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     

Aerosolized surfactant therapy for endotoxin-induced experimental acute respiratory distress syndrome in rats

We have compared the effects of inhalation of aerosolized surfactanton experimental acute respiratory distress syndrome. Escherichiacoli endotoxin (55 (SD 20) mg kg^–1) was injected intothe tracheas of 36 adult rats anaesthetized and mechanicallyventilated with pure oxygen. When the Pa_O2 decreased to 11.3(3.3) kPa, the animals were randomly subjected to inhalationof aerosolized modified natural surfactant (MNS) for 0 min (controlgroup), 30, 60, and 120 min. In the control group, Pa_O2 remainedbelow 12 kPa for 180 min. In the groups receiving inhalationof surfactant for 30 and 60 min, Pa_O2 increased but decreasedsoon after termination of the inhalation. In contrast, Pa_O2of the group receiving inhalation of surfactant for 120 mincontinued to increase, reaching 52.1 (12.5) kPa at 180 min (P<0.05vs control). Thus, we conclude that improvement in gas exchangeas a result of inhalation of MNS depends on the duration ofinhalation. Br J Anaesth 2001; 87: 266–71     

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目的 探讨重症急性胰腺炎并发成人呼吸窘迫综合征(ARDS)的有效治疗方法。方法 对1992年8月至1997年7月(第一阶段)和1997年8月至2001年8月(第二阶段)收治的重症急性胰腺炎并发ARDS病人治疗结果进行回顾性分析和总结。结果 第一阶段收治重症急性胰腺炎23例，发生ARDS者15例(65．2％)，死亡11例，病死率73．3％；第二阶段收治重症急性胰腺炎34例，发生ARDS者13例(38．2％)，死亡4例，病死率30．8％，结论 早期积极控制ARDS的发生、发展，重视腹部情况的处理，同时有效地控制感染，是降低ARDS发生率、提高治愈率的关键。     

Perioperative risk analysis for acute respiratory distress syndrome after elective oesophagectomy

Background: Acute respiratory distress syndrome (ARDS) is a major contributor to respiratory morbidity and mortality after oesophagectomy. Several pre‐, intra‐ and post‐operative factors are thought to predispose to its development in the post‐oesophagectomy period. The aim of this study was to determine factors predisposing to ARDS in the post‐oesophagectomy period. Methods: A total of 112 patients who underwent elective oesophagectomy for oesophageal cancer (gastro‐oesophageal adenocarcinoma and high‐grade dysplasia, 93; oesophageal squamous cell carcinoma, 16; oesophageal oat cell tumour, 1; oesophageal anaplastic carcinoma, 1; oesophageal colloid carcinoma, 1) between 1 January 2003 and 31 December 2006 formed the study group in this retrospective study. The pre‐, intra and post‐operative data for these patients (male : female = 89:23, mean age 60.8 years) were collected from an oesophagectomy database and hospital medical records. Results: The incidence of ARDS was 13%. The in‐hospital mortality among ARDS cases was 20% and 1‐year mortality was 40%. Various factors such as preoperative chronic respiratory disease (P‐value = 0.000, odds ratio = 17.76), smoking pack‐years (P‐value = 0.045, odds ratio = 1.02), abnormal preoperative forced expiratory volume in 1 s (P‐value = 0.009, odds ratio = 7.97), high percentage of oxygen in inspired air (P‐value = 0.041, odds ratio = 1.24) and use of perioperative inotropes (P‐value = 0.021, odds ratio = 4.26) were associated with ARDS. Conclusions: Preoperative physiological status as indicated by a preoperative history of chronic respiratory disease and preoperative pulmonary function influenced the post‐operative outcome in our patients. The use of perioperative inotropes suggests perioperative cardiorespiratory instability, and could also predispose to the development of ARDS in the post‐operative period.     

Acute respiratory distress syndrome

Acute respiratory distress syndrome is a clinically and radiologically defined syndrome that is commonly diagnosed and managed in intensive care. It results in hypoxaemia and often requires mechanical ventilation. This article describes the most recent diagnostic classification and outlines the pathophysiology and current management of patients suffering from this syndrome.     

