MacIntyre N R, Silver R M, Miller C W, Schuler F, Coleman R E
Crit Care Med. 1985 Feb;13(2):81-4. doi: 10.1097/00003246-198502000-00005.
To study the effects of respiratory failure and mechanical ventilation on aerosol delivery to the lungs, we performed nuclear scans after aerosolization of 5 to 9 mCi of Tc-99m diethylenetriamine pentaacetic acid in seven stable, intubated, and mechanically ventilated patients. The radioactivity reaching the lungs was 2.9 +/- .7% (mean +/- SD) of the administered dose, an amount significantly less than that in three healthy nonintubated subjects and also less than what would be expected in nonintubated subjects from other published reports. We then performed a subsequent study in 15 additional mechanically ventilated patients who were receiving aerosolized bronchodilators through their endotracheal tube. In these patients, heart rate and lung mechanical function values before and after treatment were not significantly different. We conclude from these studies that aerosol delivery in mechanically ventilated patients is significantly reduced and that this is probably due to a combination of suboptimal breathing pattern, intrinsic airway disease, and the endotracheal tube functioning as both a site for aerosol deposition through impaction as well as a barrier to gastrointestinal absorption.
为研究呼吸衰竭和机械通气对气溶胶输送至肺部的影响，我们对7名病情稳定、已插管并接受机械通气的患者雾化吸入5至9毫居里的锝-99m二乙三胺五乙酸后进行了核扫描。到达肺部的放射性为给药剂量的2.9±0.7%（均值±标准差），这一数值显著低于3名健康未插管受试者，也低于其他已发表报告中未插管受试者的预期值。随后，我们对另外15名通过气管内导管接受雾化支气管扩张剂治疗的机械通气患者进行了研究。在这些患者中，治疗前后的心率和肺机械功能值无显著差异。我们从这些研究中得出结论，机械通气患者的气溶胶输送显著减少，这可能是由于呼吸模式欠佳、气道固有疾病以及气管内导管既是气溶胶通过撞击沉积的部位又是胃肠道吸收的屏障共同作用的结果。
