3项指标在急性肺栓塞患者临床诊断中的价值分析

目的探讨血浆肌钙蛋白、B型钠尿肽及D-二聚体在急性肺栓塞临床诊断中的价值。方法随机选取住院治疗的116例急性肺栓塞患者,根据患者病情分为高危组58例和低危组58例。采用ELISA法检测2组患者的血浆肌钙蛋白、B型钠尿肽及D-二聚体水平并进行分析。结果高危组的血浆肌钙蛋白和B型钠尿肽水平明显高于低危组,差异有统计学意义(P0.05),2组D-二聚体水平差异无统计学意义(P0.05)。血浆肌钙蛋白(61.21%)、B型钠尿肽(74.14%)的阳性率明显高于D-二聚体(36.21%),差异有统计学意义(P0.05)。D-二聚体对急性肺栓塞检测的灵敏度为81.4%,特异度为86.7%;血浆肌钙蛋白的灵敏度为95.6%,特异度为86.7%;B型钠尿肽的灵敏度为97.1%,特异度为95.9%;血浆肌钙蛋白、B型钠尿肽的灵敏度和特异度明显高于D-二聚体,差异有统计学意义(P0.05)。结论血浆肌钙蛋白、B型钠尿肽及D-二聚体对于急性肺栓塞的临床诊断均具有一定意义,但是血浆肌钙蛋白、B型钠尿肽比D-二聚体具有更好的灵敏度和特异度。     

老年冠心病患者D-二聚体和超敏C-反应蛋白水平变化的意义

目的 探讨D-二聚体和超敏C-反应蛋白(hs-CRP)对早期诊断老年冠心病并判断其急危重症的临床意义.方法 122例老年冠心痛患者,分为4个亚组:陈旧性心肌梗死(OM1)组27例、稳定型心绞痛(SAP)组29例、急性冠状动脉综合征(ACS)组32例、陈旧性心肌梗死新发急性冠状动脉综合征(OMI+ACS)组34例.30例非冠心病患者作为对照组.应用免疫比浊法测定各组的hs-CRP,应用免疫散射法测定各组的D-二聚体,并进行比较分析.结果 各组间患者D-二聚体水平进行两两比较,OMI组[(0.25±007)mg/L]与SAP组[(0.27±0.08)mg/L]、OMI+ACS组[(0.58±0.80)mg/L]与ACS组[(0.56±0.72)mg/L]差异均无统计学意义(P均>0.05);OMI组与对照组比较差异有统计学意义(P<0.05);其余各组间比较差异均有统计学意义(P均<0.01).各组间患者hs-CRP水平进行两两比较,OMI组[(3.76±0.61)mg/L]与SAP组[(3.90±0.81)mg/L]、OMI+ACS组[(6.57±2.09)mg/L]与ACS组[(6.19±1.84)mg/L]差异均无统计学意义(P均>0.05);其余各组差异均有统计学意义(P均<0.01).老年冠心病患者D-二聚体与hs-CRP水平之间存在显著正相关(r=0.81,P<0.01).结论 D-二聚体和hs-CRP可作为判断老年人冠心病发生或存在的指标.D-二聚体和hs-CRP可作为临床判断冠状动脉斑块是否处于稳定期,是否发生急性冠状动脉综合征的指标;可作为陈旧性心肌梗死患者是否新发急性冠状动脉综合征的指标.但不能用于鉴别发生急性冠状动脉综合征的患者是否已经存在陈旧性心肌梗死.老年冠心病患者D-二聚体与hs-CRP水平存在正相关性.     

