潮气末二氧化碳分压评价心跳骤停患者心肺复苏的预后

目的探讨潮气末二氧化碳分压(PetCO2)预测急诊科心跳骤停患者心肺复苏(CPR)结果的临床意义。方法入选北京大学第一医院急诊科发生心跳骤停并符合入选标准的患者,按照标准的2005年国际CPR指南给予患者CPR,连续测定PetCO2。选取复苏即刻(0min、5min、10min、20min)的测定值,依据复苏20min是否达到自主循环恢复分为初始复苏成功组和失败组作统计学分析。结果初始复苏成功组和失败组复苏即刻PetCO2水平差异无统计学意义(P<0.05)。两组患者PetCO2水平在其他3个时间点比较差异有统计学意义(P<0.01)。ACLS20min时PetCO2≤10mmHg预测复苏失败:敏感性,特异性,阳性预测值和阴性预测值均为100%。结论ETCO2水平与心跳骤停患者心肺复苏的预后相关,标准高级生命支持(ACLS)后20minETCO2水平不超过10mmHg可能能够提示救助者停止进一步复苏努力。     

Electrophysiological and functional effects of shock waves on the sciatic nerve of rats

Extracorporeal shockwave therapy (ESWT) has been applied in lithotripsy and treatments of musculoskeletal disorders over the past decade, but its effects on peripheral nerves remain unclear. This study investigated the short-term effects of shockwaves on the sciatic nerve of rats. The nerves were surgically exposed and then stimulated with shockwaves at three intensities. We evaluated the motor nerve conduction velocity (MNCV) of treated sciatic nerves before, immediately after (day 0) and at 1, 4, 7 and 14 d after shockwave treatment. Two functional tests-the sciatic functional index and the withdrawal reflex latency-were evaluated before and at 1, 4, 7 and 14 d after shockwave application. The rats were sacrificed on days 0, 1, 4, 7 and 14 for morphologic observation. The degassed treatment group received high-intensity shockwave treatment using degassed normal saline as the contact medium, and MNCV was measured before and on days 0, 1, 4, 7 and 14. The sham group received the same procedure as the treatment groups (i.e., the surgical operation to expose the sciatic nerve) but with no shockwave treatment. The control group received no surgical operation or shockwave treatment. The results showed moderate decrease in the MNCV after shockwave treatment and damage to the myelin sheath of large-diameter myelinated fibers. The effect was largest (reduction to 60.9% of baseline MNCV) and of longest duration (7 to 14 d) in the high-intensity group. There were no significant changes in functional tests. These results indicated that direct application of shockwaves can induce reversible segmental demyelination in large-diameter fibers, with the electrophysiological changes being positively correlated with the intensity of the shockwaves.     

Shock waves activate in vitro cultured progenitors and precursors of cardiac cell lineages from the human heart

Postischemic cardiomyopathy remains one of the disorders in urgent need of effective noninvasive therapy. It is currently accepted that the isolation, expansion and application of resident cardiac stem cells may hold therapeutic promise for the future. Recently, it has been demonstrated that shock waves (SW) could enhance the expression of vascular endothelial growth factor (VEGF) and its receptor, Flt-1. As the development of angiogenic noninvasive therapy is very important for future therapeutic strategies in cardiovascular diseases, we examined in vitro, the effects of SW treatment on adult resident cardiac primitive cells isolated from bioptic fragments of normal human hearts and from explanted pathologic hearts with postischemic cardiomyopathy. This study demonstrates that SW have positive influence on both the proliferation and the differentiation of cardiomyocytes, smooth muscle and endothelial cells precursors, with a more obvious effect being evident in the cells from normal heart than in those taken from pathologic hearts. Our results suggest that SW treatment could inhibit or retard the pathologic remodeling and functional degradation of the heart if applied during the early stages of heart failure.     

