0
Clinical Investigations: PULMONARY EMBOLISM |

Volumetric Capnography as a Screening Test for Pulmonary Embolism in the Emergency Department*

Franck Verschuren; Giuseppe Liistro; René Coffeng; Frédéric Thys; Jean Roeseler; Francis Zech; Marc Reynaert
Author and Funding Information

*From the Departments of Emergency and Intensive Care (Drs. Verschuren, Thys, Zech, and Reynaert, and Mr. Roeseler), and Pneumology (Dr. Liistro), Cliniques Universitaires Saint-Luc, Université Catholique de Louvain, Bruxelles, Belgium; and Datex-Ohmeda Division of Instrumentarium Corp (Mr. Coffeng), Helsinki, Finland.

Correspondence to: Franck Verschuren, MD, Service des Urgences, Cliniques Universitaires Saint-Luc, Université Catholique de Louvain, Ave Hippocrate 10, B-1200 Bruxelles, Belgium; e-mail: Franck.verschuren@clin.ucl.ac.be



Chest. 2004;125(3):841-850. doi:10.1378/chest.125.3.841
Text Size: A A A
Published online

Study objective: To compare the diagnostic performance of volumetric capnography (VCap), which is the plot of the expired CO2 partial pressure against the expired volume during a single breath, with the Paco2 to end-tidal CO2 (EtCO2) gradient, in the case of suspected pulmonary embolism (PE).

Design: Single-center, prospective study.

Setting: Emergency department of a teaching hospital.

Patients: A total of 45 outpatients with positive enzyme-linked immunosorbent assay d-dimer levels of > 500 ng/mL. The diagnosis of PE was confirmed in 18 outpatients according to a validated procedure based on the ventilation-perfusion lung scan and/or spiral CT scanning.

Interventions: Curves of VCap were obtained from a compact monitor connected to a computer. A sequence of four to six stable breaths allowed the calculation of the following several variables: alveolar dead space fraction; the ratio of alveolar dead space (VDalv) to airway dead space (VDaw); the VDalv to physiologic dead space (VDphys) fraction; the slope of phase 3; and the late dead space fraction (Fdlate) corresponding to the extrapolation of the capnographic curve to a volume of 15% of the predicted total lung capacity.

Results: The mean (± SD) Paco2-EtCO2 gradient was 5.3 ± 0.7 mm Hg in the PE-positive group and 2.8 ± 0.7 mm Hg in the PE-negative group (p = 0.019). Four variables of the VCap exhibited a statistical difference between both groups, as follows: the VDalv/VDaw fraction; the slope of phase 3; the VDalv/VDphys fraction; and the Fdlate, which was 8.2 ± 3.3% vs −7.7 ± 2.8%, respectively (p = 0.000011). The diagnostic performance expressed as the mean area under a receiver operating characteristic curve comparison was 75.9 ± 7.4% for the Paco2-EtCO2 gradient and 87.6 ± 4.9% for the Fdlate (p = 0.02).

Conclusion: Fdlate, a variable of VCap, had a statistically better diagnostic performance in suspected PE than the Paco2-EtCO2 gradient. VCap is a promising computer-assisted bedside application of pulmonary pathophysiology. Future research should define the place of this technique in the diagnostic workup of PE, especially in the presence of positive d-dimers.

Figures in this Article

Sign In to Access Full Content

MEMBER & INDIVIDUAL SUBSCRIBER

Want Access?

NEW TO CHEST?

Become a CHEST member and receive a FREE subscription as a benefit of membership.

Individuals can purchase this article on ScienceDirect.

Individuals can purchase a subscription to the journal.

Individuals can purchase a subscription to the journal or buy individual articles.

Learn more about membership or Purchase a Full Subscription.

INSTITUTIONAL ACCESS

Institutional access is now available through ScienceDirect and can be purchased at myelsevier.com.

Sign In to Access Full Content

MEMBER & INDIVIDUAL SUBSCRIBER

Want Access?

NEW TO CHEST?

Become a CHEST member and receive a FREE subscription as a benefit of membership.

Individuals can purchase this article on ScienceDirect.

Individuals can purchase a subscription to the journal.

Individuals can purchase a subscription to the journal or buy individual articles.

Learn more about membership or Purchase a Full Subscription.

INSTITUTIONAL ACCESS

Institutional access is now available through ScienceDirect and can be purchased at myelsevier.com.

Figures

Tables

References

NOTE:
Citing articles are presented as examples only. In non-demo SCM6 implementation, integration with CrossRef’s "Cited By" API will populate this tab (http://www.crossref.org/citedby.html).

Some tools below are only available to our subscribers or users with an online account.

Sign In to Access Full Content

MEMBER & INDIVIDUAL SUBSCRIBER

Want Access?

NEW TO CHEST?

Become a CHEST member and receive a FREE subscription as a benefit of membership.

Individuals can purchase this article on ScienceDirect.

Individuals can purchase a subscription to the journal.

Individuals can purchase a subscription to the journal or buy individual articles.

Learn more about membership or Purchase a Full Subscription.

INSTITUTIONAL ACCESS

Institutional access is now available through ScienceDirect and can be purchased at myelsevier.com.

Related Content

Customize your page view by dragging & repositioning the boxes below.

Find Similar Articles
CHEST Journal Articles
  • CHEST Journal
    Print ISSN: 0012-3692
    Online ISSN: 1931-3543