高原地区创伤和感染性急性呼吸窘迫综合征94例死亡原因分析

目的探索高原地区急性呼吸窘迫综合征（ＡＲＤＳ）发病特征、诊断标准。方法 通过病案复习,对近１０年２．３２５例院内死亡病例进行初筛,排除因恶性肿瘤、心脑血管病、慢性阻塞性肺疾病等所致慢性多器官衰竭,按照国内ＡＲＤＳ诊断标准,参照全身炎症反应综合征／多器官功能障碍综合征（ＳＩＲＳ／ＭＯＤＳ）诊断模式（１９９１年美国）和欧美联席会议１９９２年ＡＲＤＳ诊断标准进行死亡原因的回顾性分析。结果 ９４例（４．０     

High-frequency oscillatory ventilation in adults with traumatic brain injury and acute respiratory distress syndrome

BACKGROUND: This study observed adverse events of rescue treatment with high-frequency oscillatory ventilation (HFOV) in head-injured patients with acute respiratory distress syndrome (ARDS). METHODS: Data of five male patients with ARDS and traumatic brain injury, median age 28 years, who failed to respond to conventional pressure-controlled ventilation (PCV) were analyzed retrospectively during HFOV. Adjusted mean airway pressure at initiation of HFOV was set to 5 cm H2O above the last measured mean airway pressure during PCV. Frequency of pulmonary air leak, mucus obstruction, tracheal injury, and need of HFOV termination due to increased intracranial pressure, decreased cerebral perfusion pressure, or deterioration in P(a)CO2 were analyzed. RESULTS: During HFOV we found no complications. We recorded 390 datasets of intracranial pressure, cerebral perfusion pressure and P(a)CO2 simultaneously. Intracranial pressure increased (>25 mmHg) in 11 of 390 datasets, cerebral perfusion pressure was reduced (<70 mmHg) in 66 of 390 datasets, and P(a)CO2 variations (<4.7 kPa; >6.0 kPa) were observed in eight of 390 datasets after initiation of HFOV. All these alterations were responsive to treatment. P(a)O2/F(I)O2-ratio improved in four patients during HFOV. Conclusion: High-frequency oscillatory ventilation appears to be a promising alternative rescue treatment in head-injured patients with ARDS if continuous monitoring of intracranial pressure, cerebral perfusion pressure and P(a)CO2 are provided, in particular during initiation of HFOV.     

Protective ventilation of patients with acute respiratory distress syndrome

The majority of patients with acute respiratory distress syndrome(ARDS) require mechanical ventilation. This support providestime for the lungs to heal, but the adverse effects of mechanicalventilation significantly influence patient outcome. Traditionally,these were ascribed to mechanical effects, such as haemodynamiccompromise from decreased venous return or gross air leaks inducedby large transpulmonary pressures. More recently, however, theARDS Network study has established the clinical importance oflowering the tidal volume to limit overdistension of the lungwhen ventilating patients with ARDS. This study suggests thatventilator-associated lung injury (VALI) caused by overdistensionof the lung contributes to the mortality of patients with ARDS.Moreover, the results from clinical and basic research haverevealed more subtle types of VALI, including upregulation ofthe inflammatory response in the injured and overdistended lung.This not only damages the lung, but the overflow of inflammatorymediators into the systemic circulation may explain why mostpatients who die with ARDS succumb to multi-organ failure ratherthan respiratory failure. The results of these studies, thepresent understanding of the pathophysiology of VALI, and protectiveventilatory strategies are reviewed. Br J Anaesth 2004; 92: 261–70     

高频振荡通气治疗急性呼吸窘迫综合征新进展

背景 高频振荡通气(high frequency oscillatory ventilation,HFOV)理论上符合肺保护通气策略,越来越多地应用于常规机械通气(conventional mechanical ventilation,CMV)下仍有低氧血症的急性呼吸窘迫综合征(acute respiratory distress syndrome,ARDS)患者. 目的 研究表明HFOV可以有效地改善低氧血症,但肺保护作用利用欠佳,文章旨在阐述如何更好地发挥HFOV的肺保护作用并同时满足氧合和安全性要求. 内容 总结以往HFOV应用于ARDS患者的研究,并讨论HFOV临床应用的相关问题. 趋向 基于大规模前瞻性随机对照研究结果,建议HFOV目前应作为常规肺保护性通气失败的补救措施.在使用HFOV前,要慎重考虑深度镇静肌松、血流动力学变化和噪音等对患者病情的影响.     

