From Admission in Adult Intensive Care Unit to Discharge: a Review about Daily Use of Expired CO2 Monitoring

Use of Expired CO2 in Adult Intensive Care Unit

Abstract

The objective of this review is to make a check-up of the CO₂ expired monitoring indications in intensive care units (ICU). Because of its physiology, CO₂ measurement is a good reflection of hemodynamic, respiratory, and metabolic state of the patient. Infra-red spectrometry is the most common method. The usual capnography (CO₂ expired over time) consist of several parts and its visual form analysis gives a lot of respiratory diagnosis. Volumetric capnography measures the alveolar dead space. Capnometry is recommended in ICU to confirm tracheal intubation during cardiac arrest as a prognostic factor. Each patient treated by mechanical ventilation, especially during transport, should be equipped with a capnograph to anticipate respiratory complications (extubation, bronchospasm, hypo-ventilation). PetCO₂ is a useful estimation of PaCO₂ (arterial pressure of CO₂) to decrease number of blood sample, in neurological ICU for example, but a lot of factors modified the gradient between this two indicators. Studies give no proof for the use of volumetric capnography in pulmonary embolism diagnosis. In patients suffering from acute respiratory distress syndrome, there are no sufficient proof for the daily clinical use of the volumetric capnography which seems limited to the field of research.