Noise Exposure From High-Flow Nasal Cannula Oxygen Therapy: A Bench Study on Noise Reduction.

BACKGROUND: High-flow nasal cannula (HFNC) oxygen therapy produces noise at a level such that patients often complain. However, the noise level has not been measured digitally.

METHODS: We evaluated 3 types of HFNCs without filters and 2 types with filters attached for noise reduction. Optiflow (with and without a filter), MaxVenturi (with and without a filter) and AIRVO2 (without a filter only) were positioned at the center of a hospital room. We measured the noise levels at the distance of 1 m from the equipment at various total flows (30, 40, 50, 60 L/min) and FIO2 (0.40, 0.60, and 0.90).

RESULTS: Noise levels were increased with the AIRVO2 and MaxVenturi when total flow and FIO2 were increased. Noise levels decreased with the MaxVenturi when a filter was used. The noise level did not change with the Optiflow when total flow and FIO2 were increased. The noise level decreased in the groups with AIRVO2 and Optiflow compared with MaxVenturi without a filter.

CONCLUSIONS: The findings in this study show that the noise level of HFNC/Venturi could be reduced by attaching an intake filter. However, the noise level of HFNC/blender and HFNC/turbine decreased in comparison with HFNC/Venturi without an intake filter.