Effects of Cardiopulmonary Support With a Novel Pediatric Pump‐Lung in a 30‐Day Ovine Animal Model

The scarcity of donor organs has led to the development of devices that provide optimal long‐term respiratory or cardiopulmonary support to bridge recipients as they wait for lung and/or heart transplantation. This study was designed to evaluate the 30‐day in vivo performance of the newly developed pediatric pump‐lung (PediPL) for cardiopulmonary support using a juvenile sheep model. The PediPL device was placed surgically between the right atrium and descending aorta in eight sheep (25.4–31.2 kg) and evaluated for 30 days. Anticoagulation was maintained with continuous heparin infusion (activated clotting time 150–200 s). The flow rate was measured continually, and gas transfer was measured daily. Plasma free hemoglobin, platelet activation, hematologic data, and blood biochemistry were assessed twice a week. Sheep were euthanized after 30 days. The explanted devices were examined for gross thrombosis. Six sheep survived for 30–32 days. During the study, the oxygen transfer rate of the devices was 54.9 ± 13.2 mL/min at a mean flow rate of 1.14 ± 0.46 L/min with blood oxygen saturation of 95.4% ± 1.7%. Plasma free hemoglobin was 8.2 ± 3.7 mg/dL. Platelet activation was 5.35 ± 2.65%. The animals had normal organ chemistries except for surgery‐related transient alterations in kidney and liver function. Although we found some scattered thrombi on the membrane surfaces of some explanted devices during the necropsy, the device function and performance did not degrade. The PediPL device was capable of providing cardiopulmonary support with long‐term reliability and good biocompatibility over the 30‐day duration and offers the potential option for bridging pediatric patients with end‐stage heart or lung disease to heart and/or lung transplantation.     

Implementing an Innovative Cardiac Assist System in a Nonuniversity Hospital—Feasibility,Complications, and First Results

To evaluate the feasibility of implementing a cardiac assist system in a nonuniversity hospital we analyzed 18 consecutive patients treated with venoarterial membrane oxygenation. The system was used electively in 5/18 (27.8%) patients during high‐risk interventions. Thirteen patients (72.2%) were treated in emergency situations. The extracorporal system could be initiated successfully in all patients. Periprocedural complications were hemolysis in 3/18 (16.7%), disseminated intravascular coagulation in 2/18 (11.1%), cerebral ischemia in 1/18 (5.6%), and local infection in 2/18 (11.1%) patients. None of these led to a discontinuation of the therapy. All electively treated patients were successfully weaned from the extracorporeal system. In 9/13 (69.2%) emergency patients the system was removed successfully. The 60‐day survival rate of the emergency patients was 53.8% (7/13). Our experience confirms that an innovative extracorporeal circulatory support system can be implemented in a nonuniversity hospital at a tolerable risk and a low complication and high procedural success rate.     

Multisite Near Infrared Spectroscopy During Cardiopulmonary Bypass in Pediatric Patients

Multisite near infrared spectroscopy (NIRS) monitoring during pediatric cardiopulmonary bypass (CPB) has not been extensively validated. Although it might be rational to explore regional tissue saturation at different body sites (namely brain, kidney, upper body, lower body), conflicting results are currently provided by experience in children. The aim of our study was to evaluate absolute values of multisite NIRS saturation during CPB in a cohort of infants undergoing pediatric cardiac surgery to describe average differences between cerebral, renal, upper body (arm), and lower body (thigh) regional saturation. Furthermore, the correlation between cerebral NIRS and cardiac index (CI) at CPB weaning was evaluated. Twenty‐five infants were enrolled: their median weight, age, and body surface area were 3.9 (3.3–6) kg, 111 (47–203) days, and 0.24 (0.22–0.33) m², respectively. Median Aristotle score was 8 (6–10), and vasoactive inotropic score at CPB weaning was 16 (14–25). A total of 17 430 data points were recorded by each sensor: two‐way ANOVA showed that time (P < 0.0001) and site (P = 0.0001) significantly affected variations of NIRS values: however, if cerebral NIRS values are excluded, sensor site is no more significant (P = 0.184 in the no circulatory arrest [noCA] group and P = 0.42 in the circulatory arrest [CA] group). Analysis of NIRS saturation changes over time showed that, at all sites, average NIRS values increased after CPB start, even if the increase of cerebral saturation was less intense than other sites (P < 0.0001). Detailed analysis of interaction between site of NIRS measurement and time point showed that cerebral NIRS (ranging from 65 to 75%) was always significantly lower than that of other channels (P < 0.0001) that tended to be in the range of oversaturation (80–90%), especially during the CPB phase. Average cerebral NIRS values of patients who did not undergo circulatory arrest (CA) during CPB, 10 min after CPB weaning, were associated with average CI values with a significant correlation (r = 0.7, P = 0.003). In conclusion, during CPB, cerebral NIRS values are expected to remain constantly lower than somatic sensors, which instead tend to show similar elevated saturations, regardless of their position. Based on these results, positioning of noncerebral NIRS sensors during CPB without CA may be questioned.     