Doppler estimation of reduced coronary flow reserve in mice with pressure overload cardiac hypertrophy

Aortic banding produces pressure overload cardiac hypertrophy in mice, leading to decompensated heart failure in four to eight weeks, but the effects on coronary blood flow velocity and reserve are unknown. To determine whether coronary flow reserve (CFR) was reduced, we used noninvasive 20-MHz Doppler ultrasound to measure left main coronary flow velocity at baseline (B) and at hyperemia (H) induced by low (1%) and high (2.5%) concentrations of isoflurane gas anesthesia. Ten mice were studied before (Pre) and at 1 d, 7 d, 14 d and 21 d after constricting the aortic arch to 0.4 mm diameter distal to the innominate artery. We also measured cardiac inflow and outflow velocities at the mitral and aortic valves and velocity at the jet distal to the aortic constriction. The pressure drop as estimated by 4V2 at the jet was 51 +/- 5.1 (mean +/- SE) mm Hg at 1 d, increasing progressively to 74 +/- 5.2 mm Hg at 21 d. Aortic and mitral blood velocities were not significantly different after banding (p = NS), but CFR, as estimated by H/B, dropped progressively from 3.2 +/- 0.3 before banding to 2.2 +/- 0.4, 1.7 +/- 0.3, 1.4 +/- 0.2 and 1.1 +/- 0.1 at 1 d, 7 d, 14 d and 21 d, respectively (all p < 0.01 vs. Pre). There was also a significant and progressive increase the systolic/diastolic velocity ratio (0.17 Pre to 0.92 at 21 d, all p < 0.01 vs. Pre) suggesting a redistribution of perfusion from subendocardium to subepicardium. We show for the first time that CFR, as estimated by the hyperemic response to isoflurane and measured by Doppler ultrasound, can be measured serially in mice and conclude that CFR is virtually eliminated in banded mice after 21 d of remodeling and hypertrophy. These results demonstrate that CFR is reduced in mice as in humans with cardiac disease but before the onset of decompensated heart failure.     

Osteogenic effects of low-intensity pulsed ultrasound, extracorporeal shockwaves and their combination - an in vitro comparative study on human periosteal cells

Our previous studies have shown that on human periosteal cells, low-intensity pulsed ultrasound (LIPUS) has an immediate stimulatory effect whereas extracorporeal shockwaves (ESW) have an delayed stimulatory effect. Therefore, we hypothesized that a combined ESW and LIPUS treatment might provide additive or synergistic effects on periosteal cells, by using ESW to trigger a biological activity while using LIPUS to maintain the stimulated activity. Human periosteal cells were subjected to a single session of ESW treatment on day 0 and/or daily LIPUS treatments or no treatment (control). The cell viability, proliferation, and alkaline phosphatase activity on day 6 and day 18 as well as matrix mineralization on day 35 were measured. Results revealed that LIPUS alone had early positive effects on the activities on day 6 only. In contrast, ESW alone had an early destructive effect but exerted delayed stimulatory effects on the cellular activities on day 18. The combined treatment of ESW plus LIPUS produced effects that were comparable to the ESW treatment alone. Although these findings suggest that ESW and LIPUS stimulate the periosteal cells in two different ways and at different times, their additive or synergistic effects could not be proven.     

Enhanced fluid management with continuous venovenous hemofiltration in pediatric respiratory failure patients receiving extracorporeal membrane oxygenation support

Background/purpose  Children receiving extracorporeal membrane oxygenation (ECMO) for respiratory failure can have significant fluid overload and renal insufficiency. Addition of inline continuous venovenous hemofiltration (CVVH) could provide additional benefits in fluid management compared to use of standard medical therapies with ECMO. Methods  Patients with pediatric respiratory failure receiving ECMO with CVVH were case-matched to similar patients receiving ECMO without CVVH to compare fluid balance, medication use, and clinical outcomes. Results  Twenty-six of eighty-six patients with pediatric respiratory failure on ECMO (30%) received CVVH for >24 h (median 7.5 days on CVVH). Survival was not significantly different between patients receiving CVVH and those who did not receive CVVH (P = 0.51). For ECMO survivors receiving CVVH, overall fluid balance was less than that in non-CVVH survivors (median 25.1 ml kg⁻¹ day⁻¹; range −40.2 to 71.2 vs. 40.2, 1.1 to 134.9; P = 0.028). Time to desired caloric intake was faster in patients receiving CVVH (1 day, 1–5) than in patients who did not receive CVVH (5 days; 1–11; P < 0.001). Patients receiving CVVH–ECMO also received less furosemide (0.67 vs. 2.11 mg kg⁻¹ day⁻¹; P = 0.009). Conclusions  Use of CVVH in ECMO was associated with improved fluid balance and caloric intake and less diuretics than in case-matched ECMO controls.     

Multilaser photoplethysmography technique

New technique for parallel recording of reflection photoplethysmography signals in broad spectral band (violet to NIR) has been developed based on fiber-coupled laser irradiation and time-resolved spectrometric detection. Differences in photoplethysmography waveforms that were recorded simultaneously at different wavelengths confirmed the depth variety of the skin blood pulsation dynamics, thus the proposed methodology has a potential for application in skin microcirculation studies.     

