Abstract

In the field of respiratory clinical practice, the importance of measuring carbon dioxide (CO2) concentrations cannot be overemphasized. Within the body, assessment of the arterial partial pressure of CO2 (PaCO2) has been the gold standard for many decades. Non-invasive assessments are usually predicated on the measurement of CO2 concentrations in the air, usually using an infrared analyzer, and these data are clearly important regarding climate changes as well as regulations of air quality in buildings to ascertain adequate ventilation. Measurements of CO2 production with oxygen consumption yield important indices such as the respiratory quotient and estimates of energy expenditure, which may be used for further investigation in the various fields of metabolism, obesity, sleep disorders, and lifestyle-related issues. Measures of PaCO2 are nowadays performed using the Severinghaus electrode in arterial blood or in arterialized capillary blood, while the same electrode system has been modified to enable relatively accurate non-invasive monitoring of the transcutaneous partial pressure of CO2 (PtcCO2). PtcCO2 monitoring during sleep can be helpful for evaluating sleep apnea syndrome, particularly in children. End-tidal PCO2 is inferior to PtcCO2 as far as accuracy, but it provides breath-by-breath estimates of respiratory gas exchange, while PtcCO2 reflects temporal trends in alveolar ventilation. The frequency of monitoring end-tidal PCO2 has markedly increased in light of its multiple applications (e.g., verify endotracheal intubation, anesthesia or mechanical ventilation, exercise testing, respiratory patterning during sleep, etc.).

Highlights

  • Atmospheric carbon dioxide (CO2 ) concentration is increasing worldwide by the increasing consumption of carbon-based combustibles along with progressive deforestation [1,2]

  • Continuous measurements of atmospheric CO2 concentrations have been viewed as being helpful for the evaluation of ventilation conditions in rooms or buildings, and it has been utilized as guidance to avoid the transmission of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) [5]

  • Apart from atmospheric CO2 concentration measures, it is frequently necessary to measure the partial pressure of CO2 (PCO2 ) in blood in respiratory clinical practice

Read more

Summary

Introduction

Atmospheric carbon dioxide (CO2 ) concentration is increasing worldwide by the increasing consumption of carbon-based combustibles along with progressive deforestation [1,2]. Non-invasive alternative methods such as end-tidal CO2 partial pressure of exhaled gas (PetCO2 ) and transcutaneous partial pressure of CO2 (PtcCO2 ) have been developed, and their accuracy and usefulness have been evaluated by Bland–Altman analysis [12]. Another use of CO2 concentration measurements in exhaled air involves assessment of CO2 production [9]. The difference of partial pressure of oxygen (PO2 ) between mean alveolar gas and arterial blood can be calculated [10] This approach has been used for the evaluation of gas exchange impairment in various lung diseases [9,10,13]. In order to better understand the considerations involved in such choices, we will discuss the principles, sensitivity, and limitations of the various methods available for measuring CO2 concentrations

Atmospheric Carbon Dioxide Concentration
Globally averaged monthly mole fraction of CO
Measuring system of2 by COusing
Blood Gas Analysis
Non-Invasive Alternative Methods to Estimate PaCO2
End-Tidal PCO2
Evaluation
Comparison of Accuracy
Usefulness and limitation of Transcutaneous Blood Gas Analysis
Various Subgroup Analyses on the PtcCO2 Bias
PaCO2 Level
PaO2 Level
Among Various Respiratory Diseases
Usefulness
Limitations
Other Applications of Measuring CO2 Mainly for Research Use
Conclusions
Full Text
Published version (Free)

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call