Evaluation of transpulmonary ultrasound dilution cardiac output in piglets: accuracy,precision and trending ability with room temperature injectate

ObjectiveTranspulmonary ultrasound dilution (TPUD) is a minimally invasive technique to measure cardiac output (CO) using a 1 mL kg^–1 isotonic 37 °C saline injectate indicator. The objective was to evaluate the performance of TPUD using a room temperature saline injectate.Study designProspective experimental trial.AnimalsA total of seven anesthetized male Yorkshire piglets.MethodsPiglets aged 1 month and weighing 7.7–9.0 kg were anesthetized with detomidine–ketamine–hydromorphone–isoflurane and a pulmonary artery flow probe (PAFP) placed via a median sternotomy. The thoracic cavity remained open during measurement of CO by PAFP and TPUD. The TPUD indicators of 1 mL kg^–1 0.9% saline at 37 °C and 20 °C were compared during infusions of phenylephrine and dobutamine, blood withdrawal and replacement. Bias, limits of agreement (LoAs) and percentage error (PE) between each iteration of PAFP and TPUD were measured with Bland–Altman plots. Trending ability via concordance, angular bias and radial LoA were compared.ResultsBland–Altman plots showed negligible bias with varying LoAs. PEs of 22% and 38% were found for 37 °C and 20 °C saline injectates, respectively. In the four-quadrant plots, the concordance rate was 94% and 100% for measurements obtained with 37 °C and 20 °C saline injectates, respectively. Angular bias for both were < ±5 °, with radial LoA < ±7 °.ConclusionsTPUD was accurate when using 1 mL kg^–1 of isotonic saline at 37 °C in a range of CO within 0.2–0.8 L minute^–1, and it reliably tracked positive and negative changes in CO. Room temperature (20 °C) indicator was less accurate but equally able to track direction of changes in CO.Clinical relevanceThe use of room temperature injectates allows an easy, readily available clinical application of TPUD CO monitoring while preserving the trending ability of the monitor.     

Effect of anesthetic induction with propofol,alfaxalone or ketamine on intraocular pressure in cats: a randomized masked clinical investigation

ObjectiveTo compare the effect of propofol, alfaxalone and ketamine on intraocular pressure (IOP) in cats.Study designProspective, masked, randomized clinical trial.AnimalsA total of 43 ophthalmologically normal cats scheduled to undergo general anesthesia for various procedures.MethodsFollowing baseline IOP measurements using applanation tonometry, anesthesia was induced with propofol (n = 15), alfaxalone (n = 14) or ketamine (n = 14) administered intravenously to effect. Then, midazolam (0.3 mg kg^?1) was administered intravenously and endotracheal intubation was performed without application of topical anesthesia. The IOP was measured following each intervention. Data was analyzed using one-way anova and repeated-measures mixed design with post hoc analysis. A p-value <0.05 was considered significant.ResultsMean ± standard error IOP at baseline was not different among groups (propofol, 18 ± 0.6; alfaxalone, 18 ± 0.7; ketamine, 17 ± 0.5 mmHg). Following induction of anesthesia, IOP increased significantly compared with baseline in the propofol (20 ± 0.7 mmHg), but not in the alfaxalone (19 ± 0.8 mmHg) or ketamine (16 ± 0.7 mmHg) groups. Midazolam administration resulted in significant decrease from the previous measurement in the alfaxalone group (16 ± 0.7 mmHg), but not in the propofol group (19 ± 0.7 mmHg) or the ketamine (16 ± 0.8 mmHg) group. A further decrease was measured after intubation in the alfaxalone group (15 ± 0.9 mmHg).Conclusions and clinical relevancePropofol should be used with caution in cats predisposed to perforation or glaucoma, as any increase in IOP should be avoided.     

