Groeneveld A B Johan, Jansen Evert K, Verheij Joanne
Department of Intensive Care, VU University Medical Center, Amsterdam, The Netherlands.
J Cardiothorac Surg. 2007 Feb 14;2:11. doi: 10.1186/1749-8090-2-11.
Pulmonary dysfunction following cardiac surgery is believed to be caused, at least in part, by a lung vascular injury and/or atelectasis following cardiopulmonary bypass (CPB) perfusion and collapse of non-ventilated lungs.
To test this hypothesis, we studied the postoperative pulmonary leak index (PLI) for 67Ga-transferrin and (transpulmonary) extravascular lung water (EVLW) in consecutive patients undergoing on-pump (n = 31) and off-pump (n = 8) cardiac surgery. We also studied transfusion history, radiographs, ventilatory and gas exchange variables.
The postoperative PLI and EVLW were elevated above normal in 42 and 29% after on-pump surgery and 63 and 37% after off-pump surgery, respectively (ns). Transfusion of red blood cell (RBC) concentrates, PLI, EVLW, occurrence of atelectasis, ventilatory variables and duration of mechanical ventilation did not differ between groups, whereas patients with atelectasis had higher venous admixture and airway pressures than patients without atelectasis (P = 0.037 and 0.049). The PLI related to number of RBC concentrates infused (P = 0.025).
The lung vascular injury in about half of patients after cardiac surgery is not caused by CPB perfusion but by trauma necessitating RBC transfusion, so that off-pump surgery may not afford a benefit in this respect. However, atelectasis rather than lung vascular injury is a major determinant of postoperative pulmonary dysfunction, irrespective of CPB perfusion.
心脏手术后的肺功能障碍被认为至少部分是由体外循环（CPB）灌注后肺血管损伤和/或肺不张以及非通气肺萎陷引起的。
为验证这一假设，我们研究了连续接受体外循环心脏手术（n = 31）和非体外循环心脏手术（n = 8）患者的术后67Ga - 转铁蛋白肺渗漏指数（PLI）和（经肺）血管外肺水（EVLW）。我们还研究了输血史、X光片、通气和气体交换变量。
体外循环心脏手术后，术后PLI和EVLW分别有42%和29%高于正常水平；非体外循环心脏手术后，分别有63%和37%高于正常水平（无显著性差异）。两组之间红细胞（RBC）浓缩液输注量、PLI、EVLW、肺不张发生率、通气变量及机械通气时间无差异，然而，发生肺不张的患者比未发生肺不张的患者有更高的静脉血掺杂和气道压力（P = 0.037和0.049）。PLI与输注的RBC浓缩液数量相关（P = 0.025）。
心脏手术后约一半患者的肺血管损伤并非由CPB灌注引起，而是由需要输注RBC的创伤导致，因此在这方面非体外循环手术可能并无益处。然而，无论CPB灌注情况如何，肺不张而非肺血管损伤是术后肺功能障碍的主要决定因素。
