缺氧性肺动脉高压发病机制及靶向治疗研究

缺氧性肺动脉高压（hypoxia pulmonary hypertension,HPH）是慢性肺源性心脏病及慢性高原病等临床疾病发病的重要病理生理变化之一,是由于长期慢性缺氧导致的,其主要特征为低氧性肺动脉收缩增强,肺小动脉中层平滑肌异常增生,肺血管重构,最终导致右心室肥大及右心衰竭[1].WHO对肺高压的分型中,将“伴发肺脏疾病和/或低氧血症的肺高血压”归纳为第Ⅲ型,包括慢性阻塞性肺疾病（chronic obstructive pulmonary disease,COPD）间质性肺疾病（结缔组织疾病,硬皮病）,睡眠呼吸障碍,慢性高原病,肺泡低通气综合征及肺泡毛细血管发育不良[2].     

慢性阻塞性肺病患者睡眠时低氧血症及其处理

慢性阻塞性肺病患者往往伴有睡眠障碍和夜间低氧血症。低氧务 的发生与睡眠时肺泡低通气和通气／灌注比例失调等因素相关。严重的夜间低氧血症可引起肺动脉高压，心律失常及神经精神损害等并发症，纠正夜间低氧血症可以改善慢性阻塞性肺病患者的生命质量和预后。     

霉酚酸酯与肺动脉高压

肺动脉高压(pulmonary arterial hypertension,PAH)是以肺动脉压力升高而导致的右心室衰竭为特点的病理状态[1].根据美国国立卫生研究院制定的标准,肺动脉高压定义为在静息状态下心导管测定肺动脉平均压>25 mm Hg(1 mm Hg=0.133 kPa)或在运动状态下>30 mm Hg,伴有平均肺毛细血管锲压和左心室收缩末期压力<15 mm Hg[2].     

HIF-1α、BNP表达在缺氧性肺动脉高压中的研究进展

<正>肺动脉高压指肺动脉平均压在静息状态时大于25 mm Hg或运动状态时30 mm Hg。临床上见肺动脉高压多为继发性肺动脉高压,它的形成是由于机体长期处于缺氧状态、高碳酸血症及呼吸性酸中毒时,肺血管失调,最终造成肺血管重建,缺氧性肺血管收缩反应(HPV)与缺氧性肺血管重塑(HPSR)是肺动脉高压形成中两个最重要的环节,慢性缺氧时常导致许多内源性的细胞因子调节失衡[1]。本文     

霉酚酸酯与肺动脉高压

肺动脉高压(pulmonary arterial hypertension,PAH)是以肺动脉压力升高而导致的右心室衰竭为特点的病理状态[1].根据美国国立卫生研究院制定的标准,肺动脉高压定义为在静息状态下心导管测定肺动脉平均压>25 mm Hg(1 mm Hg=0.133 kPa)或在运动状态下>30 mm Hg,伴有平均肺毛细血管锲压和左心室收缩末期压力<15 mm Hg[2].     

霉酚酸酯与肺动脉高压

肺动脉高压(pulmonary arterial hypertension,PAH)是以肺动脉压力升高而导致的右心室衰竭为特点的病理状态[1].根据美国国立卫生研究院制定的标准,肺动脉高压定义为在静息状态下心导管测定肺动脉平均压>25 mm Hg(1 mm Hg=0.133 kPa)或在运动状态下>30 mm Hg,伴有平均肺毛细血管锲压和左心室收缩末期压力<15 mm Hg[2].     

