Spanish experience with heart transplants from controlled donation after the circulatory determination of death using thoraco-abdominal normothermic regional perfusion and cold storage

Heart transplantation from controlled donation after the circulatory determination of death (cDCDD) may help to increase the availability of hearts for transplantation. During 2020, four heart transplants were performed at three different Spanish hospitals based on the use of thoraco-abdominal normothermic regional perfusion (TA-NRP) followed by cold storage (CS). All donors were young adults <45 years. The functional warms ischemic time ranged from 8 to 16 minutes. In all cases, the heart recovered sinus rhythm within 1 minute of TA-NRP. TA-NRP was weaned off or decreased <1L within 25 minutes. No recipient required mechanical support after transplantation and all were immediately extubated and discharged home (median hospital stay: 21 days) with an excellent outcome. Four livers, eight kidneys, and two pancreata were also recovered and transplanted. All abdominal grafts recipients experienced an excellent outcome. The use of TA-NRP makes heart transplantation feasible and allows assessing heart function before organ procurement without any negative impact on the preservation of abdominal organs. The use of TA-NRP in cDCDD heart donors in conjunction with cold storage following retrieval can eliminate the need to use ex situ machine perfusion devices, making cDCDD heart transplantation economically possible in other countries.     

高压氧对沙鼠脑缺血时微血管内皮细胞形态及其粘附性的影响

以沙鼠为对象探讨急性脑缺血动物经不同氧压暴露对脑膜微血管内皮细胞形态变化与粘附性的影响。结果显示,脑缺血动物经高压氧治疗后,脑膜微血管内皮细胞轮廓清楚,与白细胞、红细胞、血小板的粘附程度明显减轻。表明高压氧可能具有抑制血细胞与血管内皮细胞粘附作用。实验还观察到,动物在300kPa氧压暴露时脑膜微血管出现节段性痉挛,400kPa氧压下,痉挛程度加重,并可见有内皮细胞裂隙增宽,血管内容物外溢,而在250kPa氧压暴露时则未见此现象。提示在大于300kPa氧压暴露时微血管的这种反应,可能是饥体氧中毒在微循环环节上的征象。     

Vastus medialis muscle oxygenation trends during a simulated 20-km cycle time trial

In this study we examined the oxygenation trend of the vastus medialis muscle during sustained high-intensity exercise. Ten cyclists performed an incremental cycle ergometer test to voluntary exhaustion [mean (SD) maximum oxygen uptake 4.29 (0.63) l·min^–1; relative to body mass 60.8 (2.4) ml·kg^–1·min^–1] and a simulated 20-km time trial (20TT) on a wind-loaded roller system using their own bicycle (group time = 23–31 min) in two separate sessions. Cardiorespiratory responses were monitored using an automated metabolic cart and a wireless heart rate monitor. Tissue absorbency, which was used as an index of muscle oxygenation, was recorded simultaneously from the vastus medialis using near-infrared spectroscopy. Group mean values for oxygen uptake, ventilation, heart rate, respiratory exchange ratio, power output, and rating of perceived exhaustion were significantly (P≤0.05) higher during the incremental test compared to the 20TT [4.29 (0.63) l·min^–1 vs 4.01 (0.55) l·min^–1, 120.4 (26) l·min^–1 vs 97.6 (16.1) l·min^–1, 195 (8) beats·min^–1 vs 177 (9) beats·min^–1, 1.15 (0.06) vs 0.93 (0.06), 330.1 (31) W vs 307.2 (24.5) W, and 19 (1.5) vs 16 (1.7), respectively]. Oxygen uptake and heart rate during the 20TT corresponded to 93.5% and 90.7%, respectively, of the maximal values observed during the incremental test. Comparison of the muscle oxygenation trends between the two tests indicated a significantly greater degree of deoxygenation during the 20TT [–699 (250) mV vs –439 (273) mV; P≤0.05] and a significant delay in the recovery oxygenation from the 20TT. The mismatching of whole-body oxygen uptake and localised tissue oxygenation between the two tests could be due to differences in muscle temperature, pH, localised blood flow and motor unit recruitment patterns between the two tests. Electronic Publication     

