脑电双频指数用于心脏瓣膜置换术的临床观察

目的:探讨BIS监测用于体外循环(CPB)瓣膜置换手术麻醉,对术中血流动力学、麻醉药和血管活性药用量的影响.方法:择期CPB下行心脏瓣膜置换术患者40例,随机分为BIS指导麻醉组(BIS组)和临床指导麻醉组(对照组).分别于麻醉诱导前(T0)、诱导后(T1)、气管插管后2 min(T2)、锯胸骨后2 min(T3)、CPB前(T4)、停CPB 10 min(T5)及术毕(T6)记录患者的HR、MAP、SpO2、CVP、BIS.统计麻醉药物的用量,术后记录患者苏醒时间、拔管时间、ICU停留时间、术后住院时间,停CPB后及术后血管活性药物多巴胺等的用量.结果:两组患者诱导后各时点心率与诱导前相比均明显降低(P<0.05),两组间差异无统计学意义(P>0.05).与诱导前相比,两组MAP诱导后均有所降低,但BIS组MAP在T1～T5时点明显高于对照组(P<0.05).异丙酚、咪达唑仑和依托咪酯的用量BIS组比对照组明显减少(P<0.05),需要处理的低血压发生率也明显低于对照组.BIS组患者术后苏醒、拔管和ICU停留时间较对照组明显缩短 (P<0.05).BIS组术中术后多巴胺及硝酸甘油的用量少于对照组(P<0.05).结论:CPB下行瓣膜置换术中应用BIS指导的麻醉可减少镇静药物的使用,ICU停留时间的缩短,使麻醉安全性大大增加.     

右美托咪定对CPB瓣膜置换术患者手术前后炎性因子及肝肾功能的影响

目的探讨右美托咪定对体外循环(CPB)瓣膜置换术患者手术前后炎性因子及肝肾功能的影响。方法选取2012年7月至2016年7月该院行CPB瓣膜置换术患者80例,按随机数字表法分为对照组和试验组,试验组患者静脉持续泵入0.6μg/(kg·h)的右美托咪定至术毕,对照组患者给予同体积的生理盐水。检测和对比2组患者术前(T1)、阻断升主动脉前(T2)、转流停止时(T3)、术后1d(T4)、术后2d(T5)、术后3d(T6)6个时间点的血中性粒细胞百分比(N%)、白细胞计数(WBC)和血清肿瘤坏死因子(TNF)-α、IL(白细胞介素)-6、高迁移率族蛋白(HMGB)-1、尿素氮(BUN)、丙氨酸氨基转移酶(ALT)、肌酐(Cr)的水平。结果试验组患者T2~T6的N%、TNF-α、IL-6、BUN、Cr水平均低于对照组,差异有统计学意义(P0.05);试验组患者T1~T6的WBC水平均低于对照组,差异有统计学意义(P0.05);试验组患者T3~T6的HMGB-1水平均低于对照组,差异有统计学意义(P0.05);试验组患者T2、T5的ALT水平均低于对照组,差异有统计学意义(P0.05)。结论右美托咪定能够降低CPB瓣膜置换术引起的炎性反应程度,对肾脏具有保护作用,但对肝脏的保护作用不明显。     

SIRS MODS患者活化血小板与细胞因子关系的研究

目的　研究全身炎症反应综合征 (SIRS)、多器官功能障碍综合征 (MODS)患者活化血小板、细胞因子变化及其两者之间关系。方法　采用流式细胞仪测定SIRS、MODS患者的CD6 2P、CD6 3阳性血小板的百分率 ,采用酶放大化学发光免疫法测定TNF -α、IL - 6、IL - 8、sIL - 2R值 ,同时对两者之间进行相关性分析。结果　SIRS、MODS患者的CD6 2P、CD6 3、TNF -α、IL - 6、IL - 8、sIL - 2R值较正常对照组均明显升高 (P均 <0 0 1) ;MODS组CD6 2P、CD6 3、TNF -α、IL - 6、IL - 8、sIL - 2R值均高于SIRS组 (P <0 0 1或P <0 0 5 ) ;死亡组CD6 2P、CD6 3、TNF -α、IL - 6、IL - 8、sIL - 2R值均高于存活组 (P <0 0 1或P <0 0 5 ) ;相关性分析显示 ,CD6 2P、CD6 3与TNF -α、IL - 6、IL - 8呈正相关 (P <0 0 5 )。结论　SIRS、MODS患者血小板活化明显 ,促炎细胞因子高表达 ,血小板活化与促炎细胞因子高表达正相关 ,两者均与病情、预后有关。     

