Autotransfusion after open heart surgery: the oxygen delivery capacity of shed mediastinal blood is maintained

Autotransfusion of mediastinal shed blood after open heart surgery has become a common and accepted procedure in reducing the need for homologous transfusion during the last 15 years. The objectives of the present study were to investigate the oxygen delivery capacity of autotransfused shed mediastinal blood, compared to patient-blood, during cardiopulmonary bypass and in the postoperative period.
Ten consecutive patients undergoing elective cardiac surgery were studied. Mediastinal shed blood was collected in the cardiotomy reservoir and retransfused during the first 18 postoperative hours. The oxygen delivery capacity of the blood to the tissues was calculated by use of the oxygen status algorithm (OSA 2.0) programme and measurement of the 2,3-diphosphoglycerate (2,3-DPG) concentration.
Autotransfusion volume ranged from 450–1530 ml per patient (median 824 ml). Shed blood had a mean haemoglobin level of 8.8 g/dl and 7.4 g/dl at 1 h and 6 h of autotransfusion, respectively. There were no significant changes of 2,3-DPG concentration in the patient-blood during cardiopulmonary bypass or after autotransfusion compared to preoperative values. P50 for oxygen (3.6 and 3.6 kPa) and 2,3-DPG concentrations (5.3 and 5.1 mikromol/ml erythrocyte) in shed mediastinal blood (1h and 6h postoperatively) were not significantly different compared to patient-blood.
The results demonstrate that the oxygen delivery capacity of shed mediastinal blood is maintained and that the oxygen affinity of patient-blood is not influenced by autotransfusion.     

Estimation of average flow in ungated 3D phase contrast angiograms

Three dimensional (3D) phase contrast angiograms contain velocity data, which is discarded after the reconstruction of the projections. In extension to earlier work on velocity quantification with ungated 2D phase data, this paper shows that a useful estimate of the average velocity and flow rate can be extracted from ungated 3D phase contrast angiograms. Simulations and experiments in a phantom and in vivo were performed. For pulsatile flow and strong spin saturation, an over-estimation of the flow rate at the net in-flow end of the imaging volume and underestimation at the net out-flow end was observed. Imaging at lower RF tip angles yielded flow rates close to the correct value within the entire imaging volume. In contrast to ungated 2D experiments, the flow rates determined by repeated 3D experiments showed no variation.     

Central circulation in rats with different tolerance to acute blood loss

Study of the dynamics of cardiac output in rats with different tolerance to acute massive blood loss showed that the pumping ability of the heart remains intact during the entire posthemorrhagic period in all high-resistant and in 65% low-resistant rats. In 35% rats that were low-resistant to blood loss, the cardiac output deficiency syndrome developed after cessation of bleeding against the background fall in arterial pressure and a decrease in the hepatic blood flow, which are the signs of rapid variant of the dysfunction produced by acute blood loss. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 126, No. 10, pp. 384–388, October, 1998     

1例安置埋藏式自动复律除颤器病人的随访

埋藏式自动复律除颤器(AICD)能降低恶性快速室性心律失常患者的猝死发生率,已经得到基本肯定,但其猝死率的降低,在相当程度上取决于能否对置入AICD患者进行认真随访,不断完善其治疗。本文报告1例随访16个月经验,并就随访结果,结合文献,略予讨论。     

~(99m)Tc-甲氧基异丁基异腈首次通过法心室显像评价左心室收缩功能

应用９９ｍＴｃ－甲氧基异丁基异腈（ＭＩＢＩ）对２９例受检者进行首次通过法心室显像，测定左室射血分数（ＬＶＥＦ），并与同期平衡法心室显像测得的ＬＶＥＦ进行相关分析。结果：首次通过法和平衡法心室显像测得的ＬＶＥＦ分别为（４６．５±１６．７）％、（４９．１±１６．１）％（Ｐ＞０．０５）。相关分析结果显示，二者有明显的相关（ｒ＝０．７８７，Ｐ＜０．０１）。结果表明：９９ｍＴｃ－ＭＩＢＩ为心肌显像剂，采用首次通过法心室显像，在观察心肌血流改变的同时，可准确可靠地评价左室收缩功能状态。     

Pregnancy and uncomplicated vaginal delivery only 13 months after cardiac transplantation (case report)