某三甲医院ECMO相关医院感染的危险因素研究

 目的 分析体外膜肺氧合（Extracorporeal membrane oxygenation,ECMO）相关医院感染患者的临床特征及危险因素,为ECMO相关医院感染的防控提供理论依据。方法 回顾性分析某院2014年6月—2018年9月行ECMO治疗的患者,按照1∶2配对方法选择未接受ECMO治疗的患者作为对照组（非ECMO组）,比较两组患者基本资料及住院费用。根据是否发生ECMO相关医院感染分为ECMO感染组,未发生医院感染的作为ECMO对照组,比较两组患者临床特征,评估ECMO相关医院感染的危险因素、病死率和医疗费用。结果 共有30例接受ECMO治疗的患者纳入研究,平均年龄（41.9±16.2）岁,76.7%的患者为男性,22例患者行静脉-静脉ECMO模式（venovenous ECMO,VV ECMO）。15例患者出现24例次ECMO相关医院感染,包括12例次血流感染、9例次肺部感染、1例次尿路感染、1例次手术部位感染及1例次胃肠道感染。ECMO感染组的患者ECMO治疗时间更长、气管切开的比例较高、血红蛋白较低。多因素logistic回归分析显示ECMO治疗时间≥10 d是ECMO相关医院感染的独立危险因素。发生ECMO相关医院感染的患者较ECMO对照组,其住院时间延长［（44.5±39.6）d VS （18.4±11.7）d,P=0.021］、医疗费用增加［（413 359.9±204 887.0）元VS （264 925.3±76 079.7）元,P=0.004］。结论 医院感染是ECMO治疗的常见并发症,显著增加医疗费用和住院时间,明确ECMO治疗的适应证,尽快停止呼吸循环辅助可减少ECMO相关感染的发生。     

Extension of the indication for living related liver transplantation from children to adults based on resolution of graft size mismatch in relation to tissue oxygenation and metabolic load: a case report

Abstract  We extended the indication for living related partial liver transplantation from pediatric to adult cases. Our first case was a 49-year-old woman with primary biliary cirrhosis. Her sister's left lobe, weighing 280 g, was employed as a graft, and the graft weight/recipient's body weight ratio was calculated as 0.59 %. To decrease the metabolic load to the relatively small graft, the total bilirubin was decreased from a maximum value of 75.0 mg/dl to the most recent preop-erative value of 36.2 mg/dl by plasma exchange. Intraoperative recovery of tissue oxygenation and its heterogeneity were satisfactory due to a relatively high blood supply. A postoperative decrease in bilirubin and increase in cholesterol esterifi-cation were facilitated, concomitant with regeneration of the graft, which weighed 280 g, to 860 c at 3 weeks. Linear regression analysis with respect to tissue oxygenation and metabolic capacity obtained in pediatric cases were applied to this adult case.     

Effect of pentobarbital anesthesia on regional cerebral metabolic rate for glucose during hyperbaric oxygenation in rat

Hyperbaric oxygenation (HBO) at different pressures and durations of exposure produces an increase in regional cerebral metabolic rate for glucose (rCMRgl) in conscious rats. Pentobarbital anesthesia is known to significantly reduce rCMRgl in rats during air breathing. To test if pentobarbital anesthesia is also effective in reducing HBO-induced increases in rCMRgl, the combined effect of pentobarbital anesthesia and HBO on rCMRgl was autoradiographically measured in 28 neuroanatomical structures. Two groups of rats (11 each) were chronically cannulated in one femoral artery and vein 3 days prior to the experiments. Thirty minutes before the rCMRgl measurements the rats were anesthetized with intravenous injection of 50 mg/kg pentobarbital and exposed to either 1-h air breathing at atmospheric pressure or oxygen at 2 atm absolute. No differences in rCMRgl between oxygen-exposed and air-exposed anesthetized rats were observed in 27 of the 28 neuroanatomical structures examined. The superior olivary nucleus was the only one of the 28 structures showing a significant reduction in rCMRgl following anesthesia and HBO. The possible factors involved in the elimination by anesthesia of the previously observed increases in rCMRgl in conscious rats exposed to HBO are discussed.     

Risk Factor Screening Scale to Optimize Treatment for Potential Heart Transplant Candidates under Extracorporeal Membrane Oxygenation

We developed a risk factor-scaling score (RFSS) to select which patients supported by extracorporeal membrane oxygenation (ECMO) were suitable for ventricular assist device (VAD) implantation or heart transplantation (HTx). A total of 78 patients supported with ECMO for more than 48 h due to cardiac origin were included in this study. Patients were categorized into two groups based on the outcomes: the poor outcome group (n = 33) consisted of for those who later died or were later excluded from VAD or HTx; the favorable outcome group (n = 45) consisted of those who were weaned off ECMO finally and survived or were deemed suitable candidates for VAD or HTx. Seven risk factors were significant according to univariate analyses. Based on the regression coefficients of multivariate analysis, the RFSS was developed: (lung dysfunction x 7) + (systemic infection x 3) + (peak lactate > 3 mmole/L x 3) + (kidney dysfunction x 2) + (creatine kinase > 10,000 U/L x 1). Patients with an RFSS of 7 or more were be allocated to the poor outcome group. The RFSS was validated by another group of 30 patients with good correlation. The RFSS provides a way to predict which ECMO-supported patients are suitable candidates for VAD implantation or HTx.