B-lines quantify the lung water content: a lung ultrasound versus lung gravimetry study in acute lung injury

B-lines (also termed ultrasound lung comets) obtained with lung ultrasound detect experimental acute lung injury (ALI) very early and before hemogasanalytic changes, with a simple, noninvasive, nonionizing and real-time method. Our aim was to estimate the correlation between B-lines number and the wet/dry ratio of the lung tissue, measured by gravimetry, in an experimental model of ALI. Seventeen Na-pentobarbital anesthetized, cannulated (central vein and carotid artery) minipigs were studied: five sham-operated animals served as controls and, in 12 animals, ALI was induced by injection of oleic acid (0.1 mL/kg) via the central venous catheter. B-lines were measured by echographic scanner in four predetermined chest scanning sites in each animal. At the end of each experiment, both lungs were dissected, weighed and dried to determine wet/dry weight ratio by gravimetry. After the injection of oleic acid, B-lines number increased over time. A significant correlation was found between the wet/dry ratio and B-lines number (r = 0.91, p < 0.001). These data suggest that in an experimental pig model of ALI/ARDS, B-lines assessed by lung ultrasound provide a simple, semiquantitative, noninvasive index of lung water accumulation, strongly correlated to invasive gravimetric assessment.     

Endogenous lung stem cells for lung regeneration

Introduction: Lifelong maintenance of a healthy lung requires resident stem cells to proliferate according to tissue requirements. Once thought to be a quiescent tissue, evolving views of the complex differentiation landscape of lung stem and progenitor cells have broad implications for our understanding of how the lung is maintained, as well as the development of new therapies for promoting endogenous regeneration in lung disease.

Areas covered: This review collates a large body of research relating to the hierarchical organization of epithelial stem cells in the adult lung and their role in tissue homeostasis and regeneration after injury. To identify relevant studies, PubMed was queried using one or a combination of the terms ‘lung’, ‘airway’, ‘alveoli’, ‘stem cells’, ‘progenitor’, ‘repair’ and ‘regeneration’.

Expert opinion: This review discusses how new technologies and injury models have challenged the demarcations between stem and progenitor cell populations.     

单肺通气中肺保护策略研究进展

目的 通过对单肺通气中肺保护策略研究进展的分析,为临床工作提供理论指导,减少单肺通气术中低氧血症和术后肺部并发症的发生.方法 应用计算机在Pubmed上检索2007年1月～ 2012年5月有关单肺通气的文章,检索词为:one lung ventilation,hypoxemia,lungprotection,限定文章语言种类为English.对资料进行初审,并查找全文.纳入标准:①有关单肺通气的实验及临床研究;②有关肺保护的试验研究.排除标准:①综述文献;②重复研究.共收集到200多篇有关单肺通气方面的文献,纳入14篇.结果 纳入的14篇文章中有关单肺通气术中管理方面的文献12篇,有关单肺通气时低氧血症方面的文献2篇.通过对入选文献进行分析、整理,将单肺通气术中管理从通气模式选择、潮气量与呼吸频率的设置、PEEP及CPAP的运用、吸入氧浓度及液体管理等5方面进行分析,归纳总结出目前在单肺通气时的肺保护策略和麻醉管理进展.结论 随着对单肺通气中肺保护的深入研究,单肺通气的麻醉管理将更加有效、合理.     

终末期肺病肺移植术后并发症的影像学表现

目的探讨肺移植术后并发症的影像学改变。方法6例患者进行了同种异体肺移植术,其中4例终末期慢性阻塞性肺疾病患者和1例为中毒性细支气管炎患者接受单肺移植,另1例为外周型肺腺鳞癌并双肺转移接受双肺移植。用胸片及CT观察术后并发症的影像学变化。结果6例肺移植手术全部成功,6例中围手术期3例死亡,3例已存活16~36个月。术后2例发生急性排斥反应,5例出现再移植肺水肿,3例并发肺部感染,2例出现气胸,2例术后1~2个月出现吻合口狭窄。结论及时的胸片和CT检查对肺移植术后并发症的防治有非常重要的指导价值。     

Massive brain injury enhances lung damage in an isolated lung model of ventilator-induced lung injury

