体外膜肺氧合在严重胸外伤抢救中的应用

<正>胸外伤是临床上一种常见的胸外科疾病,可引起急性肺损伤,导致低氧血症,从而出现呼吸窘迫综合征,改善低氧血症一直是严重胸外伤抢救中的重点~([1,2])。为保证良好的气体交换,避免通气过度和气道高压,体外膜肺氧合(extracorporeal membrane oxygenation,ECMO)技术是最佳的选择~([3,4])。ECMO能有效改善低氧血症,提高组织氧摄取率,降低手术风险[5,6]。本文报道2例严重胸外伤抢救患者,探讨ECMO在严重胸外伤     

机械通气策略在体外膜肺氧合过程中的应用

体外膜肺氧合是一种为常规治疗(机械通气)难以治愈的呼吸衰竭患者提供了临时体外呼吸循环支持的技术,在静脉-静脉体外膜肺氧合的过程中,血液从患者的静脉系统进入人工膜肺,进行氧合与二氧化碳的去除,随之再从静脉系统回输至患者体内。为了避免正常肺功能的丧失,机械通气在体外膜肺氧合的过程中仍然有必要,但如何设置体外膜肺氧合过程中的机械通气参数,至今没有明确的指南。因此,本文将简述体外膜肺氧合期间气体交换的病理生理学机制,并就现有证据和文献总结体外膜肺氧合过程中的机械通气策略。     

体外膜肺氧合的临床应用现状和发展趋势

体外膜肺氧合原理和现状体外膜肺氧合(extracorporeal membrane oxygenation,ECMO)是将血液从体内引到体外,经膜肺氧合再用泵将血灌入体内,可进行长时间心肺支持。ECMO治疗期间,心脏和肺得到充分休息,全身氧供和血流动力学处在相对稳定状态。此时膜式氧合器     

肺复张对肺内外源性ARDS患者氧代谢及血流动力学的影响

目的研究肺复张(RM)对肺内外源性ARDS患者氧代谢及血流动力学的影响。方法选取30例中度ARDS患者,分为肺内源性ARDS(ARDSp)组、肺外源性ARDS (ARDSexp)组,每组15例。均行肺保护通气策略(LPVS)及脉搏指示连续心输出量(PICCO)监测。观察RM前后氧代谢及血流动力学指标的变化。结果两组在RM后动脉血氧分压(PaO_2)、静脉血氧分压(PvO_2)、中心静脉血氧饱和度(ScvO_2)和氧输送(DO_2)明显升高(P 0. 05),氧摄取率(ERO_2)明显降低(P 0. 05); ARDSexp组的PaO_2、PvO_2、ScvO_2和DO_2高于ARDSp组(P 0. 05),ERO_2低于ARDSp组(P 0. 05)。两组心率(HR)无变化; RM时中心静脉压(CVP)明显升高,两组无明显差异(P 0. 05),RM后很快恢复至基础值; RM时平均动脉压(MAP)和心脏指数(CI)明显下降(P 0. 05),RM后很快恢复至基础值,ARDSp组下降更显著(P 0. 05)。结论 RM能有效改善ARDS特别是ARDSexp患者氧代谢,对ARDS尤其ARDSp患者实施RM时需警惕血流动力学变化。     