右美托咪定在肠道手术患者麻醉中的效果及对炎性反应影响

目的评价右美托咪定在肠道手术麻醉中的效果及其对炎性反应的影响。方法选取我院2017年2月—2018年1月择期行肠道手术68例作为研究对象,按照随机数字法分为观察组(n=31)和对照组(n=37)。所有患者均行基础麻醉,观察组麻醉诱导前10 min静脉输注负荷剂量右美托咪定1μg/kg,以0. 4μg/(kg·h)的速度输注至术毕;对照组予等容量0. 9%氯化钠注射液。观察给药前(T0)、泵入右美托咪定10 min后(T1)、手术开始即刻(T2)、手术开始后30 min(T3)和手术结束即刻(T4)时心率(heart rate,HR)、平均动脉压(mean arterial pressure,MAP)、脑电双频指数(bispectral index,BIS)、白细胞介素(interleukin,IL)-6、IL-8、IL-10、肿瘤坏死因子(tumor necrosis factor,TNF)-α、C-反应蛋白(C reactive protein,CRP)及CD11b水平变化,记录术后呼吸恢复时间、拔管时间和术后躁动发生情况。结果与本组T0比较,观察组T1时HR、T1～T4时BIS下降,对照组T2～T4时HR、MAP升高且BIS下降,两组T2～T4时IL-6、IL-8、IL-10、TNF-α、CRP和CD11b水平均升高,差异有统计学意义(P 0. 05);与对照组比较,观察组T1～T4时HR、T2～T4时MAP、IL-6、IL-8、TNF-α、CRP和CD11b及T1时BIS均降低,T2～T4时IL-10水平升高,差异有统计学意义(P 0. 05)。观察组术后呼吸恢复时间、拔管时间明显短于对照组,术后躁动发生率显著低于对照组,差异均有统计学意义(P 0. 05)。结论麻醉诱导前输注右美托咪定可以稳定肠道手术患者术中血流动力学,有利于术后苏醒,减少术后躁动,抑制机体炎性反应。     

体外循环下心内直视手术前后细胞因子水平观察

目的：观察体外循环下心内直视手术前后细胞因子TNF－α、IL－6、IL－8浓度变化。方法，选择拟在CPB下行心内直视手术病人16例，病人全麻后经桡动脉测压管抽血5ml／次，时间分别为全麻后及转机开始后2h,5h,8h及20h。用双抗体夹心酶联放射免疫吸附法测定TNF－α、IL－6及IL－8含量。结果：转机开始2h下，TNF－α、IL－6及IL－8含量即开始升高，并分别于转机开始后2h,5h,8h达到高峰，术后20h仍高于正常，统计学分析显示各时间点间比较与有显著性差异（P＜0．05）。结论：细胞因子是CPB期间全身炎性反应的重要介质，标志着全身炎性反应的程度，可和为防治CPB术后全身炎性反应综合征的重要指标。     

盐酸戊乙奎醚对冠状动脉旁路移植术患者体外循环前、后白介素及肿瘤坏死因子的影响

目的:观察盐酸戊乙奎醚对体外循环冠状动脉旁路移植术患者血浆炎性因子的影响。方法:选择择期体外循环下冠状动脉旁路移植术患者40例,随机分为盐酸戊乙奎醚组20例(A组)和对照组20例(B组)。A组于体外循环前10min静脉注射盐酸戊乙奎醚3mg,对照组给予等量生理盐水。测定血浆肿瘤坏死因子-α、白细胞介素-6、和白细胞介素-10浓度。结果:组内比较B组肿瘤坏死因子-α浓度于体外循环后3h高于麻醉诱导前(P<0.01),而A组体外循环30min、主动脉开放后l0min肿瘤坏死因子-α浓度较麻醉诱导前明显降低,其余时点与术前比较无明显变化。B组白细胞介素-6于体外循环后24h高于A组(P<0.05),白细胞介素-10浓度明显低于A组。2组间比较,B组坏死因子-α浓度于体外循环30min,24h各时点均高于A组(P<0.05)。结论:盐酸戊乙奎醚可部分抑制体外循环导致的炎性反应,对体外循环术后全身炎性反应综合征有一定的预防作用。     