Airway pressure release ventilation as a primary ventilatory mode in acute respiratory distress syndrome

BACKGROUND: Airway pressure release ventilation (APRV) is a ventilatory mode, which allows unsupported spontaneous breathing at any phase of the ventilatory cycle. Airway pressure release ventilation as compared with pressure support (PS), another partial ventilatory mode, has been shown to improve gas exchange and cardiac output. We hypothesized whether the use of APRV with maintained unsupported spontaneous breathing as an initial mode of ventilatory support promotes faster recovery from respiratory failure in patients with acute respiratory distress syndrome (ARDS) than PS combined with synchronized intermittent ventilation (SIMV-group). METHODS: In a randomized trial 58 patients were randomized to receive either APRV or SIMV after a predefined stabilization period. Both groups shared common physiological targets, and uniform principles of general care were followed. RESULTS: Inspiratory pressure was significantly lower in the APRV-group (25.9 +/- 0.6 vs. 28.6 +/- 0.7 cmH2O) within the first week of the study (P = 0.007). PEEP-levels and physiological variables (PaO2/FiO2-ratio, PaCO2, pH, minute ventilation, mean arterial pressure, cardiac output) were comparable between the groups. At day 28, the number of ventilator-free days was similar (13.4 +/- 1.7 in the APRV-group and 12.2 +/- 1.5 in the SIMV-group), as was the mortality (17% and 18%, respectively). CONCLUSION: We conclude that when used as a primary ventilatory mode in patients with ARDS, APRV did not differ from SIMV with PS in clinically relevant outcome.     

高频振荡通气在成年人急性呼吸窘迫综合征的临床应用

背景 高频振荡通气(high-frequency oscillatory ventilation,HFOV)作为一种新的通气模式,具有高频率、小潮气量、高平均气道压的特点,近年来被成功应用于成年人急性呼吸窘迫综合征(acute respiratory distress syndrome,ARDS)的治疗.研究表明,HFOV在改善氧合、减少呼吸机相关性肺损伤(ventilator associated lung injury,VILI)方面较常规机械通气(conventional mechanical ventilation,CMV)具有优势.但其对ARDS病死率的影响尚不明确. 目的 通过归纳HFOV在成年人ARDS中的临床应用揭示HFOV的优势和缺陷. 内容 HFOV能够高效改善氧合、减少VILI,但不能减少ARDS的病死率.HFOV技术的最适患者的筛选、最佳使用时机、最佳参数的设定以及与其他治疗手段联用等问题有待进一步探索. 趋向 HFOV应用于ARDS的治疗需要更加深入的研究和探索.     

Analysis of high risk factors related to acute respiratory distress syndrome following severe thoracoabdominal injuries

OBJECTIVE: To investigate the high risk factors related to acute respiratory distress syndrome(ARDS) following serious thoracoabdominal injuries. METHODS: The clinical data of 282 patients with serious thoracoabdominal injuries were retrospectively studied. Univariate and Cox multivariate regression analysis were used to determine the risk factors related to ARDS following serious thoracoabdominal injuries. RESULTS: The incidence of ARDS was 31.9% (90/282) in patients with serious thoracoabdominal injuries. The mortality caused by ARDS was 37.8% (34/90). The univariate analysis and multivariate analysis demonstrated that the clinical conditions such as elder age, shock, dyspnea, abnormal arterial blood gas, hemopneumothorax, pulmonary contusion, flail chest, coexisting pulmonary diseases, multiple abdominal injury and high ISS score were the independent high risk factors related to ARDS. CONCLUSION: There are many high risk factors related to ARDS following severe thoracoabdominal injuries, which should be detected early and treated timely to decrease the incidence and mortality of A RDS.     

Prone positioning ventilation for treatment of acute lung injury and acute respiratory distress syndrome

Patients who are diagnosed with acute lung injury/acute respiratory distress syndrome (ALI/ARDS) usually have ventilation-perfusion mismatch, severe decrease in lung capacity, and gas exchange abnormalities. Health care work-ers have implemented various strategies in an attempt to compensate for these pathological alterations. By rotating patients with ALI/ARDS between the supine and prone position, it is possible to achieve a significant improvement in PaO2/FiO2, decrease shunting and therefore improve oxy-genation without use of expensive, invasive and experimen-tal procedures.     

