急性肺损伤和急性呼吸窘迫综合征研究现状与展望

急性肺损伤和急性呼吸窘迫综合征是指由心源性以外的各种肺内外致病因素所导致的急性、进行性缺氧性呼吸衰竭。近年来，对急性肺损伤和急性呼吸窘迫追综合征的命名和定义进行了更新和规范，对发病机制有了新的认识，提出了临床诊断标准和综合治疗措施。随着对急性肺损伤和急性呼吸窘迫综合征的深入研究，从炎症失控、调控着手去认识发病机制，采取针对性治疗，可望取得突破性进展。     

血管内皮细胞分泌的炎性递质在急性肺损伤发病机制中的作用

肺血管内皮细胞损伤在急性肺损伤（ALI）／急性呼吸窘迫综合征（ARDS）的病理过程中起重要作用,各种血管源性炎症递质可导致血管内皮细胞损伤,提高肺泡-毛细血管通透性,肺血管间质和肺泡腔水肿,发生顽固性低氧血症、呼吸窘迫等临床表现。本文探讨了ALI时各种炎症递质的表达、对肺血管内皮的作用机制及对ALI的病理生理影响。这些可能成为ALI／ARDS新的治疗靶点和研究的方向。     

Toll样受体4信号传导通路在急性肺损伤发病机制中的作用

炎症反应失控是急性肺损伤/急性呼吸窘迫综合征重要的发病机制之一。Toll样受体4介导生成的炎症介质是急性肺损伤炎症反应中重要的分子生物学基础之一。作者就Toll样受体4的炎症信号传导通路在急性肺损伤/急性呼吸窘迫综合征中的作用机制进行综述。     

急性肺损伤/急性呼吸窘迫综合征与细胞信号转导

急性肺损伤/急性呼吸窘迫综合征是以多种复杂病理生理过程和发病机制为特点的临床综合征,其病死率可达30%~40%,是现代呼吸和危重医学的一大难题。在急性肺损伤/急性呼吸窘迫综合征复杂的发病机制中,失控的炎症反应与细胞信号转导密切相关。     

内毒素急性肺损伤相关标志物变化的研究

急性肺损伤(ALI)是直接或间接致伤因素导致肺泡上皮细胞及毛细血管内皮细胞损伤,造成弥漫性肺间质和/或肺泡水肿,导致的急性低氧性呼吸功能不全。以肺容积减小、顺应性减少、通气-灌注比例失调(死腔增加)为病理生理特征,临床上表现为进行性低氧血症和呼吸窘迫。X线表现为两肺渗出性病变,氧合指数(动脉氧分压Pa O2/吸入氧分数Fi O2)<300[1]。其发展至严重阶段(氧合指数<200)被称为急性呼吸窘迫综合征(ARDS)。ALI/ARDS的发病机制     

急性肺损伤及急性呼吸窘迫综合征机械通气治疗进展

机械通气是治疗急性肺损伤/急性呼吸窘迫综合征的重要措施之一.40年来的时间,尤其是近10年来,人们试图探寻能降低急性肺损伤/急性呼吸窘迫综合征病死率的通气策略.小潮气量通气能降低急性肺损伤/急性呼吸窘迫综合征的病死率,其最佳潮气量为6～9 ml/kg;低呼气终末正压(小于10 cm H2O)、适当高的呼吸频率、维持相对安全的pH值和PaCO2,对降低急性肺损伤和急性呼吸窘迫综合征的病死率有重要的作用.近年来,非常规通气支持治疗的研究包括俯卧位通气、部分液体通气及气管内吹气等,也有一定成果.     

高氧诱导的急性肺损伤研究现状及治疗靶点

长时间暴露于氧气中可导致急性肺损伤的发生,目前对于高氧诱导的急性肺损伤的发病机制尚未完全明确,且缺乏有效的治疗措施。本文就近年对高氧诱导的急性肺损伤的研究现状作一综述,探讨活性氧族、炎症细胞、信号转导通路及转录因子在肺型氧中毒发病中的作用,同时展望治疗靶点。     

氧合指数对预测急性肺损伤的预后价值评估

急性肺损伤(acute lung injury,ALI)是由淹水误吸、严重脓毒症等原因导致的急性低氧性肺功能不全,以肺容积减少、通气/血流比例失调为主要的病理生理特征。ALI患者在误吸、胸腔积水等创伤下,肺泡上皮细胞及毛细血管内皮细胞刺激损伤后,造成弥漫性肺间质及肺泡水肿,严重者甚至发生呼吸衰竭,因此常需要机械通气辅助呼吸。研究显示,部分机械通气的ALI患者会发展为急性呼吸窘迫综合征(acute respiratory distress syndrome,ARDS),其死亡率高达32%~50%。目前,临床上尚无准确评估ALI预后的标准。有学者采用肺血管通透性指数、肺功能、心功能等指标预测ALI预后的死亡情况,但结果不一。本研究旨在分析ALI患者氧合指标如PaO2、PaCO2、SaO2等的变化,探讨氧合指数(PaO2/FiO2)及肺损伤评分(lung injury score,LIS)对ALI患者死亡结局的预测价值,为临床治疗及预防不良结局提供参考。     

一氧化氮治疗急性呼吸窘迫综合征的临床进展

急性肺损伤(ALI)/急性呼吸窘迫综合征(ARDS)是在严重感染、休克、创伤及烧伤等非心源性疾病过程中,肺毛细血管内皮细胞和肺泡上皮细胞损伤造成弥散性肺间质及肺泡水肿,导致的急性低氧性呼吸功能不全或衰竭.目前对于ARDS的治疗手段众多,其中之一的选择性肺血管扩张剂一氧化氮(NO)于20世纪后期开始进入临床治疗领域.NO...     