氨茶碱对心肌的保护作用

目的探讨氨茶碱在体外循环(CPB)心脏瓣膜置换术中的心肌保护作用及其可能机制。方法将择期行心脏瓣膜置换术的30例风湿性心脏瓣膜病患者随机分为氨茶碱组和对照组,每组各15例。氨茶碱组麻醉诱导后静脉滴注氨茶碱(5 mg/kg)。分别测定CPB转流前及术后不同时期血浆肌钙蛋白Ⅰ(cTnI)、心肌环磷酸腺苷(cAMP)和髓过氧化物酶(MPO)以及主动脉血/冠状静脉窦血中性粒细胞(PMN)比值等;同时观察血流动力学等临床指标。结果两组患者各临床指标差异均无统计学意义;升主动脉开放后两组cTnI均比CPB前升高,但氨茶碱组显著低于对照组;升主动脉开放后30 min,两组cAMP均降低,但氨茶碱组心肌cAMP含量显著高于对照组,MPO活性及主动脉血,冠状静脉窦血PMN比值显著低于对照组。结论在CPB心脏瓣膜置换术中,氨茶碱具有一定的心肌保护作用;其机制可能与升高心肌cAMP、抑制白细胞对心肌组织的浸润有关。     

血浆MMP-9与体外循环炎性反应相关性研究

目的 :探讨体外循环 (CPB)围术期血浆基质金属蛋白酶 9(MMP 9)和细胞因子之间的关系。方法 :选择 3 0例接受CPB的病人 ,分别在CPB开始前、开始后 3 0min、结束时、结束后 2h采集血标本 ,采用酶联免疫吸附分析方法检测血浆MMP 9和TNF α、IL 8、IL 6的浓度。结果 :(1)血浆MMP 9和TNF α、IL 8的浓度在CPB期间呈逐渐升高 ,在CPB结束时达到最高峰值 ,之后呈下降趋势 ,IL 6在CPB结束后仍继续升高。 (2 )围CPB期血浆MMP 9与TNF α、IL 8、IL 6之间均呈明显的正相关性。结论 :CPB期间血浆MMP 9、TNF α、IL 8、IL 6释放均明显增加 ,除IL 6外在CPB结束时达到最高峰值 ,围CPB期细胞因子可以诱导MMP 9的激活和释放 ,同时MMP 9可以通过对细胞因子的正反馈作用而参与CPB过程的炎症反应。     

地氟醚预处理对体外循环术后早期循环黏附分子和脂质过氧化影响

目的：研究地氟醚预处理对心肺旁路术后早期心肌缺血再灌注损伤的保护作用及可能机制。方法：30例行二尖瓣及主动脉瓣双瓣替换术的患者，随机分为对照组和实验组。对照组不用吸入麻醉药，地氟醚预处理组在气管插管后至体外循环转流前吸入地氟醚，使地氟醚呼气末浓度达到1MAC左右，累积维持时间不少于30min。分别于主动脉阻断前、开放后30min及1h抽取抗凝动脉血，测定PMN表面CD11b的表达、血浆sICAM-1浓度、MDA、SOD浓度。结果：（1）主动脉阻断前，组间比较血浆sICAM-1浓度无显著差异（P〉0．05），开放后30min、60min血浆sICAM-1浓度较主动脉阻断前明显降低（P〈0．05），组间比较各时间点无显著差异（P〉0．05）。（2）主动脉阻断前，组间比较PMN表面CD11b的表达无显著差异（P〉0．05），但地氟醚预处理组开放后30min、60minCD11b的表达较主动脉阻断前明显升高（P〈0．05），PMN表面CD11b的表达较对照组有降低趋势，主动脉开放后30min地氟醚预处理组CD11b的表达明显降低（P〈0．05）。（3）体外循环前，组间比较血浆SOD、MDA浓度无显著差异（P〉0．05），体外循环主动脉开放后30min、60min，MDA的血浆浓度较主动脉阻断前明显升高（P〈0．05），SOD较主动脉阻断前明显降低（P〈0．05）。地氟醚预处理组，体外循环主动脉开放后各时间点，SOD有升高趋势；MDA较对照组明显降低（P〈0．05）。结论：地氟醚预处理可降低心肺旁路术后早期MDA的释放，增加SOD活性的趋势，与再灌注早期地氟醚预处理可降低PMN表面CD11b有关，地氟醚预处理在心肺旁路术后早期对心肌细胞有保护作用，与内皮细胞粘附分子表达无关系。     

