第一秒与六秒用力呼气容积比值检测气流阻塞的临床研究

目的 探讨在肺功能测定中能否用第1秒用力呼气量与6秒用力呼气量比值（FEV1/FEV6）代替第1秒用力呼气量与肺活量比值（FEV1/FVc）的可行性.方法 对256名慢性阻塞性肺病（COPD）患者和174名非COPD患者进行肺功能检测,收集FVC、FEV6、FEV1/FVC、FEV1/FEV6等数据.比较FEV6与FVC以及FEV1/FEV6与FEV1/FVC的相关性;并以FEV1/FVC〈70%作为判断气流阻塞的标准,计算相应FEV1/FEV6检测气流阻塞的敏感性和特异性.结果 （1）FEV6与FVC以及FEV1/FEV6与FEV1/FVC均呈强正相关关系;（2）根据ROC曲线结果,取FEV1/FEV6为〈72.6%,其诊断气流阻塞的敏感性和特异性分别达到97.7%和98.4%.结论 FEV1/FEV6能够代替FEV1/FVC检测气流阻塞。     

COPD和哮喘患者支气管舒张实验用力肺活量和呼气容积的变化

目的 探讨COPD和哮喘患者支气管舒张实验用力肺活量和呼气容积变化.方法 随机选取COPD急性加重期78例和哮喘急性发作期64例,采用支气管舒张实验比较COPD和哮喘患者实验前后用力肺活量(FVC)、一秒用力呼气容积(FEV1)的增加量和增加率.结果 支气管舒张实验后,COPD患者的用力肺活量(FVC)的增加量191 ml,较舒张前增加12.93%,而一秒用力呼气容积(FEV1)的增加量63 ml,较舒张前增加10.01%;哮喘患者的用力肺活量(FVC)的增加量363 ml,较舒张前增加15.34%,而一秒用力呼气容积(FEV1)的增加量289 ml,较舒张前增加23.57%.结论 COPD患者支气管舒张试验后用力肺活量的增加幅度大于呼气容积的增加幅度,而哮喘患者正好相反,因此用力肺活量可鉴别COPD和哮喘患者病情的客观指标.     

测定慢性阻塞性肺疾病患者6s用力呼气容积的意义

目前判断气流受限的常用肺功能指标是时间肺活量,包括:第1秒用力呼气容积(FEV1)和1 s率(FEV1与用力呼气容积比值)的降低来确定的。气道阻塞患者呼气时间可明显延长,最长可达20 s或以上,但呼气时间过长会使患者出现过度通气,导致头晕、呼吸困难、肢体麻木,甚至危及性命,尤其慢性阻塞性肺疾病(COPD)患者多见于老年人,体质较差,容易出现并发症。6 s呼气容积(FEV6)是指最大吸气至肺总量位后6 s之内快速呼出气量。由于呼气时间相对较短,患者比较容易接受,不良反应少。本文就COPD患者肺功能指标用力肺活量(FVC)与FEV6及FEV1/FVC与FEV1/FEV6进行相关性分析。     

一秒钟用力呼气容积与用力肺活量之比值在慢性阻塞性肺疾病诊断分级中的价值

目的 探讨一秒钟用力呼气容积（FEV1）与用力肺活量（FVC）之比值FEV1/FVC的影响因素、变化情况以及慢性阻塞性肺疾病（COPD）诊断分级中的实际价值。方法 选择FEV1%预计值在吸入支气管扩张剂后仍低于80%，但FEV1/FVC≥70%的“可疑”COPD患者的肺功能测定数据结合历史文献进行分析、推论、求证。结果 29例“可疑”COPD患者基础肺功能情况符合我国1997年制定的COPD诊断标准，且吸入支气管扩张剂前后FEV1%预计值及FEV1/FVC无显著差异（P〉0.05），FEV1%预计值仍低于80%，FEV1/FVC则大于70%，但仍低于83%这一经典数值。结论 FEV1/FVC受年龄、呼吸肌力及肺泡伸缩程度等诸因素的影响，具有较明显的变异性，其值在70%以上时未必一定就不存在气流阻塞，它在COPD诊断分级中的价值并不象GOLD所说的那样重要，GOLD关于COPD的诊断分级标准在临床实践中的可操作性较低且容易造成混乱，建议重新修订为“使用支气管扩张剂后FEV1%预计值〈80%或FEV1/FVC仍处于减低状态可确定为不完全可逆性气流阻塞”，在对COPD轻重程度的分级时则应取消FEV1/FVC〈70%这一前提条件。     

