Lane Fox Respiratory Unit, St Thomas' Hospital, Westminster Bridge Road, London SE1 7EH, UK.
Thorax. 2011 Jul;66(7):602-8. doi: 10.1136/thx.2010.151332. Epub 2011 May 19.
Acute exacerbations of chronic obstructive pulmonary disease have a significant negative impact on both patients and healthcare systems. Currently, there are no physiological biomarkers that effectively monitor clinical change or predict respiratory readmission. Acute exacerbations impose a change in the respiratory muscle load-capacity-drive relationship. It was hypothesised that lack of a fall in neural respiratory drive would identify patients at risk of treatment failure and early hospital readmission.
An observational study was performed at two UK teaching hospitals. Routine clinical physiological parameters and neural respiratory drive index (NRDI), calculated as the product of second intercostal space parasternal electromyography (EMG) activity normalised to the peak EMG activity during a maximum inspiratory sniff manoeuvre and respiratory rate, were recorded daily from admission to discharge.
30 acutely unwell patients of mean (SD) age 72 (10) years, forced expiratory volume in 1 s 0.60 (1.65) l, NRDI 455 (263) AU and median length of stay 6 days were studied. Changes in NRDI correlated with changes in Borg score (r=+0.60; p<0.001), discriminated between patients deemed to have clinically improved rather than deteriorated (mean difference 339 AU; 95% CI 234 to 444; p<0.001) and identified those patients readmitted within 14 days (mean difference 203 AU; 95% CI 39 to 366; p=0.017).
NRDI is a feasible clinical physiological parameter in patients with an acute exacerbation of chronic obstructive pulmonary disease and can provide useful information on treatment response and risk of readmission.
慢性阻塞性肺疾病（COPD）的急性加重对患者和医疗系统都有重大负面影响。目前，没有有效的生理生物标志物来监测临床变化或预测呼吸再入院。急性加重会改变呼吸肌的负荷-容量-驱动关系。研究假设，缺乏神经呼吸驱动的下降将识别出有治疗失败和早期医院再入院风险的患者。
在两家英国教学医院进行了一项观察性研究。从入院到出院，每天记录常规临床生理参数和神经呼吸驱动指数（NRDI），NRDI 计算为第二肋间胸骨旁肌电图（EMG）活动与最大吸气嗅探动作期间最大 EMG 活动的乘积，除以呼吸频率。
研究纳入了 30 名病情急性恶化的患者，平均（标准差）年龄 72（10）岁，1 秒用力呼气量 0.60（1.65）升，NRDI 为 455（263）AU，中位住院时间为 6 天。NRDI 的变化与 Borg 评分的变化相关（r=+0.60；p<0.001），可区分被认为临床改善而非恶化的患者（平均差异 339 AU；95%CI 234 至 444；p<0.001），并可识别出 14 天内再次入院的患者（平均差异 203 AU；95%CI 39 至 366；p=0.017）。
NRDI 是 COPD 急性加重患者可行的临床生理参数，可提供有关治疗反应和再入院风险的有用信息。