体外循环心内直视术对中性粒细胞CD_(11b)表达的影响

观察体外循环 (CPB)心内直视术对中性粒细胞整合素(CD1 1 b)表达的影响 ,以期明确体外循环所致炎性反应的机理。1　对象和方法1 .1　对象　双瓣膜替换术 1 6例 ,术前心功能 ～ 级 ,肝、肾功能及出凝血功能无异常。男 1 0例 ,女 6例 ;年龄 35.4岁±1 2 .2岁 ;体重 58.6kg± 9.6kg;手术时间 2 65.9min± 1 2 1 .5min;阻断升主动脉时间 96.2 min± 33.5min;体外循环时间 1 56.2 min± 93.5min。1 .2　方法　麻醉采用静脉芬太尼、维库溴铵加间断吸入 1 %～3%安氟醚。 CPB使用 Sarn's80 0型人工体外循环机 ,带有动脉端过滤器的中空纤维膜氧…     

Determination of creatine kinase isoenzyme MB activity in serum using immunological inhibition of creatine kinase M subunit activity. Activity kinetics and diagnostic significance in myocardial infarction.

This is a new method for the determination of creatine kinase isoenzyme MB activity in serum. The method uses direct activity measurement of creatine kinase B subunit activity after blocking of CK-M subunit activity by inhibiting antibodies. The test takes no longer than 15 min. The method yields an intra-serial C.V. of 2.0-12.9%, and a C.V. from day to day of 5.5%. The detection limit is 3.4 U/l creatine kinase MB. In the 95 cases with proven myocardial infarction several types of creatine kinase MB activity kinetics could be determined. The percentage of creatine kinase MB of peak CK-total is 6-25%, with a mean of 11.1%. The amount of creatine kinase MB with respect to total CK activity after reinfarction is higher than the amount after initial infarction.     

俯卧位通气对高海拔地区肺复张治疗无效急性呼吸窘迫综合征患者氧合的影响

目的 探讨俯卧位通气对高海拔地区肺复张术(RM)治疗无效急性呼吸窘迫综合征(ARDS)患者的治疗作用.方法 从海拔2260m的地区医院筛选RM治疗无效的41例ARDS患者[平均氧合指数( PaO2/FiO2)较RM前升高＜20％视为RM无效],依不同病因分为肺内源性ARDS组(ARDSp组)和肺外源性ARDS组(ARDSexp组),每组再按信封法随机分为俯卧位组和仰卧位组,即ARDSp俯卧位组(11例)、ARDSp仰卧位组(9例)、ARDSexp俯卧位组(10例)、ARDSexp仰卧位组(11例).在通气前及通气1、2、3、4h监测动脉血氧分压( PaO2)、PaO2/FiO2、静态顺应性(Cst)、气道阻力(Raw)的变化.结果 通气lh时,ARDSexp俯卧位组PaO2/FiO2( mm Hg,l mm Hg=0.133 kPa)即较通气前显著升高(157.4±40.6比129.3±48.7,P＜0.05),并随通气时间延长呈持续增高趋势,4h达峰值(219.1 ±41.1);且ARDSexp俯卧位组通气3h内PaO2/FiO2较其他3组显著增高,另3组间则差异无统计学意义.ARDSp俯卧位组、ARDSexp俯卧位组通气4h时PaO2/FiO2均较相应仰卧位组显著增高(208.8±39.7比127.4±47.1,219.1±41.1比124.9±50.8,均P＜0.05).4组通气前后Cst无显著改变,各组间差异也无统计学意义.ARDSp俯卧位组通气4h时Raw(cmH2O·L-1·s-1)较通气前显著降低(6.8±1.7比10.7±1.8,P＜0.05),且明显低于其他3组;其他3组各时间点Raw组内及组间比较差异均无统计学意义.结论 俯卧位通气作为ARDS机械通气重要策略之一,可以改善RM无效高原ARDS患者的氧合,为抢救患者赢得宝贵的时间.     

