Kuzkov Vsevolod V, Suborov Evgeny V, Kirov Mikhail Y, Kuklin Vladimir N, Sobhkhez Mehrdad, Johnsen Solveig, Waerhaug Kristine, Bjertnaes Lars J
Department of Anesthesiology, Institute of Clinical Medicine, University of Tromsø, Tromsø, Norway.
Crit Care Med. 2007 Jun;35(6):1550-9. doi: 10.1097/01.CCM.0000265739.51887.2B.
To compare the single thermodilution and the thermal-dye dilution techniques with postmortem gravimetry for assessment of changes in extravascular lung water after pneumonectomy and to explore the evolution of edema after injurious ventilation of the left lung.
Experimental study.
University laboratory.
A total of 30 sheep weighing 35.6 +/- 4.6 kg. The study included two parts: a pneumonectomy study (n = 18) and an injurious ventilation study (n = 12).
Sheep were anesthetized and mechanically ventilated with an FiO2 of 0.5, tidal volume of 6 mL/kg, and positive end-expiratory pressure of 2 cm H2O. In the pneumonectomy study, sheep were assigned to right-sided pneumonectomy (n = 7), left-sided pneumonectomy (n = 7), or lateral thoracotomy only (sham operation, n = 4). In the injurious ventilation study, right-sided pneumonectomy was followed by ventilation with a tidal volume of 12 mL/kg and positive end-expiratory pressure of 0 cm H2O (n = 6) or by ventilation with a tidal volume of 6 mL/kg and positive end-expiratory pressure of 2 cm H2O for 4 hrs (n = 6). Volumetric variables, including extravascular lung water index (EVLWI), were measured with single thermodilution (STD; EVLWI(STD)) and thermal-dye dilution (TDD; EVLWI(TDD)) techniques. We monitored pulmonary hemodynamics and respiratory variables. After the sheep were killed, EVLWI was determined for each lung by gravimetry (EVLWI(G)).
In total, the study yielded strong correlations of EVLWI(STD) and EVLWI(TDD) with EVLWI(G) (n = 30; r = .83 and .94, respectively; p < .0001). After pneumonectomy, both the left- and the right-sided pneumonectomy groups displayed significant decreases in EVLWI(STD) and EVLWI(TDD). The injuriously ventilated sheep demonstrated significant increases in EVLWI that were detected by both techniques. The mean biases (+/-2 SD) compared with EVLWI(G) were 3.0 +/- 2.6 mL/kg for EVLWI(STD) and 0.4 +/- 1.6 mL/kg for EVLWI(TDD).
After pneumonectomy and injurious ventilation of the left lung, TDD and STD displayed changes in extravascular lung water with acceptable accuracy when compared with postmortem gravimetry. Ventilator-induced lung injury seems to be a crucial mechanism of pulmonary edema after pneumonectomy.
比较单次热稀释法和热染料稀释技术与尸体重量法，以评估肺叶切除术后血管外肺水的变化，并探讨左肺损伤性通气后水肿的演变情况。
实验研究。
大学实验室。
共30只体重为35.6±4.6千克的绵羊。该研究包括两个部分：肺叶切除术研究（n = 18）和损伤性通气研究（n = 12）。
绵羊麻醉后，以0.5的吸入氧分数、6毫升/千克的潮气量和2厘米水柱的呼气末正压进行机械通气。在肺叶切除术研究中，绵羊被分配接受右侧肺叶切除术（n = 7）、左侧肺叶切除术（n = 7）或仅行开胸术（假手术，n = 4）。在损伤性通气研究中，右侧肺叶切除术后，分别给予12毫升/千克的潮气量和0厘米水柱的呼气末正压通气（n = 6），或给予6毫升/千克的潮气量和2厘米水柱的呼气末正压通气4小时（n = 6）。采用单次热稀释法（STD；EVLWI(STD)）和热染料稀释法（TDD；EVLWI(TDD)）测量包括血管外肺水指数（EVLWI）在内的容积变量。监测肺血流动力学和呼吸变量。绵羊处死后，通过重量法测定每侧肺的EVLWI（EVLWI(G)）。
总体而言，该研究得出EVLWI(STD)和EVLWI(TDD)与EVLWI(G)之间具有强相关性（n = 30；r分别为0.83和0.94；p <.0001）。肺叶切除术后，左侧和右侧肺叶切除组的EVLWI(STD)和EVLWI(TDD)均显著降低。损伤性通气的绵羊在两种技术检测下均显示EVLWI显著增加。与EVLWI(G)相比，EVLWI(STD)的平均偏差（±2 SD）为3.0±2.6毫升/千克，EVLWI(TDD)为0.4±1.6毫升/千克。
与尸体重量法相比，在肺叶切除和左肺损伤性通气后，TDD和STD在检测血管外肺水变化方面具有可接受的准确性。呼吸机诱导的肺损伤似乎是肺叶切除术后肺水肿的关键机制。