急性脑梗死患者颈动脉粥样硬化与血浆同型半胱氨酸及D-二聚体的关系

目的 探讨急性脑梗死患者颈动脉粥样硬化与血浆同型半胱氨酸和D-二聚体水平的关系.方法 选择2011年1月至2012年3月首次在上海市浦东医院住院治疗的287例急性脑梗死患者(观察组)和287例未患脑梗死的健康人或医院内其他与脑血管病无关的患者(对照组)为研究对象.应用荧光偏振免疫法检测血浆同型半胱氨酸浓度和双抗体夹心法测定D-二聚体浓度,同时使用美国GE公司MycoCardRReaderⅡ型超声诊断仪行颈部血管动脉超声检查,比较两组颈动脉粥样硬化与血浆同型半胱氨酸和D-二聚体的关系.结果 对照组和观察组总胆固醇[(4.25±0.92)、(4.98±0.88) mmol/L]、甘油三酯[(1.48±0.82)、(1.78±1.09) mmol/L]、低密度脂蛋白胆固醇[(2.52±0.76)、(2.92±0.73)mmol/L]、高密度脂蛋白胆固醇[(1.38±0.26)、(1.06±0.29) mmol/L]、收缩压[(130.28±14.78)、(152.98±20.45)mmHg]、舒张压[(78.45±16.02)、(93.81±16.88) mm Hg]和颈总动脉内膜中层厚度[对照组左、右颈总动脉内膜中层厚度分别为(0.86±0.41)、(0.87±0.39)mm,观察组分别为(1.18±0.25)、(1.12±0.29)mm],两组比较差异有统计学意义(t值分别为3.244、3.564、2.987、3.964、3.264、2.785、2.164、2.254,P均＜0.05);颈动脉粥样硬化组的同型半胱氨酸浓度[(12.89±6.56) μmol/L]和D-二聚体[(1.53±0.59) mg/L]明显高于非颈动脉粥样硬化组[(3.17±0.12)μmol/L,(0.33±0.23) mg/L],两组比较差异有统计学意义(t值分别为2.324、2.753,P均＜0.05).结论 急性脑梗死患者血浆同型半胱氨酸和D-二聚体水平高低与急性脑梗死患者颈动脉粥样硬化有关.     

血浆肌钙蛋白、B型钠尿肽及D-二聚体在急性肺栓塞临床诊断中的价值

目的探讨在急性肺栓塞患者的诊断中检测血浆肌钙蛋白、B型钠尿肽及D-二聚体的临床价值。方法以成都市西区医院2014年1月至2016年1月收治的93例急性肺栓塞患者为研究对象,其中低危患者(低危组)52例,高危患者(高危组)41例,采集患者血浆并用化学发光法测定其血浆肌钙蛋白、B型钠尿肽及D-二聚体水平,并比较三者检测的阳性率、灵敏度和特异度。结果高危组患者血浆肌钙蛋白、B型钠尿肽及D-二聚体检测水平明显高于低危组患者,差异有统计学意义(P0.05);血浆肌钙蛋白和B型钠尿肽检出阳性率分别为62.37%和74.19%,明显高于D-二聚体检出阳性率(37.63%),差异有统计学意义(P0.05);血浆肌钙蛋白和B型钠尿肽对急性肺栓塞的灵敏度和特异度明显高于D-二聚体。结论检测血浆肌钙蛋白、B型钠尿肽及D-二聚体水平都有助于急性肺栓塞的临床诊断,相对于D-二聚体,血浆肌钙蛋白和B型钠尿肽在急性肺栓塞的诊断中具有更好的灵敏度和特异度。     

检测窒息新生儿血浆D-二聚体的临床意义

目的:探讨检测窒息新生儿血浆D-二聚体的临床应用价值.方法:以窒息新生儿为研究对象,分为重度窒息组22例、轻度窒息组18例.另取同期正常新生儿20名作为对照组.重度窒息组中用肝素治疗14例.用酶联免疫吸附试验检测各组静脉血浆D-二聚体含量.比较各组的血浆D-二聚体检测结果.结果:重度窒息组、轻度窒息组、正常新生儿组的血浆D-二聚体值分别为(4.2±2.0)mg/L、(2.2±1.4)mg/L和(0.7±0.2)mg/L,3组间比较差异有统计学意义(P＜0.01);重度窒息组中14例予小剂量肝素治疗前后D-二聚体水平分别为(4.2±2.0)mg/L、(0.8±0.5)mg/L,治疗前后比较差异有统计学意义(P＜0.01).结论:检测窒息新生儿血浆D-二聚体,可了解窒息新生儿体内凝血与溶血功能的变化,为早期诊断DIC提供依据,并可作为窒息合并凝血功能障碍新生儿的疗效监测指标.     

