High‐flow nasal cannula oxygen therapy in acute hypoxemic respiratory failure in 22 dogs requiring oxygen support escalation

Abstract

Abstract Objective To determine the effect of high‐flow nasal cannula (HFNC) oxygen therapy on cardiorespiratory variables and outcome in dogs with acute hypoxemic respiratory failure. Design Prospective, sequential clinical trial. Setting University veterinary teaching hospital. Animals Twenty‐two client‐owned dogs that failed to respond to traditional oxygen support. Interventions Initiation of HFNC therapy after traditional oxygen supplementation failed to increase Sp o 2 > 96% and Pa o 2 > 75 mm Hg or improve respiratory rate/effort. Measurements and Main Results Physiological variables, blood gas analyses, and dyspnea/sedation/tolerance scores were collected prior to HFNC initiation (on traditional oxygen support [time 0 or T0]), and subsequently during HFNC oxygen administration at time 30 minutes, 60 minutes, and 7 ± 1 hours. Relative to T0, use of HFNC resulted in a decreased respiratory rate at 1 hour ( P = 0.022) and 7 hours ( P = 0.012), a decrease in dyspnea score at all times ( P < 0.01), and an increase in Sp o 2 at all times ( P < 0.01). There was no difference in arterial/venous P co 2 relative to T0, although Pa co 2 was correlated with flow rate. Based on respiratory assessment, 60% of dogs responded to HFNC use by 30 minutes, and 45% ultimately responded to HFNC use and survived. No clinical air‐leak syndromes were observed. Conclusions HFNC use improved oxygenation and work of breathing relative to traditional oxygen therapies, without impairing ventilation. HFNC use appears to be a beneficial oxygen support modality to bridge the gap between standard oxygen supplementation and mechanical ventilation.