Heated, humidified, high-flow nasal oxygen usage in the adult Emergency Department.

OBJECTIVE: The aim of this study was to determine the role that heated, humidified high-flow nasal oxygen (HHHFNO) plays in the adult ED with particular focus on the indications and outcomes of use.

METHODS: An explorative study was undertaken using retrospective chart review to identify characteristics of adult patients who received HHHFNO in a tertiary adult ED between January and December 2014.

RESULTS: Thirty-nine patients were identified as having received HHHFNO during the study period with a range of indications for this use. No clear guidelines existed for initiation of this use. Two patients failed on HHHFNO therapy, requiring increased respiratory support; twenty-seven patients were admitted to hospital with HHHFNO still being delivered and seven patients were successfully treated with HHHFNO in the ED. The use of HHHFNO was associated with a 4.91bpm (95% CI 2.23-7.59; P=0.001) decrease in mean RR and an 11.26bpm (95% CI 4.62-17.90; P=0.002) decrease in mean HR from baseline at 120min of use. Hypercapnic patients showed a significant decrease in mean PaCO2 levels after one hour of HHHFNO use (70.33mmHg (SD 19.63) vs. 55.00mmHg (SD 13.28), P=0.041) with no change in PaCO2 levels in patients who were not hypercapnic prior to HHHFNO use (PaCO2 32.71mmHg (SD 5.28) vs. 32.38mmHg (SD 3.70), P=0.919).

CONCLUSIONS: HHHFNO is currently being used as a device for supplemental oxygen delivery within the adult Emergency Department; however, further research is needed in this area to quantify its use in many of the indications seen.