Alphonso N, Tan C, Utley M, Cameron R, Dussek J, Lang-Lazdunski L, Treasure T
Guy's Hospital, London SE1 9RT, UK.
Eur J Cardiothorac Surg. 2005 Mar;27(3):391-4. doi: 10.1016/j.ejcts.2004.12.004. Epub 2005 Jan 13.
Practice varies as to whether or not suction is applied to under-water seal drains following lung surgery. We tested the null hypothesis that there is no difference with respect to air leak duration.
Patients undergoing thoracotomy or video assisted thoracoscopic surgery for lobectomy or wedge resection had either low-pressure suction or no suction applied to their underwater seal bottles postoperatively. Patients were allocated using minimization, a method of unbiased allocation ensuring balance between the arms of a trial with respect to known or suspected confounding factors. The trial was powered for duration of air leak. If an air leak persisted on the 7th post-operative day, the surgeon determined further management. Kaplan-Meier survival analysis of air leak duration and a log rank test were performed on an intention-to-treat basis, with observations censored at 144h (6 complete days).
Of the 254 patients that entered the trial, data were available for analysis for 239 (123 no-suction and 116 suction). There was no significant difference in the cumulative persistence of air leaks between the two groups (P=0.62) and inspection of the Kaplan-Meier curves suggests that any difference is negligible.
Applying suction to the underwater seal drains following lung surgery makes no difference in terms of air leak duration. In the light of this finding we have adopted a uniform policy of no suction being applied to the underwater seal, from the time of surgery, unless a specific clinical judgment is made to use it. The anticipated gains are that this will reduce work and cost and aid mobilization.
肺手术后是否对水封引流管进行吸引，实践中做法不一。我们检验了零假设，即漏气持续时间无差异。
接受开胸手术或电视辅助胸腔镜手术进行肺叶切除术或楔形切除术的患者，术后对其水封瓶要么施加低压吸引，要么不进行吸引。采用最小化法分配患者，这是一种无偏分配方法，可确保试验组在已知或疑似混杂因素方面保持平衡。该试验以漏气持续时间为效能指标。如果术后第7天仍有漏气，外科医生决定进一步处理措施。基于意向性分析对漏气持续时间进行Kaplan-Meier生存分析并进行对数秩检验，观察在144小时（6整天）时进行截尾。
进入试验的254例患者中，有239例（123例未吸引和116例吸引）的数据可供分析。两组之间漏气的累积持续时间无显著差异（P = 0.62），对Kaplan-Meier曲线的检查表明，任何差异都可忽略不计。
肺手术后对水封引流管进行吸引，在漏气持续时间方面没有差异。鉴于这一发现，我们采用了统一的政策，即从手术时起，除非有特殊临床判断需要使用，否则不对水封管进行吸引。预期的好处是，这将减少工作量和成本，并有助于患者活动。
