咪达唑仑对人离体肺段肺泡液体清除率的影响

摘要

目的：咪达唑仑是一种常用的静脉麻醉药，该研究旨在探讨咪达唑仑对人离体肺段肺泡液体清除率（Alveolar fluid clearance, AFC）的作用。方法应用临床外科手术肺切除病人的肺段标本，将药物通过插管注入远端肺组织。应用考马斯亮兰法测定肺泡液体内小牛血清白蛋白的浓度的方法测定人离体肺段AFC。结果离体肺段插管注入0.1 mmol/L咪达唑仑后，AFC明显降低。与1 mmol/L阿米洛利（特异性钠通道阻断剂）合用后抑制效应未见进一步增强。结论咪达唑仑能够抑制与上皮钠通道有关的阿米洛利敏感性AFC，从而降低肺泡上皮液体的清除。临床上对伴有肺水肿的病人应用咪达唑仑时应考虑其可能对肺脏液体清除作用的影响。%Objective Midazolam is a broadly used intravenous anesthetic. We aim to investigate the effect of midazolam on alveolar fluid clearance (AFC) of isolated human lungs. Methods Human lungs were obtained from patients who underwent pneumonectomy for lung cancer. A warmed normal saline solution containing 5%bovine serum albumin with or without amiloride (1 mmol/L) or midazolam (0.1 mmol/L) was instilled into the distal air spaces through the catheter. AFC was measured using bovine serum albumin protein assays. Results The rate of AFC was significantly reduced in human lungs with administrated midazolam (0.1 mmol/L). When midazolam was instilled into the lung segments together with amiloride (a specific ENaC inhibitor), no further inhibition effect occurred. Conclusion Our observations demonstrate that midazolam may decrease ENaC-associated fluid clearance across the distal lung epithelium.