Mouloudi E, Katsanoulas K, Anastasaki M, Askitopoulou E, Georgopoulos D
Intensive Care Unit, University Hospital of Heraklion, University of Crete, Greece.
Eur Respir J. 1998 Jul;12(1):165-9. doi: 10.1183/09031936.98.12010165.
The delivery of bronchodilators with a metered-dose inhaler (MDI) and a spacer in mechanically ventilated patients has become widespread practice. However, the various ventilator settings that influence the efficacy of MDI are not well established. Application of an end-inspiratory pause (EIP) during drug delivery has been suggested as one of the factors that might increase the effectiveness of this therapy. To test this, the effect of EIP on the bronchodilation induced by beta2-agonists administered with MDI and a spacer in a group of mechanically ventilated patients with chronic obstructive pulmonary disease (COPD) was examined. Twelve patients with COPD, mechanically ventilated on volume-controlled mode, were prospectively randomized to receive six puffs of salbutamol (100 microg x puff(-1)) either with or without EIP of 5 s duration. Salbutamol was administered with an MDI adapted to the inspiratory limb of the ventilator circuit using an aerosol cloud-enhancer spacer. After a 6 h wash-out, patients were crossed over to receive salbutamol by the alternative mode of administration. Static and dynamic airway pressures, minimum (Rmin) and maximum (Rmax) airflow resistance, the difference between Rmax and Rmin (deltaR), static end-inspiratory respiratory system compliance (Cst,rs) and cardiac frequency (fc) were measured before and at 15, 30 and 60 min after salbutamol administration. Salbutamol caused a significant decrease in dynamic and static airway pressures, Rmin and Rmax. These changes were not influenced by application of EIP and were evident at 15, 30 and 60 min after salbutamol. With and without EIP, Cst,rs,deltaR and fc did not change after salbutamol. In conclusion, salbutamol delivered with a metered-dose inhaler and a spacer device induced significant bronchodilation in mechanically ventilated patients with chronic obstructive pulmonary disease, the magnitude of which was not affected by an end-expiratory pause of 5 s. These results do not support the use of end-inspiratory pause when bronchodilators are administered in adequate doses during controlled mechanical ventilation.
在机械通气患者中，使用定量吸入器（MDI）和储雾罐输送支气管扩张剂已成为普遍做法。然而，影响MDI疗效的各种通气设置尚不完全明确。在药物输送过程中应用吸气末暂停（EIP）被认为是可能提高该治疗效果的因素之一。为了验证这一点，研究了EIP对一组慢性阻塞性肺疾病（COPD）机械通气患者使用MDI和储雾罐给予β2激动剂所诱导的支气管扩张的影响。12例采用容量控制模式进行机械通气的COPD患者被前瞻性随机分为两组，分别接受6喷沙丁胺醇（每喷100μg），一组伴有5秒的EIP，另一组不伴有。使用气溶胶云增强储雾罐，将与呼吸机回路吸气支适配的MDI用于给予沙丁胺醇。经过6小时的洗脱期后，患者交叉接受另一种给药方式的沙丁胺醇。在给予沙丁胺醇之前以及给药后15、30和60分钟，测量静态和动态气道压力、最小（Rmin）和最大（Rmax）气流阻力、Rmax与Rmin之差（ΔR）、静态吸气末呼吸系统顺应性（Cst,rs）和心率（fc）。沙丁胺醇使动态和静态气道压力、Rmin和Rmax显著降低。这些变化不受EIP应用的影响，且在给予沙丁胺醇后15、30和60分钟时明显。无论有无EIP，给予沙丁胺醇后Cst,rs、ΔR和fc均无变化。总之，在慢性阻塞性肺疾病机械通气患者中，使用定量吸入器和储雾罐装置给予沙丁胺醇可诱导显著的支气管扩张，其程度不受5秒呼气末暂停的影响。这些结果不支持在控制机械通气期间给予足够剂量支气管扩张剂时使用吸气末暂停。
