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This clinical study evaluated the speed of reversal of profound rocuronium block in ponies using sugammadex and investigated the differences in onset and recovery from block in three different muscle groups.Anaesthesia was induced and maintained with isoflurane in oxygen 100% in eight ponies. Neuromuscular monitoring was performed at each site using acceleromyography: in the extensor muscles of the pelvic limb (peroneal nerve) and thoracic limb (radial nerve), and in the orbicularis oris muscle (OOM; facial nerve). Rocuronium 0.6 mg kg(-1) i.v. was administered, followed 5 min later by sugammadex 4 mg kg(-1) i.v. Onset time (onsetROC), maximum block, and time to recovery of the train-of-four ratio to 0.9 (TOFR=0.9) were recorded. The differences between monitored sites were compared using one-way anova followed by a post hoc Dunn's test.Onset of ROC was significantly delayed in OOM compared with both limbs [pelvic limb, thoracic limb, and OOM: 43.1 (sd 16.9), 50.6 (15.9), and 204.4 (35.8) s, respectively; P0.001]. Complete block was achieved in the pelvic and thoracic limbs, but in none of the eight ponies in the OOM [mean T1=15.3 (9.4)%; range: 7-36%]. No differences were observed between muscle sites in recovery to TOFR=0.9 [pelvic limb, thoracic limb, and OOM: 2.3 (0.9), 3.4 (1.7), and 2.8 (2.1) min, respectively]. No adverse effects of sugammadex were detected throughout the study period.Sugammadex can be used to reverse profound rocuronium-induced block in ponies during isoflurane anaesthesia. Thoracic limb muscles represent a suitable alternative for monitoring neuromuscular block compared with pelvic limb muscles.

Sixteen captive female red deer were successfully anesthetized to surgically implant a telemetry system. The deer were immobilized with (mean±SD) 1.79±0.29 mg/kg xylazine and 1.79±0.29 mg/kg tiletamine/zolazepam given intramuscularly with a dart gun. Anesthesia was maintained for 69±2 min using a total intravenous protocol with a catheter placed in the jugular vein. Group X received xylazine (0.5±0.055 mg/kg/hr) and group D, detomidine (2±0.22 μg/kg/hr), both in combination with ketamine (2±0.02 mg/kg/hr) and midazolam (0.03±0.0033 mg/kg/hr), as a constant rate infusion. Anesthesia was reversed with 0.09±0.01 mg/kg atipamezole and 8.7±1.21 μg/kg sarmazenil given intravenously in both groups. These drug combinations provided smooth induction, stable anesthesia for surgery, and rapid recovery. Respiratory depression and mild hypoxemia were seen, and we, therefore, recommend using supplemental intranasal oxygen.

Observations A case of a pony with severe cyanide intoxication as a result of cherry ingestion is presented. General anaesthesia was performed for colic surgery. Severe metabolic lactate acidosis in combination with a high arterial oxygen partial pressure and clinically good peripheral perfusion parameters were the remarkable signs during anaesthesia. Severe hypothermia was obvious during recovery. Ten hours post‐surgery the pony was euthanized as a result of neurological signs. The diagnosis of cyanide intoxication was made post‐mortem. Conclusion Cherry ingestion can lead to lethal cyanide intoxication in horses indicated by severe nonhypoxic lactic acidosis during anaesthesia.

The purpose of this study was to evaluate if pre-anaesthetic thoracic radiographs contribute to the anaesthetic management of trauma patients by comparing American Society of Anesthesiologists Physical Status Classification (ASA grade) with and without information from thoracic radiography findings. Case records of 157 dogs and cats being anaesthetized with or without post-traumatic, pre-anaesthetic chest radiographs were retrospectively evaluated for clinical parameters, radiographic abnormalities and anaesthetic protocol. Animals were retrospectively assigned an ASA grade. ASA grades, clinical signs of respiratory abnormalities and anaesthesia protocols were compared between animals with and without chest radiographs. The group of animals without pre-anaesthetic radiographs was anaesthetized earlier after trauma and showed less respiratory abnormalities at presentation. The retrospectively evaluated ASA grade significantly increased with the information from thoracic radiography. Animals with a higher ASA grade were less frequently mechanically ventilated. Pre-anaesthetic radiographs may provide important information to assess the ASA grade in traumatized patients and may therefore influence the anesthesia protocol.

