABSTRACT FROM AUTHOR]

Background The COstatus monitor measures cardiac output via the transpulmonary ultrasound dilution method ( COTPUD) after injection of normal saline, and can calculate continuous cardiac output ( CCO) from the arterial pressure waveform. The relationship between arterial waveform and COTPUD however, might be degraded during vasoconstriction/vasodilation. Objectives To examine if recalibration of arterial waveform-derived CCO is required during mild vasoconstriction/vasodilation. Methods In 10 anesthetized piglets (6.6-10.1 kg), two COstatus monitors calculated the CCO from the same femoral arterial waveform before and during infusions of phenylephrine ( PE; 1 or 3 mg·kg−1·min−1) and sodium nitroprusside ( SNP; 1 or 5 mg·kg−1·min−1), administered in random order. One monitor was recalibrated (CCO Recal) after each intervention, while the other monitor was not (CCO Non-Recal). Recalibration was performed with COTPUD with 1 ml·kg−1 normal saline as indicator. The effects of each infusion on hemodynamic parameters were compared with baseline using paired t-tests. The bias, limits of agreement ( LOA), and percentage error between simultaneous measurements (CCO Recal and CCO Non-Recal) were examined with Bland-Altman plots. Results Infusion of PE significantly increased COTPUD, heart rate ( HR), and arterial pressures but not systemic vascular resistance ( SVR). Infusion of SNP decreased arterial pressures without affecting COTPUD, HR, and SVR. There was no bias between CCO Recal and CCO Non-Recal at the baseline, but a small bias was observed during PE and SNP infusions. The LOA increased approximately 10 fold during vasoconstriction and vasodilation. The percentage error increased from ≤ 5% to 32% and 27% during PE and SNP infusions, respectively. Conclusion Continuous cardiac output ( CO) measured with the COstatus monitor requires recalibration during vasoconstriction and vasodilation, even if changes in COTPUD or SVR are not substantial. [ABSTRACT FROM AUTHOR]

The article focuses on a study which observed that previously that end-expired carbon dioxide decreased when immobilized black rhinoceroses in Namibia. Study immobilized 21 wild black rhinoceroses with hypoxemic and had lactic and respiratory acidemia. Study found that positioning immobilized rhinoceroses in lateral recumbency does not confer any advantage over sternal in terms of ventilation.

Observations A 1-month-old Nubian goat presented for sialocyst resection. Physical examination and bloodwork were unremarkable. While pre-oxygenating, the goat was sedated with midazolam and morphine (0.1 mg kg−1 each) intravenously (IV). General anesthesia was induced 5 minutes later with 1.7 mg kg−1 propofol. Sevoflurane was administered in oxygen without assisted ventilation via a cuffed orotracheal tube. Throughout the first 85 minutes of anesthesia, the goat was well-oxygenated (SpO2, ≥97%), ventilating adequately (Pe′CO2, 36–48 mmHg), and had normal mean arterial blood pressure (MAP, 60–85 mmHg). Blood-gas values at 45 minutes were consistent with adequate ventilation on oxygen. At 75 minutes, the goat moved in response to surgical stimulation, requiring additional propofol (0.4 mg kg−1). After 10 minutes, MAP dropped precipitously to 40 mmHg and frequent multiform premature ventricular contractions (PVCs) were observed. Crystalloids, hetastarch, and dopamine (5 μg kg−1 minute−1) were administered to correct the hypotension. Arterial blood-gas analysis revealed that the goat had become hypoxemic (PaO2, 50 mmHg). Intermittent positive pressure ventilation (IPPV) was initiated. Subsequent blood-gas analysis did not show significant improvement in PaO2 (53 and 56 mmHg, respectively). Occasional PVCs were observed thereafter. Surgery ended, and sevoflurane and IPPV were discontinued. The goat was extubated within 7 minutes and received 100% oxygen by mask. Diffuse crackles were ausculted over both hemithoraces. Suspecting pulmonary edema, furosemide (1 mg kg−1) was administered IV. Radiographs taken immediately post-operatively revealed a severe, caudodorsal airspace (alveolar) pattern, confirming the diagnosis. Respiration improved considerably within an hour with nasal oxygen and two additional doses of furosemide. Conclusions The goat developed acute, drug-induced, noncardiogenic pulmonary edema in response to the second dose of propofol. [ABSTRACT FROM AUTHOR]