Airway pressure release ventilation and prone positioning in severe acute respiratory distress syndrome

BACKGROUND: Implementation of lung protective strategy in the treatment of severe Acute Respiratory Distress Syndrome (ARDS) has been reported to be associated with improved outcome. To fulfil this approach, sedation, neuromuscular blocking agents and full mechanical ventilatory support are often used in critical failure of gas exchange. CASE REPORT: We present a patient who developed multiple organ failure, including severe ARDS, after severe skin injuries and septic shock. Ventilatory strategy consisted of lung protective approach, permissive hypercapnia and prone positioning. Airway pressure release ventilation (APRV) with the patient's superimposed spontaneous breathing was implemented and maintained, also during prone episodes. Improvement of gas exhange occurred after application of combined use of APRV and prone positioning. CONCLUSION: APRV and maintenance of patients' spontaneous ventilation is feasible during prone positioning, and this approach may have beneficial synergistic effects on gas exhange in patients with severe acute lung injury.     

The use of prone ventilation in acute lung injury and acute respiratory distress syndrome

Prone positioning has been suggested since 1974 as a ventilatory strategy to improve oxygenation and pulmonary mechanics in patients with acute lung injury and acute respiratory distress syndrome. Although this mode of ventilation can improve gas exchange, the optimal role of the prone position is uncertain. The aim of this article is to examine the evidence in support of this mode of ventilation in adult patients with acute lung injury and acute respiratory distress syndrome. Limitations of the currently available evidence upon which the recommendations are made must be recognized. With these limitations in mind, however, the available evidence has been considered and conclusions presented. Considerable clinical experience confirms that prone ventilation can improve oxygenation in the majority of patients. It is difficult to predict which patients will respond. There are few contraindications and with experienced staff it can be achieved safely. Most patients should therefore be considered for a trial of prone positioning. Prolonged and repeated prone ventilation may be more effective. Whether the improvement in physiological parameters translates into improved clinical outcomes is less certain and well-designed randomized controlled trials will be required to address this issue.     

双相气道正压通气对急性呼吸窘迫综合征模型犬心肺功能的影响

目的：研究在消除自主呼吸前、后,双相气道正压通气（BIPAP）对急性呼吸窘迫综合征（ARDS）模型犬心肺功能的不同影响。方法：选择健康杂种犬12只,全麻后用油酸制成ARDS模型,采用自身对照法观察其在机械通气前、BIPAP（包括用肌松药消除自主呼吸前、后）等3种状态下呼吸、循环及血气的变化。结果：在保留自主呼吸时,BIPAP通气状态下犬的PaO2、CO、DO2、CL均显著高于消除自主呼吸后相应参数值,VO2／DO2、Qs/Qt、VD／VT、RL则显著降低（P＜0．05）;和基础值相比,BIPAP通气时的PaQ2、DO2、RL均显著增加（P＜0．05）,而保留自主呼吸时,BIPAP的CL、CO显著增加;Qs/Qt、VD／VT VO2／DO2显著降低;消除自主呼吸后,其Qs/Qt、VD／VT、RL、PVR显著增加,CD显著降低（P＜0．05）。结论：与消除自主呼吸后相比,保留自主呼吸时,BIPAP能明显改善ARDS模型犬氧合状态和通气血流分布,对循环亦无明显的抑制作用,是较为理想的通气方式。     