The objectives of this study were to measure the pressure in the caudal extradural space of standing horses and to evaluate the usefulness of pressure waves to identify correct needle placement. Caudal extradural pressure was measured in 12 healthy horses. The pressure and any extradural pressure waves were recorded for 3min after puncture, for 1min after testing for lack of resistance (LOR), and for 10min after lidocaine injection. Successful extradural drug administration was confirmed in all horses. The median extradural pressure findings after puncture, after LOR, immediately after injection and 10min after needle placement were -1.60kPa (range -2.27 to 1.33kPa), -0.67kPa (-2.27 to 5.73kPa), 5.00kPa (0.93 to 9.87kPa) and 0.13kPa (-0.67 to 4.53kPa), respectively. Extradural pressure waves were not always present. Extradural space pressure was sub-atmospheric in most horses and extradural injection significantly increased this pressure for up to 10min. Extradural pressure waves had limited usefulness in the confirmation of the correct placement of the needle.

Purpose The purpose of this study was to determine if intravenous hypertonic hydroxyethyl starch (7.5%/6%) (HES) could decrease the intraocular pressure (IOP) in healthy normotensive dogs, and compare its effect with that of mannitol (20%) (experimental study). In addition, the potential IOP-lowering effect of hypertonic HES was evaluated in six dogs with primary glaucoma (clinical study). Material and methods Experimental study: eight male ophthalmoscopically and clinically healthy Beagles were included in this study. The IOP of each dog was measured by applanation tonometry in both eyes to obtain control values at 10:00, 10:15, 10:30, 10:45, 11:00 a.m., and then every hour until 6:00 p.m. prior to the first treatment (control period). Each dog received, with at least 2-week intervals and in a random order, an intravenous (IV) infusion of 4 mL/kg hypertonic HES (1.2 g/kg NaCl; 0.96 g/kg HES) and 4 mL/kg mannitol 20% (1 g/kg) over a period of 15 min starting at 10:00 a.m. IOP was measured oculus uterque (OU) at the same time intervals as in the control study. The differences in IOP between the treatment groups and the baseline IOP (before the start of infusion), between oculus sinister (OS) and oculus dexter (OD) and between the same time points of all groups were determined with a Student's t-test for paired samples (P = 0.05). Clinical study: six dogs with primary glaucoma (representing seven eyes) received an IV infusion of 4 mL/kg hypertonic HES over a period of 15 min. IOP was measured before and 15 and 30 min after starting the infusion. Results Experimental study: no significant difference between IOP of both eyes was found. A significant decrease in IOP from baseline value was recorded at 15, 30, 45, and 60 min after the start of mannitol infusion (mean amplitude in IOP decrease 3.21 mmHg; P