Objective To assess whether administration of hydromorphone and, or ketamine are associated with post-anesthetic hyperthermia in cats undergoing routine surgery. Study design Prospective clinical study. Animals Forty healthy, adult cats undergoing ovariohysterectomy (OVH), castration, or declaw surgery. Materials and methods Each cat was assigned randomly to one of four groups ( n = 10). For pre-anesthetic medication, all cats received subcutaneous (SC) glycopyrrolate (0.01 mg kg−1) and acepromazine (0.02 mg kg−1) and either hydromorphone (0.1 mg kg−1 SC) or medetomidine (7.5 μg kg−1 SC). Anesthesia was induced with either diazepam (0.1 mg kg−1) and ketamine (5 mg kg−1) or propofol (6 mg kg−1 injected to effect). Group 1 (HDK) received hydromorphone and diazepam-ketamine. Group 2 (HP) received hydromorphone and propofol. Group 3 (MDK) received medetomidine and diazepam-ketamine. Group 4 (MP) received medetomidine and propofol. Rectal temperature was measured before drugs were given, at tracheal extubation and at hourly intervals for 5 hours thereafter. Results During the 5 hours after anesthesia and surgery, at least one cat in every group had a rectal temperature >39.2 °C (102.5 °F). The percentage of observations for which a cat's temperature exceeded its pre-anesthetic temperature in groups HDK, HP, MDK, and MP were 86%, 80%, 25%, and 34%, respectively. Maximum temperatures in groups HDK, HP, MDK, and MP were 41.6 °C (107.0 °F), 40.3 °C (104.2 °F), 39.2 °C (102.6 °F), and 40.1 °C (104.1 °F), respectively. By 5 hours after tracheal extubation there were no differences in temperature between the treatment groups. Conclusion For up to 5 hours following anesthesia and surgery, cats might have body temperatures that exceed their pre-anesthesia body temperatures. The use of hydromorphone is associated with post-anesthetic hyperthermia. However, hyperthermia may occur when other drugs are used. Clinical relevance Cats given hydromorphone should be closely monitored for hyperthermia following anesthesia and surgery. [ABSTRACT FROM AUTHOR]

OBJECTIVE: To describe the acquisition and pitfalls of a 3-view transesophageal echocardiography (TEE) protocol in anesthetized, dorsally recumbent dogs. ANIMALS: 8 beagles, 1 to 2 years old, 7.4 to 11.2 kg. METHODS: Dogs were anesthetized, mechanically ventilated, and placed in dorsal recumbency. A TEE probe was advanced, and 3 views were performed: midesophageal 4-chamber and long axis (ME 4C and ME LAX) and caudal esophageal short axis (CE SAX) at the level of the papillary muscles. Probe insertion depth, flexion, omniplane angle, and image acquisition time were recorded. Two observers assessed 24 video clips each and identified anatomical structures. RESULTS: The ME 4C and ME LAX were obtained at 35 (30 to 40) cm insertion depth, omniplane at 0° and 103° (90 to 116), respectively. Views were obtained in ≥30 seconds once the TEE was in the cervical esophagus. Left-sided structures were identified in all cases, whereas right-sided structures were not always simultaneously obtained in the ME 4C, requiring further probe manipulation. All structures were identified on ME LAX. CE SAX was obtained at 40 (35 to 45) cm, omniplane at 0°, and in 15 (10 to 90) seconds. A true SAX view (circular left ventricle at the level of papillary muscles) could not be obtained in all dogs. CLINICAL RELEVANCE: A 3-view TEE protocol using core views as those described in humans may be applicable to dogs under general anesthesia and in dorsal recumbency. The CE SAX view at the level of the papillary muscles appears more difficult to obtain with consistency than midesophageal views. [ABSTRACT FROM AUTHOR]

