The features of AECOPD with carbon dioxide retention

Xia Wei,Youmin Guo,Jiuyun Mi,Jianying Li,Jingting Ren,Lu Bai,Min Qi,Nan Yu,Qi Ding

doi:10.1186/s12890-018-0691-8

Abstract

BackgroundChronic obstructive pulmonary disease (COPD) with carbon dioxide retention is associated with a worsening clinical condition and the beginning of pulmonary ventilation decompensation. This study aimed to identify the factors associated with carbon dioxide retention.MethodsThis was a retrospective study of consecutive patients with COPD (meeting the Global Initiative for Chronic Obstructive Lung Disease diagnostic criteria) hospitalized at The Ninth Hospital of Xi’an Affiliated Hospital of Xi’an Jiaotong University between October 2014 and September 2017. The baseline demographic, clinical, laboratory, pulmonary function, and imaging data were compared between the 86 cases with carbon dioxide retention and the 144 cases without carbon dioxide retention.ResultsCompared with the non-carbon dioxide retention group, the group with carbon dioxide retention had a higher number of hospitalizations in the previous 12 months (p = 0.013), higher modified Medical Research Council (mMRC) dyspnea scores (p = 0.034), lower arterial oxygen pressure (p = 0.018), worse pulmonary function (forced expiratory volume in one second/forced vital capacity [FEV1/FVC; p < 0.001], FEV1%pred [p < 0.001], Z5%pred [p = 0.004], R5%pred [p = 0.008], R5-R20 [p = 0.009], X5 [p = 0.022], and Ax [p = 0.011]), more severe lung damage (such as increased lung volume [p = 0.011], more emphysema range [p = 0.007], and lower mean lung density [p = 0.043]). FEV1 < 1 L (odds ratio [OR] = 4.011, 95% confidence interval [CI]: 2.216–7.262) and emphysema index (EI) > 20% (OR = 1.926, 95% CI: 1.080–3.432) were independently associated with carbon dioxide retention in COPD.ConclusionCompared with the non-carbon dioxide retention group, the group with carbon dioxide retention had different clinical, pulmonary function, and imaging features. FEV1 < 1 L and EI > 20% were independently associated with carbon dioxide retention in AECOPD.Trial registrationChiCTR-OCH-14004904. Registered 25 June 2014.

Highlights

Chronic obstructive pulmonary disease (COPD) with carbon dioxide retention is associated with a worsening clinical condition and the beginning of pulmonary ventilation decompensation
Comparison of traditional lung function and impulse oscillometry (IOS) parameters between the groups In traditional lung function tests, compared with the non-carbon dioxide retention group, the carbon dioxide retention group had lower forced expiratory volume in one second (FEV1), FEV1%pred, FEV1 / forced vital capacity (FVC), and MMEF25–75% (P < 0.001), and higher residual volume/ total lung capacity (RV/TLC) (P = 0.017)
In the IOS test, compared with the non-carbon dioxide retention group, the carbon dioxide retention group possessed higher total airway resistance Total respiratory impedance (Z5)%pred and resistance at 5 Hz (R5)%pred (P = 0.004 and 0.008, respectively), and higher peripheral airway resistance parameters R5-resistance at 20 Hz (R20) and reactance area (Ax) (P = 0.009 and P = 0.011, respectively)

Summary

Introduction

Chronic obstructive pulmonary disease (COPD) with carbon dioxide retention is associated with a worsening clinical condition and the beginning of pulmonary ventilation decompensation. Chronic obstructive pulmonary disease (COPD) is the fourth leading cause of death worldwide and is expected to be the third leading cause of death by 2020 [1]. COPD is a major chronic disease that produces a large economic and social burden worldwide [2]. Wei et al BMC Pulmonary Medicine (2018) 18:124 because they can reflect one of the key characteristics of COPD - airflow limitation, but according to the Global Initiative for Chronic Obstructive Lung Disease (GOLD) update in 2017 [5], FEV1 was used for grading of disease severity but was not a variable used to guide treatment. Yamasawa [8] reported that CT could be used as a non-invasive tool to predict aerobic capacity in COPD

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