重症急性胰腺炎伴成人呼吸窘迫综合征的救治

目的：探讨如何降低ＳＡＰ所伴发的ＡＲＤＳ的发病率及救治方案。临床资料：１９９１．１￣１９９８．１２ＳＡＰ病人５４例。手术组３１例,三天内手术１２例,发生ＡＲＤＳ７例,死亡６例;三天后手术１９例,发生ＡＲＤＳ４例,死亡１例。非手术组２３例,早期（三天内）发生ＡＲＤＳ５例,死亡３例,后期发生ＡＲＤＳ２例,死亡１例。一旦明确ＳＡＰ诊断,给予积极抗休克,有计划的手术,控制感染,营养支持。一旦出现难于纠正的     

氨溴索和戊乙奎醚用于治疗急性呼吸窘迫综合征的临床观察

目的 探讨盐酸氨溴索和盐酸戊乙奎醚治疗呼吸窘迫综合征的疗效及安全性.方法 创伤性湿肺所致急性呼吸窘迫综合征并行气管插管机械通气成年患者28例,随机分为氨溴索（沐舒坦）组（M组）、沐舒坦-盐酸戊奎醚（长托宁）组（M-C组）.入室后重症监护,其他镇静评分和治疗方法相同.M组沐舒坦300 mg静脉滴注,每天二次;M-C组沐舒坦300 mg,静脉滴注,每天二次,长托宁1 mg肌注,每天一次.观察患者72 h内排痰量和痰液性质,撤机拔管时间及ICU住院时间.结果 M-C组与M组比较每天排痰量明显减少;撤机拔管时间明显缩短（P ＜0.05）.结论 氨溴索与戊乙奎醚联合使用治疗急性呼吸窘迫综合征临床效果显著.     

Effectiveness of ECMO for burn-related acute respiratory distress syndrome

Introduction

Acute respiratory distress syndrome (ARDS) is a complication that affects approximately 40% of burn patients and is associated with high mortality rates. Extracorporeal membrane oxygenation (ECMO) therapy is a management option for severe refractory hypoxemic respiratory failure; however, there is little literature reporting the effectiveness of this therapy in burns. Our study objective was to review patient outcomes in burns following severe ARDS treated with ECMO.

Acute respiratory distress syndrome due to pulmonary involvement by neoplastic plasma cells in multiple myeloma

Pulmonary involvement with multiple myeloma occurs infrequently and may be difficult to distinguish from more common primary lung tumours, metastatic disease, or other pleural and parenchymal abnormalities. A patient who developed acute respiratory distress syndrome (ARDS) was subsequently found to have multiple myeloma with involvement of lung parenchyma by neoplastic plasma cells. Only one other report of ARDS in association with multiple myeloma was found, and there are no previous reports where the appearance of ARDS antedated a diagnosis of multiple myeloma. In patients with ARDS, parenchymal involvement from multiple myeloma should be included in the differential diagnosis.     

Extracorporeal life support for posttraumatic acute respiratory distress syndrome at a children's medical center

Background: Primary traumatic injury was considered previously a contraindication for institution of extracorporeal life support because of high risk for persistent or new bleeding. Published experience in adults suggests that extracorporeal membrane oxygenation (ECMO) can successfully support trauma victims with pulmonary failure. The authors reviewed their experience with the use of ECMO in pediatric and adult trauma patients with acute respiratory distress syndrome (ARDS) at a children’s medical center.Methods: ECMO Center records from 1991 through 2001 (76 children, 8 adults) were reviewed to identify all patients with a primary or secondary ICD-9 diagnostic code of posttraumatic ARDS in addition to documented trauma.Results: Five children and 3 adults with traumatic injury and ARDS received ECMO support. Seven patients were injured in motor vehicle collisions; one patient suffered a gunshot wound to the chest. Patient ages ranged from 21 months to 29 years (pediatric median, 4 years; range, 21 months to 18 years). Four patients had pre-ECMO laparotomies, including 3 who required splenectomy. Four patients had liver lacerations, 3 had pulmonary contusions, and 1 had a renal contusion. Median ventilation before ECMO was 6 days (range, 2 to 10). Seven of 8 patients were placed on venovenous (VV) ECMO. Seven patients had significant bleeding on ECMO. Patients were treated with blood product replacement, epsilon-aminocaproic acid (EACA), and aprotinin infusions. Surgical intervention was not required for bleeding. Six patients received hemofiltration. Median time on ECMO was 653 hours (range, 190 to 921 hours). Six of 8 patients overall survived (75%). Four of 5 pediatric patients survived.Conclusions: Children and adults with severe posttraumatic ARDS can be treated successfully on VV extracorporeal support. Hemorrhage occurs frequently but is manageable.     

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.     

肺泡上皮细胞在急性呼吸窘迫综合征的作用

背景 肺泡上皮是急性呼吸窘迫综合征(acute respiratory distress syndrome,ARDS)的发病机制和康复机制所涉及的一种重要结构.肺泡上皮细胞(alveolar epithelial cells,AEC)在ARDS中对维护肺血屏障的完整性和受损屏障的修复有着关键的作用. 目的 了解AEC在ARDS中的作用,启发临床治疗ARDS的新思路. 内容 从AEC的基本作用、在ARDS的免疫调节、损伤与修复、凋亡及其机制方面进行文献综述. 趋向 目前临床上仍然没有有效的措施治疗ARDS,今后仍需要在寻找新的治疗方向上做出进一步的探索.     