体外循环术对先天性心脏病患儿手术前后神经系统发育障碍的影响

随着临床治疗和外科技术的改善,先天性心脏病患儿体外循环术后早期和长期成活率显著增加.因此,已有越来越多的患儿进入学校学习.在过去20年中,对于这些术后存活患儿神经发育的研究结果证实这些患儿的学习和生活质量受到严重影响.神经发育障碍由多种因素引起,可大致分为术前、术中和术后3类,另有基因及社会经济条件等因素.现着重阐述先天性心脏病患儿体外循环后,导致神经发育异常影响因素的最新研究进展.理解这些才能改善现有技术和治疗方法,最终改善患儿生活质量.     

A cadaveric model for transesophageal echocardiography transducer placement training: A pilot study

BACKGROUND: Transesophageal echocardiography(TEE) is used in the emergency department to guide resuscitation during cardiac arrest. Insertion of a TEE transducer requires manual skill and experience, yet in some residency programs cardiac arrest is uncommon, so some physicians may lack the means to acquire the manual skills to perform TEE in clinical practice. For other infrequently performed procedural skills, simulation models are used. However, there is currently no model that adequately simulates TEE transducer insertion. The aim of this study is to evaluate the feasibility and efficacy of using a cadaveric model to teach TEE transducer placement among novice users.METHODS: A convenience sample of emergency medicine residents was enrolled during a procedure education session using cadavers as tissue models. A pre-session assessment was used to determine prior knowledge and confidence regarding TEE manipulation. Participants subsequently attended a didactic and hands-on education session on TEE placement. All participants practised placing the TEE transducer until they were able to pass a standardized assessment of technical skill(SATS). After the educational session, participants completed a post-session assessment. RESULTS: Twenty-five residents participated in the training session. Mean assessment of knowledge improved from 6.2/10 to 8.7/10(95% confidence interval [CI] of knowledge difference 1.6–3.2, P<0.001) and confidence improved from 1.6/5 to 3.1/5(95% CI of confidence difference 1.1–2.0, P<0.001). There was no relationship between training level and the delta in knowledge or confidence.CONCLUSIONS: In this pilot study, the use of a cadaveric model to teach TEE transducer placement methods among novice users is feasible and improves both TEE manipulation knowledge and confidence levels.     

Endothelial glycocalyx shedding in patients with burns

Shedding of syndecan-1 from the endothelial glycocalyx layer (EGL), referred to as endotheliopathy of trauma (EoT), is associated with poorer outcomes. This study aims to determine if EoT is also present in the burn population. We enrolled 458 burn and non-burn trauma patients at a Level 1 trauma center and defined EoT by a syndecan-1 level of ≥40 ng/mL. Sixty-eight of the enrolled patients had burns with a median TBSA of 19%, with 27.9% also suffering inhalational injury (II). Mortality was similar between the burn and non-burn group, also for patients with EoT. The incidence of II was significantly greater in the EoT+ burn group compared to the EoT− group (p = 0.038). Patients with II received significantly larger amounts of i.v. fluids (p = 0.001). The incidence of EoT was significantly different between the II-groups, as was mortality (p_EoT = 0.038, p_mortality < 0.001).EoT is attributed to the shock rather than the mechanism of trauma and may in burns be associated to II rather than TBSA. Patients with burns and II had worse outcomes and higher mortality compared to patients with burns alone. Burn injury induces EGL shedding similar to that in non-burn patients with EoT, and results in similar higher rate of mortality.     

