Helium in critical care: from fluid dynamics to the bedside

Abstract

Due to its low density, helium promotes laminar flow conditions in the airways, while reducing resistance to flow in turbulent conditions. These effects make helium an attractive option in patients with upper or lower airway obstructive disease. Several studies have shown favourable clinical and pathophysiological effects in these situations, both in spontaneous breathing and during invasive and noninvasive mechanical ventilation. However, to date, no study has shown that these beneficial effects can impact patient outcome. Until well-conducted studies provide more insight into this issue, the routine use of helium-O₂ mixtures cannot be recommended and should be restricted to individual patient situations with well-defined treatment endpoints.