压力控制法肺复张对ARDS患者氧代谢和血流动力学的影响

目的探讨压力控制法肺复张对急性呼吸窘迫综合征(ARDS)患者氧代谢和血流动力学的影响。方法选择苏州市立医院重症医学科(ICU)收治的行机械通气及脉搏轮廓法持续血流动力学监测(PiCCO)的ARDS患者30例,采用肺保护通气策略(LPVS),给予压力控制法(PCV)肺复张(RM)。压力上限为高位转折点(UIP),呼气末正压(PEEP)为低位转折点(LIP)+2 cmH2O,维持时间60 s,RM后维持原方案通气。观察不同时间段氧代谢指标和血流动力学的变化。结果患者在RM后动脉血氧分压(PaO2)、静脉血氧分压(PvO2)、中心静脉血氧饱和度(ScvO2)和氧输送量(DO2)均明显升高(P0.05),氧摄取率(ERO2)明显降低(P0.05)。患者心率(HR)无明显变化;RM时中心静脉压(CVP)显著增加(P0.05),但RM结束后很快恢复至基础水平。RM时平均动脉压(MAP)和心脏指数(CI)均有下降(P0.05),但很快恢复至基础水平。两组均未发生气胸、纵隔及皮下气肿等并发症。结论压力控制法肺复张可提高ARDS患者氧输送,改善组织缺氧;ARDS患者在进行压力控制法肺复张时血液动力学会有短暂变化;压力控制法肺复张安全易行。     

体外膜肺氧合治疗呼吸窘迫综合征的临床疗效研究

目的：探讨体外膜肺氧合（ ECMO）治疗呼吸窘迫综合征（ ARDS）的临床疗效。方法选择2011年11月—2013年11月我院收治的ARDS患者48例,按照就诊时间顺序将患者分为对照组和观察组,各24例。对照组患者单纯应用呼吸机通气治疗,观察组患者应用ECMO治疗。比较治疗前和治疗4 h及24 h后两组患者血流动力学监测指标〔肺动脉压（ PAP ）、心率（ HR ）、心脏指数（ CI ）〕,治疗前和治疗24 h 后全身氧代谢检测指标〔氧分压（ PaO2）、二氧化碳分压（ PaCO2）、血氧饱和度（ SaO2）、混合静脉血氧分压（ PvO2）、混合静脉血二氧化碳分压（PvCO2）、混合静脉血氧饱和度（SvO2）〕,治疗后败血症、感染等不良反应发生率及病死率。结果（1）血流动力学监测指标：治疗前和治疗4 h后两组患者HR、 PAP、 CI比较,差异无统计学意义（ P＞0.05）;治疗24 h后观察组患者上述指标均高于对照组（P＜0.05）。（2）全身氧代谢检测指标：治疗前两组患者PaO2、 PaCO2、 SaO2、 PvO2、PvCO2及SvO2比较,差异均无统计学意义（P＞0.05）;治疗24 h后观察组患者PaO2、 SaO2、 PvO2及SvO2高于对照组, PaCO2、 PvCO2低于对照组（P＜0.05）。（3）观察组患者不良反应发生率为8.3％（2／24）、病死率为29.2％（7／24）,分别低于对照组的25.0％（6／24）、67.7％（16／24）（P＜0.05）。结论采用ECMO治疗ARDS可有效改善患者血、氧代谢,降低不良反应发生率及病死率,可作为临床治疗ARDS的有效手段。     

体外膜肺氧合治疗呼吸窘迫综合征的临床疗效研究

目的：探讨体外膜肺氧合（ ECMO）治疗呼吸窘迫综合征（ ARDS）的临床疗效。方法选择2011年11月—2013年11月我院收治的ARDS患者48例,按照就诊时间顺序将患者分为对照组和观察组,各24例。对照组患者单纯应用呼吸机通气治疗,观察组患者应用ECMO治疗。比较治疗前和治疗4 h及24 h后两组患者血流动力学监测指标〔肺动脉压（ PAP ）、心率（ HR ）、心脏指数（ CI ）〕,治疗前和治疗24 h 后全身氧代谢检测指标〔氧分压（ PaO2）、二氧化碳分压（ PaCO2）、血氧饱和度（ SaO2）、混合静脉血氧分压（ PvO2）、混合静脉血二氧化碳分压（PvCO2）、混合静脉血氧饱和度（SvO2）〕,治疗后败血症、感染等不良反应发生率及病死率。结果（1）血流动力学监测指标：治疗前和治疗4 h后两组患者HR、 PAP、 CI比较,差异无统计学意义（ P＞0.05）;治疗24 h后观察组患者上述指标均高于对照组（P＜0.05）。（2）全身氧代谢检测指标：治疗前两组患者PaO2、 PaCO2、 SaO2、 PvO2、PvCO2及SvO2比较,差异均无统计学意义（P＞0.05）;治疗24 h后观察组患者PaO2、 SaO2、 PvO2及SvO2高于对照组, PaCO2、 PvCO2低于对照组（P＜0.05）。（3）观察组患者不良反应发生率为8.3％（2／24）、病死率为29.2％（7／24）,分别低于对照组的25.0％（6／24）、67.7％（16／24）（P＜0.05）。结论采用ECMO治疗ARDS可有效改善患者血、氧代谢,降低不良反应发生率及病死率,可作为临床治疗ARDS的有效手段。     