The effect of inhaled nitric oxide in acute respiratory distress syndrome in children and adults: a Cochrane Systematic Review with trial sequential analysis

Acute respiratory distress syndrome is associated with high mortality and morbidity. Inhaled nitric oxide has been used to improve oxygenation but its role remains controversial. Our primary objective in this systematic review was to examine the effects of inhaled nitric oxide administration on mortality in adults and children with acute respiratory distress syndrome. We included all randomised, controlled trials, irrespective of date of publication, blinding status, outcomes reported or language. Our primary outcome measure was all‐cause mortality. We performed several subgroup and sensitivity analyses to assess the effect of inhaled nitric oxide. There was no statistically significant effect of inhaled nitric oxide on longest follow‐up mortality (inhaled nitric oxide group 250/654 deaths (38.2%) vs. control group 221/589 deaths (37.5%; relative risk (95% CI) 1.04 (0.9–1.19)). We found a significant improvement in PaO₂/F_IO₂ ratio at 24 h (mean difference (95% CI) 15.91 (8.25–23.56)), but not at 48 h or 72 h, while four trials indicated improved oxygenation in the inhaled nitric oxide group at 96 h (mean difference (95% CI) 14.51 (3.64–25.38)). There were no statistically significant differences in ventilator‐free days, duration of mechanical ventilation, resolution of multi‐organ failure, quality of life, length of stay in intensive care unit or hospital, cost‐benefit analysis and methaemoglobin and nitrogen dioxide levels. There was an increased risk of renal impairment (risk ratio (95% CI) 1.59 (1.17–2.16)) with inhaled nitric oxide. In conclusion, there is insufficient evidence to support inhaled nitric oxide in any category of critically ill patients with acute respiratory distress syndrome despite a transient improvement in oxygenation, since mortality is not reduced and it may induce renal impairment.     

限制补液在胸外伤继发急性肺损伤或急性呼吸窘迫综合征治疗中的应用

目的总结限制补液在胸外伤合并急性肺损伤(ALI)或急性呼吸窘迫综合征(ARDS)治疗中的应用效果。方法单纯胸外伤合并ALI或ARDS患者132例,采用限制补液技术,适当减少补液,加控制性降压技术,收缩压控制在95~110mmHg之间,早期以维持一个满足基本灌注的偏低血压作为目标血压,减少输液量和速度。通过单纯胸部外伤(排除其他部位重症损伤的干扰)的救治,总结呼吸窘迫防治特点。结果 ALL/ARDS气管插管率为17.4%(23/132),气管切开的发生率为3.8%(5/132),死亡率为2.3%(3/132)。结论 ALI时不恰当的补液过多引发肺水肿是单纯胸外伤并发ARDS主因,而不是反常呼吸所致。适当控制输液,辅以控制性降压技术能大大降低重症胸外伤死亡率。     

急性肺损伤/急性呼吸窘迫综合征液体治疗策略

背景 高通透性肺水肿是急性肺损伤/急性呼吸窘迫综合征(acute lung injury/acute respiratory distress syndrome,ALI/ARDS)的基本病理生理特征,其程度与ALI/ARDS的预后密切相关.目的 对ALI/ARDS患者合理的液体管理,有助于改善ALI/ARDS患者的肺水肿,降低该病病死率.内容 回顾了ALI/ARDS液体治疗策略探索过程中存在争议的问题(如限制性或开放性的液体治疗策略及治疗液体种类的选择),总结了该领域近年来的研究进展(如ALI/ARDS病程不同阶段的差异化治疗及液体治疗的监测指标).趋向 今后将进一步探索该病在不同的病理生理状态下特异性的液体治疗方法,寻求高效敏感的监测指标,指导液体治疗策略的选择和调整.     

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.     

Tracheostomy in a patient with severe acute respiratory syndrome

The coronavirus which causes severe acute respiratory syndrome(SARS) is a virulent and highly contagious organism. Of the1755 SARS patients in Hong Kong, over 400 were healthcare workers.Meticulous attention to infection control and teamwork are essentialto minimize cross-contamination and prevent staff from contractingthe illness. These points are especially pertinent when anaesthetizingSARS patients for high-risk procedures such as tracheostomy.We describe the management of such a case. Br J Anaesth 2004; 92: 280–2