Department of Anaesthesia and Pain Medicine, University of Edinburgh, Royal Infirmary, 51 Little France Crescent, Edinburgh EH16 4HA, UK.
Br J Anaesth. 2013 Dec;111(6):971-8. doi: 10.1093/bja/aet259. Epub 2013 Aug 21.
Respiratory rate is an important measurement in patient care, but accurate measurement is often difficult. We have developed a simple non-invasive device to measure respiratory movements in clinical circumstances, with minimal interference with the patient. We investigated respiratory patterns in patients receiving postoperative morphine analgesia to assess the capacity of the device to detect abnormalities.
We studied subjects during self-administered opioid analgesia after major gynaecological surgery, and related the derived signals with a signal from a nasal cannula. Respiratory movement signals were transmitted wirelessly to a recorder from two encapsulated tri-axial accelerometer (RESpeck) sensors. We analysed the signals using two different sensor placements, each for 30 min. The nasal cannula signal was used to classify breathing patterns as obstructive or non-obstructed.
We studied 20 patients for a mean duration of 49 min each. Breathing patterns were very variable, between and within patients. The median breathing rates ranged from 6.4 to 19.5 bpm. Breathing was partly obstructed in 10 patients, and six patients had repeated cycles of obstruction and transient recovery. In these patients, we found a consistent and statistically significant pattern of changes in chest wall movement, with increased abdominal and decreased rib cage movement during obstruction. In patients with slow respiratory rates, breath-to-breath times were highly variable.
In undisturbed subjects receiving patient-controlled morphine analgesia after surgery, abnormal breathing patterns are extremely common. Cyclical airway obstruction is frequent and associated with a typical pattern of changes in chest wall movement.
呼吸频率是患者护理中的一个重要测量指标，但准确测量往往很困难。我们开发了一种简单的无创设备，可在临床环境下测量呼吸运动，对患者的干扰最小。我们研究了接受术后吗啡镇痛的患者的呼吸模式，以评估该设备检测异常的能力。
我们在妇科大手术后接受自我管理阿片类药物镇痛的患者中进行了研究，并将衍生信号与鼻导管信号相关联。呼吸运动信号通过两个封装的三轴加速度计（RESpeck）传感器无线传输到记录仪。我们使用两种不同的传感器放置方式分析信号，每种方式持续 30 分钟。鼻导管信号用于将呼吸模式分类为阻塞性或非阻塞性。
我们研究了 20 名患者，每位患者的平均持续时间为 49 分钟。患者之间和患者内部的呼吸模式变化非常大。中位数呼吸频率范围为 6.4 至 19.5 bpm。10 名患者的呼吸部分受阻，6 名患者出现阻塞和短暂恢复的周期性循环。在这些患者中，我们发现了一个一致且具有统计学意义的胸壁运动变化模式，在阻塞期间，腹部运动增加，肋骨运动减少。在呼吸频率较慢的患者中，呼吸间时间高度可变。
在接受手术后接受患者自控吗啡镇痛的未受干扰的患者中，异常呼吸模式非常常见。周期性气道阻塞很常见，并伴有胸壁运动变化的典型模式。