高频喷射通气联合气管内吹气治疗急性肺损伤的临床研究

分别采用高频喷射通气(HFJV)联合联合气管内吹气(TGI)及单纯HFJV治疗急性肺损伤患者,并记录血气指标及血流动力学指标变化.结果HFJV联合TGI可明显降低急性肺损伤患者二氧化碳分压及呼气末二氧化碳分压,升高动脉血氧分压及血氧饱和度,单纯HFJV可提高氧分压(P均<0.05);与单纯HFJV治疗后比较,HFJV联合TGI氧分压及血氧饱和度升高,二氧化碳分压下降(P均<0.05).表明HFJV联合TGI可有效提高肺损伤患者的氧合,且不影响其血流动力学.     

同期双侧开胸手术麻醉对血气和血流动力学的影响

目的探讨同期双侧开胸手术麻醉对血气和血流动力学的影响。方法 40例择期同期双侧开胸手术分为两组：A组20例,行双侧肺大疱缝扎术;B组20例,行双侧支扩支气管剔除术。患者入室后监测血压、心电图、脉搏、氧饱和度并进行桡动脉穿刺置管和中心静脉穿刺置管。患者安静10 min后采集动脉血气并记录该时间点（T0）平均动脉压和心率作为基础值。插管后分别于双肺通气10 min（T1）、单肺通气10 min（T2）、再次双肺通气10 min（T3）、二次开胸后单肺通气10 min（T4）、双肺通气10 min（T5）采集动脉血气并同时记录平均动脉压和心率。比较两组开胸手术同一时间点以及各组内不同时间点的动脉血气和血流动力学情况。结果两组患者同一时间点动脉血气与血流动力学比较差异无统计学意义,组内各时间点动脉血气与血流动力学比较差异亦无统计学意义。结论双侧肺部疾病手术患者可安全地实施同期双侧开胸单肺麻醉。     

预防性静脉-动脉体外膜肺氧合支持下的经导管主动脉瓣植入术

经导管主动脉瓣植入术是治疗重度主动脉瓣狭窄的有效方法,当遇到诸如低射血分数的极高危患者,可能需要静脉-动脉体外膜肺氧合这样的机械设备的辅助治疗.现通过介绍1例成功在预防性静脉-动脉体外膜肺氧合应用下进行经导管主动脉瓣植入术的高危、低射血分数患者,进一步讨论当前国内外静脉-动脉体外膜肺氧合在经导管主动脉瓣植入术中的应用情...     

Cerebral oxygen monitoring during neonatal cardiopulmonary bypass and deep hypothermic circulatory arrest

BACKGROUND: This study was undertaken to investigate the physiological effects of cardiopulmonary bypass (CPB) and deep hypothermic circulatory arrest (DHCA) on cerebral oxygen metabolism estimated by near-infrared spectroscopy (NIRS). METHODS: Ten newborn piglets (2.1 to 2.6 kg) were monitored with right frontal NIRS; the right jugular bulb was cannulated for intermittent sampling of jugular venous blood. All animals underwent CPB, cooling to a core temperature below 15 degrees C, 60 minutes of DHCA followed by subsequent reperfusion and rewarming. Continuously recorded NIRS data and intermittent jugular venous blood values were compared. RESULTS: NIRS performance was examined over the jugular venous oxygen saturation (SjvO2) range of 40 to 98 %, a linear correlation was found between SjvO2 and NIRS-derived regional cerebral oxygen saturation (rSO2) (r = 0.91, p < 0.001). A correlation was observed between the cellular oxidation NIRS-parameter cytochrome oxidase aa3 (CytOx) slope during the DHCA period in relation to rectal and nasopharyngeal temperature immediately before the onset of DHCA (r = 0.75 and 0.85, p < 0.001). CONCLUSIONS: This study suggests that NIRS-measured hemoglobin oxygenation parameters may reflect functional changes in cerebral hemodynamics and brain tissue oxygenation, while CytOx values represent related effects on intracellular oxidative metabolism.     