Development and evaluation of an anatomically designed and 3D printed device to enhance orotracheal intubation success in rabbits by inexperienced veterinarians

ObjectiveTo assess whether the use of a three-dimensional (3D) printed device enhances the success rate of orotracheal intubation in rabbits.Study designProspective, crossover randomized controlled trial.AnimalsA total of six mixed-breed rabbits.MethodsA device to guide the endotracheal tube was designed based on computed tomography images and then manufactured using 3D printing. Rabbits were randomly assigned for intubation by two inexperienced veterinarians using the blind (BLI), borescope- (BOR) or device- (DEV) guided techniques. Success rate, number of attempts, time to success, injury scores and propofol dose were recorded and compared. Significance was considered when p < 0.05.ResultsSuccess rate was higher in DEV (58.3%) than in BLI (8.3%) (p < 0.023), but not different from that in BOR (41.6%). Total time until successful intubation was lower in DEV (45 ± 23 seconds) and BOR (85 ± 62 seconds) than in BLI (290 seconds; p < 0.006). Time for the successful attempt was lower for DEV (35 ± 10 seconds) and BOR (74 ± 43 seconds) than in BLI (290 seconds; p < 0.0001). The propofol dose required was lower for DEV (2.3 ± 1.2 mg kg^–1) than for BLI (3.4 ± 1.6 mg kg^–1) (p < 0.031), but not different from BOR (2.4 ± 0.9 mg kg^–1). Number of attempts and oxygen desaturation events were not different among techniques (p < 0.051 and p < 0.326, respectively). Injury scores [median (range)] before and after attempts were different in BLI [0 versus 1 (0–3), p < 0.005] and BOR [0 (0–1) versus 1 (0–3), p < 0.002] but not in DEV [0 (0–2) versus 0 (0–3), p < 0.109].Conclusions and clinical relevanceThe device facilitated orotracheal intubation with a time similar to the borescope-guided technique but faster than the traditional blind technique.     

A non-inferiority study comparing the ultrasound-guided parasacral with a novel greater ischiatic notch plane approach in canine cadavers

ObjectiveTo describe the gross and ultrasound anatomy of the parasacral region and an ultrasound-guided greater ischiatic notch (GIN) plane approach aimed at staining the lumbosacral trunk (LST) in canine cadavers. To evaluate if the ultrasound-guided GIN plane approach is non-inferior to the previously described ultrasound-guided parasacral approach at staining the LST.Study designProspective, randomized, non-inferiority experimental anatomic study.AnimalsA total of 17 (23.9 ± 5.2 kg) mesocephalic canine cadavers.MethodsAnatomic and echographic landmarks, and the feasibility of performing a GIN plane technique were evaluated using two canine cadavers. The remaining 15 cadavers had each hemipelvis randomly assigned to be administered either parasacral or GIN plane injection of 0.15 mL kg^–1 dye solution. The parasacral region was dissected after injections to assess the staining of LST, cranial gluteal nerve, pararectal fossa and pelvic cavity. The stained LST were removed and processed for histological evaluation of intraneural injections. A one-sided z-test for non-inferiority (non-inferiority margin –14%) was used to statistically evaluate the success of the GIN plane versus the parasacral approach. Data were considered statistically significant when p < 0.05.ResultsThe GIN plane and parasacral approach stained the LST in 100% and 93.3% of the injections, respectively. The success rate difference between treatments was 6.7% [95% confidence interval, –0.6 to 19.0%; p < 0.001 for non-inferiority]. The GIN plane and parasacral injections stained the LST for 32.7 ± 16.8 mm and 43.1 ± 24.3 mm, respectively (p = 0.18). No evidence of intraneural injection was found.Conclusions and clinical relevanceThe ultrasound-guided GIN plane technique resulted in nerve staining that was non-inferior to the parasacral technique and may be considered an alternative to the parasacral approach to block the LST in dogs.     

