静脉-静脉体外膜肺运转对绵羊胸肺顺应性及肺表面活性物质的影响

目的　为了解静脉 静脉体外膜肺 (venovenousextracorporealmembraneoxygenation ,VV ECMO)过程中绵羊胸肺动态顺应性的变化及VV ECMO治疗对健康绵羊肺表面活性物质的影响。方法　绵羊 2 0只 ,随机分为ECMO组及供血组各 10只。供血组颈内静脉插管放血供体外循环机预充血 ;ECMO组气管插管机械通气 ,右颈内静脉及右股静脉内放置静脉导管接体外循环装置。测定ECMO前、ECMO后 5、15、30、6 0、90、12 0、180min时胸肺动态顺应性 ,同时监测动脉血压、心率及肛温。两组动物均经气管插管用生理盐水 2 0ml/kg行支气管肺灌 3次 ,分析支气管肺灌洗液中总磷脂、磷脂酰胆碱及蛋白质的浓度。结果　动物ECMO前、ECMO后 5、15、30、6 0、90、12 0、180min时胸肺动态顺应性分别为 (1 19± 0 16 )、(0 77± 0 0 9)、(0 72± 0 13)、(0 71± 0 12 )、(0 71± 0 13)、(0 71± 0 16 )、(0 71± 0 16 )及 (0 76± 0 2 0 )ml/ (mmHg·kg) ,运转前胸肺动态顺应性显著高于运转后 (P <0 0 1) ,运转后各时间胸肺动态顺应性差异无显著意义 (P均 >0 0 5 )。ECMO组支气管肺灌洗液中总磷脂、磷脂酰胆碱及蛋白质的浓度分别为 (130 2± 9 9)、(83 5± 11 6 )及 (5 2 2 4± 6 6 3)mg/L ;供血组分别为 (132 2± 8 7)     

静脉-静脉体外膜肺氧合在儿科急性呼吸衰竭的应用

静脉-静脉体外膜肺氧合技术近年来在新生儿和儿童急性呼吸衰竭治疗中应用日益增多,静脉-静脉体外膜肺氧合可暂时替代肺大部分或部分功能,减轻肺负荷,使其在病变可逆前提下,获得功能改善和病理修复的时间.大量证据表明,急性严重呼吸衰竭采用静脉-静脉体外膜肺氧合支持效果良好.

Abstract：

Veno-venous extracorporeal membrane oxygenation (V-V ECMO) provides support for the neonate,infants and children with acute severe reversible respiratory failure by substituting for the most or part of the lung function and providing enough time for disease resolution.Mounting evidence shows V-V ECMO is effective therapy for acute severe respiratory failure.     

静脉-静脉小流量膜肺治疗中超滤技术的应用

目的评价超滤技术在实验羊静脉-静脉(V-V)小流量膜肺治疗中清除尿素氮的效果和小流量膜肺治疗清除二氧化碳(CO2)和氧合的作用。方法绵羊16只。体质量(20±3)kg。麻醉后气管插管,应用呼吸机,分别于右颈内静脉和股静脉插管,调整呼吸机使实验羊窒息5～8min,建立高碳酸血症模型。随机将实验羊分为膜肺组和膜肺超滤组各8只。二组膜肺治疗的泵流速为30mL/(kg.min)。分别于治疗后30、60、90、120和180min从膜肺前后和股动脉取血做血气分析,测尿素氮,监测血压、心率和肛温等。结果膜肺和膜肺超滤组治疗前、后血压、心率和肛温均无显著差异(Pa>0.05)。二组治疗前股动脉血尿素氮分别为4.8±0.9和4.6±0.7mmoL/L;pH、pa(CO2)、pa(O2)分别为(7.168±0.062)和(7.168±0.085);(10.9±1.6)kPa和(10.8±1.5)kPa;(18.8±2.7)kPa和(18.1±6.7)kPa,二组各项均无显著差异(Pa>0.05)。治疗30、60、90和120min,膜肺组尿素氮基本不变,膜肺超滤组逐渐下降,但二组无显著差异,二组比较有显著差异(Pa>0.05);180min尿素氮分别为(4.9±0.7)和(4.0±0.6)mmoL/L,二组比较差异显著(P<0.05),膜肺超滤组较治疗前也显著下降(P<0.05);二组血pH上升为(7.368±0.040)和(7.342±0.078);pa(CO2)下降为(6.3±0.8)和(6.5±0.9)kPa;pa(O2)为(12.6±2.1)和(13.7±4.4)kPa,以上各项二组间均无显著差异(Pa>0.05)。膜氧合器后二组p(CO2)均较膜氧合器前显著下降,p(O2)和血氧饱和度(SO2)明显上升,但二组间无显著差异(Pa>0.05)。结论在V-V小流量膜肺治疗中超滤的应用能有效清除尿素氮但未造成血液分流,小流量静脉膜肺治疗有效排除CO2和进行氧合。     