主动脉球囊反搏与体外膜肺氧合联合辅助救治心脏术后重症患者的价值

目的:总结应用主动脉球囊反搏（IABP）与体外膜肺氧合（ECMO）联合辅助救治成人心脏术后重症患者的价值。方法:对14例成人心脏术后重症患者同时行IABP和ECMO联合辅助,通过观察患者辅助前、后收缩压（SBP）、舒张压（DBP）、左室射血分数（LVEF）以及血气指标和肾功能指标来评价辅助效果。结果:血流动力学指标、血气指标以及肾功能在联合辅助后显著改善（均P<0.05）。结论:联合辅助救治成人心脏术后重症患者的疗效显著。     

Effects of octreotide on central hemodynamics and systemic oxygen use in patients with viral cirrhosis

OBJECTIVE: Octreotide has potentially beneficial effects in patients with cirrhosis. However, the effects of octreotide on central hemodynamics and oxygen use have not been established. The present study was undertaken to evaluate the effect of octreotide on central hemodynamics and oxygen use in patients with viral cirrhosis. METHODS: Twenty-five patients with cirrhosis were enrolled in the study. They were randomly assigned to receive either placebo (n = 10) or a continuous infusion of 100 microg/h of octreotide after an initial 100-microg bolus (n = 15). Hemodynamic measurements and oxygenation values were obtained before and 60 min after octreotide or placebo administration. RESULTS: Placebo administration did not have any effect on hemodynamic and oxygenation values. In patients who received octreotide, systemic hemodynamic values including cardiac index, mean arterial pressure, and systemic vascular resistance were not affected. The mean pulmonary arterial pressure tended to increase after octreotide administration but was statistically insignificant. There was a significant increase in pulmonary arterial vascular resistance, whereas the pulmonary capillary wedge pressure and right atrial pressure were significantly decreased. Arterial oxygen tension, systemic oxygen uptake, and oxygen extraction ratio were significantly decreased after octreotide administration, whereas oxygen transport as well as arterial and mixed venous oxygen contents remained unchanged. CONCLUSIONS: In patients with viral cirrhosis, octreotide administration exerted a significant effect on pulmonary circulation. It also resulted in a decrease in systemic oxygen uptake and oxygen extraction ratio. These results suggested that octreotide may impair tissue oxygenation in patients with viral cirrhosis.     

重症急性呼吸窘迫综合征体外膜肺治疗的探讨

目的 回顾性分析体外膜氧合(ECMO)在重症急性呼吸窘迫综合征(ARDS)治疗中的作用.方法 应用股静脉-股动脉途径的ECMO支持对1例吸入烟雾弹致严重ARDS患者治疗41 d.连续观察患者血液动力学、肺影像学、呼吸机参数、经皮脉氧氧饱和度、酸碱平衡、血乳酸含量以及心、肝、肾、脑功能的变化.结果 ECMO支持技术可使重症ARDS患者较长时间维持生理水平的动脉血气、组织氧供及酸碱平衡,保持良好的心、肺、肾、脑功能,但患者在行ECMO支持治疗的第41天因严重的肺部感染并可能的脑出血失去继续治疗的价值而终止治疗.结论 ECMO可提供有效的肺功能支持,可为ARDS患者肺的恢复和临床进一步处理创造了机会.出血与栓塞是维持ECMO顺利运行的关键问题.     

