Spontaneous arterial baroreflex control of the heart rate during head-down tilt in heat-stressed humans

The purpose of this study was to elucidate the effect of raised body temperature per se during acute heat stress on the spontaneous arterial baroreflex control of heart rate (f _c) in humans. To investigate whether unloading of cardiopulmonary baroreceptors during whole-body heating would alter the arterial baroreflex control of f _c, we controlled loading of the cardiopulmonary baroreceptors by head-down tilt (HDT) at angles of 5°, 10°, 15°, and 30° during heat stress produced by hot-water-perfused suits. The sensitivity of the arterial baroreceptor-cardiac reflex was calculated from the spontaneous changes in beat-to-beat arterial pressure and f _c. As an index of cardiopulmonary baroreceptor loading, the left atrial diameter (LAD) was measured by echocardiography. During whole-body heating, the LAD decreased with the rising body core temperature and increased with the HDT. The decreased LAD during heating almost recovered to the normothermic control level by 10° HDT. In the supine position, cardiac baroreflex sensitivity remained unchanged during heating. Arterial pressure, f _c and cardiac baroreflex sensitivity were not changed by HDT ranging from 5° to 30° during heating. These results suggest that cardiac baroreflex sensitivity remain unchanged during graded loading of the cardiopulmonary baroreceptors in heat-stressed humans. Also, we conclude that the sensitivity of the spontaneous arterial baroreflex controlling the f _c is not influenced by raised body temperature per se during acute heat stress. Electronic Publication     

血液回收对非体外循环冠状动脉旁路移植患者红细胞和血液粘度的影响

目的观察血液回收技术对非体外循环冠状动脉旁路移植患者红细胞、血小板和血液粘度的影响。方法2005年8月~2007年10月间,共完成46例非体外循环冠状动脉旁路移植术,随机分为实验组(血液回收组)和对照组(不使用血液回收机组),每组23例。观察两组用血液制品的数量和术后24h的引流量,比较两组术前和术后24h的红细胞计数、血红蛋白、红细胞压积、血小板计数、低切全血粘度和高切全血粘度。结果实验组用浓缩红细胞和血浆的量明显少于对照组,两组术后24h引流量、术前和术后24h的红细胞计数、血红蛋白、红细胞压积、血小板计数、低切全血粘度和高切全血粘度之间的差异无显著性意义。结论血液回收技术在非体外循环冠状动脉旁路移植患者中能减少输血,对红细胞、血小板和血液粘度无不利影响。     

Regional left ventricular function in the three main coronary artery territories at rest and during exercise

Summary Twenty consecutive patients (mean age 51.6 years) with persistent severe angina pectoris underwent aorto-coronary bypass surgery receiving an overall of 60 anastomosis. On an average, 9.4±1.5 months p.o. first pass radionuclide ventriculograms (18 to 24 mCi 99 m Technetium-Pertechnetate i.v.) were performed at rest and after excerise. Besides measurement of global ejection fraction (GEF), regional ejection fraction (REF) was assessed employing for the first time a new technique: each RAO-view of p.o. radionuclide left ventriculogram was subdivided into three regions according to supply of the three main coronary arteries and their branches as visualized on pre-operative coronary angiogram.GEF improved after maximum exercise in 13 cases by 8.1% points (from 50.4 to 58.5%), remained unchanged three times and decreased four times by 7.1 points (from 51.6 to 44.5%; all changesp<0.05).In completely revascularized regions (n=35) REF improved 24 times by 9.7 points (from 51.1 to 60.8%), did not differ from rest REF six times and decreased in three case by 7.3 points (from 48.6 to 41.3%; all changesp<0.05). Completely revascularized regions responded to exercise like normally perfused areas (increase 7.8 points (from 50.6 to 58.4%;n=7;p<0.05).REF deteriorated in incompletely revascularized regions (n=9) six times by 12.8 points (from 58.0 to 45.2%), remained unchanged twice and improved once by 4.5 points. Total group's REF decreased by 7.3 points (from 56.8 to 49.5%;p<0.05). Exercise REF of incompletely revascularized regions was highly significant inferior to that of completely revascularized regions (49.5 to 58.4%;p<0.01).GEF is a weighted balance of the three regional ejection fractions. The most important parameter is REF of LAD territory.     