俯卧位通气下急性呼吸窘迫综合征患者氧合的变化

目的探讨俯卧位通气下急性呼吸窘迫综合征(ARDS)患者氧合的变化及其机制。方法23例早期ARDS患者(病程<72 h),在镇静、肌松下持续俯卧位通气2 h。呼吸机参数设定为潮气量6-8 ml/kg,吸气时间1.0-1.2 s,吸气流速40 L/min,呼吸频率12-20次/min。吸入氧浓度0.4- 1.0,呼气末正压6-18 cm H2O。观察俯卧位前即刻、俯卧位0.5、2 h及恢复仰卧位2 h的氧合指数(PaO2/FiO2)、呼吸系统静态顺应性(Cst)、心率(HR)、平均动脉压(MAP)、中心静脉压(CVP)、平均肺动脉压(MPAP)。肺动脉楔压(PAWP)、心脏指数(CI)、气道峰压(PIP)及气道阻力(Paw)。俯卧位后PaO2/FiO2比俯卧位前上升超过20%作为氧合改善的判断标准。结果与俯卧位前比较,87%患者俯卧位0.5、2 h、恢复仰卧位2 h时PaO2/FiO2和PaO2升高(P<0.01);Cst HR、MAP、CVP、MPAP、PAWP、CI、Raw、PaCO2、PIP差异无统计学意义;87%氧合改善的患者在俯卧位0.5、2 h时Cst差异无统计学意义, 恢复仰卧位2 h时Cst升高(P<0.05)。结论俯卧位通气可改善早期ARDS患者的氧合,且恢复仰卧位后氧合改善持续存在。     

盐酸戊乙奎醚对大鼠创伤性急性肺损伤时细胞凋亡的影响

目的 探讨盐酸戊乙奎醚对大鼠创伤性急性肺损伤时细胞凋亡的影响.方法健康雄性SD大鼠54只,体重225～275kg,采用随机数字表法,将大鼠随机分为对照组(C组)、创伤性急性肺损伤组(ALI组)和盐酸戊乙奎醚组(P组),每组18只.采用自制胸部撞击器撞击大鼠胸壁的方法制备创伤性急性肺损伤模型.P组分别于撞击后即刻、撞击后12 h时腹腔注射盐酸戊乙奎醚2 mg/kg.分别于撞击后3、12、24 h时各组随机取6只大鼠处死取肺,光镜和电镜下观察肺组织病理学结果,TUNEL法测定凋亡细胞,计算凋亡指数,免疫组化法检测Bax和Bcl-2的表达.结果 与C组比较,ALI组和P组各时点肺组织细胞凋亡指数、Bax和Bcl-2的表达水平升高,Bcl-2/Bax比值降低(P＜0.05);与ALI组比较,P组各时点肺组织细胞凋亡指数和Bax表达水平降低,Bcl-2的表达水平和Bcl-2/Bax比值升高(P＜0.01).P组肺组织病理学损伤程度较ALI组减轻.结论 盐酸戊乙奎醚可通过抑制细胞凋亡减轻大鼠创伤性急性肺损伤.

Abstract：

Objective To investigate the effect of penehyclidine hydrochloride on the cell apoptosis in lung tissues in a rat model of traumatic acute lung injury (ALI) .Methods Fifty-four SD rats weighing 225-275 kg were randomly divided into 3 groups ( n = 18 each) : control group (group C) , ALI group, penehyclidine hydrochloride group ( group P) . Traumatic ALI was induced by dropping a self-made impact device on the chest of anesthetized rats according to the technique described by Raghavendran et al. Intraperitoneal penehyclidine hydrochloride 2 mg/kg was injected immediately after blunt chest trauma and at 12 h after blunt chest trauma in group P. Six rats in each group were sacrificed at 3, 12 and 24 h after blunt chest trauma and the lung tissues collected for microscopic examination and determination of cell apoptosis (by TUNEL) and expression of Bax and Bcl-2 (by immuno-histochemical staining) . The apoptosis index was calculated. Results The apoptosis index and expression of Bax and Bcl-2 were significantly higher, while the ratio of Bcl-2/Bax was significantly lower at each time point in groups ALI and P than in group C ( P ＜ 0.05) . The apoptosis index and Bax expression were significantly lower,while the Bcl-2 expression and ratio of Bcl-2/ Bax higher at each time point in group P than in group ALI.The microscopic examination showed that penehyclidine hydrochloride injection significantly attenuated the pathologic changes. Conclusion Penehyclidine hydrochloride can reduce the traumatic ALI through inhibiting the cell apoptosis in rat lung tissues.     

