Trajectory of the arterial-alveolar oxygen gradient in COPD for a decade.

<h4>Background</h4>Chronic respiratory failure (CRF) is a critical complication in patients with chronic obstructive pulmonary disease (COPD) and is characterized by an increase in the arterial-alveolar oxygen gradient (A-aDO2). The long-term trajectory and prognostic significance remain...

Full description

Saved in:
Bibliographic Details
Main Authors: Kazuma Nagata, Susumu Sato, Kiyoshi Uemasu, Naoya Tanabe, Atsuyasu Sato, Shigeo Muro, Toyohiro Hirai
Format: Article
Language:English
Published: Public Library of Science (PLoS) 2025-01-01
Series:PLoS ONE
Online Access:https://doi.org/10.1371/journal.pone.0318377
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:<h4>Background</h4>Chronic respiratory failure (CRF) is a critical complication in patients with chronic obstructive pulmonary disease (COPD) and is characterized by an increase in the arterial-alveolar oxygen gradient (A-aDO2). The long-term trajectory and prognostic significance remain unclear. This study aimed to assess the prognostic impact of A-aDO2 and elucidate its trajectory over ten years.<h4>Methods</h4>We enrolled 170 outpatients with COPD from a prospective cohort study. Arterial blood gas (ABG) analyses were conducted annually for ten years while monitoring the development of CRF.<h4>Results</h4>157 patients completed the observation period, of whom 21 developed CRF (CRF group) and 136 did not (non-CRF group). In the CRF group, there was a gradual increase in A-aDO2 along with decreases in partial pressure of oxygen (PaO2) and partial pressure of carbon dioxide (PaCO2) over ten years, although there were no changes in the non-CRF group. The CRF group had higher baseline A-aDO2 and higher ΔA-aDO2 in the first year than the non-CRF group (3.76 vs. 0.42 Torr/year, p = 0.030). Kaplan-Meier analyses, and multivariate Cox proportional hazards analysis revealed that both baseline A-aDO2 and ΔA-aDO2 were significantly associated with the development of CRF. Retrospective tracking from the initiation of long-term oxygen therapy (LTOT) revealed significant increases in A-aDO2 from 5 years prior to LTOT initiation in the CRF group when compared to the non-CRF group.<h4>Conclusions</h4>An increasing trend in A-aDO2 may be a significant sign for the future development of CRF. A transition of the annual change of A-aDO2 from a stable state to a deterioration phase can serve as a prognostic factor for developing CRF within 5 years.
ISSN:1932-6203