Graduate Institute of Medical Sciences, National Defense Medical Center, No 161, Sec. 6, Mincyuan E Rd, Neihu District, Taipei City 114, Taiwan, ROC.
Chest. 2010 Apr;137(4):777-82. doi: 10.1378/chest.07-2808. Epub 2010 Jan 22.
Removing the artificial airway is the last step in the mechanical ventilation withdrawal process. In order to assess cough effectiveness, a critical component of this process, we evaluated the involuntary cough peak flow (CPFi) to predict the extubation outcome for patients weaned from mechanical ventilation in ICUs.
One hundred fifty patients were weaned from ventilators, passed a spontaneous breathing trial (SBT), and were judged by their physician to be ready for extubation in the Tri-Service General Hospital ICUs from February 2003 to July 2003. CPFi was induced by 2 mL of normal saline solution at the end of inspiration and measured using a hand-held respiratory mechanics monitor. All patients were then extubated.
Of 150 enrolled patients for this study, 118 (78.7%) had successful extubation and 32 (21.3%) failed. In the univariate analysis, there were higher Acute Physiology and Chronic Health Evaluation (APACHE) II scores (16.0 vs 18.5, P = .018), less negative maximum inspiratory pressure (-45.0 vs -39.0, P = .010), lower cough peak flows (CPFs) (74.0 vs 42.0 L/min, P < .001), longer postextubation hospital stays (15.0 vs 31.5 days, P < .001), and longer postextubation ICU stays (1.0 vs 9.5 days, P < .001) in the extubation failures compared with the extubation successes. In the multivariate analysis, we found that a higher APACHE II score and a lower CPF were related to increasing risk of extubation failure (odds ratio [OR] = 1.13; 95% CI, 1.03-1.25; and OR = 0.95; 95% CI, 0.93-0.98, respectively). The receiver operator characteristic curve cutoff point for CPF was 58.5 L/min, with a sensitivity of 78.8% and specificity of 78.1%.
CPFi as an indication of cough reflex has the potential to predict successful extubation in patients who pass an SBT.
移除人工气道是机械通气撤离过程的最后一步。为了评估咳嗽的有效性，这一过程的一个关键组成部分，我们评估了不自主咳嗽峰流速（CPFi），以预测我们在三军总医院重症监护病房（ICUs）中从机械通气中撤机的患者的拔管结局。
2003 年 2 月至 2003 年 7 月，我们从三军总医院 ICU 中筛选了 150 名接受呼吸机通气、通过自主呼吸试验（SBT）并被医生判断为准备好拔管的患者。在吸气末，使用手持式呼吸力学监测仪向患者的气道内注入 2 毫升生理盐水，以诱发咳嗽，测量 CPFi。所有患者随后均被拔管。
在这项研究中，共有 150 名患者入组，其中 118 名（78.7%）成功拔管，32 名（21.3%）失败。单因素分析显示，急性生理学和慢性健康评估（APACHE）Ⅱ评分较高（16.0 分 vs. 18.5 分，P =.018），最大吸气负压较低（-45.0 分 vs. -39.0 分，P =.010），咳嗽峰流速（CPF）较低（74.0 分 vs. 42.0 分/分钟，P <.001），拔管后住院时间较长（15.0 天 vs. 31.5 天，P <.001），拔管后 ICU 住院时间较长（1.0 天 vs. 9.5 天，P <.001）。多因素分析显示，APACHE Ⅱ评分较高和 CPF 较低与拔管失败的风险增加相关（比值比[OR] = 1.13；95%可信区间[CI]，1.03-1.25；OR = 0.95；95%CI，0.93-0.98）。CPF 的受试者工作特征曲线（ROC）截断值为 58.5 分/分钟，灵敏度为 78.8%，特异性为 78.1%。
CPFi 作为咳嗽反射的一个指标，有可能预测通过 SBT 的患者的成功拔管。
