A role for classical music in veterinary practice: does exposure to classical music reduce stress in hospitalised dogs?

CLINICAL SCENARIO: Classical music has been extensively studied and acknowledged for its ability to reduce stress and improve patient outcomes in human medicine. It has also been shown to influence the disposition of many captive species within the animal kingdom. Some studies have hypothesised that classical music can also benefit dogs, offering the potential to provide a simple and cost-effective method to improve patient outcomes and canine welfare when dogs are placed in unfamiliar and potentially stressful environments. This critical appraisal examines the current evidence available on the use of classical music for the purpose of stress reduction in hospitalised dogs. CLINICAL BOTTOM LINE: Based on six experimental studies, there is only weak evidence which demonstrates that exposure to classical music reduces stress in hospitalised dogs undergoing veterinary intervention. However; it was shown that classical music has the ability to significantly influence specific behaviours and physiological parameters that have been associated with the canine stress response such as heart rate variability, level of vocalisation and time spent resting.

Hydrodynamic evaluation of aortic cardiopulmonary bypass cannulae using particle image velocimetry.

The high velocity jet from aortic arterial cannulae used during cardiopulmonary bypass potentially causes a "sandblasting" injury to the aorta, increasing the possibility of embolisation of atheromatous plaque. We investigated a range of commonly available dispersion and non-dispersion cannulae, using particle image velocimetry. The maximum velocity of the exit jet was assessed 20 and 40 mm from the cannula tip at flow rates of 3 and 5 L/min. The dispersion cannulae had lower maximum velocities compared to the non-dispersion cannulae. Dispersion cannulae had fan-shaped exit profiles and maximum velocities ranged from 0.63 to 1.52 m/s when measured at 20 mm and 5 L/min. Non-dispersion cannulae had maximum velocities ranging from 1.52 to 3.06 m/s at 20 mm and 5 L/min, with corresponding narrow velocity profiles. This study highlights the importance of understanding the hydrodynamic performance of these cannulae as it may help in selecting the most appropriate cannula to minimize the risk of thromboembolic events or aortic injury.

Transfusion of packed red blood cells reduces selenium levels and increases lipid peroxidation in an in vivo ovine model.

BACKGROUND: Oxidative stress from surgery or critically illness has been shown to adversely contribute to morbidity and mortality. Recent studies record that oxidative stress is heightened following packed red blood cell (PRBC) transfusions and that products of oxidative stress accumulate as the PRBC ages. However, there are no studies that investigate if transfusion of aged PRBC actually increases the recipient's oxidative stress profile more than fresh PRBC. OBJECTIVE: To compare the effect of fresh vs aged PRBC transfusions on the recipient's oxidative stress using an ovine model. MATERIALS AND METHODS: Male sheep were transfused with either fresh (n = 6) or aged (n = 6) ovine PRBC, and serial blood samples taken. Plasma samples were analysed for lipid peroxidation using the thiobarbituric acid reactive substances (TBARS) assay. This served as an indicator of oxidative injury. Antioxidant function and trace element levels were also measured. RESULTS: Like human PRBC, the ovine PRBC had negligible selenium levels. Irrespective of age, PRBC transfusion was associated with reduced selenium levels and antioxidant function, which correlated with increased markers of lipid peroxidation. CONCLUSION: Transfusion of selenium poor PRBC can dilute selenium levels and compromise glutathione peroxidase antioxidant activity and thereby allow lipid peroxidation. As there was no evidence that aged PRBC induced more severe oxidative injury this suggests that selenium dilution is a key underlying mechanism. Further studies are needed to assess the impact of transfusion-related oxidative stress in massive transfusions.