体外膜肺技术的应用进展

体外膜肺 (ＥＣＭＯ)作为一项新的生命支持技术 ,运用生物医学工程方法 ,使机体在脱离或部分脱离自身肺的情况下进行气体交换 ,暂时替代肺的部分功能或减轻肺的负荷 ,使其获得一定时间来完成功能上的改善和病理上的修复。自用于临床以来 ,挽救了成千上万的生命。当常规治疗如机械通气、一氧化氮吸入、高频通气、表面活性物质替代等治疗无效时 ,已成为严重呼吸、循环衰竭的最终治疗手段[1～ 3 ] ,国外已广泛用于新生儿、儿童及成人。发展历史1944年Ｋｏｌｆｆ依据血液透析可提高氧浓度得到启发 ,提出ＥＣＭＯ的概念及设想 ,1972年用硅胶膜制…     

静脉-静脉体外膜肺氧合抢救严重塑型性支气管炎三例并文献复习

目的分析静脉-静脉体外膜肺氧合在抢救严重塑型性支气管炎患儿的临床有效性。方法回顾性分析西安市儿童医院儿童重症医学科2021年9月至2021年11月收治的3例经静脉-静脉体外膜肺氧合抢救严重塑型性支气管炎患儿的临床资料, 并对相关国内外文献进行复习。结果 3例患儿中, 男2例, 女1例, 年龄分别为6岁7个月、3岁1个月、7岁7个月。3例患儿既往体健, 无基础疾病。3例均以双向性呼吸困难伴有严重喘息为主要临床表现。3例患儿影像学均提示不同程度斑片影, 同时合并肺不张, 2例患儿存在气胸, 1例存在纵隔积气及皮下积气。3例患儿均为社区获得性感染, 主要感染病原有乙型流感病毒、人类疱疹病毒4型、肺炎支原体、肺炎链球菌、金黄色葡萄球菌等。3例入院时均存在严重呼吸困难, 有创呼吸机辅助通气下呼吸困难改善不佳, 氧合无改善, 二氧化碳潴留进行性加重, 伴意识障碍。2例入院后立即行床旁纤维支气管镜检查发现主气道塑型, 取出困难, 并术中出现心率下降, 均行心肺复苏, 复苏后氧合仍差, 另外1例入院后即出现心率下降, 经心肺复苏抢救后恢复自主心率, 3例患儿经评估后立即行静脉-静脉体外膜肺氧合治疗。生...     

体外膜肺治疗新生儿呼吸衰竭

自本世纪70年代应用体外膜肺治疗新生儿呼吸衰竭以来,重症新生儿呼吸衰竭的存活率已由20%提高到75%左右。近期及远期随访均表明大多数幸存儿的体格、智力及呼吸系统发育均正常或接近正常。近年来体外膜肺的应用范围不断扩大,已用于救治哮喘持续状态及心脏手术的支持疗法。本文就体外膜肺在近年来的技术、装置、适应症、禁忌症、合并症及转归方面的进展作一简要介绍。     

体外膜肺期间脑血流及脑代谢的研究进展

体外膜肺（ｅｘｔｒａｃｏｒｐｏｒｅａｌｍｅｍｂｒａｎｅｏｘｙｇｅｎａｔｉｏｎ,ＥＣＭＯ）是近１０余年儿科抢救危重患儿生命的一种较新的技术,发展快,效果好。但应用中仍存在许多问题,其中脑保护是目前研究热点之一。（一）ＥＣＭＯ的发展及其工作原理：自１９８...     

膜肺（体外生命支持）的临床应用与研究

打破传统医学方式,采用全新的手段抢救危重病人的生命,已成为急救医学进展的突出特点。体外生命支持(ECLS),通常也称膜肺(ECMO),是国际急救医学领域里最有代表性的新技术之一。近年来,这一高新技术发展十分迅速。北美、欧洲及     

最大呼气峰流速在儿童哮喘中的应用

目的　探讨最大呼气峰流速 (PEFR)在儿童哮喘诊治中的临床应用价值。方法　用呼气峰速仪测定 43例哮喘患儿急性发作期PEFR。测定缓解期PEFR个人最佳值 ,求出个体化PEFR下降率及警戒值 ,观察2 0例规范监测组和 2 3例非规范监测组个体化PEFR下降率与哮喘发作关系。结果　哮喘发作期时PEFR越低 ,临床表现越重。缓解期规范监测组根据个体化PEFR下降率变化指导预防用药 ,哮喘发作人数、次数及发病呈中、重度表现者分别为 15%、2 3 .5%、2 5% ;非规范监测组分别为 43 .5%、75.5%、76.9% ,两组比较均有显著性差异 (P均 <0 .0 1)。结论　PEFR可作为诊断儿童哮喘和病情严重程度分级依据 ,指导治疗。个体化PE FR下降率较PEFR变异率更灵敏反映病情变化 ,可作为哮喘发作警报 ,指导预防用药 ,以减少发作次数及利于肺功能恢复     

Bedside detection of low systemic flow in the very low birth weight infant on day 1 of life

