Comparison of analyses of respiratory gases made with the K4b2 portable and Quark laboratory analysers in horses.
Authors: Leprêtre P-M, Metayer N, Giovagnoli G, Pagliei E, Barrey E
Journal: The Veterinary record
Summary
# Editorial Summary Researchers compared two metabolic analysers—the portable K4b2 telemetric system and the stationary Quark laboratory cart—by measuring respiratory parameters in seven warmblood horses during standardised incremental treadmill exercise at submaximal intensities. Both devices produced equivalent measurements of minute ventilation (VE), expired oxygen and carbon dioxide fractions (FeO₂ and FeCO₂), and derived values for oxygen consumption (VO₂) and carbon dioxide production (VCO₂) calculated via the Haldane equation, indicating the K4b2's reliability as a field alternative to laboratory equipment. Despite this agreement between devices, the study identified a notable discrepancy when comparing their results to published reference values: VE readings at canter (10 m/s) were substantially higher than previously reported in the literature, which warrants investigation into potential methodological or population-specific factors. For practitioners, this validation supports confidence in using portable telemetric systems for on-site metabolic assessment during ridden or racetrack work, though comparative baseline data for your specific horse population may be worth establishing given the literature variance observed.
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Practical Takeaways
- •The portable K4b2 device is a reliable alternative to laboratory metabolic carts for field-based respiratory assessment in horses during exercise testing
- •Either device can be confidently used for exercise physiology research and performance monitoring in equine athletes
- •Clinicians and researchers should be aware that ventilation measurements at canter may trend higher than historical reference values, warranting caution in interpretation
Key Findings
- •No significant differences in VE, FeO2, FeCO2, VO2, and VCO2 measurements between portable K4b2 and laboratory Quark analysers
- •K4b2 portable telemetric unit produced comparable results to laboratory-grade equipment for respiratory gas measurements in horses
- •VE was overestimated at canter speed of 10 m/s compared to published literature values
- •Both devices can validly measure minute ventilation and expired gas fractions during standardised incremental treadmill exercise tests