{
  "abstract": "Background\n\nEnd-tidal carbon dioxide tension (P ETCO₂ ) may be reduced when lung units are ventilated but under-perfused, as occurs in pulmonary embolism (PE). We sought to determine whether early P ETCO₂ measurement reflects PE severity according to European Society of Cardiology (ESC) risk categories and identifies shock-level haemodynamics among patients undergoing catheter-directed therapy (CDT).Methods\n\nPatients admitted with acute PE confirmed by computed tomography pulmonary angiography were enrolled in this prospective observational study. P ETCO₂ was measured using nasal capnography within 24 h of presentation or immediately prior to urgent CDT. P ETCO₂ was compared between lower and higher severity PE groups and between patients referred for CDT or not. In patients undergoing mechanical thrombectomy (CDT) with invasive haemodynamic assessment, pulmonary arterial pressures and cardiac indices were recorded. A subgroup analysis evaluated patients with cardiogenic shock defined as cardiac index ≤1.8 L·min⁻¹·m⁻².Results\n\n62 patients were analysed. P ETCO₂ was significantly lower in the combined higher risk group compared to the combined lower risk group (mean 21.7 (95% CI 20.2-23.3) versus 30.2 (95% CI 27.8-32.6) mmHg; p<0.001). P ETCO₂ was also lower in patients referred for CDT compared to those not referred (mean 20.4 (95% CI 18.7-22.0) versus 28.2 (95% CI 26.2-30.1) mmHg; p<0.001). Among patients who underwent CDT and met haemodynamic criteria for cardiogenic shock (n=16), P ETCO₂ was the lowest (mean 18.6 (95% CI 16.1-21.1) mmHg).Conclusions\n\nP ETCO₂ can be rapidly obtained early in PE evaluation and reflects ESC-defined severity. A P ETCO₂ level <20 mmHg was associated with shock-level haemodynamics among normotensive intermediate-high-risk patients undergoing CDT. P ETCO₂ may serve as a non-invasive marker of physiological severity.",
  "abstract_shown": true,
  "affiliations": [
    "Department of Pulmonary and Critical Care, Lankenau Medical Center, Main Line Health, Wynnewood, PA, USA.",
    "Department of Interventional Cardiology, Lankenau Medical Center, Main Line Health, Wynnewood, PA, USA.",
    "Department of Emergency Medicine, Lankenau Medical Center, Main Line Health, Wynnewood, PA, USA.",
    "Main Line Health Center for Population Research, Main Line Health, Wynnewood, PA, USA."
  ],
  "article_type": "research article",
  "arxiv": null,
  "author_total": 10,
  "authors": [
    {
      "affs": [
        0
      ],
      "name": "Lee W Greenspon",
      "orcid": "0000-0002-6940-0059"
    },
    {
      "affs": [
        0
      ],
      "name": "Patrick Ho",
      "orcid": "0009-0009-5447-2568"
    },
    {
      "affs": [
        0
      ],
      "name": "Jason George"
    },
    {
      "affs": [
        0
      ],
      "name": "Spencer Whealon"
    },
    {
      "affs": [
        0
      ],
      "name": "Margarita Gianniosis"
    },
    {
      "affs": [
        1
      ],
      "name": "Betsy Develin"
    },
    {
      "affs": [
        2
      ],
      "name": "Jonathan Fischer"
    },
    {
      "affs": [
        3
      ],
      "name": "Stephanie Kjelstrom"
    },
    {
      "affs": [
        1
      ],
      "name": "Mara Caroline"
    },
    {
      "affs": [
        1
      ],
      "name": "Eric Gnall"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/2ddq4ybnptxsr.bib",
  "cited_by": 1,
  "doi": "10.1183/23120541.00062-2026",
  "fulltext_url": "https://europepmc.org/articles/PMC13678851",
  "id": "2ddq4ybnptxsr",
  "issns": [
    "2312-0541"
  ],
  "landing_url": "https://europepmc.org/article/MED/42899109",
  "language": "eng",
  "licence": "CC-BY-NC",
  "licence_label": "CC BY-NC",
  "licence_source": "article",
  "licence_url": "https://creativecommons.org/licenses/by-nc/4.0/",
  "metadata_licence": null,
  "native_subjects": [
    [
      "openalex",
      "2724|Venous Thromboembolism Diagnosis and Management"
    ]
  ],
  "openalex": "W7163577465",
  "pdf_url": "https://europepmc.org/articles/PMC13678851?pdf=render",
  "pmcid": "PMC13678851",
  "pmid": "42899109",
  "published": "2026-09-01",
  "publisher": null,
  "ris": "https://research.draconitic.com/paper/2ddq4ybnptxsr.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:19:41Z",
      "native_id": "MED:42899109",
      "source": "europepmc",
      "url": "https://europepmc.org/article/MED/42899109"
    }
  ],
  "subjects": [
    {
      "field": "medicine",
      "origin": "openalex:2724|Venous Thromboembolism Diagnosis and Management",
      "subfield": "general"
    }
  ],
  "title": "Low end-tidal carbon dioxide identifies high-severity pulmonary embolism and shock-level haemodynamics.",
  "title_text": "Low end-tidal carbon dioxide identifies high-severity pulmonary embolism and shock-level haemodynamics.",
  "type": "peer-reviewed",
  "updated_at": "2026-10-30T12:19:41Z",
  "url": "https://research.draconitic.com/paper/2ddq4ybnptxsr",
  "venue": "ERJ open research",
  "versions": []
}