Objective To assess whether recovery from general anesthesia, in an illuminated or a darkened stall, has an effect on time to first movement, time to standing, and recovery score. Study design Prospective randomized clinical study. Animals Twenty-nine healthy, 2- to 5-year-old horses undergoing surgical correction of dorsal displacement of the soft palate. Methods Each horse was assigned randomly to recover in either an illuminated ( n = 15) or a darkened stall ( n = 14). For pre-anesthetic medication, all horses received intravenous (IV) xylazine (0.4 mg kg−1) and butorphanol (0.02 mg kg−1). Anesthesia was induced with midazolam (0.1 mg kg−1) and ketamine (2.2 mg kg−1) IV and maintained on isoflurane in oxygen. Vital parameters, end-tidal CO2 and isoflurane were recorded at 5-minute intervals. At the conclusion of anesthesia, horses were placed in either an illuminated or a darkened stall and xylazine (0.2 mg kg−1) IV was administered at extubation. Video cameras were used to record the horses while they were allowed to recover undisturbed. Video recordings were later viewed and recoveries were evaluated on a 100-point scale by three graders. Results Horses in illuminated and darkened recovery stalls were evaluated on total anesthesia time, minimum alveolar concentration hours of isoflurane, time to first movement, time to standing, and total recovery score. There were no significant differences between the two groups in any of the measured parameters. Conclusion Recovering horses in a darkened versus an illuminated recovery stall may provide no benefit. Clinical relevance Darkening the recovery stalls for horses recovering from general anesthesia may be unnecessary. [ABSTRACT FROM AUTHOR]

To collect data about the current practice of recovering horses from general anesthesia and recovery personnel safety. Online survey. An online questionnaire, including questions on general demographic data, recovery drugs, modality and characteristics of equine recovery and morbidity and mortality, was designed and distributed via e-mail to equine practitioners worldwide. Practitioners from 22 countries completed 373 questionnaires; 53% of the participants were board-certified equine surgeons, and the remainder were board-certified anesthesiologists (18%), large animal residents (8%), general practitioners (7%), large animal interns (6%), anesthesia residents (4.5%) and veterinary technicians (1.6%). Respondents were employed by academia (58%) or private practice (42%). Of the respondents employed at a university, 93% had a board-certified anesthesiologist on staff compared with 7% of respondents employed at a private practice. Most of the respondents assist horses during recovery, with 23% assisting every recovery and 44% assisting recovery in the majority of cases. Reasons for choosing to assist horses during recovery were: orthopedic procedures (57%), neurological deficits (49%), bad health (47%), history of poor recovery (44%), foals (42%), draft breeds (30%), magnetic resonance imaging (17%) and computed tomography (16%). Unacceptable recoveries were reported by 77% of participants. Commonly reported complications during recovery with any method were: orthopedic injury (66%), myopathy (54%), skin abrasion (53%) and airway obstruction (37%). The incidences of unacceptable quality of recovery (p = 0.09) or personnel injury (p = 0.56) were not different between assisted and nonassisted recoveries; however, more equine fatalities were reported for assisted recoveries (p < 0.006). Practitioners in academia reported more unacceptable recoveries (p < 0.0007) and personnel injuries (p < 0.002) compared with those in private practice. The method of recovery differs among hospitals. Recovery personnel injuries associated with assisting horses during recovery are an important and previously unreported finding. [ABSTRACT FROM AUTHOR]

Abstract Objective To assess the ability to visually detect fade during train-of-four (TOF) or double burst stimulation (DBS) in anesthetized dogs recovering from nondepolarizing neuromuscular block. Study design Online anonymous survey. Population Data from 112 participants. Methods A web-based survey containing 12 videos of the response to ulnar nerve stimulation with TOF and 12 with DBS obtained at different levels of recovery from rocuronium-induced block was distributed to participants of the American College of Veterinary Anesthesia and Analgesia and the Academy of Veterinary Technicians in Anesthesia and Analgesia e-mail lists. Participants were asked to provide their highest training degree in anesthesiology, watch each video no more than twice, and determine whether fade was present. The probability to correctly recognize fade was calculated using binomial general linear models. General linear models and Tukey's tests were used to assess the effects of level of neuromuscular block, pattern of stimulation, and observers' training on the probability to detect fade. Results The survey was completed by 53 diplomates, 29 licensed veterinary technicians, 24 residents and six doctors of veterinary medicine (DVMs). The probability to detect fade decreased as partial neuromuscular block became more shallow (p < 0.0001). A TOF or DBS ratio of 0.7 had a 50% chance of being detected. DBS was superior to TOF for detecting fade when the ratio was 0.3–0.69. TOF was superior to DBS when the ratio was 0.7–0.9 (p < 0.0001). There were no differences among groups of observers when assessing fade with TOF or DBS. Conclusions and clinical relevance Detection of fade from observations of the response to TOF in dogs is unreliable. Advance training in anesthesiology or the use of DBS confers little to no advantage for this subjective test. [ABSTRACT FROM AUTHOR]

