American journal of veterinary research
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To determine pharmacokinetic and pharmacodynamic properties of the injectable formulation of dexmedetomidine administered via the oral transmucosal (OTM) route to healthy dogs. ⋯ OTM administration of the injectable formulation of dexmedetomidine resulted in a similar degree of sedation and prolonged duration of action, compared with results for IV administration, despite relatively low bioavailability.
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To assess effects of nitrogen and helium on efficacy of an alveolar recruitment maneuver (ARM) for improving pulmonary mechanics and oxygen exchange in anesthetized horses. ⋯ An ARM in anesthetized horses might be more efficacious in improving Pao2 and Cdyn when animals breathe helium instead of nitrogen as the inert gas.
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OBJECTIVE To evaluate the effects of 4 gas compositions at various volumes (simulated tidal volumes [VTs]) on accuracy of measurements obtained with 2 types of flow sensors and accuracy of gas volume delivery by a piston-driven ventilator. SAMPLE 4 gas mixtures (medical air [21% O2:79% N2], > 95% O2, O2-enriched air [30% O2:70% N2], and heliox [30% O2:70% He]). PROCEDURES For each gas mixture, reference VTs of 1 to 8 L were delivered into an anesthetic breathing circuit via calibration syringe; measurements recorded by a Pitot tube-based flow sensor (PTFS) connected to a multiparameter host anesthesia monitor and by a thermal mass flow and volume meter (TMFVM) were compared with the reference values. ⋯ There were no significant differences between ventilator-delivered and reference VTs regardless of gas volume or composition. Bland-Altman analysis yielded biases of -0.046 L, -0.007 L, -0.002 L, and 0.031 L for medical air, > 95% O2, O2-enriched air, and heliox, respectively. CONCLUSIONS AND CLINICAL RELEVANCE The PTFS and the TMFVM measured VTs and the piston-driven ventilator delivered VTs with error rates of < 5% for all gas compositions and volumes tested.
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OBJECTIVE To determine the in vitro effect of calcitriol on indicators of immune system function in endotoxin-primed blood samples from healthy dogs. SAMPLE Blood samples from 6 healthy adult dogs. PROCEDURES Leukocytes were primed by incubation of blood samples with lipopolysaccharide (LPS; endotoxin) or PBS solution (unprimed control group) for 1 hour. ⋯ Conversely, calcitriol exposure had no effect on IL10 production by unprimed leukocytes but did significantly increase IL10 production by endotoxin-primed leukocytes. Calcitriol had no significant effect on the degree of neutrophil or lymphocyte apoptosis, nor was neutrophil and monocyte TLR4 expression affected in unprimed or endotoxin-primed leukocytes. CONCLUSIONS AND CLINICAL RELEVANCE These data indicated that calcitriol induced an anti-inflammatory shift in unprimed and endotoxin-primed canine leukocytes in vitro, without compromising neutrophil and monocyte TLR4 expression or altering the viability of neutrophils and lymphocytes in canine blood samples.
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OBJECTIVE To evaluate efficacy of an alveolar recruitment maneuver (ARM) with positive end-expiratory pressures (PEEPs) in anesthetized horses ventilated with oxygen or heliox (70% helium and 30% oxygen). ANIMALS 6 healthy adult horses. PROCEDURES In a randomized crossover study, horses were anesthetized and positioned in dorsal recumbency. ⋯ RESULTS For both ventilation gases, ARM significantly increased pulmonary oxygen exchange indices and Cdyn. Mean ± SD Cdyn (506 ± 35 mL/cm H2O) and Pao2-to-Fio2 ratio (439 ± 36) were significantly higher and alveolar-arterial difference in Pao2 (38 ± 11 mm Hg) was significantly lower for heliox, compared with values for oxygen (357 ± 50 mL/cm H2O, 380 ± 92, and 266 ± 88 mm Hg, respectively). CONCLUSIONS AND CLINICAL RELEVANCE An ARM in isoflurane-anesthetized horses ventilated with heliox significantly improved pulmonary oxygen exchange and respiratory mechanics by decreasing resistive properties of the respiratory system and reducing turbulent gas flow in small airways.