[Mechanical ventilation monitoring: gas analysis and acid base balance]

Analysis of blood gases and acid-base status is essential for monitoring mechanical ventilation. The most commonly used methods are based on intermittent blood gases, continuous pulse oximetry and capnography, and less frequently on continuous intraarterial gasometry. The most useful parameters for analyzing oxygenation are PaO2, hemoglobin saturation, PaO2/FiO2 ratio, oxygenation index, PaCO2 to evaluate ventilation, and pH and base excess to analyze acid-base status. A method for analyzing the results of blood gases and derivative parameters is recommended and the interpretation of different states of acidosis and alkalosis is discussed.