尼莫地平控制性降压对颅内动脉瘤夹闭术中脑氧代谢的影响

目的观察颅内动脉瘤夹闭术中应用尼莫地平控制性降压对脑氧代谢的影响。方法选择颅内动脉瘤夹闭术患者30例,根据控制降压药随机分为2组:硝酸甘油组(A组,n=15)和尼莫地平组(B组,n=15),于不同时间段行动静脉血气分析和血乳酸含量测定。结果(1)A组的心率在降压中的两时间点明显快于降压前,差异有统计学意义(P<0.05),在降压30min和夹闭后两时间点上,B组的HR明显较A组慢,差异有统计学意义(P<0.05)。(2)B组的D(a-jv)O2和D(jv-a)BG在降压30min、夹闭后及停降压30min时3个时间点明显少于A组,差异有统计学意义(P<0.01);与降压前比较,B组的D(a-jv)O2和D(jv-a)BG在降压30min和夹闭后两时间点明显下降,差异有统计学意义(P<0.01)。结论尼莫地平可安全用于动脉瘤夹闭术中控制性降压,降低脑氧代谢和改善脑氧合,有较好的脑保护作用。     

Effect of oral propranolol on splanchnic oxygen uptake and haemodynamics in patients with cirrhosis

In order to elucidate the effect of beta-adrenergic blockade on liver metabolism and haemodynamics, splanchnic oxygen uptake, hepatic removal of indocyanine green (ICG) and splanchnic and systemic haemodynamics were studied in 13 patients with cirrhosis before and 1.5-2 h after an oral dose of 80 mg propranolol. All patients underwent hepatic vein catheterization and had a primed continuous intravenous infusion of ICG. Azygos vein catheterization was performed in six patients. Splanchnic (hepatic-intestinal) oxygen uptake (median control 68 ml/min vs. beta-blockade 56 ml/min, P less than 0.01), azygos venous oxygen saturation (76 vs. 67%, P less than 0.05), ICG clearance (263 vs. 226 ml/min, P less than 0.01), wedged-to-free hepatic vein pressure (16 vs. 13.5 mm Hg, P less than 0.01), hepatic blood flow (1.18 vs. 0.78 l/min, P less than 0.01), cardiac index (3.42 vs. 2.53 l/min . min 2, P less than 0.01), and heart rate (72 vs. 56 beats per min, P less than 0.01) decreased significantly after oral beta-blockade. The hepatic extraction ratio of ICG increased significantly (0.32 vs. 0.45, P less than 0.01), whereas estimated 'intrinsic' ICG clearance (289 vs. 300 ml/min, n.s.), arterial blood pressure, stroke volume, and systemic vascular resistance remained essentially unchanged. The results indicate that besides the well-known cardiovascular effects of propranolol, beta-adrenergic blockade may also reduce hepatic metabolic functions as evidenced by the significantly decreased splanchnic oxygen uptake. The raised hepatic extraction ratio of ICG may be caused by reduction in hepatic blood flow as well as in intrahepatic shunting.     

Effects of Endoscopic Variceal Ligation on Oxygen Transport and the Arterial Lactate Levels in Patients With Cirrhosis

Objective: Despite the increased cardiac output and oxygen delivery, an impaired oxygen uptake has been noted in patients with cirrhosis. We recently observed that endoscopic variceal ligation decreased the cardiac output due to a reduction in the cardiac preload. It is thus possible that a variceal ligation decreases the oxygen delivery and thereby negatively influences tissue oxygenation in patients receiving such treatment. We thus investigated the effects of variceal ligation on oxygen delivery, oxygen uptake, and the arterial lactate levels.
Methods: There were 22 patients with compensated cirrhosis and risky esophageal varices (Child's class  A:B = 13:9  ). Twelve patients underwent an endoscopic variceal ligation and 10 patients received gastroscopy as a control. The cardiac function, blood gas status, oxygen delivery, and arterial lactate concentration were also assessed before and after variceal ligation. The oxygen uptake was calculated by the Fick equation.
Results: Following variceal ligation, there was an immediate decrease in the cardiac output and oxygen delivery. The reduction in oxygen delivery was associated with a slight but significant increase in the arterial lactate concentration. The decreased oxygen delivery was also associated with a concomitant decrease in the oxygen uptake. In the control subjects, gastroscopy did not alter the systemic hemodynamics, arterial oxygen status, or arterial lactate levels.
Conclusion: We found a significant decrease in the oxygen delivery in patients undergoing an endoscopic variceal ligation. Such deteriorated tissue oxygenation may be serious especially in patients with a low oxygen transport ability such as in patients with variceal hemorrhage with anemia. However, the clinical significance of these changes remains unclear and further studies are therefore warranted.     