第三秒用力呼气容积/用力肺活量下降在早期轻度气道功能障碍中的临床意义

目的探讨第三秒用力呼气容积(FEV3)/用力肺活量(FVC)在早期轻度气道功能障碍中的临床意义。方法收集294例肺功能检查患者并分为3组。正常组164例,第一秒用力呼气容积(FEV1)/FVC、FEV3/FVC均正常; FEV3组39例,仅FEV3/FVC降低,但FEV1/FVC正常; FEV1组91例,FEV1/FVC降低。比较各组一般资料及肺功能指标。结果①正常组平均年龄及吸烟比例显著小于FEV3组(P<0. 05); FEV3组与FEV1组相比,平均年龄及吸烟比例差异无统计学意义(P>0. 05)。②FEV3组与正常组相比及FEV1组与FEV3组相比,FEV1%pred、FEV1/FVC较低,肺总量(TLC)、残气量(RV)、RV/TLC较高,一氧化碳弥散量(DLCO)较低,差异均有统计学意义(P<0. 05)。结论 FEV3/FVC检测应作为肺功能检测的常规检查,仅FEV3/FVC下降可能是早期判断轻度气道功能障碍的指标。     

慢阻肺中第一秒与六秒用力呼气容积比值应用研究

目的探讨第1秒用力呼气容积与6秒用力呼气容积比值（FEV1／FEV6）在慢性阻塞性肺疾病（COPD）诊断方面的临床价值。方法对120例COPD稳定期患者和80例健康者进行肺量测定,前者依据中华医学会制定的《慢性阻塞性肺疾病诊治指南（2007年修订版）》进行分级,分为COPDI-Ⅱ级组、Ⅲ-Ⅳ级组。结果COPDI-Ⅱ级组FEV1／pre、FEV1／FVC、FEV1／FEV6较对照组明显降低,而COPI）Ⅲ-Ⅳ级组与对照组相比,FVC／pre、FEV6／pre、FEV1／pre、FEV1／FVC、FEV1／FEV1显著降低。COPDI-Ⅱ级组FEV1／pre、FVC／pre下降幅度比FEV1／FVC、FEV1／FEV6低;在COPDⅢ-Ⅳ级组FEV,／pre、FVC／pre的下降幅度比FEV。／FVC、FEV,／FEV。的下降幅度要高。COPDⅢ-Ⅳ级组的CV[FVC]高于COPDI-Ⅱ级组和对照组。FEV1／FEV6和FEV1／FVC呈显著正相关。结论相比FVC,FEV6有着更好的重复性,而FEV1／FEV6和FEV1／FVC也有着显著的相关性,同样可以准确反映气流受限,且测试更为简单。     

γ-谷氨酰转肽酶在慢性阻塞性肺疾病患者血清中的表达变化及诊断价值

目的研究血清γ-谷氨酰转肽酶(GGT)的变化与慢性阻塞性肺疾病(COPD)之间的关系,探讨其诊断价值。方法收集行肺功能检查的COPD患者及健康体检者,排除相关剔除标准后分为两组:COPD患者113例、健康体检者119例。检测血清谷丙转氨酶(ALT)、谷草转氨酶(AST)、总胆红素及GGT水平。采用肺功能仪对受试者进行第1秒用力呼气容积(FEV1)占预计值的百分比(FEV1%)、FEV1/用力肺活量(FVC)等的检测。对两组间相关资料进行比较并研究各因素与血清GGT水平的相关性。绘制受试者工作特征曲线(ROC),并计算曲线下面积(AUC)及诊断界限值(cutoff)。结果 COPD组的GGT水平明显高于对照组,其水平与FEV1/FVC呈负相关,而肝功能的其他指标未发生明显变化。GGT的AUC值高于0.7,其在cut off为21.5时有较好的敏感度及特异度。结论血清GGT与COPD发病相关,它可作为预测及筛查COPD的新的参考指标。     

第6秒用力呼气量在肺功能评价中的临床意义

用力肺活量(FVC)和第1秒用力呼气量是用来诊断与鉴别诊断阻塞性和限制性通气功能障碍的两个重要指标.近几年来的研究显示第6秒用力呼气量能很好地替代FVC,不仅能减少患者呼气时间,降低因呼气延长诱发呼吸困难的风险,使患者更易配合完成合格的测定,同时还能提高气道阻塞高危因素受试者的检出率,为早期诊断和治疗提供可能.     