深低温体外循环对犬趾蹼微循环指标的研究

本研究表明,深低温体外循环时,犬趾蹼微循环发生的变化与温度有关。平均动脉压(MAP)的变化不能反映组织灌注的优劣情况。毛细血管内的血流速度与灌注流量的高低有关。     

人TFPI基因转染对兔移植静脉血栓形成和近期通畅率的影响

目的： 为减少冠状动脉旁路移植术后血栓形成，探讨人组织因子途径抑制因子(TFPI)基因转染对兔移植静脉血栓生成的影响。方法：构建真核表达质粒pCMV-(Kozak)TFPI。采用阳离子脂质体和腔内加压灌注法，转染移植静脉内皮细胞。RT-PCR、Western blotting和免疫组化法检测外源基因在兔移植静脉中的表达。病理标本、扫描电镜观察移植静脉血栓形成情况，血管多普勒观测其通畅率。结果：移植静脉中有人TFPI基因和蛋白表达。静脉移植术后3 d，基因转染组、空载体和空白对照组分别有1条、8条和7条移植静脉发生血栓，术后30 d，以上各组分别有0条、5条和5条移植静脉完全闭塞，前者静脉血栓发生率和闭塞率均低于后两者(P<0.05)。扫描电镜显示两对照组内皮表面有红细胞和血小板黏附、聚集，而转染组基本正常。结论：人TFPI基因干预，减少了兔移植静脉血栓形成，提高了近期通畅率。     

不同类型心脏患者心内直视手术期间呼气末CO2分压与动脉血CO2分压及其差值的变化

目的探讨不同类型心脏患者心内直视手术期间呼气末二氧化碳分压（PETCO2）与动脉血二氧化碳分压（PaCO2）的相关性及二者差值[P（a-ET）、CO2]的临床意义。方法45例患者分成3组，每组15例。A组：左向右分流组；B组：无分流组；C组：右向左分流组。3组分别于术前（T0）、插管后15min（T1）、手术开始时（T2）、转流前（T3）、转流停止后15min（T4）、术毕时（T5）共6个时点，用旁气流法监测PETCO2，同时抽动脉血测定PaCO2，应用直线回归分析3组各时点PETCO2与PaCO2的相关性，同时计算并分析各组不同时点的P（a-ET）CO2。结果（1）A组、B组各时点PETCO2与PaCO2呈正相关，A组r为0．70—0．85（P〈0．01），B组r为0．71—0．79（P〈0．01）；C组麻醉开始至转停后PETCO2与PaCO2均无相关（0．46—0．54，P〉0．05），而到术毕时则呈正相关（r=0．66，P〈0．05）。（2）3组患者转流前的P（a-ET）CO2变化不大，停转流后A组、B组P[a-ET）CO2增加，其中以A组增加较明显（P〈0．01），而C组P（a-ET）CO2显著减少（P〈0．05）。结论无分流或左向右分流心脏患者在体外循环转流前后PETCO2与PaCO2的相关性较好；右向左分流心脏患者转流前的相关性较差，心内畸形纠正后其相关性可发生变化。P（a-ET）CO2在不同的心脏患者之间差异较大，必须与PaCO2相结合，才能正确指导临床。     

桡动脉在冠状动脉旁路术中的应用解剖学研究

目的：为应用桡动脉作冠状动脉旁路术(coronary artery bypass grafting，CABG)的动脉桥提供解剖学依据。方法：观测了35具成人尸体的两侧桡动脉长度、外径、毗邻结构和可用于CABG的长度和外径。结果：桡动脉总长度为20．87cm，可用于CABG的长度为19．99cm；桡动脉上端外径为3．18mm，可用于CABG的桡动脉上端、中点、下端外径分别是2．66mm、2．28mm、2．29mm。结论：桡动脉有足够的长度和与冠状动脉相匹配的外径，可作为CABG的动脉桥。     

桡动脉解剖及获取技术在冠状动脉搭桥手术中的应用

目的：探讨冠状动脉搭桥术中桡动脉的获取技术方法及应用效果。方法：回顾性总结72例冠状动脉搭桥手术中取桡动脉的经验，介绍获取桡动脉的技术方法和体会。结果：在使用桡动脉获取技术的患者中，3例出现手术切口及手背皮肤术后短时间内麻木，其他患者无前臂感觉及活动障碍，无前臂缺血并发症。结论：当术前评价证实手部桡动脉供血区域有足够的侧枝循环时，桡动脉是最好的搭桥血管之一.     