Lumbosacral plexus block using a combination of ultrasound-guided lateral pre-iliac and parasacral approaches in cats

ObjectiveTo describe an ultrasound-guided lateral pre-iliac (LPI) and parasacral (PS) approach in feline cadavers (phase I) and compare the perioperative analgesic use and complications in cats administered LPI and PS blocks (group PNB) or epidural anesthesia (group EPI) for pelvic limb surgery (phase II).Study designExperimental uncontrolled, anatomic and retrospective cohort study.AnimalsA group of eight feline cadavers and 52 medical records.MethodsBilateral LPI and PS approaches with 0.1 mL kg^–1 of dye to stain the femoral and obturator nerves and the lumbosacral trunk, respectively, were performed on each cadaver. Nerve staining effect was evaluated upon dissections (phase I). Perioperative analgesics use, and complication rates were retrospectively compared between groups PNB and EPI (phase II). Continuous data were compared using the Mann–Whitney U test and the prevalence of events with Fisher’s exact test. Differences were considered significant when p < 0.05.ResultsDissections revealed that the LPI approach stained 94% and 75% of the femoral and obturator nerves, respectively. The PS approach stained 100% of the lumbosacral trunks. Cats enrolled in group PNB (n = 23) were administered lower doses of intraoperative opioids than those in group EPI (n = 25) (p = 0.006). Intraoperative rescue analgesia was required in 60% and 17.4% of cats enrolled in groups EPI and PNB, respectively (p = 0.003). Group PNB required more intraoperative anticholinergics than group EPI (p = 0.02). There were no differences in postoperative pain scores, analgesic use and complication rates.Conclusions and clinical relevanceThe ultrasound-guided LPI and PS approach stained the femoral/obturator nerves and the lumbosacral trunk, respectively, in feline cadavers. Furthermore, PNB was associated with lower intraoperative opioid use and similar postoperative pain and analgesic use compared with epidural anesthesia in a cohort of cats undergoing surgery of the pelvic limb.     

Anesthetic and analgesic techniques used for cats undergoing ovariohysterectomies in general practice in the United States

ObjectiveTo better document anesthetic and analgesic protocols used by veterinarians in general practice within the United States (US) when performing elective ovariohysterectomy in cats.Study designCross-sectional survey.PopulationVeterinary practitioners in the US who are members of the Veterinary Information Network Inc. (VIN).MethodsAn online anonymous survey was distributed to VIN members. The survey included questions pertaining to preanesthetic evaluation, premedication, induction, monitoring and maintenance protocols, and postoperative analgesia and sedation protocols when performing ovariohysterectomy in cats.ResultsA total of 1324 veterinarians completed the survey. Respondents (number; %) reported performing preanesthetic laboratory tests [packed cell volume (256; 19.3%), complete blood cell count (893; 67.4%) and biochemistry panels (1101; 83.2%)] and preanesthetic examinations (1186; 89.6%) on the morning of surgery. The most frequently administered drugs for premedication were dexmedetomidine (353; 26.7%) and buprenorphine (424; 32.0%). The most frequently administered induction agent was propofol (451; 61.3%), and isoflurane (668; 50.4%) was the most common agent for maintenance of anesthesia. The majority of respondents reported placing intravenous catheters (885; 66.8%), administering crystalloid fluids (689; 52.0%) and providing heat support (1142; 86.3%). Participants reported using perioperative and postoperative analgesia including opioids (791; 59.7%), non-steroidal anti-inflammatory drugs (NSAIDs; 697; 52.6%) and NSAIDs dispensed for home use (665; 50.2%). Cats were commonly released home on the day of surgery (1150; 86.9%), and most participants reported contacting owners for follow-up within 1–2 days (989; 74.7%).Conclusions and clinical relevanceAnesthetic protocols and management techniques for routine feline ovariohysterectomy differ widely among US veterinarians who are VIN members, and results from this study may be of use to evaluate anesthetic practices from this population of veterinarians.     

