Work

Higher intraoperative arterial-to-end-tidal carbon dioxide gradients are associated with postoperative respiratory morbidity after lung cancer resection: a retrospective INSPIRE cohort study

Year: 2026

Type: article

Abstract: Background The arterial-to-end-tidal carbon dioxide gradient may reflect impaired gas exchange during thoracic surgery. We examined its association with postoperative respiratory morbidity after lung cancer resection. Methods We conducted a retrospective cohort study using INSPIRE version 1.4.2. Each intraoperative arterial carbon dioxide (PaCO 2 ) measurement was paired with the nearest positive end-tidal carbon dioxide (EtCO 2 ) measurement within 10 min, and the primary exposure was each patient's median gradient. Respiratory morbidity was defined from new respiratory diagnoses and qualifying postoperative ventilation records during the index admission. We used multivariable regression, repeated-measurement analyses, sensitivity analyses, and exploratory internally validated prediction models. Results Among 2,665 eligible patients, 85 (3.2%) had respiratory morbidity. A valid gradient was available in 2,527 patients; the primary complete-case analysis included 2,436 patients and 80 events. Each 5 mmHg higher gradient was associated with greater morbidity (adjusted odds ratio 1.53, 95% confidence interval 1.17–2.00; adjusted risk ratio 1.48, 1.14–1.91). Standardised risk increased from 2.28% at the first gradient quartile to 3.46% at the third, a difference of 1.18 percentage points (0.49–1.83). In a post hoc comparison, adding the gradient to a model already containing PaCO 2 and clinical covariates did not materially change internally cross-validated discrimination (AUROC 0.7324 vs. 0.7325). Conclusion A higher intraoperative PaCO 2 –EtCO 2 gradient was associated with postoperative respiratory morbidity after lung cancer resection, but its incremental prognostic value beyond PaCO 2 was limited in exploratory analyses. Prospective external validation is required before clinical use.

Source: Frontiers in Medicine

DOI: 10.3389/fmed.2026.1995794

Authors: Long Li, Dan Wang, Qingyi Zhou, Bin Shang

Institution: The Second Affiliated Hospital of Bengbu Medical College

Language: English

Topic: Respiratory Support and Mechanisms

Subfield: Pulmonary and Respiratory Medicine

Field: Medicine

Domain: Health Sciences

SDG: Good health and well-being

Open Access status: gold

Estimated APC paid: $3,801