Logo Medical Science Monitor

Call: +1.631.470.9640
Mon - Fri 10:00 am - 02:00 pm EST

Contact Us

Logo Medical Science Monitor Logo Medical Science Monitor Logo Medical Science Monitor

29 August 2008

Capnometry in spontaneously breathing patients: the influence of chronic obstructive pulmonary disease and expiration maneuvers

Manel LujanABCDEF, Elisa CanturriBCD, Amalia MorenoBC, Maribel ArranzBC, Laura VigilEF, Christian DomingoABCDEF

Med Sci Monit 2008; 14(9): CR485-492 :: ID: 867967

Abstract

Background
In spontaneously breathing patients, the differences between arterial PaCO2 and end-tidal CO2 (EtCO2) and the influence of bronchial obstruction have not clearly established.
Material and Method
This was a prospective observational study. Patients (n=120) were classified according to spirometric criteria into groups with normal, mild, moderate, and severe obstruction. Arterial blood gases and capnography were performed in two ways: with a tidal volume (Vt) and a non-forced maximal expiration maneuver. Pearson correlation coefficients (r) between PaCO2 and capnographic values were determined for the entire cohort and the subgroups. A concordance study was performed with Bland-Altman analysis.
Results
Comparison of PaCO2 and EtCO2 measured at Vt showed a significant correlation (r=0.722, p<0.01) for the entire cohort, but with a significant mean infra-estimation: P(a-et)CO2=5.2+/-4.4 mmHg, p<0.05. Analysis of subgroups: At Vt, P(a-et)CO2 was 1.7+/-2.9 mmHg (p=ns) in patients with normal spirometry, being maximal in the group with greater obstruction (8.2+/-5.6 mmHg, p<0.05). At maximal expiration, the comparison between PaCO2 and EtCO2 showed a significant correlation (r=0.88, p<0.001), but a significant lack of concordance for the entire cohort (P(a-et)CO2=-4.8+/-4 mmHg, p<0.05) and subgroups. Finally, comparison of PaCO2 and mean EtCO2 values showed a significant correlation (r=0.74, p<0.001) and concordance (P(a-et)CO2= 0.2+/-3.3 mmHg, p=ns) for the entire cohort and subgroups.
Conclusions
Capnographic results at Vt are accurate predictors of true PaCO2 only in patients without bronchial obstruction. The maneuvers of slow maximal expiration overestimate PaCO2 in all groups. The best concordance was obtained comparing PaCO2 with mean EtCO2.

Keywords: Respiration, Tidal Volume, Pulmonary Disease, Chronic Obstructive - physiopathology, Prospective Studies, Partial Pressure, Exhalation, Statistics as Topic, Carbon Dioxide - blood, Capnography - methods, Blood Gas Analysis

Add Comment 0 Comments

Editorial

01 July 2024 : Editorial  

Editorial: The Global Threats of Increasing Antimicrobial Resistance Require New Approaches to Drug Development, Including Molecular Antimicrobial Adjuvants

Dinah V. Parums

DOI: 10.12659/MSM.945583

Med Sci Monit 2024; 30:e945583

0:00

In Press

Clinical Research  

Cost-Effectiveness Analysis of Hepatic Arterial Chemotherapy for Advanced Hepatocellular Carcinoma in China...

Med Sci Monit In Press; DOI: 10.12659/MSM.944526  

0:00

Clinical Research  

Comparative Analysis of Antihypertensive and Anticonvulsant Regimens in Managing Pre-eclampsia and Eclampsi...

Med Sci Monit In Press; DOI: 10.12659/MSM.944985  

Clinical Research  

Reduced Radial Artery Occlusion in Transradial Cerebral Angiography: Key Predictive Factors and Preventive ...

Med Sci Monit In Press; DOI: 10.12659/MSM.944297  

Database Analysis  

Enhanced Outcomes in Femoral Subtrochanteric Fractures Using Long INTERTAN Nails with Titanium Cable Cercla...

Med Sci Monit In Press; DOI: 10.12659/MSM.944383  

Most Viewed Current Articles

17 Jan 2024 : Review article   4,116,598

Vaccination Guidelines for Pregnant Women: Addressing COVID-19 and the Omicron Variant

DOI :10.12659/MSM.942799

Med Sci Monit 2024; 30:e942799

0:00

14 Dec 2022 : Clinical Research   1,594,331

Prevalence and Variability of Allergen-Specific Immunoglobulin E in Patients with Elevated Tryptase Levels

DOI :10.12659/MSM.937990

Med Sci Monit 2022; 28:e937990

0:00

16 May 2023 : Clinical Research   691,000

Electrophysiological Testing for an Auditory Processing Disorder and Reading Performance in 54 School Stude...

DOI :10.12659/MSM.940387

Med Sci Monit 2023; 29:e940387

0:00

01 Jan 2022 : Editorial   50,822

Editorial: Current Status of Oral Antiviral Drug Treatments for SARS-CoV-2 Infection in Non-Hospitalized Pa...

DOI :10.12659/MSM.935952

Med Sci Monit 2022; 28:e935952

0:00

Your Privacy

We use cookies to ensure the functionality of our website, to personalize content and advertising, to provide social media features, and to analyze our traffic. If you allow us to do so, we also inform our social media, advertising and analysis partners about your use of our website, You can decise for yourself which categories you you want to deny or allow. Please note that based on your settings not all functionalities of the site are available. View our privacy policy.

Medical Science Monitor eISSN: 1643-3750
Medical Science Monitor eISSN: 1643-3750