气道压力释放通气对急性肺损伤或急性呼吸窘迫综合征患者呼吸功能的影响

目的评价气道压力释放通气（APRV）对急性肺损伤（ALI）或急性呼吸窘迫综合征（ARDS）患者呼吸功能的影响。方法ALI患者42例、ARDS患者33例，随机分2组，APRV组（n=37）、同步间歇指令通气（SIMV）组（n=38）；两组均用SIMV加用呼气末正压通气30min后，APRV组采用APRV模式通气，SIMV组仍用初始参数，分别于APRV前（基础值）、APRV1、8、16、24h测定动脉血气、气道峰压（Ppeak）、气道平均压（Pmean）、中心静脉压（CVP）、氧合指数（PaO2／FiO2）、心率（HR），并记录芬太尼、咪达唑仑、多巴胺用量及尿量。结果与SIMV组比较，APRV组APRV1～24h各时点Ppeak、Pmean降低，APRV16、24h时动脉血PaCO2降低，PaO2／FiO2升高，APRV1—24h时CVP和HR降低，芬太尼用量和咪达唑仑用量明显减少，APRV8—24h各时点尿量升高，多巴胺用量减少（P〈0．05或0．01）。结论APRV用于ARDS或ALI患者的机械通气治疗，不仅能提供更好的通气，而且血液动力学平稳，减少镇静剂和麻醉药用量。     

Combination of inhaled nitric oxide therapy and inverse ratio ventilation in patients with sepsis-associated acute respiratory distress syndrome

Inverse ratio ventilation (IRV) is a ventilatory technique that uses an inspiratory to expiratory ratio (I:E) greater than 1:1. We studied the effects of mechanical ventilation with an I:E of 1:3, 1:1, and 2:1 on arterial oxygenation in 10 patients with sepsis-associated acute respiratory distress syndrome (ARDS). At each I:E, patients received 0 and 4 ppm of inhaled nitric oxide (INO) in random order for 30 min. Respiratory and cardiovascular parameters were measured. Of the 10 patients studied, 7 responded to IRV and 3 did not. An increase in the I:E and the addition of INO significantly improved arterial oxygenation in the responders (p < 0. 0001 and p < 0.006, respectively). The combination of an increase in the I:E and INO had an additive effect on arterial oxygenation. The combined use of IRV and INO is a more effective method of avoiding hypoxemia than either INO or IRV alone.     

Retrospective analysis on acute respiratory distress yndrome in ICU

OBJECTIVE: To assess the incidence, etiology, physiological and clinical features, mortality, and predictors of acute respiratory distress syndrome (ARDS) in intensive care unit (ICU). METHODS: A retrospective analysis of 5 314 patients admitted to the ICU of our hospital from April 1994 to December 2003 was performed in this study. The ARDS patients were identified with the criteria of the American-European Consensus Conference (AECC). Acute physiology and chronic health evaluation III (APACHE III), multiple organ dysfunction syndrome score (MODS score), and lung injury score (LIS) were determined on the onset day of ARDS for all the patients. Other recorded variables included age, sex, biochemical indicators, blood gas analysis, length of stay in ICU, length of ventilation, presence or absence of tracheostomy, ventilation variables, elective operation or emergency operation. RESULTS: Totally, 131 patients (2.5%) developed ARDS, among whom, 12 patients were excluded from this study because they died within 24 hours and other 4 patients were also excluded for their incomplete information. Therefore, there were only 115 cases (62 males and 53 females, aged 22-75 years, 58 years on average) left, accounting for 2.2% of the total admitted patients. Their average ICU stay was (11.27+/-7.24) days and APACHE III score was 17.23+/-7.21. Pneumonia and sepsis were the main cause of ARDS. The non-survivors were obviously older and showed significant difference in the ICU length of stay and length of ventilation as compared with the survivors. On admission, the non-survivors had significantly higher MODS and lower BE (base excess). The hospital mortality was 55.7%. The main cause of death was multiple organ failure. Predictors of death at the onset of ARDS were advanced age, MODS > or = to 8, and LIS > or = 2.76. CONCLUSIONS: ARDS is a frequent syndrome in this cohort. Sepsis and pneumonia are the most common risk factors. The main cause of death is multiple organ failure. The mortality is high but similar to most recent series including severe comorbidities. Based on this patient population, advanced age, MODS score, and LIS may be the important prognostic indicators for ARDS.     