Extracorporeal membrane oxygenation as a bridge to definitive tracheal reconstruction in neonates

Purpose

Infants born with severe tracheal anomalies may not survive beyond the first few hours of life without aggressive cardiopulmonary support and/or emergent airway surgery. The purpose of this study was to review our experience with critically ill neonates supported on extracorporeal membrane oxygenation (ECMO) before tracheal reconstruction.

Methods

A retrospective review of a single institution ECMO registry was conducted. Outcomes of neonates requiring tracheal repair were examined.

Results

Three children with tracheal anomalies (complete tracheal rings [n = 2]; bronchogenic cyst [n = 1]) underwent definitive airway reconstruction. All were placed on ECMO (venovenous [n = 2]; venoarterial [n = 1]) within 24 hours after birth. Tracheoplasties (tracheal resection with end-to-end anastomosis [n = 1]; slide tracheoplasty [n = 1]; carinal resection and reconstruction [n = 1]) were performed at 3.7 ± 2.2 days of life. There were no hemorrhagic or thrombotic complications for an ECMO time of 117.3 ± 60.1 hours. The postoperative durations until extubation and hospital discharge were 12.0 ± 3.2 and 34.3 ± 11.6 days, respectively. All children remain alive and well without cardiopulmonary and neurologic sequelae at a mean follow-up of 4.5 years.

Conclusions

Excellent clinical outcomes can be achieved in neonates born with severe tracheal anomalies using ECMO as a bridge to definitive tracheal reconstruction.     

解毒活血中药配伍对载脂蛋白E基因敲除小鼠主动脉NF-κB与MMP-9表达的调控作用

目的 观察解毒活血中药配伍对栽脂蛋白E基因敲除小鼠[apolipoprotein E knocked-outmice,ApoE（-／-）mice]主动脉核因子-κB（NF-κB）和基质金属蛋白酶-9（MMP-9）表达水平的调控作用。方法 13周龄ApoE（-／-）小鼠分为高脂组（给予高脂饲料）和普通饲料组（给予普通饲料）,同时设13周龄C57BL／6J小鼠对照组（给予普通饲料）。19周后进行干预,普通饲料模型组、C57BL／6J小鼠对照组灌服生理盐水,高脂组随机分为解毒组[灌服虎杖苷26．6mg／（kg·d）],活血组[灌服芎芍胶囊110mg／（kg·d）],解毒活血配伍高剂量组（灌服虎杖提取物53．2mg／（kg·d）,芎芍胶囊220mg／（kg·d）];解毒活血配伍中剂量组[灌服虎杖提取物26．6mg／（kg·d）,芎芍胶囊110mg／（kg·d）];解毒活血配伍低剂量组（灌服虎杖提取物13．3mg／（kg·d）,芎芍胶囊55rag／（kg·d）],洛伐他汀组[灌服洛伐他汀3．3mg／（kg·d）],高脂饲料模型组（灌服生理盐水）。17周后,取主动脉做常规石蜡切片,免疫组化观察其NF-κB和MMP-9表达的程度。结果 模型组ApoE（-／-）小鼠主动脉及粥样斑块NF-κB和MMP-9表达明显增加,虎杖苷、芎芍胶囊、洛伐他汀及解毒活血配伍治则的虎杖苷与芎芍胶囊配伍均可降低其主动脉NF-κB和MMP-9表达（P〈0．01）,且以解毒活血配伍高剂量组疗效最好（P〈0．01）。结论 解毒活血配伍可降低ApoE（-／-）小鼠主动脉NF-κB和MMP-9表达,且优于单纯解毒和活血组。     

ECMO用于治疗晚期心脏病人和心肺支持初步经验

目的总结阜外心血管病医院应用体外膜肺氧合(extracorporeal membrane oxygenation,ECMO)治疗晚期心脏病人和心脏术后心肺辅助的经验。方法总结2004年12月～2006年9月应用ECMO治疗的40例病例,病种包括先心病、冠心病、瓣膜病、主动脉疾病、肺动脉栓塞、心脏移植术后。结果辅助循环时间0.25～33天,成功脱离ECMO27例(67.5%),脱离EC-MO后恢复出院为50%,主要并发症包括:出血、感染、栓塞等。结论ECMO是治疗晚期心脏病人和心脏术后病人心肺功能障碍的有效治疗方法,但应正确掌握其应用指征。