A stroke volume-based fluid resuscitation protocol decreases vasopressor support and may increase organ yield in brain-dead donors

Brain-dead donors are frequently hypovolemic and hypotensive requiring vasopressor support. We studied a stroke volume-based fluid resuscitation and vasopressor weaning protocol prospectively on 64 hypotensive donors, with a recent control cohort of 30 hypotensive donors treated without a protocol. Stroke volume was measured every 30 minutes for 4 hours by pulse contour analysis or esophageal Doppler. A 500 mL saline fluid bolus was infused over 30 minutes and repeated if the stroke volume increased by 10%. No fluid was infused if the stroke volume did not increase by 10%. Vasopressors were weaned every 10 minutes if the mean arterial pressure was greater than 65 mm Hg. The protocol group received 1937 ± 906 mL fluid compared to 1323 ± 919 mL in the control group (P = .003). Mean time on vasopressors was decreased from 957.6 ± 586.2 to 176.3 ± 82.2 minutes (P<.001). Donors in the protocol group were more likely to donate four or more organs than donors in the control group (OR = 4.114, 95% Confidence Interval (CI) = 1.003-16.876). While more organs were transplanted per donor in the protocol group (3.39 ± 1.52) than in the control group (2.93 ± 1.44) (P = .268), the difference did not reach statistical significance. A goal-directed fluid resuscitation protocol decreased organ ischemia and may increase organs transplanted.     

肾区域组织氧饱和度预测紫绀型患儿心脏手术后急性肾损伤的效果

目的探讨紫绀型先天性心脏病患儿心脏手术围术期肾区域组织氧饱和度(RrSO_2)对术后急性肾损伤(AKI)的预测价值。方法选取心肺转流(CPB)下接受心脏手术的紫绀型先天性心脏病患儿36例,男22例,女14例,年龄≤1岁,分别于气管插管后5 min(T_1)、升主动脉夹闭后5 min(T_2)、升主动脉开放后5 min(T_3)、CPB结束(T_4)、超滤结束(T_5)、CPB结束后3 h(T_6)、CPB结束后8 h(T_7)、CPB结束后24 h(T_8)记录MAP、RrSO_2、鼻咽温,同时抽取动脉血和中心静脉血进行血气分析,记录动脉血氧饱和度(SaO_2)、动脉血Hb、乳酸(Lac)、中心静脉血氧饱和度(ScvO_2),根据改善全球肾脏病预后组织(KDIGO)诊断标准将患儿分为两组:急性肾损伤组(D组)和正常组(N组)。单因素分析两组患儿的临床资料,将不同时点MAP、RrSO_2、鼻咽温、Hb、SaO_2、Lac、ScvO_2值、有意义变量纳入二元Logistic回归分析,采用受试者工作特征(ROC)曲线分析RrSO_2对AKI的预测价值。结果 T_3—T_6时D组RrSO_2明显低于N组(P0.01)。两组不同时点MAP、鼻咽温、SaO_2、Hb、Lac和ScvO_2差异无统计学意义。二元Logistic回归分析显示,T_3—T_6时RrSO_2是紫绀型先天性心脏病患儿心脏术后AKI的危险因素(P0.05)。ROC曲线分析结果显示,T_3—T_6时RrSO_2临界值分别为60.2%、57.2%、55.0%、54.0%,敏感性分别为66.7%、83.3%、66.7%、83.3%,特异性分别为100%、92%、100%、75%,曲线下面积分别为0.896、0.861、0.792、0.840。结论 RrSO_2可作为紫绀型先天性心脏病患儿心脏AKI的一项无创预测指标。