Digital imaging among medical facilities

The Department of Veterans Affairs (VA) in the USA operates a network of 172 medical centres which all utilize a hospital information system (HIS) which has been developed and is currently maintained by the VA. During the past several years, an image management and communication module has been developed, installed and clinically utilized at the Washington DC and Maryland VA Medical Centres. This image management and communication system, referred to as the decentralized hospital computer program (DHCP) imaging system, is fully integrated with a commercial picture archiving and communication system (PACS). The system is utilized to capture, archive, and display all images generated within the hospital including radiology, nuclear medicine, pathology, endoscopy, bronchoscopy, and dermatology, intraoperative photographs, ECG data, and a limited number of paper documents. The ultimate goal of the project is to have all patient text and image data available at any clinical workstation to any authorized user anywhere within the network of medical centres. Clinical requirements for an imaging workstation include ease of use, rapid and reliable access to the complete set of patient information, and images which are of acceptable quality to meet the requirements of the user and the subspecialty. Patient confidentiality and data security must be safeguarded at all times. Integration of the images with the remainder of the patient's database was found to be critical to the success of the project. The experience at the Washington and Maryland facilities suggests that an imaging system that is successfully integrated with a hospital information system can provide substantial clinical and economic benefits both within and among medical centres. Clinical acceptance and utilization of the system has been excellent, particularly in diagnostic radiology where DHCP Imaging has been interfaced to a commercial PAC system. Based upon this initial experience, the VA has begun to deploy the system throughout its large network of medical centres.     

Myocardial elastography at both high temporal and spatial resolution for the detection of infarcts

Myocardial elastography is a novel method for noninvasively assessing regional myocardial function, with the advantages of high spatial and temporal resolution and high signal-to-noise ratio (SNR). In this paper, in-vivo experiments were performed in anesthetized normal and infarcted mice (one day after left anterior descending coronary artery [LAD] ligation) using a high-resolution (30 MHz) ultrasound system (Vevo 770, VisualSonics Inc., Toronto, ON, Canada). Radiofrequency (RF) signals of the left ventricle (LV) in longitudinal (long-axis) view and the associated electrocardiogram (ECG) were simultaneously acquired. Using a retrospective ECG gating technique, 2-D full field-of-view RF frames were acquired at an extremely high frame rate (8 kHz) that resulted in high-quality incremental displacement and strain estimation of the myocardium. The incremental results were further accumulated to obtain the cumulative displacements and strains. Two-dimensional and M-mode displacement images and strain images (elastograms), as well as displacement and strain profiles as a function of time, were compared between normal and infarcted mice. Incremental results clearly depicted cardiac events including LV contraction, LV relaxation and isovolumetric phases in both normal and infarcted mice, and also evidently indicated reduced motion and deformation in the infarcted myocardium. The elastograms indicated that the infarcted regions underwent thinning during systole rather than thickening, as in the normal case. The cumulative elastograms were found to have higher elastographic SNR (SNR(e)) than the incremental elastograms (e.g., 10.6 vs. 4.7 in a normal myocardium, and 6.0 vs. 2.4 in an infarcted myocardium). Finally, preliminary statistical results from nine normal (m = 9) and seven infarcted (n = 7) mice indicated the capability of the cumulative strain in differentiating infracted from normal myocardia. In conclusion, myocardial elastography could provide regional strain information at simultaneously high temporal (>/=0.125 ms) and spatial ( approximately 55 microm) resolution as well as high precision ( approximately 0.05 microm displacement). This technique was thus capable of accurately characterizing normal myocardial function throughout an entire cardiac cycle, at the same high resolution, and detecting and localizing myocardial infarction in vivo.     

Clinical Pharmacokinetics of Morphine

Morphine, the most widely used mu-opioid analgesic for acute and chronic pain, is the standard against which new analgesics are measured. A thorough understanding of the pharmacokinetics of morphine is required in order to safely and effectively use this analgesic in a wide variety of patients with different levels of organ function. A MEDLINE search was conducted to identify literature published between 1966 and January 2002 relevant to the pharmacokinetics of morphine. These publications were reviewed and the literature summarized regarding unique and clinically important elements of morphine disposition relative to its parenteral administration (including intravenous, intramuscular, subcutaneous, epidural and intrathecal administration), absorption profile (immediate release, controlled release, and sublingual/buccal, and rectal administration), distribution, and its metabolism/ excretion. Special populations, including infants, elderly, and those with renal/liver failure, have a unique morphine pharmacokinetic profile that must be taken into account in order to maximize analgesic efficacy and reduce the risk of adverse events.     