Objective To evaluate the neuromuscular blocking and chronotropic effects of rocuronium bromide in cats anaesthetized for surgery. Study design Prospective clinical trial. Animals Twenty-two healthy cats of mixed breed presented for ovariectomy (n = 13) or castration (n = 9). Mean body mass (±SD) was 3.6 ± 0.65 kg and mean age was 10.25 ± 2.63 months. Methods Anaesthesia was induced with intravenous (IV) midazolam (0.3 mg kg−1), ketamine (3 mg kg−1) and butorphanol (0.4 mg kg−1). Tracheal intubation was performed and anaesthesia was maintained with isoflurane delivered in 100% oxygen. Neuromuscular function was monitored using acceleromyography applied at the ulnar nerve. This was stimulated by using the train-of-four (TOF) stimulus pattern (2 Hz) delivered every 15 seconds. The first train was made to establish baseline values for the first twitch (T1) and the TOF-ratio (T4:T1). Rocuronium (0.6 mg kg−1 IV) was given and the following periods were recorded beginning at the end of injection: (1) lag time (LT) – to the first signs of T1 depression; (2) onset time (OT) – to the total ablation of T1; (3) duration of action (T125) – to 25% recovery of the baseline value for T1; (4) T150– to 50% baseline T1 restoration; (5) to TOF-ratios of 0.7 and 0.9. The time taken for T1 to recover from 75% to 25% depression (T125−75) was also recorded. Heart rate (HR) was taken every minute for 15 minutes, beginning 5 minutes before rocuronium was injected. Results Rocuronium (0.6 mg kg−1) had a mean LT of 15.0 ± 0 seconds, OT of 46 ± 11 seconds and T125 of 13.2 ± 2.7 minutes. The mean time for TOF 0.7 and 0.9 was 17.3 ± 5.4 and 20.7 ± 5.4 minutes respectively. The mean T125−75 was 4.8 ± 2.4 minutes. No significant changes in HR were observed at any of the time intervals recorded. Conclusion Rocuronium is an effective nondepolarizing muscle relaxant in the cat under the clinical conditions of this study. It has a rapid onset, a short duration of action and did not cause significant changes in HR.

To compare haemodynamic and respiratory variables during isoflurane-fentanyl (IF) and propofol-fentanyl (PF) anaesthesia for surgery in injured cats.Prospective, randomized, controlled clinical study.Thirty-three client-owned injured cats undergoing orthopaedic surgery.Pre-anaesthetic medication was intravenous midazolam 1 mg kg(-1), butorphanol 0.4 mg kg(-1) and ketamine 2 mg kg(-1). Anaesthesia was induced with propofol (P) and maintained with either: (a) a continuous rate infusion (CRI) of fentanyl (F) 0.02 mg kg(-1) hour(-1) and isoflurane (initial end-tidal concentration of 1%), (b) a fentanyl CRI (dose as before) and sevoflurane (initial end-tidal concentration of 2%) or (c) a CRI of propofol (12 mg kg(-1) hour(-1)). All three techniques were given to effect until surgical anaesthesia was achieved. Heart rate and rhythm (ECG), mean arterial blood pressure, respiratory rate, tidal volume and end-tidal CO(2) concentration were recorded. Venous blood gas analysis was performed before and after sedation, and at the end of anaesthesia. Blood chemistry and blood cell counts were assessed before, at the end of, and 24 hours after anaesthesia. The variables recorded from cats anaesthetized with IF and PF were compared.Mean end-expiratory isoflurane concentration was 1.19 +/- 0.19%. The propofol infusion rate was 11.4 +/- 0.8 mg kg(-1) hour(-1). No significant differences between the two groups in heart rate were identified; no cardiac dysrhythmias were recorded. Mean arterial blood pressure was significantly lower in IF cats during skin incision (p = 0.01), during surgery without intense surgical stimulation (p0.01) and during surgery with intense surgical stimulation (p = 0.01). Nine of 11 cats in the IF group were markedly hypotensive (34-49 mmHg) while seven of 11 cats in group PF were mildly hypotensive (49-59 mmHg). One of 11 cats in group IF and nine of 11 cats in group PF required intermittent positive pressure ventilation (IPPV) to maintain end-tidal CO(2) levels below 6.66 kPa (50 mmHg).Despite the necessity to ventilate the lungs of cats in the PF group, arterial blood pressure was better maintained. Propofol-fentanyl anaesthesia is better for surgery in injured cats providing the means to impose IPPV are available.