OBJECTIVE: To assess the influence of massive brain injury on pulmonary susceptibility to injury attending subsequent mechanical or ischemia/reperfusion stress. DESIGN: Prospective experimental study. SETTING: Animal research laboratory. SUBJECTS: Twenty-four anesthetized New Zealand White rabbits randomized to control (n = 12) or induced brain injury (n = 12) group. INTERVENTIONS: After randomization, brain injury was induced by inflation of an intracranial balloon-tipped catheter, and animals were ventilated with a tidal volume of 10 mL/kg and zero end-expiratory pressure for 120 mins. Following heart-lung block extraction, isolated and perfused lungs were subjected to injurious ventilation with peak airway pressure 30 cm H2O and positive end-expiratory pressure 5 cm H2O for 30 mins. MEASUREMENTS AND MAIN RESULTS: No difference was observed between groups in gas exchange, lung mechanics, or hemodynamics during the 2-hr in vivo period following induction of brain injury. However, after 30 mins of ex vivo injurious mechanical ventilation, lungs from the brain injury group showed greater change in ultrafiltration coefficient, weight gain, and alveolar hemorrhage (all p < .05). CONCLUSIONS: Massive brain injury might increase lung vulnerability to subsequent injurious mechanical or ischemia-reperfusion insults, thereby increasing the risk of clinical posttransplant graft failure.     

CT引导下经皮穿刺肺活检术诊断肺部弥漫性病变

目的 评价CT引导下经皮穿刺肺活检术在诊断肺部弥漫性病变中的价值.方法 回顾性分析68例接受CT引导下经皮穿刺肺活检术的肺部弥漫性病变患者的资料.主要影像学改变包括弥漫性网状结节或结节、弥漫性线网状影、弥漫性磨玻璃样密度.采用18CT或20G穿刺活检针进行活检.结果 68例患者均一次性穿刺成功,且均能做出明确诊断.其中恶性病变19例,包括细支气管肺泡癌9例,转移癌10例;良性病变49例,为血型播散型肺结核27例,结节病8例,矽肺与煤工肺7例,间质性肺炎2例,肺泡蛋白沉着症4例,过敏性肺炎1例;主要并发症为气胸和出血,并发症的发生率为17.65%.结论 在肺部弥漫性疾病的诊断中,CT引导下经皮肺穿刺肺活检术是一种实用、安全、并发症少、准确性高、创伤小的定性诊断方法.     

Fetal lung to liver reflectivity ratio and lung maturity

A pilot study examined 23 patients who underwent simultaneous ultrasound and amniocentesis to determine whether the ratio of densitometrically determined tissue densities of fetal lung and liver correlate with the L/S, the OD 650, or phosphatidylglycerol levels. The incidence of a lung/liver ratio greater than 1 of 65% was similar to that of maturity levels of the standard tests. However, there was no statistically significant correlation between an L/L greater than 1 and/or any maturity parameter tested, nor was there any correlation with the absence of pulmonary maturity. We conclude that this test cannot be reliably used to predict L/S, OD 650 reading, or PG levels.     

PEEP decreases atelectasis and extravascular lung water but not lung tissue volume in surfactant-washout lung injury

Objective To examine the effects of positive end-expiratory pressure (PEEP) on extravascular lung water (EVLW), lung tissue, and lung volume.Design and setting Experimental animal study at a university research facility.Subjects Fifteen adult sheep.Interventions All animals were studied before and after saline washout-induced lung injury while ventilated with sequentially increasing PEEP (0, 7, 14, or 21 cmH₂O).Measurements and results Lung volume was determined by computed tomography and EVLW by the thermal dye dilution technique. Saline washout significantly increased lung tissue volume (21±3 to 37±5 ml/kg) and EVLW (9±2 to 36±9 ml/kg). While increasing levels of PEEP reduced EVLW (30±7, 24±8, and 18±4 ml/kg), lung tissue volume remained constant. Total lung volume significantly increased (50±8 ml/kg at PEEP 0 to 77±12 ml/kg at PEEP 21). Nonaerated lung volume significantly decreased and was closely correlated with the changes in EVLW (r=0.67). In addition, a highly significant correlation was found between PEEP-induced decrease in nonaerated lung volume and decrease in transpulmonary shunt (r=0.83).Conclusions The main findings are as follows: (a) PEEP effectively decreases EVLW. (b) The decrease in EVLW is closely correlated with the PEEP-induced decrease in nonaerated lung volume, making EVLW a valuable bedside parameter indicating alveolar recruitment, similar to measurements of transpulmonary shunt. (c) As excess tissue volume remained constant, however, EVLW may not be suitable to reflect overall severity of lung diseaseThis study was supported by a grant from the Faculty of Clinical Medicine, University of Mannheim.     