Objective To evaluate the hypothesis that epidural morphine (0.1 mg kg−1) decreases pain in horses after laparoscopic surgery without adversely affecting gastrointestinal ( GI) motility. Study design Randomized clinical trial. Animals Eighteen horses undergoing laparoscopic cryptorchidectomy under general anesthesia. Methods Horses were randomly assigned to receive either epidural morphine (0.1 mg kg−1) or no epidural before the start of surgery. Pain behaviors were assessed during the first two post-operative days using a numerical rating scale. Barium-filled spheres were administered through a nasogastric tube before anesthesia. GI motility was assessed by recording manure production, by quantitating the spheres in the manure, and by abdominal auscultation of intestinal sounds. Heart rates and cortisol concentrations were also measured during the post-operative period. Results Pain scores increased for 12 hours after surgery in the control group and were significantly higher than in the morphine group for the first 6 hours. Pain scores remained unaltered in the morphine group throughout the observation period. Heart rate and plasma cortisol concentrations did not differ between groups or with time. No signs of colic were observed in any horse. Conclusion and clinical relevance Epidural morphine (0.1 mg kg−1) did not adversely affect GI motility in horses after laparoscopic surgery under general anesthesia. [ABSTRACT FROM AUTHOR]

Objective To evaluate the potency and duration of three subparalyzing doses of vecuronium (VEC) in isoflurane-anesthetized horses. Study design Prospective experimental study. Animals Thirteen healthy adult horses undergoing arthroscopic surgery. Methods During isoflurane anesthesia, horses received one of three doses of vecuronium (25, 50, or 100 μg kg−1). Neuromuscular transmission was monitored with acceleromyography (AMG) with train-of-four (TOF) stimulation of the radial nerve. Maximal depression of the first twitch (T1), and onset time were recorded for each dose. Recovery time to a TOF ratio >90% was also evaluated. Results Vecuronium 25 μg kg−1 produced no observable T1 depression in four horses. VEC 50 μg kg−1 ( n = 5) produced a maximal T1 depression of [median (min, max)] 41 (20, 71) % in four horses, and no neuromuscular block was seen in the fifth. VEC 100 μg kg−1 was given to four horses and produced a T1 depression of 73 (64, 78) %. Of the four horses in which VEC 50 μg kg−1 produced a measurable neuromuscular block, three recovered spontaneously 43 (40, 52) minutes after VEC administration; a fourth subject received edrophonium to reverse residual block at the end of the surgery. Spontaneous recovery after VEC 100 μg kg−1 occurred by 112 minutes in one horse, and had to be facilitated by edrophonium in the remaining three horses, more than 2 hours after VEC had been given. Conclusions and clinical relevance A dose of 100 μg kg−1 VEC in isoflurane anesthetized horses failed to produce complete paralysis. The partial neuromuscular block lasted at least 2 hours after this dose had been administered. Edrophonium was required to reverse the neuromuscular block in three of four horses. It is likely that more than 100 μg kg−1 VEC would be necessary for complete neuromuscular blockade in horses, and that this dose will last >2 hours. [ABSTRACT FROM AUTHOR]

History Ten dogs weighing 36 (21.4-75) kg [median (min-max)] and aged 3 (1-9) years scheduled for orthopedic surgery involving the stifle and structures distal to it. Physical Examination Patients were classified as ASA I or II based on physical examination and basic hematology and biochemistry. Management Each dog was managed using combined femoral and sciatic nerve blocks and procedural sedation with an intravenous infusion of propofol (0.07-0.15 mg kg−1 minute−1) and dexmedetomidine (1 μg kg−1 hour−1). None of the patients required conversion to general anesthesia as a result of response to surgical stimulation. The level of sedation was considered adequate in all patients and was characterized by occasional head lifting, thoracic limb stretching, yawning, lingual movements and swallowing. The eye position ranged from central to partial ventromedial rotation and was accompanied by spontaneous blinking. Intra-operative cardiovascular and ventilatory variables were considered within acceptable limits. Muscle relaxation at the surgical field was adequate and surgical conditions were indistinguishable from those produced by general anesthesia. Intraoperatively, no additional analgesics were considered necessary. The quality of the recoveries was considered excellent in all cases. Follow up No additional pain relief was required in any of the dogs within the 10 hours following blockade. All dogs ate 5.5 (3.5-12) hours after recovery. Ambulation occurred at 4 (2-6) hours. No evidence of esophagitis or aspiration pneumonitis has been reported during a period of 1 year after the procedures in any of the dogs. Conclusion When combined with femoral and sciatic nerve blocks, procedural sedation has the potential of being an alternative to general anesthesia for orthopedic surgery involving the stifle and structures distal to it in the dog. [ABSTRACT FROM AUTHOR]

