Evaluation of a minimally invasive non-calibrated pulse contour cardiac output monitor (FloTrac/Vigileo) in anaesthetized dogs

ObjectiveTo evaluate the accuracy of a new cardiac output monitor (FloTrac/Vigileo), originally designed for humans, in dogs. This pulse contour cardiac output monitoring system cannot be calibrated and measures cardiac output (

t) from a standard arterial catheter.Study designProspective experimental trial.AnimalsEight adult Beagle dogs weighing 13.1 (9.8–17.1) kg [median (range)].MethodsAnaesthesia in the dogs was maintained using isoflurane. A pulmonary artery catheter and a metatarsal arterial catheter (22 gauge) were placed. Cardiac output was measured simultaneously 331 times by thermodilution and FloTrac technique. A broad spectrum of

t measurements was achieved through alterations of isoflurane concentration, administration of propofol boluses and dobutamine infusions. Agreement between the methods was quantified with Bland Altman analysis and disagreement was assessed with linear mixed models.ResultsMedian (10th and 90th percentile) cardiac output as measured with thermodilution was 2.54 (1.47 and 5.15) L minute^?1 and as measured with FloTrac 8.6 (3.9 and 17.3) L minute^?1. FloTrac measurements were consistently higher with a mean bias of 7 L minute^?1 and limits of agreement of ?3.15 to 17.17 L minute^?1. Difference between the methods was most pronounced in high

t measurements. Linear mixed models showed an estimated difference between the two methods of 8.05 (standard error 1.18) L minute^?1 and a significant interaction between mean arterial pressure and method. Standard deviation (4.45 higher) with the FloTrac method compared to thermodilution was increased.ConclusionCompared to thermodilution measurements, the FloTrac system was influenced to a higher degree by arterial blood pressure, resulting in consistent overestimation of cardiac output.Clinical RelevanceThe FloTrac monitor, whose algorithms were developed based on human data, cannot be used as an alternative for thermodilution in dogs.     

Myoglobin as a prognostic indicator for outcome in dogs with gastric dilatation-volvulus

Objective – To determine whether myoglobin (Mb) is a useful prognostic indicator for outcome and to investigate any relationship between Mb and mortality in dogs with gastric dilatation‐volvulus (GDV). Design – Prospective study. Setting – Veterinary teaching hospital. Animals – Seventy‐two dogs with GDV. Interventions – Blood sampling. Measurements and Main Results – Mb levels were measured at the time of diagnosis (Mbt₀), 24 hours (Mbt₁), and 48 hours (Mbt₂) after signs of GDV were recognized. Fifty‐seven dogs survived (group I) and 15 dogs did not survive (group II). Mb t₀ differed significantly between groups (P=0.04). Mbt₀ in group I ranged from <30 to >700 ng/mL (n=57, median 74 ng/mL), and in group II from 34 to >700 ng/mL (n=15, median 238 ng/mL). Analysis of a receiver operating characteristic curve of Mbt₀ suggested that the best single cutpoint would be 168 ng/mL (sensitivity 60.0%, specificity 84.2%). Fifty percent of dogs with Mbt₀>168 ng/mL were euthanized, while 88.9% with Mbt₀<168 ng/mL survived. Mbt₁ and Mbt₂ differed significantly between groups I and II. Mbt₁ in group I ranged from 32 to >700 ng/mL (n=55, median 123 ng/mL), and Mbt₁ in group II ranged from 131 to 643 ng/mL (n=7, median 343 ng/mL) (P=0.006). Mbt₂ in group I ranged from 30 to 597 ng/mL (n=54, median 101 ng/mL), and in group II from 141 to >700 ng/mL (n=8, median 203 ng/mL) (P=0.02). Conclusions – In this study, Mbt₀ is a moderately sensitive and specific prognostic indicator. Almost 90% of the dogs below the cutpoint survived to discharge, whereas 50% with Mbt₀ above the cutpoint did not survive.     

Dexmedetomidine low dose followed by constant rate infusion and antagonism by atipamezole in isoflurane-anesthetized cats: an echocardiographic study

Objective

To investigate the effects of a low dose of dexmedetomidine (DEX) followed by constant rate infusion (CRI) and reversal with atipamezole on systolic and diastolic functions in isoflurane-anesthetized healthy cats.

夹竹桃（Nerium indicum）皂甙对鲫鱼（Carassius auratus）幼鱼的影响

为了评价夹竹桃皂甙对非靶标生物的潜在危害,采用半静态法研究了不同浓度（0、5.89、20.12mg·L-1和80.76mg·L-1）的夹竹桃皂甙对鲫鱼幼苗的死亡情况、特定生长率、糖原、蛋白质含量、SOD酶活性和微核率的影响。结果表明,当夹竹桃皂甙处理浓度≤20.12mg·L-1时,处理组的鲫鱼在试验期间无死亡;而在80.76mg·L-1皂甙的处理下,鲫鱼5d后全部死亡。当皂甙染毒浓度达20.12mg·L-1时,随处理时间的增加,特定生长率、糖原和蛋白质含量逐渐下降,而SOD活性先上升后下降;在清水中恢复饲养7d后,鲫鱼幼苗特定生长率和SOD活性受到的抑制作用逐渐减弱,糖原和蛋白含量恢复至与对照组相比无显著差异。此外,微核试验表明夹竹桃皂甙对鲫鱼幼苗的微核率无影响。研究结果表明,夹竹桃皂甙对鲫鱼的毒性属低等毒性且未发现遗传毒性,但高浓度的皂甙能影响鲫鱼幼鱼的正常生理代谢,导致生长受到抑制,严重时可致其死亡。