D-二聚体和P-选择素及B型钠尿肽的检测对于窦性心律心力衰竭患者的临床意义

目的通过检测窦性心律的慢性心力衰竭患者血浆中D-二聚体、P-选择素和B型钠尿肽(BNP)的水平,探索窦性心律心力衰竭患者抗凝、抗栓治疗的必要性及治疗的时机。方法选取窦性心律慢性心力衰竭患者68例。根据射血分数(EF)进行分组:A组EF≥45%,20例;B组45%EF35%,22例;C组EF≤35%,26例。分别测定血浆D-二聚体、P-选择素、BNP水平。结果 C组患者血浆D-二聚体[(4.7±2.79)μg/m L比(3.01±1.15)μg/m L]、P-选择素[(17.2±2.4)μg/L比(14.6±3.7)μg/L]、BNP[(1347.8±158.4)μg/L比(478.9±26.0)μg/L]明显高于B组,B组患者血浆D-二聚体、P-选择素、BNP明显高于A组[(3.01±1.15)μg/m L比(2.15±0.28)μg/m L,(14.6±3.7)μg/L比(10.9±2.5)μg/L,(478.9±26.0)μg/L比(264.5±27.1)μg/L],差异有统计学意义(P0.05)。结论在窦性心律的心力衰竭患者中,发现BNP升高与D-二聚体,P-选择素升高成正相关。     

血浆PCT、Copeptin及D-二聚体水平对急性胰腺炎病情严重程度及预后评估的价值

目的:探讨血浆降钙素原(PCT)、和肽素(Copeptin)及D-二聚体水平对急性胰腺炎(AP)病情严重程度及预后评估的价值。方法:选取2017-01-01—2019-12-31期间三亚中心医院收治的AP患者175例,根据其病情严重程度分为轻度胰腺炎(MAP)组(78例)、中度重型胰腺炎(MSAP)组(50例)和重症胰腺炎(SAP)组(47例)。47例SAP患者根据其预后情况分成存活组(30例)和死亡组(17例)。另选取60例健康体检者作为对照组。比较各组血浆PCT、Copeptin及D-二聚体水平。应用受试者工作特征(ROC)曲线分析血浆PCT、Copeptin及D-二聚体水平对SAP诊断及预后评估的价值。结果:AP组血浆PCT(2.65±0.84 vs. 0.03±0.01,ng/mL)、Copeptin(2.37±0.45 vs. 0.28±0.03,ng/mL)及D-二聚体(1.31±0.26 vs. 0.35±0.04,mg/L)水平明显高于对照组(P0.05)。SAP组血浆PCT(4.16±1.08 vs. 2.73±0.92,1.51±0.36,ng/mL)、Copeptin(3.40±0.72 vs. 2.58±0.53,1.40±0.28,ng/mL)及D-二聚体(2.17±0.85 vs. 1.48±0.32,0.64±0.11,mg/L)水平均明显高于MSAP组和MAP组(P0.05)。死亡组血浆PCT(4.82±1.58 vs. 3.60±1.02,ng/mL)、Copeptin(4.17±0.95 vs. 2.80±0.64,ng/mL)及D-二聚体(2.66±1.04 vs. 1.75±0.42,mg/L)水平均明显高于存活组(P0.05)。ROC曲线显示,PCT、Copeptin及D-二聚体3项联合诊断SAP的曲线下面积(0.894,95%CI:0.836～0.955)最大,其敏感度和特异度为90.4%和83.6%;3项联合预测SAP发生死亡的曲线下面积(0.930,95%CI:0.872～0.993)最大,其敏感度和特异度为95.0%和87.2%。结论:血浆PCT、Copeptin及D-二聚体水平升高与AP患者的病情严重程度相关,3项联合检测对SAP诊断和预后评估具有一定价值。     