Immobilization of captive plains zebras (Equus quagga) with a combination of etorphine hydrochloride,acepromazine, and xylazine hydrochloride

The plains zebra (Equus quagga) is a zebra species commonly kept in zoos around the world. However, they are not tame like their domestic relatives and are difficult to immobilize. We immobilized 30 captive plains zebra with a combination of etorphine hydrochloride (2–4 mg), acepromazine (8 mg), and xylazine hydrochloride (30 or 50 mg) to perform physical examination and blood sample collection for disease diagnostics. Physiological parameters including heart rate, respiratory rate, body temperature, and hemoglobin oxygen saturation were recorded. All zebras exhibited satisfactory anesthesia and fully recovered without re-narcotization. The results suggest that etorphine hydrochloride-acepromazine-xylazine hydrochloride combination for plains zebra immobilization is a safe and sufficient regimen for short procedures such as wellness examinations and sample collection.     

MS-222对鳊鱼麻醉保活运输效果的研究

为研究MS-222对鳊鱼保活运输的影响,分析比较了在不同质量浓度MS-222(0、20、40、60、80、100 mg/L和120 mg/L)、不同水温(2、7、15、20℃)和不同鱼水质量比(2∶1、1∶1、1∶3、1∶5)下鳊鱼的存活率,从而确定及筛选最佳的保活运输条件,并检测和分析在保活运输试验中水质指标和鱼体生化指标的变化和影响。试验结果显示,当MS-222质量浓度为60 mg/L、水温7℃、鱼水比1∶3时,保活时间最长,鱼体存活率最高;随着保活时间的延长,水体指标中氨氮含量、微生物、pH均呈上升趋势,而溶解氧水平则呈下降趋势;在鱼体指标中,肌肉中糖原、pH下降,乳酸含量上升;在血液指标中乳酸脱氢酶、谷草转氨酶、血糖、尿素和肌酐均显著增加(P<0.05),说明随着保活时间的延长,鱼体肝脏和肾脏组织代谢水平受到一定的影响,但其变化幅度均小于对照组。研究结果表明,在鳊鱼保活过程中可适当使用MS-222麻醉剂以延长存活时间和提高存活率。     

Recommended doses of medetomidine-midazolam-butorphanol with atipamezole for preventing hypothermia in mice

A non-narcotic anesthetic combination (Me/Mi/Bu) of medetomidine (Me), midazolam (Mi), and butorphanol (Bu) has been recommended as the injectable anesthesia in mice. An original dose of Me/Mi/Bu (0.3/4.0/5.0 mg/kg) has provided sufficient anesthetic duration of 40–50 min in mice. In addition, atipamezole is available for reversal of Me/Mi/Bu anesthesia. As an adverse effect of Me/Mi/Bu anesthesia, however, severe hypothermia has been also observed in mice. In the present study, we investigated 1) the main agent in Me/Mi/Bu to cause of hypothermia, 2) the effects of the differential doses of atipamezole on hypothermia induced by Me/Mi/Bu anesthesia and on the plasma levels of creatinine phosphokinase and transaminases, and 3) those recommended doses for preventing hypothermia induced by Me/Mi/Bu anesthesia in mice. The results suggested that 1) the α₂-agonist medetomidine is most likely to induce hypothermia in mice under Me/Mi/Bu anesthesia, 2) the antagonism of atipamezole within proper dose range is effective in promoting the recovery from Me/Mi/Bu-induced hypothermia, and 3) Me/Mi/Bu at the recommended dose of 0.2/6.0/10.0 mg/kg enable to provide anesthetic effects for 40 min and is more considerable to prevent the hypothermia than that at the original dose of 0.3/4.0/5.0 mg/kg.     

Effects of Ropivacaine-sufentanil Epidural Analgesia on Labor and Maternal and Neonatal Outcomes

[Objectives]This study aimed to investigate the effects of ropivacaine-sufentanil epidural analgesia on labor and maternal and neonatal outcomes.[Methods]A tota...