Objective To evaluate the efficacy of combined femoral and sciatic nerve blocks as an alternative to epidural anesthesia and analgesia in dogs undergoing stifle surgery under general anesthesia. Study design Prospective, blinded, randomized, clinical comparison. Animals Twenty dogs weighing 37 ± 11 (mean ± SD) kg, aged 3 (1-8) [median (minimum-maximum)] years undergoing elective unilateral tibial-plateau leveling osteotomy. Methods Dogs were assigned randomly to receive either epidural anesthesia (bupivacaine 0.5%, 0.5 mg kg−1 + morphine 0.1%, 0.1 mg kg−1, in 0.2 mL kg−1; EPID) or femoral and sciatic nerve blocks (Bupivacaine 0.5%, 0.1 mL kg−1, was administered at each site; F + S) guided by electrolocation. All patients received a standard general anesthesia technique. Pain and sedation were scored (on scales of 0-10 and 0-3, respectively) pre-operatively, at extubation, and at 1, 4 and then every 4 hours thereafter up to 24 hours. Postoperatively, hydromorphone was administered to any patient with a pain score of >5 or whenever the blinded caregiver determined that more hydromorphone was necessary. Intraoperative heart rate (HR), mean arterial pressure (MAP), end tidal isoflurane (F E′ISO), body temperature, post-operative pain scores, time to first hydromorphone dose after surgery, time to first feeding, time to first drinking, time to first urination, time to first ambulation (walk on a lead) and cumulative dose of hydromorphone were recorded. Results Intra-operatively, F E′ISO and MAP were significantly lower in the EPID group ( p = 0.05 and p = 0.04, respectively). Postoperatively, the cumulative hydromorphone consumption ( p = 0.04) and the incidence of urinary retention ( p = 0.03) were higher in the EPID group. Conclusion and clinical relevance F + S is a practical alternative to EPID that produces less urine retention and reduces opioid consumption in the 24 hours after surgery. EPID might be associated with a lower isoflurane requirement and lower systemic blood pressure. [ABSTRACT FROM AUTHOR]

Objective To evaluate the non-depolarizing neuromuscular blocking drug cis-atracurium in dogs with porto-systemic shunts, and to compare it in clinically normal animals. Animals Thirteen dogs of mixed breed and sex, aged between 3 and 31 months old, weighing 2.2–25.5 kg, with ASA physical status II–IV, and undergoing surgical attenuation of porto-systemic shunt. A control group of 11 bitches of mixed breed, between 8 and 60 months old, and weighing 4.5–41.0 kg, all ASA physical status I, undergoing routine ovarohysterectomy were also studied. Materials and methods Pre-anaesthetic medication was an opioid analgesic, given either alone or in combination with acepromazine. Following induction of general anaesthesia with intravenous (IV) propofol and oro-tracheal intubation, anaesthesia was maintained using isoflurane in either oxygen or oxygen and nitrous oxide. Ventilation was controlled. The train of four (TOF) technique was used to monitor neuromuscular blockade. An initial dose of 0.1 mg kg−1 cis-atracurium was given IV and additional doses of 0.03 mg kg−1 cis-atracurium were administered when at least one twitch of the TOF was present. Results Except for one dog that was killed during surgery because its anomaly was inoperable, all animals recovered satisfactorily from anaesthesia and surgery. In dogs with porto-systemic shunt, onset of neuromuscular blockade was 3.1 ± 1.1 minutes (mean ± SD) and in control dogs was 3.4 ± 0.7 minutes (not significantly different). Neuromuscular blockade lasted 34 ± 13 minutes in dogs with porto-systemic shunt and 29 ± 17 minutes in control dogs (not significantly different). Conclusions The presence of porto-systemic shunt did not affect the rate of onset or duration of action of cis-atracurium. Clinical relevance cis-Atracurium may have a use in veterinary anaesthesia for producing neuromuscular blockade in dogs with hepatic insufficiency, including those with porto-systemic shunt. [ABSTRACT FROM AUTHOR]