Summary Background Pregnancy is prossible in female patients who underwent cardiac transplantation but is associated with unpredictable risks. Methods A 23-year old female patient underwent cardiac transplantation because of dilatative cardiomyopathy. Results Against our advice, she became pregnant 4 months after transplantation. Following an uneventful pregnancy, spontaneous vaginal delivery occurred 13 months after transplantation. The patient gave birth to a healthy new-born in good physical condition. Thereafter, the patient refused to attend any further routine follow-up control. 9 months after delivery, the patient was admitted to hospital in severe cardiac shock. Biopsy showed a serious, acute rejection which was treated with a course of methylprednisolone. Clinically, the patient recovered within 1 week, but died from acute myocardial infarction 1 day after discharge from hospital. Conclusions Only women without a history of rejection episodes, with good kidney function, good graft function, and high compliance should be counselled to become pregnant.      

Left Ventricular Transvenous Electrode Dislodgement After Mustard Repair for Transposition of the Great Arteries

An 11-year-old girl who underwent Mustard's operation for complete transposition of the great arteries in infancy, developed Mobitz type II second-degree AV block 81/2 years later. A transvenous, active fixation left ventricular lead was inserted and connected to a rate responsive pacemaker. Two years later the lead dislodged due to the child's growth. A new active fixation electrode was positioned in the left ventricle below the pulmonary valve, leaving an electrode loop in the ventricle. Such an approach may prevent lead dislodgement due to growth after intraatrial repair for transposition of the great arteries, but regular radiological or echocardiographic follow-up of lead position is recommended in these patients.     

Validation of impedance cardiography measurements of cardiac output during limited exercise in heart transplant recipients

Abstract. Twenty-one patients were studied at rest and during exercise after heart transplantation to compare cardiac output measured by thermodilution and impedance cardiography. Exercise was performed on a bicycle ergometer over a limited range of work load (25 and 50 watt) whilst metabolic gas exchange was recorded. One patient was studied at rest whilst his circulation was maintained by a Jarvik-7 artificial heart. The values of cardiac output measured by impedance cardiography corresponded closely with the flow rate from the artificial heart. There was also close agreement between the impedance and thermodilution measurements of cardiac output at rest and during exercise. Both measurements followed the changes in heart rate and oxygen consumption. Both thermodilution and impedance cardiography methods elicited good reproducibility of cardiac output measurements at rest and during exercise. These observations suggest that the noninvasive and continuous record of cardiac output obtained by impedance cardiography can be used for the postoperative monitoring of heart transplant recipients.     

兔心肌挫伤心功能障碍与心肌细胞内Ca2+和线粒体ATP酶的变化

目的：探讨心肌细胞内游离钙([Ca^2 ]i)和心肌ATP酶变化在心肌挫伤（MC）后心功能障碍发生机制中的意义。方法：随机选取兔36只，分为6组：正常对照、伤后2、4、8、12、24h，每组6只。经右颈总动脉插管至左心室测左室压力。采用BIM-II型生物撞击机致成MC模型。在上述时相点测定左室压力，并测定心肌细胞内[Ca^2 ]i和心肌匀浆组织及线粒体ATP酶活力。结果：心脏收缩/舒张功能受到损害，心肌细胞内[Ca^2 ]i升高，心肌匀浆组织及线粒体ATP酶下降，相关分析表明心功能障碍与心肌细胞内[Ca^2 ]i含量升高呈明显负相关，与ATP酶活性降低呈明显正相关。结论：MC后心脏功能下降，心肌细胞内[Ca^2 ]i含量升高和ATP酶活性下降可能是其原因之一。     

同种异体胎颅骨结合碱性成纤维细胞生长因子移植治疗骨不连

目的寻找一种治疗骨不连接所需植骨材料,利用碱性成纤维细胞生长因子的活性诱导作用,促进骨修复.方法13例成人骨不连患者,选择4-10个月龄胎颅骨（FCB）作可吸收载体,结合碱性成纤维细胞生长因子（bFGF）制备成复合碱性成纤维细胞生长因子胎颅骨（bFGF/FCB）,植入受骨区,以适当的内固定重新构建骨修复支架.结果所有患者均得到骨性修复,且成骨效应明显.结论胎颅骨作为植骨材料既可以起到植骨作用,增大植骨面,增加骨再生诱发点,屏蔽了骨断面,也避免了自体植骨的手术创伤;碱性成纤维细胞生长因子可以诱导和促进骨修复,二者复合物是治疗骨不连接的一种较好材料.