颅脑手术中颅内操作期间吸入不同浓度七氟醚对脑氧及脑糖代谢的影响

目的观察颅脑手术患者行颅内操作期间应用不同浓度七氟醚联合瑞芬太尼麻醉对脑氧及脑糖代谢的影响。方法将30例颅内幕上占位患者随机分为S1组和S2组各15例。于术中切皮前10min分别予1.0、1.5MAC七氟醚联合瑞芬太尼靶控输注,于切开硬膜即刻（T0）、切开硬膜1h后（T1）、2h后（T2）、关闭硬膜即刻（T3）各个时点分别采取颈内静脉球部血及桡动脉血进行血气分析,测定颈内静脉球氧饱和度（SjvO2）、动脉—颈内静脉球氧含量差（Da-jvO2）和脑氧摄取率（COER）、脑动静脉血糖含量差（Da-jvGlu）、脑动静脉乳酸含量差（Da-jvLac）。结果与T0比较,两组T1、T2、T3时点SjvO2均明显升高（P均〈0.05）;AjvDO2、COER均明显降低（P均〈0.05）;Da-jvGlu、Da-jvLac无明显变化。结论 1.0MAC或1.5MAC七氟醚联合瑞芬太尼麻醉均能降低脑氧代谢,而对脑糖代谢无明显影响。     

Adequacy of perfusion during hypothermia: regional distribution of cardiopulmonary bypass flow, mixed venous and regional venous oxygen saturation - hypothermia and distribution of flow and oxygen

BACKGROUND: Hypothermia during CPB is used to reduce metabolic activity, thus protecting organs and tissues. The aim of this study was to investigate the relationship between regional and mixed venous oxygen saturation and distribution of pump flow with respect to hypothermia. METHODS: Twenty-five patients undergoing a Ross procedure were included in a prospective, controlled study. During standard CPB, temperature was reduced stepwise to 28 degrees C. Blood gases (a-stat regimen) were analysed in samples from the inferior (IVC) and the superior vena cava (SVC), arterial and mixed venous blood. Flow was detected separately in the SVC, IVC, arterial, and collecting venous line. Samples were taken, and flows were measured before CPB, during hypothermia, during rewarming, and 30 min after CPB discontinuation. RESULTS: Oxygen saturation in the IVC was lower than in the SVC and in mixed venous blood at all times (max. difference - 17.3 +/- 3.0 % during hypothermia, - 23.8 +/- 2.9 % during rewarming, p < 0.01). There was a statistical correlation of mixed and IVC venous oxygen saturation (r = 0.79, p < 0.001) but not of SVC venous blood. Hypothermia had a major influence on pump flow distribution as backflow from the SVC decreased significantly in favour of IVC flow with increasing degree of hypothermia (increase of flow difference from 1.15 +/- 0.23 l/min to 1.49 +/- 0.36 l/min, p < 0.01). Temperature profiles were similar when detected in aorta, pulmonary artery, tympanum and nasopharygeum, but differed significantly from other sites. CONCLUSIONS: During hypothermic CPB, regional deoxygenation occurs in spite of normal mixed venous saturation. The level of hypothermia has a major impact on bypass flow distribution with cerebral perfusion reduction. Methods of regional oxygenation assessment are needed, and altered strategies during hypothermia have to be taken into consideration.