Objective To compare the effects of intravenous (IV) and extradural (ED) methadone on end-tidal isoflurane concentration (F e ′ISO) and postoperative analgesic requirements in dogs undergoing femoro-tibial joint surgery. Study design Randomized, blinded, clinical study. Animals Twenty-four healthy client-owned dogs undergoing surgical repair of ruptured cruciate ligaments. Methods Dogs were randomly assigned to two groups of 12 animals and received either ED or IV methadone (0.3 mg kg−1 diluted with saline to 0.2 mL kg−1). Pre-anaesthetic medication was IV acepromazine (0.05 mg kg−1). Anaesthesia was induced with propofol and maintained initially with an F e ′ISO of 1.0% delivered in oxygen. Methadone was injected with the dogs in sternal recumbency; the observer was unaware of the administration route. At 10 minutes (stimulation 1) and 20 minutes (stimulation 2) after methadone administration pelvic limb reflexes were tested by digit-clamping. The time at skin incision (stimulation 3), joint-capsule incision (stimulation 4), tibial tuberosity drilling (stimulation 5), fabellar suturing (stimulation 6) and extracapsular tightening (stimulation 7) were noted. Changes in heart rate (HR) and respiratory rate and arterial blood pressure associated with surgery were recorded along with the corresponding F e ′ISO. After 20 minutes of anaesthesia, F e ′ISO was decreased to the minimum required to maintain stable anaesthesia. Immediately after tracheal extubation, 1, 2, 3 and 6 hours postoperatively and on the morning after surgery, the degree of pain present was assessed using a numerical rating scale. The HR, respiratory rates and blood pressure were also recorded at these times. Serum cortisol and blood glucose concentrations were measured before pre-anaesthetic medication and at each postoperative pain scoring interval except at 1 and 2 hours. Ketoprofen (2 mg kg−1), carprofen (4 mg kg−1) or meloxicam (0.2 mg kg−1) were given by subcutaneous injection whenever pain scoring indicated moderate discomfort was present. Results Controlled ventilation was required in six dogs which stopped breathing after IV methadone. The median F e ′ISO at stimulus 5 was 1.0% in the IV and 0.83% in the ED group. At stimulus 6, F e ′ISO was 1.0% in the IV and 0.8% in the ED group; the difference was statistically significant (p ≤ 0.05). There was no significant difference in the duration of postoperative analgesia associated with administration route. Conclusions Extradural methadone significantly reduces the isoflurane requirement compared with IV methadone during femoro-tibial joint surgery in dogs. Clinical relevance Extradural methadone provides safe and effective pain relief in dogs undergoing cruciate ligament repair.

Zusammenfassung Gegenstand und Ziel: Beschreibung einer Katze mit Atem- und Kreislaufstillstand verursacht durch Hyperkaliämie nach ischämischer Muskelnekrose. Pathogenese, Klinik, Komplikationen und Therapie von ischämischer Muskelnekrose werden diskutiert und mögliche Ursachen, Symptome und Therapiemöglichkeiten einer Hyperkaliämie beschrieben. Material und Methoden: Fallbericht einer vierjährigen, männlich-kastrierten Hauskatze. Ergebnisse: Die Katze wurde erfolgreich reanimiert und die Hyperkaliämie ließ sich mittels verschiedener Therapieansätze normalisieren. Der Kater konnte nach Hause entlassen werden. Schlussfolgerungen: Bei ischämischer Muskelnekrose kann es während der Reperfusionsphase zu einer lebensgefährlichen Hyperkaliämie kommen, die überwacht und entsprechend therapiert werden muss. Bei aggressiver Flüssigkeitstherapie ist das Risiko einer Kaliumund Toxinfreisetzung aus dem ischämischen Muskel unter Umständen größer. Klinische Relevanz: Bei ischämischer Muskelnekrose sollten Kaliumkonzentration und Säure-Basen-Haushalt regelmäßig überwacht werden.

