Nagata Kazuma, Sato Susumu, Uemasu Kiyoshi, Tanabe Naoya, Sato Atsuyasu, Muro Shigeo, Hirai Toyohiro
Department of Respiratory Medicine, Graduate School of Medicine, Kyoto University, Kyoto, Kyoto, Japan.
Department of Respiratory Care and Sleep Control Medicine, Graduate School of Medicine, Kyoto University, Kyoto, Kyoto, Japan.
PLoS One. 2025 Jan 29;20(1):e0318377. doi: 10.1371/journal.pone.0318377. eCollection 2025.
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.
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.
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.
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.
慢性呼吸衰竭（CRF）是慢性阻塞性肺疾病（COPD）患者的一种严重并发症，其特征是动脉-肺泡氧梯度（A-aDO2）升高。其长期轨迹和预后意义仍不明确。本研究旨在评估A-aDO2的预后影响，并阐明其十年间的变化轨迹。
我们从一项前瞻性队列研究中纳入了170例COPD门诊患者。在十年间每年进行动脉血气（ABG）分析，同时监测CRF的发生情况。
157例患者完成了观察期，其中21例发生了CRF（CRF组），136例未发生（非CRF组）。在CRF组中，十年间A-aDO2逐渐升高，同时氧分压（PaO2）和二氧化碳分压（PaCO2）降低，而非CRF组则无变化。CRF组的基线A-aDO2和第一年的ΔA-aDO2均高于非CRF组（3.76对0.42 Torr/年，p = 0.030）。Kaplan-Meier分析和多变量Cox比例风险分析显示，基线A-aDO2和ΔA-aDO2均与CRF的发生显著相关。从长期氧疗（LTOT）开始进行回顾性追踪发现，与非CRF组相比，CRF组在LTOT开始前5年A-aDO2显著升高。
A-aDO2的升高趋势可能是CRF未来发展的一个重要标志。A-aDO2年变化从稳定状态转变为恶化阶段可作为5年内发生CRF的一个预后因素。