内皮祖细胞治疗急性肺损伤的研究进展

急性肺损伤(ALI)是临床上常见的危重疾病,目前尚无特效疗法。保护内皮细胞受损并逆转已形成的损伤成为ALI治疗发展的新趋势,受到广泛关注。一系列研究提示从骨髓动员至外周血的内皮祖细胞(EPCs)在受损的肺组织处可以直接分化为血管内皮细胞,并能调节失控的炎症反应、增强受损肺组织的抗氧化能力,对血管内皮细胞的修复和维持肺泡毛细血管屏障的完整性起着重要作用,因此内皮祖细胞的移植治疗将成为降低ALI/急性呼吸窘迫综合征(ARDS)死亡率的治疗新靶向。     

Association of manifestations of acute stress disorder and acute cerebrovascular disease

The study comprised 32 patients who were with clinically, laboratory and neuroradiologically confirmed associated occurrence of acute stress disorder and stroke. All the examinees were civilians exposed to war stress, so it could be directly designated as the cause of acute stress disorder and indirectly denoted as a trigger of cardiovascular, endocrine and cerebrovascular disorder that brought to stroke.     

Gonorrhea and acute epididymitis.

To determine whether the true incidence of gonorrheal urethritis in acute epididymitis is obscured by inadequate detection methods, all males admitted to the Urology Service of an American military hospital between February 1975-April 1977 with a diagnosis of epididymitis underwent 4 separate screening tests for concomitant gonorrheal urethritis. Assessment of the 4 screening methods showed that a culture of a calcium-alginate swab of the anterior urethra obtained prior to the 1st morning urination was positive in every case of gonorrhea detected, and was the most consistent means of detection. In the 2nd test, neither a gram stain smear nor the culture of the sperm sediment of a "urethral wash" proved reliable. Smears of the urethral wash yielded 36% false negatives while cultures yielded 54% false negatives. The Gram stain and culture of ejaculate were both reliable, but fewer than 1/2 of the patients with positive cultures were able or willing to provide a specimen. Among the positive cases, there was 1 false negative among the 5 ejaculates available for Gram stain, and all 5 ejaculates were positive on culture. The final method, Gram stain and culture of discharge, proved inadequate because a discharge was absent in 50% of the positive cases. Neither the patients' histories nor physical findings were diagnostic because of the overlap between positive and negative cases. 14 of the 88 consecutive patients admitted with acute epididymitis (16%) were found to have N. gonorrheae urethritis as well. The actual incidence may have been even higher since 31% of the patients were taking antibiotics prior to admission. The diagnosis of concomitant gonorrhea in acute epididymitis confirmed by culture offers the advantages of assuring adequate treatment of the patient and prompt treatment of the sex partners, preventing reinfection from untreated contacts, and assuring proper epidemiological reporting and appropriate serologic screening for concomitant syphilis.     

Water diffusion and acute stroke

The occlusion of the middle cerebral artery was used as an experimental acute stroke model in 30 cats. The diffusion of water was followed by diffusion-sensitized MRI between 1 and 15 h after induction of stroke. It is demonstrated that images representing the trace of the diffusion tensor provide a much more accurate delineation of affected area than images representing the diffusion in one direction only. The reason is that the strong contrast caused by the anisotropy and orientation of myelin fibers is completely removed in the trace of the diffusion tensor. The trace images show a small contrast between white and gray matter. The diffusion coefficient of white matter is decreased in acute stroke to approximately the same extent as gray matter. It is further shown that the average lifetime of water in extra and intracellular space is shorter than 20 ms both for healthy and ischemic tissue indicating that myelin fibers are permeable to water. The anisotropy contrast did not change before or after induction of stroke, nor after sacrifice. Together, these observations are consistent with the view that the changes in water diffusion during acute stroke are directly related to cytotoxic oedema, i.e., to the change in relative volume of intra- and extracellular spaces. Changes in membrane permeability do not appear to contribute significantly to the changes in diffusion.     

Osteomyelitis, acute and chronic

In certain patient populations, osteomyelitis is a significant clinical problem. The judicious use of plain film radiographs and radionuclide bone imaging by the imaging consultant has a critical role in the early detection and diagnosis of osteomyelitis. This complementary imaging approach produces the highest and greatest accuracy in the documentation of skeletal infections. Inadvertent delay in the initiation of appropriate therapy can be obviated utilizing these imaging techniques and undue morbidity averted.     

Alpine skiing and acute beta-blockade

The effect of acute unselective (propranolol) and beta 1-selective (atenolol) beta-adrenoceptor blockade was studied on alpine skiing in six leisure and seven elite skiers. Prior to the skiing tests a short time "all out" cycle ergometer test (Wingate muscle power test) was performed to confirm whether a beta-blocking effect (80 mg propranolol and 100 mg atenolol orally) was present or not. Peak and average power of the Wingate test showed an impairment in the order of 4%--6% (P less than 0.05--0.001). Peak blood lactate was only reduced after propranolol (0.05 greater than P greater than 0.01). During leisure skiing under submaximal exercise conditions peak blood lactate was increased (P less than 0.05) as compared to placebo, but rated perceived exertion (RPE) was unchanged as well as the estimated skiing technique. The elite skiers showed prolonged performance times (P less than 0.05) after beta-blockade and in the case of propranolol also reduced peak and mean blood lactates (P less than 0.05). It is suggested that during intense exercise propranolol reduced lactate formation, which is in line with previous reports. This might impair short time, "explosive" type muscular exercise. If there is a risk factor for injury during beta-blockade and alpine skiing, it might be connected to the impaired performance and metabolism in relation to intense exercise and propranolol treatment.