Objective To evaluate and compare the effects of caudal epidural administration of methadone (METH) and lidocaine (LIDO) on tolerance to thermal stimulation over the dermatomes of the perineal, sacral, lumbar and thoracic regions in the horse. Study design A blinded, randomized, prospective, experimental cross–over study. Animals Seven healthy horses, 15.7 ± 4.9 years (mean ± SD) of age, weighing 536 ± 37 kg. Methods The horses were randomly assigned to receive two treatments (group M: METH, 0.1 mg kg−1 or group L: LIDO, 0.35 mg kg−1) at intervals of at least 28 days. An 18–gauge 80–mm Tuohy epidural needle was placed in the first intercoccygeal space (Co1–Co2) in awake standing horses restrained in stocks. Analgesia was assessed by use of a probe maintained at a constant 62 °C by circulating hot water. The maximum stimulation time was 30 seconds. Bilateral stimulation was performed at five defined points. Before drug administration, baseline values of response time to thermal stimuli were obtained. Time to response was then measured 15 and 60 minutes after METH or LIDO administration and then hourly until the response returned to baseline at all stimulation points on two further assessments. Development of any ataxia and/or sedation was recorded. Positive pain responses were defined as purposeful avoidance movements of the head, neck, trunk, limbs and tail. Absence of attempts to kick, bite and turning of the head toward the stimulation site were used to indicate analgesia. Results Caudal epidural administration of METH and LIDO significantly increased reaction time to thermal stimulation (one–sample t–test; p = 0.05). Analgesia in the perineal region was present 15 minutes after both METH and LIDO administration and progressed from caudal to cranial dermatones with time. The duration of a significant increase in reaction time was 5 hours after METH injection compared to 3 hours following LIDO. All horses defaecated and urinated normally, and no excitement, sedation or ataxia were observed after METH administration. The horses were unable to defaecate normally and were moderately to severely ataxic with hindlimb weakness after LIDO. Conclusions Caudal epidural administration of methadone has considerable potential in the management of perineal, lumbo–sacral and thoracic pain in horses. Regional differences exist in the onset, duration and intensity of the pain relief. Clinical relevance Epidural methadone administration provides analgesia with no measured side effects in these healthy adult horses.

The aim of the study was to compare two methods of measuring physiological dead space/tidal volume ratio (Vd/Vt) and alveolar dead space (VdALV). Measurements were obtained by automated single breath CO2 analysis (Ventrak 1550/Capnoguard 1265 (V&C)) and classical calculations were carried out using the Enghoff–Bohr equation in anaesthetized dogs. The V&C consists of a mainstream capnometer, a pneumotachometer, a signal processor, and computer software to determine continuous single-breath CO2 analysis (SBT-CO2). Eleven dogs of mixed breed (five female, six male) mean body mass 35 ± 10 kg, aged 9 months to 8 years were studied. Pre-anaesthetic medication was acepromazine (0.03 mg kg−1) and methadone (0.1 mg kg−1). Anaesthesia was induced with propofol given to effect and maintained with propofol (10 mg kg−1 hour−1) and fentanyl (0.02 mg kg−1 hour−1) by infusion. The dog's trachea were intubated and the carbon dioxide and flow sensor were placed between the tube and the Y-piece of a circle system (FiO2 = 1.0). Controlled ventilation was started (tidal volume 10–15 mL kg−1) and settings were not changed throughout the measurement period. Mixed expired PCO2 (P eCO2) was measured by analyzing expired gas collected in a mixing box in the expiratory limb of the circle system. The dorsal pedal artery was cannulated for arterial blood sampling and analysis. Measurements were done every 15 minutes for 1 hour. The Vd/Vt was automatically calculated and displayed from the SBT-CO2 analysis and also obtained using the Enghoff modification of the Bohr equation (Vd/Vt = (PaCO2 − P eCO2)/PaCO2). Alveolar dead space was determined by calculating the physiological dead space (Vdphys = expired volume × (Vd/Vt)) and subtracting the anatomical dead space measured by SBT-CO2. Values for Vd/Vt and VdALV obtained with both methods were compared using Students t-test. The mean values from the automatic dead space calculation (Vd/Vt: 0.62–0.63; VdALV: 56.1–64.3 mL) did not differ significantly from those calculated arithmetically (Vd/Vt: 0.62–0.63; VdALV: 54.09–66.31 mL). The mean differences and standard deviation in Vd/Vt was 0.63 ± 0.00 and in VdALV 58.98 ± 4.28 mL for the two measurement techniques. Our data indicate that V&C can be used for accurate noninvasive online Vd/Vt and VdALV measurements in anaesthetized ventilated dogs.