肾上腺皮质功能状态与急性呼吸窘迫综合征患者预后关系的研究

目的探讨肾上腺皮质功能状态与急性呼吸窘迫综合征（ARDS）患者预后的关系。方法纳入2004年7月至2005年2月符合ARDS诊断标准的患者158例,以是否存活分为存活组和死亡组。静脉注射促肾上腺皮质激素250μg,放射免疫分析法测定注射前、注射后30min及60min血浆皮质醇水平（T0、T30及T60）。计算130或T60的最大值与T0的差值（△Tmax）,以ATmax≤248．4nmol／L作为相对肾上腺皮质功能不全的诊断标准。记录患者一般情况、急性生理和慢性健康（APACHEⅡ）评分、心率、呼吸、平均动脉压、氧合指数、动脉血pH、动脉血乳酸、血红蛋白、血小板和白细胞计数、功能衰竭器官个数和住院28d病死率。结果158例患者中存活72例,死亡86例,28d住院病死率为54．4％（86／158）,相对肾上腺皮质功能不全发生率为42．7％（68／158）。死亡组患者相对肾上腺皮质功能不全发生率明显高于存活组（62．8％vs19．4％,P〈0．01）。伴相对肾上腺皮质功能不全的ARDS患者病死率明显升高（76．5％vs36．8％,P〈0．01）。△Tmax判断预后的受试者操作曲线（ROC）下面积为0．655。Logistic多元回归分析显示功能衰竭器官数和相对肾上腺皮质功能不全是ARDS患者死亡的独立危险因素。结论肾上腺皮质功能状态对ARDS患者预后判断有指导价值。     

吸入一氧化氮对犬感染性ARDS的效应

目的研究吸入不同浓度一氧化氮(NO)对犬感染性急性呼吸窘迫综合征(ARDS)的效应。方法 感染性ARDS建立后,12只纯处毕格犬随机分成两组,单纯机械通气组(对照组,n=6),机械通气+吸入NO组(NO组,n=6)。NO吸人浓度分别为10、20、40、80 ppm,各浓度吸1 h,然后降至10 ppm吸6 h。通过以下指标变化分析判断吸入NO对ARDS的影响:体、肺循环血液动力学参数;氧合指数(PaO2/FiO2)、分流率(Qs/Qt)、肺动态顺应性(cdyn)、死腔量(VD/VT)及气道阻力(Rrs);外周血中性粒细胞计数;血、尿中亚硝酸根/硝酸根浓度(NO2-/NO3-);血正铁血红蛋白含量及动物存活时间。结果 吸人10、20、40、80 ppm.NO,PaO2/FiO2增加超过50％,Qs/Qt下降<25％,VD/VT下降至0.36,PVRI下降近50％,一定程度改善Cdyn,与单纯机械通气组相应时相点比,差异有显著性(P均<0.01),动物存活时间为(10.2±1.7)h显著高于对照组(4.4±1.2)h(P<0.01);NO浓度由80 ppm降至10 ppm时,改善的Qs/Qt,PaO2/FiO2,PVRI,VD/VT及Cdyn等指标又回落,实验最后阶段,随病程发展,肺部情况恶化;吸入NO可减轻外周血白细胞下降程度,与对照组相比差异有显著性(P<0.01)。结论 吸入10～80 ppm NO可明显降低犬感染性ARDS时肺血管阻力,改善通气,血流比例,对ARDS产生一定的治疗作用。     

Potential therapeutic application of adult stem cells in acute respiratory distress syndrome

Acute respiratory distress syndrome (ARDS) remains a poor prognosis in spite of the recent development of new therapeutic strategies. Cell-based therapy with stem cells has been considered as a promising way for the treatment of vital organ damage. Putative endogenous stem cells have been shown to be located within the adult lung in the basal layer of the upper airways, within or near pulmonary neu-roendocrine cell rests, at the bronchoalveolar junction, as well as within the alveolar epithelium. These stem cells are hypothesized to be the source of lung regeneration and repair. But this mechanism seems to be insufficient after lung injury. There is increasing excitement over the last few years with the suggestion that exogenous stem cells may offer new treatment options for ARDS. Exogenous stem cells have the abihty to differentiate and function as both airway and lung parenchymal epithelial cells in both in vitro and in-creasingly in vivo experiments. However, there is great con-troversy concerning the repair effect of adult stem cells in lung injury. This review evaluates the advances in endog-enous respiratory stem cells, and assesses the evidence for the use of stem cells in the repair of lung injury.