Left lateral intercostal region versus subxiphoid position for pleural drain during elective coronary artery bypass graft surgery: randomized clinical trial

ABSTRACT BACKGROUND: The pleural drain insertion site after coronary artery bypass graft (CABG) surgery may alter lung function, especially respiratory muscle strength. The main objective of this study was to compare the effectiveness and safety of use of the left lateral intercostal region versus the subxiphoid position for pleural drainage during elective CABG surgery using extracorporeal circulation (ECC). DESIGN AND SETTING: Randomized trial conducted in a tertiary-level hospital in Porto Alegre, Brazil. METHODS: 48 patients were assigned to group 1 (pleural drain in the left lateral intercostal region) or group 2 (pleural drain in the subxiphoid position). Respiratory muscle strength was measured in terms of maximal inspiratory pressure (MIP) and maximal expiratory pressure (MEP), in cmH2O, by means of manovacuometry preoperatively, 24 and 72 hours after drain removal and before discharge from hospital. Painand dyspnea scales, presence of infections, pleural effusion and atelectasis, duration of drain use, drainage volumes and surgical reinterventions were also evaluated. RESULTS: After adjustments, there were no significant differences between the groups at the end of the study (before discharge), in predicted percentages either for MIP (delta group 1: -17.21% versus delta group 2: -22.26%; P = 0.09) or for MEP (delta group 1: -9.38% versus delta group 2: -13.13%; P = 0.17). Therewere no differences between the groups in relation to other outcomes. CONCLUSION: There was no difference in maximal respiratory pressures in relation to the pleural drain insertion site among patients who underwent CABG surgery using ECC. TRIAL REGISTRATION: ReBEc V1111.1159.4447.

【研究背景】冠状动脉旁路移植术（coronary artery bypass graft, CABG）术后的胸腔引流置管位置可能会对肺功能产生影响，尤以呼吸肌力量为著。本研究的核心目的为对比体外循环（extracorporeal circulation, ECC）下择期冠状动脉旁路移植术中，采用左侧肋间区域与剑突下位置行胸腔引流的有效性与安全性。
【研究设计与场景】本研究为随机对照试验，于巴西阿雷格里港的一所三级医院开展。
【研究方法】将48例患者随机分配至组1（左侧肋间区域放置胸腔引流管）与组2（剑突下位置放置胸腔引流管）。分别于术前、拔管后24小时、拔管后72小时及出院前，采用呼吸压力测定法（manovacuometry）以cmH₂O为单位测量最大吸气压（maximal inspiratory pressure, MIP）与最大呼气压（maximal expiratory pressure, MEP），以此评估呼吸肌力量。同时对疼痛与呼吸困难量表评分、感染发生情况、胸腔积液与肺不张发生情况、引流管留置时长、引流量及手术再次干预情况进行评估。
【研究结果】经校正后，研究终点（出院前）时，两组患者的最大吸气压预测值变化幅度（组1变化率：-17.21%，组2变化率：-22.26%；P=0.09）及最大呼气压预测值变化幅度（组1变化率：-9.38%，组2变化率：-13.13%；P=0.17）均无显著统计学差异。其余结局指标组间亦无显著差异。
【研究结论】接受体外循环下冠状动脉旁路移植术的患者中，胸腔引流置管位置对最大呼吸压力无显著影响。
【试验注册】ReBEc V1111.1159.4447。