Summary Earplugs are occasionally used to reduce horses responsiveness to noise but there performance has not been evaluated. A modified 'micro- phone in real ear' technique was used to quantitatively assess the effects of several earplugs on sound transmission in the external ear of equine cadavers. Significant variations in the performance of the earplugs tested were identified. These results may affect the selection of earplugs for clinical use and should inform the design of future investigations into the clinical utility of earplugs in horses Ohrstopsel werden bei Pferden verwendet um Umgebungslarm zu reduzieren und dadurch das Pferd zu beruhigen oder ruhig zu halten. Die Schallreduktion der am Markt erhaltlichen Ohrstopsel wurde bisher noch nicht wissenschaftlich evaluiert. In dieser Studie wurde eine modifizierte "Mikrophon in echtem Ohr" Methode verwendet um die Abschwachung der Gerauschubertragung durch kommerziell verfug- bare Ohrstopsel zu messen. Es wurden dafur 6 Pferdekadaver verwendet, die in gleicher Weise in einer gepolsterten Aufwachbox gelagert wurden. Die Dimensionen der Pinna wurden gemessen und aufgezeichnet. Ein Mikrophon wurde in den auseren Gehorgang eingebracht und Lautsprecher wurden 1.5 Meter von der Nasenspitze entfernt aufgestellt Danach wurde eine definierte Tonabfolge uber die Lautspre- cher abgespielt und mit dem Mikrophone aufgezeichnet (Basiswert). In weiterer Folge wurden 5 verschiedene kommerziell erwerbbare Ohr- stopsel und ein selbstgemachter Wattestopsel in randomisierter Folge in den auseren Ohrkanal distal des Mikrophons eingebracht und die Tonfolge mit jedem Ohrstopsel dreimal abgespielt und aufgezeichnet. Ein neuerlicher Basiswert wurde zwischen jeder Messung aufge- zeichnet. Die Schallreduktion (minimale, maximale und mittlere "Root Mean Square" Amplitude = RMSA) von jedem einzelnen Produkt sowie die Differenz in den Basiswerten zwischen den Kadavern wurde mittels Kruskal-Wallis Test mit folgendem post-hoc Test auf Signifikanz uberpruft. Signifikante Unterschiede zwischen den 5 Produkten und dem Wattestopsel wurden in der Reduktion des Schalls gefunden. Nur ein einziger kommerziell verfugbarer Ohrstopsel (Finntrack 12704) zeigte eine bessere Reduktion der RMSA Werte als die selbstgemach- ten Wattestopsel. Ein signifikanter Unterschied wurde im Ausgangswert zwischen den Kadavern gefunden. Kein signifikanter Unterschied wurde zwischen den Basiswerten innerhalb eines Kadavers gefunden. Die Schallreduktion der einzelnen Ohrstopsel zwischen Kadavern zeigte keinen signifikanten Unterschied. Diese Pilotstudie zeigt, dass ein groser Unterschied in der Schallreduktion zwischen kommerziell verfugbaren Ohrstopseln besteht. Dies kann die klinische Wahl beeinflussen und eine wichtige Rolle bei zukunftigen Studien spielen in denen eine Schallreduktion eine wichtige Rolle spielt.

Collapse of dependent lung regions and high intrapulmonary shunt fractions are very common in anaesthetized horses. We have observed that horses show breath-holding after recovering from anaesthesia, the purpose of which has not been previously evaluated.