Visual anatomical lung CT scan assessment of lung recruitability

Purpose

The computation of lung recruitability in acute respiratory distress syndrome (ARDS) is advocated to set positive end-expiratory pressure (PEEP) for preventing lung collapse. The quantitative lung CT scan, obtained by manual image processing, is the reference method but it is time consuming. The aim of this study was to evaluate the accuracy of a visual anatomical analysis compared with a quantitative lung CT scan analysis in assessing lung recruitability.

Methods

Fifty sets of two complete lung CT scans of ALI/ARDS patients computing lung recruitment were analyzed. Lung recruitability computed at an airway pressure of 5 and 45?cmH₂O was defined as the percentage decrease in the collapsed/consolidated lung parenchyma assessed by two expert radiologists using a visual anatomical analysis and as the decrease in not aerated lung regions using a quantitative analysis computed by dedicated software.

Results

Lung recruitability was 11.3?% (interquartile range 7.39?C16.41) and 15.5?% (interquartile range 8.18?C21.43) with the visual anatomical and quantitative analysis, respectively. In the Bland?CAltman analysis, the bias and agreement bands between the visual anatomical and quantitative analysis were ?2.9?% (?11.8 to +5.9?%). The ROC curve showed that the optimal cutoff values for the visual anatomical analysis in predicting high versus low lung recruitability was 8.9?% (area under the ROC curve 0.9248, 95?% CI 0.8550?C0.9946). Considering this cutoff, the sensitivity, specificity, and diagnostic accuracy were 0.96, 0.76, and 0.86, respectively.

Conclusions

Visual anatomical analysis can classify patients into those with high and low lung recruitability allowing more intensivists to get access to lung recruitability assessment.     

CT引导下经皮肺穿刺活检在肺癌及肺部其他疾病中的诊断价值

目的探讨CT引导下经皮肺穿刺活检在肺癌及肺部其他疾病中诊断价值。方法选取2008年3月~2010年12月住院患者117例,在CT引导下经皮肺穿刺活检。观察穿刺诊断的阳性率及并发症。结果本组110例获得明确诊断,准确率为94.0%。并发症发生率为15.4%。结论 CT引导下经皮肺穿刺活检准确性高,创伤小,风险低,病人易耐受,具有较高的临床实用价值。     

Measurement of lung tissue mass in interstitial lung disease.

A gamma camera and 99m Technetium were used to obtain transmission and emission scans of the thorax in order to estimate transthoracic tissue thickness, and volumes of blood and interstitial tissue in each pixel of the gamma camera image. This technique has been applied to six patients with stage 2/3 pulmonary sarcoidosis and eight with cryptogenic fibrosing alveolitis and age and sex-matched control groups without lung disease. In both conditions transthoracic tissue thickness was significantly increased: mean values (SD) were 14.6 (1.8) cm in cryptogenic fibrosing alveolitis and 12.3 (2.2) cm in stage 2/3 sarcoidosis. This was partially accounted for by an increase in the interstitial fluid compartment. Blood volume was unaffected. Measurement of transthoracic tissue thickness involves minimal radiation exposure and may be of value in monitoring these diseases; measurement of interstitial fluid volume may give information on disease activity.     

自制肺灌洗引流装置在肺灌洗术中的应用

尘肺病是我国发病最多、危害最严重的一种职业病,每年新发病例占各类职业病总病例数的70%左右。肺灌洗术能改善患者的症状和肺功能,是治疗尘肺病的有效方法。而临床上没有专用的灌洗装置,与双腔气管导管之间的连接困难,灌洗、引流转换不便,给临床应用带来麻烦。自制灌洗装置与双腔气管导管连接紧密,无漏液现象发生,灌洗、引流转换方便,并能有效控制灌洗、引流速度,减轻手术中护士的工作最,收到良好效果。