肺心病:血管扩张剂治疗右心衰竭的利与弊

肺心病包括急性肺源性心脏病 (主要为急性肺动脉栓塞引起 )和慢性肺源性心脏病 (ＣＯＰＤ引起 )。ＣＯＰＤ急性加重期常出现右心衰竭。其发病机制多因肺部感染、严重肺泡缺氧、肺血管壁增厚、肺血管床面积减少、肺动脉高压等导致呼吸衰竭和右心衰竭。低氧是形成肺动脉高压的主要机制。积极控制感染 ,机械通气改善肺泡通气 ,即可纠治低氧血症和高碳酸血症 ,并使肺动脉压和肺循环阻力降低 ,肺血分流率 ( Ｑｓ/ Ｑｔ)降低[1] ,为呼吸衰竭和右心衰竭治疗的主要手段 ;对于右心衰竭时的血管扩张剂应用 ,目前尚有不同意见。1　血管扩张剂应用的利…     

肺动脉高压药物治疗进展

肺动脉高压(pulmonary artery hypertension,PAH)是指静息时平均肺动脉压>25 mm Hg,且肺毛细血管压或左房压<15 mm Hg [1].血管扩张剂是治疗肺动脉高压的一类重要药物,能降低肺动脉压力,改善患者血流动力学及肺通气/灌注比值,提高肺动脉高压患者的生活质量,运动耐力以及存活率.其理论基础是肺动脉高压时存在肺动脉的痉挛.当前主要的肺血管扩张剂主要有钙离子拮抗剂、前列环素类药物、内皮素受体拮抗剂、磷酸二酯酶-5抑制剂和一氧化氮.现就肺动脉高压治疗中肺血管扩张剂的应用及部分药物治疗进展进行综述.     

经鼻气道正压通气治疗重叠综合征26例临床观察

阻塞型睡眠呼吸暂停低通气综合征(OSAHS)合并慢性阻塞性肺疾病(COPD)或其他呼吸系统疾病如肺囊性纤维化、肺间质纤维化等时称之为重叠综合征(overlap syndrome)。此类患者较单纯OSAHS或COPD有更严重的与睡眠有关的低氧血症,更容易引肺动脉高压以及发展成为慢性肺源性心脏病,并导致严重的并发症。     

阻塞性睡眠呼吸暂停综合征合并慢性阻塞性肺疾病的研究进展

睡眠呼吸暂停综合征是指各种原因导致睡眠状态下反复出现呼吸暂停和（或）低通气,引起低氧血症、高碳酸血症,使机体发生一系列病理生理改变的临床综合征。其中阻塞性睡眠呼吸暂停综合征（OSAHS）是最常见的类型,患者可合并慢性阻塞性肺疾病（COPD）或其他呼吸系统疾病,如肺囊性纤维化、肺问质纤维化等,也称为重叠综合征（OS）。目前认为,与单纯OSAHS或COPD比较,OS患者与睡眠有关的低氧血症更严重,更易引起肺动脉高压,发展成慢性肺源性心脏病（PHD）。COPD是呼吸衰竭（呼衰）和PHD的最主要原因,     

Nitroglycerin-responsive pulmonary hypertension in idiopathic pulmonary hemosiderosis

Idiopathic pulmonary hemosiderosis (IPH) is an uncommon disease found predominantly in pediatric patients. It can produce severe chronic pulmonary injury that results in chronic hypoxemia, pulmonary insufficiency, and progressive pulmonary fibrosis, leading to irreversible pulmonary hypertension and death. We studied the pulmonary hemodynamics in an 9-yr-old boy with IPH to determine if pulmonary hypertension contributed to exacerbations of this disease. Our results showed that this patient demonstrated pulmonary hypertension during acute exacerbations. Initially, the elevated pulmonary artery pressure responded both to oxygen and to a pulmonary vasodilator in the form of nitroglycerin. However, this improvement was not sustained. We conclude that pulmonary hypertension is probably a result of chronic hypoxemia experienced by patients with pulmonary hemosiderosis. Further investigation is warranted to assess whether or not intervention aimed at reducing pulmonary artery pressure in IPH improves outcome.     

