Figure 1From: Clinical review: Use of helium-oxygen in critically ill patientsDensity of He/O2 versus nitrogen-oxygen mixture at 20°C and 765 mmHg atmospheric pressure. One can observe that the two densities are quite different and increase progressively with FiO2, especially in the case of helium-oxygen mixtures. FiO2, fractional inspired oxygen; He/O2, helium-oxygen mixture.Back to article page