Why did persons invited to train in cardiopulmonary resuscitation not do so?

All citizens (N = 22066) aged 16 to 65 of a medium-sized Belgiantown were personally invited to CPR training sessions held intheir neighbourhood. 1152 responded by attending a trainingsession. Those who did not so respond were surveyed (randomsample N=600) for reasons of their not coming. The sample fittedwell with census data for gender, age and suburb location butnot for job, because retired persons and women at home wereover represented. 123 persons did not want to answer the questions. 116 personssaid they were already trained in CPR, 276 said they would accepton a future occasion and 82 said they would not. Three personsdid not answer this question. There was no discrimination for job, gender and suburb locationbetween those who did and did not accept a future training opportunity,nor was the existence of a heart patient among relatives. Theolder the person, the less inclined was that person to participatein CPR training (age effect x² = 17.17, d.f. = 9, P<0.05).The 276 who accepted future training, chose their workplace(221) and/or their social meeting place (club etc.) as the placewhere this future training should be held. We suggest that CPR training is well accepted and that the trainingopportunities should be given at places of work and social gatherings.     

Endobronchiale Applikation von Adrenalin in der kardiopulmonalen Reanimation Pharmakokinetische und -dynamische Untersuchungen beim Hund

Zusammenfassung Das Ziel der vorliegenden Untersuchungen bestand darin, das pharmakokinetische Profil von Adrenalin bei endobronchialer (e.b.) und intravenöser (i.v.) Applikation zu erarbeiten und die gemessenen Adrenalin-Plasmaspiegel mit hämodynamischen Messungen zu korrelieren. Die e.b. Applikation von 100 g/kg Adrenalin erwies sich als ebenso effektiv, wie die i.v.-Gabe von 10 g/kg. Dabei war der Wirkungseintritt der e.b.-Gabe von Adrenalin nur geringfügig um einige Sekunden verzögert. Die Bioverfügbarkeit für e.b. verabreichtes Adrenalin lag zwischen 80 und 85%. Der therapeutische Effekt blieb nach e.b.-Applikation von 100 g/kg Adrenalin wesentlich länger erhalten (ca. 30 min) als nach i.v.-Gabe von 10 g/kg (ca. 3–5 min). Aus den Ergebnissen wird geschlossen, daß die tiefe endobronchiale Instillation von 2–3 mg Adrenalin (verdünnt in 5–10 ml Kochsalzlösung) als alternative Dosierungstechnik bei klinischen Reanimationen betrachtet werden kann.

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Pharmacokinetics and -dynamics of epinephrine administered endobronchially

Summary The present animal study was designed to investigate the pharmacokinetic behavior of epinephrine after endobronchial (e.b.) and intravenous (i.v.) administration and its correlation to pharmacodynamic measurements. We found the effectiveness of e.b.-epinephrine (100 g/kg BW) to be in the same magnitude as i.v.-epinephrine (100 g/kg BW) with only a slight delay in the pharmacodynamic onset of a few seconds. The bioavailability of e.b.-administration of epinephrine was in the range of 80–85%. The therapeutic effect of e.b.-epinephrine (100 pg/kg BW) lasted much longer (30 min) when compared to i.v.-epinephrine (10 g/kg BW) where the pharmacodynamic effect was terminated after 3 to 5 min. For the clinical situation of cardiopulmonary resuscitation a dose of 2–3 mg epinephrine in 5–10 ml of physiological saline instilled deeply into the bronchial system should be considered as alternative administration technique with fast onset and good effectiveness.

Herrn Prof. Dr. Dr. h.c. F. Stelzner zum 65. Geburtstag gewidmet