专项护理对剖宫产术后临床评分和下肢静脉血栓形成的影响

[目的]探讨专项护理对剖宫产产妇术后临床评分和下肢静脉血栓形成的影响。[方法]对2015年8月—2016年6月本院收治的剖宫产产妇进行术后6h的临床评分和血浆D-二聚体的检测,选择临床评分≥3分且血浆D-二聚体≤0.5mg/L的剖宫产产妇100例,随机分为两组,每组50例。观察组产妇进行术后专项护理5d,对照组产妇进行术后常规护理5d,每天对产妇进行临床评分,术后5d对产妇进行血浆D-二聚体检测和双下肢静脉彩色多普勒超声检查,比较两组产妇的临床评分、血浆D-二聚体和双下肢静脉血栓形成情况。[结果]观察组产妇术后第3天临床评分明显下降,对照组临床评分未出现明显变化;两组产妇术后第4天和第5天临床评分比较差异有统计学意义(P0.05);观察组产妇术后第5天的血浆D-二聚体(0.38mg/L±0.10mg/L)与对照组(0.45mg/L±0.12mg/L)比较差异有统计学意义(P0.05);观察组产妇术后第5天轻度下肢静脉血栓发生率为2%;对照组产妇术后第5天轻度下肢静脉血栓发生率为12%,两组比较差异有统计学意义(P0.05)。[结论]剖宫产术后对产妇进行专项护理能有效降低术后临床评分和血浆D-二聚体水平,预防术后下肢静脉血栓形成。     

血流感染患者D-二聚体测定的临床意义

目的探讨急性血流感染(BSI)患者血浆D-二聚体的水平及临床意义。方法胶乳增强免疫比浊法检测111例BSI患者和38例非BSI患者的血浆D-二聚体水平,比较两组D-二聚体水平的差异。结果 BSI患者的D-二聚体水平[2.034(1.190~4.666)mg/L]明显高于非BSI者[0.966(0.157~2.056)mg/L],差异有统计学意义(P0.01);BSI患者革兰阳性球菌感染组的D-二聚体水平[2.054(1.097~4.768)mg/L]与革兰阴性杆菌感染组[1.824(1.291~4.814)mg/L]相比,差异无统计学意义(P0.05)。结论 BSI患者体内存在着凝血和纤溶活性的异常,D-二聚体可作为非特异性炎性指标,辅助血流感染患者病情及疗效的监测。     

14例D-二聚体阴性急性肺栓塞临床分析

血浆D-二聚体(D-dimer)是交联纤维蛋白在纤溶系统作用下产生的可溶性降解产物,是一个特异性的纤溶过程标记物,其水平增高反映体内高凝状态和继发纤溶活性增强.D-二聚体对急性肺栓塞(acute pulmonary embolism,APE)诊断的敏感度高,目前普遍认为其阴性水平对急性肺血栓栓塞症有很大的排除诊断价值.我国2001年肺栓塞指南也指出,若血浆D-二聚体含量低于500 μg/L,可基本除外急性肺血栓栓塞症[1].然而,临床中仍常可见D-二聚体阴性的患者最后确诊为APE[2-3],近来更有大样本量研究发现D-二聚体阳性和阴性的疑似患者最后确诊为肺栓塞的比例差异无统计学意义[4-5].这表明D-二聚体阴性作为急性肺栓塞的排除诊断指标有待进一步研究.     

Acute respiratory distress syndrome: diagnosis and management

Acute respiratory distress syndrome manifests as rapidly progressive dyspnea, tachypnea, and hypoxemia. Diagnostic criteria include acute onset, profound hypoxemia, bilateral pulmonary infiltrates, and the absence of left atrial hypertension. Acute respiratory distress syndrome is believed to occur when a pulmonary or extrapulmonary insult causes the release of inflammatory mediators, promoting neutrophil accumulation in the microcirculation of the lung. Neutrophils damage the vascular endothelium and alveolar epithelium, leading to pulmonary edema, hyaline membrane formation, decreased lung compliance, and difficult air exchange. Most cases of acute respiratory distress syndrome are associated with pneumonia or sepsis. It is estimated that 7.1 percent of all patients admitted to an intensive care unit and 16.1 percent of all patients on mechanical ventilation develop acute lung injury or acute respiratory distress syndrome. In-hospital mortality related to these conditions is between 34 and 55 percent, and most deaths are due to multiorgan failure. Acute respiratory distress syndrome often has to be differentiated from congestive heart failure, which usually has signs of fluid overload, and from pneumonia. Treatment of acute respiratory distress syndrome is supportive and includes mechanical ventilation, prophylaxis for stress ulcers and venous thromboembolism, nutritional support, and treatment of the underlying injury. Low tidal volume, high positive end-expiratory pressure, and conservative fluid therapy may improve outcomes. A spontaneous breathing trial is indicated as the patient improves and the underlying illness resolves. Patients who survive acute respiratory distress syndrome are at risk of diminished functional capacity, mental illness, and decreased quality of life; ongoing care by a primary care physician is beneficial for these patients.     

