Evaluation of high flow oxygen therapy in healthy neonatal bull calves

BACKGROUND: Hypoxemia often requires oxygen therapy. Unlike traditional delivery via nasal cannulas, high flow oxygen therapy (HFOT) provides a warm and humidified mixture of medical air and oxygen, and positive inspiratory and end-expiratory pressures in dogs and humans. It has not been evaluated in cattle. HYPOTHESIS/OBJECTIVES: High flow oxygen therapy will be well tolerated in neonatal bull calves, result in increased oxygenation at all flow rates tested, and produce increased nasopharyngeal pressure at higher flow rates. ANIMALS: Ten healthy neonatal bull calves ≤ 10 days of age. METHODS: In this randomized cross-over study, 2 HFOT devices (Airvo 3 and Volumax) delivered 3 flow rates (0.2, 0.4, and 1.0 L/kg/min). Temperature, heart and respiratory rates, respiratory and tolerance scores, arterial blood gases, nasopharyngeal pressure, end tidal carbon dioxide (ETCO2), and fraction of inspired oxygen (FiO2) were obtained pretreatment and after a 10-min equilibration period at each flow rate. P < .05 was considered a significant change from pretreatment results. RESULTS: No differences in respiratory rate (P = .2), heart rate (P = .2), rectal temperature (P = .1), or ETCO2 (P = .1) were detected for any flow rate within each device when compared to pretreatment values. Oxygenation and nasopharyngeal pressure increased as flow rate increased on both devices (P < .05). The PaCO2 increased as flow rate increased for the Airvo 3 (P < .05), but not for the Volumax. CONCLUSIONS AND CLINICAL IMPORTANCE: High flow oxygen therapy was well tolerated in calves and resulted in increased oxygenation at all flow rates and increased nasopharyngeal pressure at higher flow rates.