Comparison of high flow nasal cannula oxygen administration to traditional nasal cannula oxygen therapy in healthy dogs

Abstract

Objective:To determine the feasibility, degree of respiratory support, and safety of high flow nasal cannula (HFNC) oxygen therapy in sedated and awake healthy dogs, when compared to traditional nasal cannula (TNC) oxygen administration.Design: Randomized experimental crossover study.Setting: University research facility. Animals: Eight healthy dogs.Interventions: Variable flow rates (L/kg/min) were assessed, TNC: 0.1, 0.2, and 0.4 and HFNC: 0.4, 1.0, 2.0, and 2.5. HFNC was assessed in sedated and awake dogs.Measurements: Variables measured included: inspiratory/expiratory airway pressures, fraction of inspired oxygen (FiO 2 ), end-tidal oxygen (ETO 2 ), end-tidal carbon dioxide (ETCO 2 ), partial pressure of oxygen (PaO 2 ), partial pressure of carbon dioxide (PaCO 2 ), temperature, heart/respiratory rate, arterial blood pressure, and pulse oximetry. Sedation status, complications, and predefined tolerance and respiratory scores were recorded.Main results: Using HFNC, continuous positive airway pressure (CPAP) was achieved at 1 and 2 L/kg/min. CPAP was not higher at 2.5 than 2 L/kg/min, with worse tolerance scores. Expiratory airway pressures were increased when sedated (P = 0.006). FiO 2 at 0.4 L/kg/min for both methods was 72%. FiO 2 with TNC 0.1 L/kg/min was 27% and not different from room air. The FiO 2 at all HFNC flow rates ≥1 L/kg/min was 95%. PaO 2 for HFNC 0.4 L/kg/min was lower than at other flow rates (P = 0.005). The only noted complication was aerophagia. PaCO 2 was increased with sedation and use of HFNC when compared to baseline (P = 0.006; P < 0.01). Conclusions:Use of HFNC in dogs is feasible and safe, provides predictable oxygen support and provides CPAP, but may cause a mild increase in PaCO 2 . Flow rates of 1-2 L/kg/min are recommended. If using TNC, flow rates above 0.1 L/kg/min may attain higher FiO 2 .

Prospective pilot study for evaluation of high‐flow oxygen therapy in dyspnoeic dogs: the HOT‐DOG study

“…() and Jagodich et al . () in healthy dogs and Keir et al . () in hypoxaemic dogs also showed this PaO 2 improvement after HOT.…”

“…Moreover, a recent study with the same system showed that, when delivering a FIO 2 of 100%, the effective delivered FIO 2 increases with flow rate and varies between 72.2 and 95% for flow rate from 0.4 to 2.5 L/kg/minute (Jagodich et al . ). In our study, flow rate ranged from 0.44 to 1.84 L/kg/minute, so we think it probable that the effective FIO 2 did not reach 100%.…”

“…Jagodich et al . () showed that at flow rates above 2 L/kg/minute, dogs became less tolerant. Our study showed that lower flow rate allowed improvement of oxygen variables with good tolerance.…”

“…, Jagodich et al . ), and a preliminary retrospective study described its successful use in six hypoxaemic dogs (Keir et al . ).…”

“…HOT has recently been shown to be a safe and effective method for oxygen delivery in sedated and awake healthy dogs (Daly et al 2017, Jagodich et al 2019, and a preliminary retrospective study described its successful use in six hypoxaemic dogs (Keir et al 2016). No prospective study reporting the use of HOT in dyspnoeic dogs has been conducted.…”