颅脑损伤后神经源性肺水肿的早期诊断

目的:通过分析颅脑损伤后神经源性肺水肿(neurogenic pulmonary edema,NPE)患者的肺功能,探讨其早期诊断标准。方法:分析1994年7月—2005年10月82例颅脑损伤患者并发神经源性肺水肿前后的肺功能,详细记录检测肺功能的各项指标,计算均数和标准差,利用统计软件分析各项指标之间的关系。结果:神经源性肺水肿发生前后的症状和体征变化无明显差异,而RR、a/APO_2、SaO_2、P(A-a)O_2、PaO_2/FiO_2、PAO_2变化显著。结论:对颅脑损伤后NPE的早期诊断除依据急性呼吸困难和X线胸片外,还应着重根据PaO_2/FiO_2、a/APO_2、P(A-a)O_2等指标的变化情况判断是否发生神经源性肺水肿,并可将其作为判断病情的参考指标。     

Acute lung injury and acute respiratory distress syndrome in pregnancy

Acute respiratory failure can be the result of a variety of clinical conditions, such as congestive heart failure, pneumonia, pulmonary embolism, exacerbation of obstructive lung diseases, and acute respiratory distress syndrome (ARDS). This article focuses on developments related to acute lung injury and ARDS and reviews epidemiology, pathogenesis and therapeutic advances with an emphasis on the obstetric population. A brief discussion of tocolytic-induced pulmonary edema, preeclampsia, venous air embolism, and aspiration-related ARDS is included. Management of pregnant women with ARDS is outlined.     

肺超声评分评估新生儿呼吸窘迫综合征肺病变及预后的可行性

目的：研究探讨肺超声评分评估新生儿呼吸窘迫综合征肺病变及预后的可行性。方法：研究对象：选择120例我院就诊且因呼吸困难而怀疑为呼吸窘迫综合征新生儿;病例收集时间：2017年9月~2018年10月。对120例呼吸困难新生儿实施肺部超声检查、胸部X线检查,以临床综合诊断结果为参照,计算和比较超声、X线在呼吸窘迫综合征诊断中的灵敏度、特异度、准确率,并分析诊断结果间的一致性。根据经腹肺分级标准和新生儿肺部超声图像,对新生儿肺部病变进行评分,比较呼吸窘迫综合征新生儿与非呼吸窘迫综合征新生儿的肺超声评分。再对呼吸窘迫综合征新生儿实施机械通气治疗和肺表面活性物质治疗,比较治疗前后患儿的肺超声评分。结果：120例呼吸困难新生儿中,有90例经临床综合诊断证实为呼吸窘迫综合征,其余30例非呼吸窘迫综合征,证实为暂时性呼吸增快症。以临床综合诊断结果为参照,超声在呼吸窘迫综合征诊断中的灵敏度、特异度、准确率均高于X线（P<0.05）。经一致性分析,X线诊断结果与临床综合诊断结果之间的一致性为中等（Kappa=0.607）,而超声诊断结果与临床综合诊断结果间的一致性为良好（Kappa=0.789）。在双肺、左肺、右肺、双肺底,呼吸窘迫综合征新生儿的肺超声评分均低于非呼吸窘迫综合征新生儿（P<0.05）;治疗后,呼吸窘迫综合征新生儿各部位的肺超声评分均较治疗前增高（P<0.05）。结论：超声可对新生儿的呼吸窘迫综合征予以灵敏、准确检出,且肺超声评分还可对新生儿肺部病变及预后情况予以反映,临床上可将超声作为新生儿呼吸窘迫综合征诊断、肺病变判断、预后评估的方法。     

The effect of furosemide infusion on serum epidermal growth factor concentration after acute lung injury.