手转胎头术失败的原因与分娩结局临床分析

目的 探讨手转胎头术失败的原因与分娩结局.方法 选择2008年1月至2010年12月于我院住院分娩的持续性枕横位、枕后位产妇198例,根据行手转胎头术后结果分为成功组126例、失败组72例.比较两组分娩结局,对比分析失败原因.结果 失败组胎儿体质量≥3500 g的发生率[76.4％(55/72)]明显高于成功组[31.7％(40/126)],差异有统计学意义(x2=30.177,P=0.001)、失败组宫缩乏力发生率[58.3％(42/72)]高于成功组[38.1％ (48/126)],差异有统计学意义(x2=7.569,P=0.006)、失败组骨盆临界或轻度狭窄发生率[38.9％ (28/72)]高于成功组[23.8％(30/126)],差异有统计学意义(x2 =5.030,P=0.002)、失败组手转胎头时机不当(宫口开大＜6 cm、胎头位于坐骨棘上及宫口开大8～10 cm、胎头位于坐骨棘下≥2 cm)发生率[61.1％(44/72)]高于成功组[38.9％(49/126)],差异有统计学意义(x2=9.084,P=0.003).失败组母儿并发症(产后出血、产褥病率、胎儿窘迫、新生儿窒息)发生率高于成功组(x2 =9.586,P=0.002、x2=9.334,P=0.002、x2=5.910,P=0.015、x2=5.240,P=0.022)、失败组剖宫产发生率[72.2％(52/72)]明显高于成功组[34.1 ％(43/126),x2=26.641,P=0.001)].结论 手转胎头术能使难产变顺产,降低剖宫产率,减少母儿并发症,但须积极预防、处理导致手转胎头术失败的原因,对矫正失败后继续矫正及试产应慎重.     

Evidence-Based Pain Management and Palliative Care in Issue Four for 2009 of The Cochrane Library

ABSTRACT

The Cochrane Library of Systematic Reviews is published quarterly. Issue 4 for 2009 contains 4027 complete reviews, 1906 protocols for reviews in production, and 11447 one-page summaries of systematic reviews published in the general medical literature. In addition, there are citations of 600,000 randomized controlled trials, and 12,200 cited papers in the Cochrane methodology register. The health technology assessment database contains over 7500 citations. This edition of the Library contains 90 new reviews, of which 19 have potential relevance for practitioners in pain and palliative medicine.     

Wie zuverlässig sind Angaben zu nichtentzündlichen ausgedehnten Schmerzen?

ZusammenfassungFragestellung Es wurde geprüft, wie sich der Differenziertheitsgrad zweier Schmerzmessmethoden auf Angaben zur Ausgedehntheit klinischer Schmerzen auswirkt. Zugleich wurde der Referenzzeitraum variiert, über den die Patienten berichten sollten.Methode Erfasst wurde der Einfluss zu Lasten der Befragungsdifferenziertheit durch den Vergleich zweier Körperschema-Bildvorlagen. Drei Referenzzeiträume (Schmerz aktuell, letzte Woche, letztes halbes Jahr) wurden vorgegeben.Ergebnisse Patienten mit ausgedehnten Schmerzen gaben bei differenzierter Befragung um so mehr Schmerzen an, je weiter die Schmerzen zurück lagen und je größer der Berichtszeitraum war. Patienten mit gelenknahen Schmerzen gaben bei hoch differenzierter Befragung weniger ausgedehnte Schmerzen in der Vergangenheit an als bei globaler Einschätzung. Patienten mit Rückenschmerzen berichteten bei differenzierter Befragung zum aktuellen Schmerz über weniger ausgedehnte Schmerzen als bei globaler Befragung.Schlussfolgerung Die Angaben zur Schmerzausdehnung variieren vor allem bei Patienten mit ausgedehnten Schmerzen in Abhängigkeit von der Differenziertheit der Befragung. In diesen Fällen ist die Wahrscheinlichkeit erhöht, dass sich die Beschwerdesymptomatik zumindest teilweise erst in der Reaktion auf die situativen Befragungsbedingungen konstituiert und daher nicht auf andere Befragungsbedingungen generalisiert werden kann.