Retrograde pulmonary perfusion improves results in pulmonary embolectomy for massive pulmonary embolism

Mortality rates for pulmonary embolectomy in patients with acute massive pulmonary embolism have decreased in recent years. However, they still range from 30% to 45% when the surgery is performed on critically ill patients, and the rates reach 60% in patients who have experienced cardiac arrest before the procedure. The causes of death in these patients are generally attributed to right heart failure due to persistent pulmonary hypertension, intractable pulmonary edema, and massive parenchymal and intrabronchial hemorrhage. Clinical and experimental findings indicate that venous air embolism causes severe or even lethal damage to the pulmonary microvasculature and the lung parenchyma consequent to the release of endothelium-derived cytokines. These findings are similar to those observed when severely compromised patients undergo pulmonary embolectomy-air entrapped in the pulmonary artery during embolectomy can lead to fatal outcomes.Besides enabling the removal of residual thrombotic material from the peripheral branches of the pulmonary artery, retrograde pulmonary perfusion fills the pulmonary artery with blood and prevents pulmonary air embolism. In this retrospective study, we analyzed a series of 21 consecutive critically ill patients in whom we applied retrograde pulmonary perfusion while performing standard pulmonary embolectomy. No patient died or experienced major postoperative complications. We believe that the use of retrograde pulmonary perfusion decreases morbidity and mortality rates associated with pulmonary embolectomy in critically ill patients.     

Hemodynamic and pulmonary studies in pulmonary alveolar microlithiasis

A 34-year-old woman with biopsy-proved pulmonary alveolar microlithiasis is described. Cardiac catheterization data and results of pulmonary function studies are presented. Mild to moderate pulmonary hypertension occurred with supine leg exercise, possibly reflecting a reduced capacity of the vascular bed evident only with increased pulmonary blood flow and tachycardia. Attention should be paid to the level of physical activity in patients with this disease, particularly if the vital capacity is reduced below 80 percent of that predicted.     

Prediction of pulmonary hypertension in idiopathic pulmonary fibrosis

BACKGROUND: Reliable, noninvasive approaches to the diagnosis of pulmonary hypertension in idiopathic pulmonary fibrosis are needed. We tested the hypothesis that the forced vital capacity to diffusing capacity ratio and room air resting pulse oximetry may be combined to predict mean pulmonary artery pressure (MPAP) in idiopathic pulmonary fibrosis. METHODS: Sixty-one idiopathic pulmonary fibrosis patients with available right-heart catheterization were studied. We regressed measured MPAP as a continuous variable on pulse oximetry (SpO(2)) and percent predicted forced vital capacity (FVC) to percent-predicted diffusing capacity ratio (% FVC/% DL(co)) in a multivariable linear regression model. RESULTS: Linear regression generated the following equation: MPAP=-11.9+0.272 x SpO(2)+0.0659 x (100-SpO(2))(2)+3.06 x (% FVC/% DL(co)); adjusted R(2)=0.55, p<0.0001. The sensitivity, specificity, positive predictive and negative predictive value of model-predicted pulmonary hypertension were 71% (95% confidence interval (CI): 50-89%), 81% (95% CI: 68-92%), 71% (95% CI: 51-87%) and 81% (95% CI: 68-94%). CONCLUSIONS: A pulmonary hypertension predictor based on room air resting pulse oximetry and FVC to diffusing capacity ratio has a relatively high negative predictive value. However, this model will require external validation before it can be used in clinical practice.     

慢性阻塞性肺疾病合并侵袭性肺曲霉病的研究进展

侵袭性肺曲霉病(invasive pulmonary aspergillosis,IPA)常常继发于免疫受损和器官移植患者,病死率较高.近年来,COPD患者继发IPA国内外均有报道,其病死率在80%以上[1],亦有文献报道[2]COPD是IPA的危险凶素.临床上治疗时机的延误是主要的死亡原因,呼吸道标本中发现其他致病微牛物是延误治疗的原因之一.COPD患者IPA的发生率较高,长时间肺部浸润影和临床病情的短时间恶化需警惕IPA发生的可能性[3].现将COPD合并IPA的进展综述如下.