Acute lung injury and its more severe form, acute respiratory distress syndrome, are clinical syndromes of progressive hypoxemia and ventilation-perfusion mismatch with decreasing pulmonary compliance in the absence of congestive heart failure. Epidermal growth factor is involved in the pathogenesis of airway inflammation as well as a proinflammatory effect in other tissues. Furosemide has been shown to improve pulmonary gas exchange and intrapulmonary shunt by a nondiuretic mechanism in animal models of acute respiratory distress syndrome. The current study was undertaken to clarify whether furosemide attenuates the inflammatory response by changing the epidermal growth factor level in patients with acute lung injury. A prospective, randomized clinical trial involving 30 patients with acute lung injury was designed and conducted over 7 days. The measured outcomes included hemodynamics, acute physiology and chronic health evaluation (APACHE II) scores, and oxygenation. The serum specimens were analyzed with enzyme-linked immunoassay (ELISA) for epidermal growth factor at baseline, then 3 and 7 days after acute lung injury. The ratio of partial pressure of arterial oxygen (PaO2) to fraction of inspired oxygen (FIO2) improved in the furosemide-treated group within 24 hours (from 180 to 264; P = .01). The mean arterial pressure and heart rate was greater in this group than in the control group (that received no furosemide) on day 7 (P = .027). The mean arterial pressure increased and the heart rate decreased over time in the treatment group, but not significantly. Serum epidermal growth factor levels also were not significantly different between the furosemide treatment group and the control group (P > .05). Continuous furosemide infusion improves oxygenation and hemodynamics in patients with acute lung injury, but not through a change in the serum epidermal growth factor level. Further study is needed to determine the exact mechanism of furosemide action in patients with acute lung injury and acute respiratory distress syndrome.     

无创正压通气在急性呼吸衰竭急救中的回顾性研究

目的：评价无创正压通气（NIPPV）在抢救急性呼吸衰竭患者中的疗效。方法：对入选的38例急性呼吸衰竭患者使用无创正压呼吸机辅助通气，动态观察治疗前和治疗后2h动脉血气及生命体征变化。结果：38例患者中23例经NIPPV治疗2h后，Pa0。明显升高（P〈0．01），PaCO2明显降低（P〈0．01），pH升高（P〈0．05），有效率达63．2％（23／38）。对病因为AECOPD、间质性肺炎、急左心衰及肺部感染的患者，疗效显著；而对病因为支气管哮喘、肺癌、ARDS及MOF患者疗效差。其中I型呼衰成功率40．0％（6／15），Ⅱ型呼衰成功率78．5％（i8／e3），NIPPV对Ⅱ型呼衰救治成功率明显高于I型呼衰（P〈0．01）。结论：NIPPV在急性呼吸衰竭急救中疗效确切，应用时应掌握指征以提高疗效。     

Indications for mechanical ventilation in adults with acute respiratory failure

Increased understanding of the mechanisms and effects of acute respiratory failure has not been accompanied by more precise criteria by which the clinician can determine when intubation should be carried out and invasive positive-pressure ventilation (IPPV) instituted in a given patient. The indications traditionally offered in reviews and textbooks have tended to be either so broad as not to be very helpful in an individual case, or of questionable clinical relevance and too cumbersome for practical use. This review updates the indications for IPPV in adult patients with acute respiratory failure by examining available evidence from clinical trials and by considering new management alternatives that have become available in the last 20 years. Indications for IPPV based on specific threshold values for P(CO2) and pH or on various indices of arterial oxygenation have generally not been validated by clinical evidence, and it is unlikely that any cutoff value would be applicable to all patients or all categories of acute respiratory failure. Stated another way, there is probably no single value for arterial P(CO2), pH, or P(O2) that by itself constitutes an indication for IPPV. Compelling face validity justifies the use of IPPV in cases of apnea or when it appears certain that respiratory arrest is about to occur. However, dyspnea, tachypnea, or the subjective impression of respiratory distress are probably not in themselves justification for emergency intubation. It should be possible to avoid IPPV and its attendant complications in many cases of acute hypercapnic respiratory failure. In acute exacerbations of chronic obstructive pulmonary disease, noninvasive positive-pressure ventilation (NPPV) should be the initial ventilation approach unless the patient has one of several specific exclusion criteria such as cardiovascular instability or severely impaired mental status. It may also be possible to avoid intubation through the use of NPPV in certain immunocompromised patients with early acute hypoxemic respiratory failure. However, in other settings of acute hypoxemic respiratory failure, such as acute lung injury and acute respiratory distress syndrome, this has not been shown. The use of IPPV may improve outcomes in patients with severe cardiogenic shock. However, IPPV has not proven to be beneficial in traumatic brain injury and flail chest, in the absence of other indications.     

