Kalinov Roman I, Marinov Blagoi I, Stoyanova Dimitrina I, Hodgev Vladimir A, Vladimirova-Kitova Lyudmila G, Nikolov Fedya P, Kostianev Stefan S
Department of Pneumonology and Phthysiatrics, St George University Hospital, Medical University of Plovdiv, Plovdiv, Bulgaria.
Section of Cardiology, First Department of Internal Diseases, Medical University of Plovdiv, Plovdiv, Bulgaria.
Folia Med (Plovdiv). 2019 Jun 1;61(2):204-212. doi: 10.2478/folmed-2018-0079.
Exercise-induced desaturation is a common finding in patients with moderate and severe COPD. It is an important marker in the course of disease that has a prognostic value for mortality risk.
To monitor over time COPD patients with and without desaturation during 6-minute walking test (6MWT) and to assess the stability of that phenomenon.
A 6MWT was administered to 70 patients with COPD which ranged in severity from stage 2A to stage 4D (GOLD 2011); the patients had a mean age of 64.5±10.1, mean pack-years - 38.8±21, FEV1% = 46.4%±15.7%, FVC% = 73.7%±1.3%, MRC = 2.31±0.84, CAT = 20.8±6.6. Oxygen saturation was monitored during the test; indications for desaturation were a decrease of SpO2 by ≥4% and a fall in SpO2 to ≤88% for at least 3 min. The patients were followed-up for mean 40.9±22.3 months and tests were repeated.
Patients were divided into two groups based on the decrease in SpO2: Group A included patients with desaturation (n=35) and Group B - patients with no desaturation (n=35). In 66 of the patients the desaturation profile was stable over time. Only two patients, who did not desaturated at baseline, experienced desaturation in the follow-up 6MWT and another two patients, who desaturated at baseline, did not have it later in the follow-up.
Desaturation is a phenomenon that is persistent over time. Based on the results, it could be concluded that exercise-induced desaturation is a major marker of a particular COPD phenotype.
运动诱发的血氧饱和度下降是中重度慢性阻塞性肺疾病（COPD）患者的常见表现。它是疾病进程中的一个重要标志物，对死亡风险具有预后价值。
在6分钟步行试验（6MWT）期间，长期监测有和没有血氧饱和度下降的COPD患者，并评估该现象的稳定性。
对70例COPD患者进行6MWT，病情严重程度从2A期到4D期（GOLD 2011）；患者平均年龄为64.5±10.1岁，平均吸烟包年数为38.8±21，第1秒用力呼气容积百分比（FEV1%）=46.4%±15.7%，用力肺活量百分比（FVC%）=73.7%±1.3%，医学研究委员会呼吸困难量表（MRC）=2.31±0.84，COPD评估测试（CAT）=20.8±6.6。在试验期间监测血氧饱和度；血氧饱和度下降的指征为血氧饱和度（SpO2）下降≥4%且SpO2降至≤88%至少持续3分钟。对患者进行平均40.9±22.3个月的随访并重复测试。
根据SpO2的下降情况将患者分为两组：A组包括有血氧饱和度下降的患者（n = 35），B组为没有血氧饱和度下降的患者（n = 35）。66例患者的血氧饱和度下降情况随时间保持稳定。只有2例在基线时未出现血氧饱和度下降的患者在随访的6MWT中出现了血氧饱和度下降，另外2例在基线时出现血氧饱和度下降的患者在随访后期未再出现。
血氧饱和度下降是一种随时间持续存在的现象。根据结果可以得出结论，运动诱发的血氧饱和度下降是特定COPD表型的主要标志物。