本刊常用的不需要标注中文的缩略语

慢性阻塞性肺病急性发作期(AECOPD);支气管肺泡灌洗液(BALF);双水平正压无创通气(BiPAP);第一秒用力呼气容积,秒容积(FEV 1);第一秒用力呼气容积与用力肺活量比值,一秒率(FEV 1/FVC);用力肺活量(FVC);重症监护病房(ICU);最低抑菌浓度(MIC)。     

回复对慢性阻塞性肺疾病诊治方案的疑问

您来信提出的有关第一秒用力呼吸容积(FEV1)／用力肺活量(FVC)在慢性阻塞性肺疾病(COPD)诊断中价值的问题很重要。肺功能检测是诊断COPD最重要的客观指标。COPD患者的肺功能异常属于阻塞性通气功能障碍，其特点就是在FEV1降低的同时，伴有FEV1／FVC减小。COPD患者由于气道阻塞，气流受限，在用力最大呼气的第一秒时段内所能呼出的气体容积明显减少，也就是FEV1明显减少。然而，尽管患者因气流受限，在每个单位时段内所能呼出的气体容积明显减少，但他们可以通过延长呼气时间，比较缓慢地将较多的气体呼出体外，     

Options for screening for colorectal cancer

Unlike other types of cancer, there are several options for screening for colorectal cancer (CRC). The most extensively examined method, faecal occult blood testing (FOBT), has been shown, in three large randomized trials, to reduce mortality from CRC by up to 20% if offered biennally and possibly more if offered every year. Recently published data from the US trial suggest that CRC incidence rates are also reduced by up to 20%, but only after 18 years. In this study, the number of positive slides was associated with the positive predictive value both for CRC and adenomas larger than 1 cm, suggesting that the reduction in CRC incidence was caused by the identification and removal of large adenomas. In this respect, this study supports the concept that removing adenomas prevents CRC. More efficient methods of detecting adenomas include the use of colonoscopy or flexible sigmoidoscopy (FS). Considerable evidence exists from case-control and uncontrolled cohort studies to suggest that endoscopic screening by sigmoidoscopy reduces incidence of distal colorectal cancer. However, in the absence of evidence from a randomized trial, several countries have been reluctant to introduce endoscopic screening. Three trialsare currently in progress (in the UK, Italy and the US) to address this issue. Two of these trials are examining the hypothesis that a single FS screen at around age 55-64 might be a cost-effective and acceptable method for reducing CRC incidence rates. Recruitment and screening are now complete in both studies and the first analysis of results on incidence rates is expected in 2004. Colonoscopy screening at 10-year intervals has recently been endorsed in the US on the basis that the reductions in incidence observed with distal CRC screening can be extrapolated to the proximal colon. However, data are lacking and a pilot study for a trial of the acceptability and efficacy of colonoscopy screening is in progress in the US. It has also been suggested that FOBT testing should be used to detect proximal CRC missed by sigmoidoscopy screening, but the small amount of published data suggest that supplementing FS with FOBT offers very little advantage over FS alone. Other forms of CRC screening are under investigation and represent exciting options for the future. Extraction of DNA from stool is now feasible and a number of research groups have shown high sensitivity for CRC using a panel of DNA markers including mutations in k-ras, APC, p53 and BAT26. Data so far indicate that, with the exception of k-ras, these markers are highly specific and therefore represent a significant improvement over FOBT. Whether these tests will replace or supplement existing methods of screening has yet to be determined. It has been suggested that BAT26, which is a marker of microsatellite instability, a feature of proximal sporadic CRC, might be a useful adjunct to sigmoidoscopy screening. Others have suggested that a test for occult blood should be included with the DNA markers to further increase sensitivity. It is not yet known how sensitive these markers are for adenomas--it is only by detecting adenomas that CRC incidence rates can be reduced. A final exciting new option for screening is virtual colonoscopy (VC), which by screening out people without neoplasia allows colonoscopy to be reserved for patients requiring a therapeutic intervention. The sensitivity of VC for large adenomas and CRC appears to be high, although results vary by centre and there is a steep learning curve. Sensitivity for small adenomas is low, but perhaps it is less essential to find such lesions. Some groups have suggested that virtual colonoscopy might be a useful option for investigating patients who test positive with stool-based screening tests. Whichever CRC screening method is finally chosen (and there is no reason why several methods should not ultimately be available), high quality endoscopy resources will always be required to investigate and treat neoplastic lesions detected.     

Indications for surgery for aortic regurgitation

Aortic valve replacement for isolated aortic regurgitation (AR) is usually not indicated unless the regurgitation is severe. However, not all patients with severe AR require aortic valve replacement. This review focuses on the causes of AR and the pathophysiology of acute versus chronic AR, and the attendant adaptive mechanisms of the left ventricle that ultimately determine their different natural histories. Aortic valve surgery must be performed in a timely manner to prevent cardiac death, ameliorate symptoms, and limit late postoperative excess mortality.