Background. Risk factors for noninvasive ventilation (NIV) failure after initial success are not fully clear in patients with acute exacerbation of chronic obstructive pulmonary disease (COPD). Methods. Patients who received NIV beyond 48 h due to acute exacerbation of COPD were enrolled. However, we excluded those whose pH was higher than 7.35 or PaCO₂ was less than 45 mmHg which was measured before NIV. Late failure of NIV was defined as patients required intubation or died during NIV after initial success. Results. We enrolled 291 patients in this study. Of them, 48 (16%) patients experienced late NIV failure (45 received intubation and 3 died during NIV). The median time from initiation of NIV to intubation was 4.8 days (IQR: 3.4–8.1). Compared with the data collected at initiation of NIV, the heart rate, respiratory rate, pH, and PaCO₂ significantly improved after 1–2 h of NIV both in the NIV success and late failure of NIV groups. Nosocomial pneumonia (odds ratio (OR) = 75, 95% confidence interval (CI): 11–537), heart rate at initiation of NIV (1.04, 1.01–1.06 beat per min), and pH at 1–2 h of NIV (2.06, 1.41–3.00 per decrease of 0.05 from 7.35) were independent risk factors for late failure of NIV. In addition, the Glasgow coma scale (OR = 0.50, 95% CI: 0.34–0.73 per one unit increase) and PaO₂/FiO₂ (0.992, 0.986–0.998 per one unit increase) were independent protective factors for late failure of NIV. In addition, patients with late failure of NIV had longer ICU stay (median 9.5 vs. 6.6 days) and higher hospital mortality (92% vs. 3%) compared with those with NIV success. Conclusions. Nosocomial pneumonia; heart rate at initiation of NIV; and consciousness, acidosis, and oxygenation at 1–2 h of NIV were associated with late failure of NIV in patients with COPD exacerbation. And, late failure of NIV was associated with increased hospital mortality.

中文翻译：

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慢性阻塞性肺疾病患者晚期无创通气失败的相关危险因素

背景。在慢性阻塞性肺疾病 (COPD) 急性加重患者中，初始成功后无创通气 (NIV) 失败的危险因素尚不完全清楚。方法。由于 COPD 急性加重而接受 NIV 超过 48 小时的患者被纳入研究。然而，我们排除了那些在 NIV 之前测量的 pH 值高于 7.35 或 PaCO ₂低于 45 mmHg 的人。NIV 晚期失败定义为患者在初始成功后需要插管或在 NIV 期间死亡。结果. 我们在这项研究中招募了 291 名患者。其中，48 名 (16%) 患者出现晚期 NIV 失败（45 名接受插管，3 名在 NIV 期间死亡）。从 NIV 开始到插管的中位时间为 4.8 天（IQR：3.4-8.1）。与 NIV 开始时收集的数据相比，NIV 成功和晚期失败组的心率、呼吸频率、pH 值和 PaCO ₂在 NIV 1-2 小时后显着改善。医院获得性肺炎（比值比 (OR) = 75，95% 置信区间 (CI)：11–537）、NIV 开始时的心率（1.04、1.01–1.06 次/分钟）和 NIV 1–2 小时时的 pH (2.06, 1.41–3.00 每比 7.35 减少 0.05) 是 NIV 晚期失败的独立危险因素。此外，格拉斯哥昏迷量表（OR = 0.50，95% CI：0.34–0.73 每增加一个单位）和 PaO ₂/ FiO ₂ (0.992, 0.986–0.998 每增加一个单位) 是 NIV 晚期失效的独立保护因素。此外，与 NIV 成功的患者相比，NIV 晚期失败的患者在 ICU 停留时间更长（中位数为 9.5 天对 6.6 天）和更高的住院死亡率（92% 对 3%）。结论。医院获得性肺炎；NIV 开始时的心率；NIV 后 1-2 小时的意识、酸中毒和氧合与 COPD 急性加重患者的 NIV 晚期失败相关。而且，NIV 晚期失败与住院死亡率增加有关。