Clinical review: Positive end-expiratory pressure and cardiac output

In patients with acute lung injury, high levels of positive end-expiratory pressure (PEEP) may be necessary to maintain or restore oxygenation, despite the fact that 'aggressive' mechanical ventilation can markedly affect cardiac function in a complex and often unpredictable fashion. As heart rate usually does not change with PEEP, the entire fall in cardiac output is a consequence of a reduction in left ventricular stroke volume (SV). PEEP-induced changes in cardiac output are analyzed, therefore, in terms of changes in SV and its determinants (preload, afterload, contractility and ventricular compliance). Mechanical ventilation with PEEP, like any other active or passive ventilatory maneuver, primarily affects cardiac function by changing lung volume and intrathoracic pressure. In order to describe the direct cardiocirculatory consequences of respiratory failure necessitating mechanical ventilation and PEEP, this review will focus on the effects of changes in lung volume, factors controlling venous return, the diastolic interactions between the ventricles and the effects of intrathoracic pressure on cardiac function, specifically left ventricular function. Finally, the hemodynamic consequences of PEEP in patients with heart failure, chronic obstructive pulmonary disease and acute respiratory distress syndrome are discussed.     

放射性核素肺通气／肺血流灌注显像在心肺疾病中的应用

目的 评估放射性核素肺通气／肺灌注显像在心肺疾病中的应用价值。方法64例胸部疾病患者，男38例，女26例。第1天静脉注射^99mTc-MAA（8mCi）做肺血流灌注显像，第2天经口雾化吸入^99mTc-DTPA做肺通气显像，两次显像采集条件与体位相同。结果28例肺癌患者病变部位肺通气／肺血流均有下降，其中央型肺癌血流降低明显。4例慢性阻塞性肺气肿患者肺通气严重降低，与肺功能测定显示肺通气功能严重受损、呼吸道阻力增加相符合。5例肺大疱患者肺通气／肺血流呈散在下降，与X线肺大疱部位一致。6例急性肺栓塞和2例肺动脉发育不良者有显著的肺血流灌注缺损，肺通气则正常，两者图像呈典型的不匹配。7例先天性心脏病患者中5例肺通气／肺血流正常，2例通气正常、血流下降。2例多发性大动脉炎肺血流灌注明显下降、通气正常。余4例原发性肺动脉高压患者、3例胸痛者和3例心肌病患者的肺通气／肺血流均正常。结论放射性肺通气／肺血流灌注显像在心、肺疾病的显像各有不同的特殊表现，尤其对急性肺栓塞和慢性阻塞性肺气肿诊断特异性很高。为临床治疗提供有意义的参考价值。     

Pulmonary and extrapulmonary acute respiratory distress syndrome: myth or reality?

PURPOSE OF REVIEW: The pathogenesis of acute respiratory distress syndrome has been explained by the presence of a direct (pulmonary) or indirect (extrapulmonary) insult to the lung parenchyma. Evidence indicates that the pathophysiology of acute respiratory distress syndrome may differ according to the type of the insult. This article presents a brief overview of the differences between pulmonary and extrapulmonary acute respiratory distress syndrome, and discusses the interactions between lung functional, morphological aspects, and response to different therapies, both in experimental models and in patients with acute respiratory distress syndrome. RECENT FINDINGS: Many researchers recognize that experimental pulmonary and extrapulmonary acute respiratory distress syndrome are not identical when considering morpho-functional aspects, the response to positive end-expiratory pressure and recruitment manoeuvre, prone position and other adjunctive therapies. Contradictory results have been reported in different clinical studies, however, which may be attributed to the difficulty of classifying acute respiratory distress syndrome in one or the other category, and being confident of the onset, the phase and the severity of acute respiratory distress syndrome in all patients. SUMMARY: Heterogeneous acute respiratory distress syndrome patients are still considered to suffer from one syndrome, and are treated in the same way. Understanding the range of different pathways that lead to pulmonary dysfunction makes it possible to better target clinical treatment.