Figure 5From: End-tidal carbon dioxide monitoring using a naso-buccal sensor is not appropriate to monitor capnia during non-invasive ventilation Evolution over time of PaCO 2 -EtCO 2 gradient for all the patients. This figure shows the evolution over time of PaCO2-EtCO2 gradient for all the patients. PaCO2, CO2 partial pressure in arterial blood; EtCO2, end-tidal CO2. Patient numbers 1, 3, 4, 5, 7, 9, 10, and 11 are COPD patients.Back to article page