We aimed to assess the relationship between the clinical and biochemical parameters of perfusion and superior vena cava (SVC) flow in a prospective observational cohort study of very low birth weight (VLBW) infants. Newborns with congenital heart disease were excluded. Echocardiographic evaluation of SVC flow was performed in the first 24 h of life. Capillary refill time (forehead, sternum and toe), mean blood pressure, urine output and serum lactate concentration were also measured simultaneously. Thirty-eight VLBW infants were examined. Eight patients (21%) had SVC flow less than 40 ml/kg/min. There was a poor correlation between the capillary refill time (in all sites), mean blood pressure, urine output and SVC flow. The correlation coefficient for the serum lactate concentration was r = −0.28, p = 0.15. The median serum lactate concentration was 3.5 (range 2.8–8.5) vs. 2.7 (range 1.2–6.9) mmol/l (p = 0.01) in low flow versus normal flow states. A serum lactate concentration of >2.8 was 100% sensitive and 60% specific for detecting a low flow state. Combining a capillary refill time of >4 s with a serum lactate concentration of >4 mmol/l had a specificity of 97% for detecting a low SVC flow state. Serum lactate concentrations are higher in low SVC flow states. A capillary refill time of >4 s combined with serum lactate concentrations >4 mmol/l increased the specificity and positive and negative predictive values of detecting a low SVC flow state.     

Prediction of peak expiratory flow rate from height and weight

Seven hundred children of either sex in the age group of 5 to 12 years were studied. A parallel progressive increase in height, weight and peak expiratory flow rate (PEFR) from age 5 years to 12 years was observed. There was highly significant positive correlation between PEFR and anthropometric measures.     

Sensitivity of peak expiratory flow rate for diagnosing bronchial obstruction on methacholine inhalation challenge in school-aged asthmatic children

To study whether forced expiratory volume in 1 s (FEV1) for the diagnosis of bronchial reactivity by means of the methacholine inhalation challenge test could be appropriately replaced by simple measurements of peak expiratory flow rate (PEFR), 75 consecutively referred asthmatic children aged 6–15 y were examined during a symptom-free period. Their baseline FEV1 and PEFR values ranged from 70 to 130% (mean 99.1) and from 77 to 122% (mean 101.4) of those predicted, respectively. The methacholine inhalation challenge was performed with stepwise doubled cumulative doses and both FEV1 and PEFR were measured at each step. Of the 67 children who had a 20% reduction in either test, the fall in FEV1 was achieved after a lower dose of methacholine than the 20% fall in PEFR in 49 cases, after a higher dose in 15 and after the same dose in 3. There was a significant correlation ( r = 0:56, p < 0:001) between the changes in FEV1 and PEFR, although considerable scatter was found in the results. The 64 children who had a reduction of 20% in FEV1 showed a corresponding drop in PEFR that varied from 1.8 to 28.8% (mean 15.3), including 9 children for whom this drop was less than 10%. The results indicate that if the challenge test were based on PEFR measurements, the reference values for the test would have to be different.     

Normal peak expiratory flow rate in urban and rural children

Objective : To establish a reference value of peak expiratory flow rates (PEFR) of normal boys and girls of urban and rural areas aged 6 to 15 years from Karnataka, South India and compare with other studies.Methods : Twelve schools from urban and rural areas were selected to participate in the study. The permission was taken from the principal and the parents of the students from I to IX standards. A total of 6568 students participated in the study from 1994 to 1999. Among them 1091 children, were excluded from the study, who had respiratory symptoms and low peak expiratory flow rates who responded well to Salbutamol inhalation therapy in a spacer of 750 ml in volume.Result : A total of 5477 normal children were selected for the study. 2838 (51.8%) were boys; 2639 (48.2%) were girls. 4817 (87.9%) were from urban area and 660 (12.1%) were from rural areas. PEFR values correlated best with height, there was no difference in sexes, religion and urban/rural children.     

Dependence of canine right coronary arterial flow upon heart rate and right ventricular pressure

There is a paucity of knowledge regarding right coronary pulsatile hemodynamics when the right ventricle is under hemodynamic overload as is often the case in pediatric patients with congenital cardiac anomalies. To elucidate the exact mechanisms for the right coronary artery (RCA) to cope with the overload, we studied nine open-chest adult Beagles and analyzed the flow signals of the RCA in relation to independently varied heart rate (pacing) and right ventricular pressure (pulmonary artery banding). Both increased heart rate and right ventricular pressure increased the total volume flow of the RCA. The diastolic over total flow ratio (D/T), however, enlarged on increasing right ventricular pressures while it declined on increasing heart rates. Our data confirmed, as well, that increased flow of RCA on rising heart rate was provided mainly by an increase in systolic phase, while the increase on augmented right ventricular pressure was provided by the increase in diastolic phase. The RCA manages to deliver blood to the right ventricular musculature in two different ways in response to increasing heart rate and right ventricular pressure.     

Postnatal development of the cerebral blood flow velocity response to changes in CO2 and mean arterial blood pressure in the piglet

Cerebral blood flow velocity was studied during changes (haemorrhage) in mean arterial blood pressure or P _aCO₂ in 56 (aged 0–26 days) anaesthetized and ventilated piglets. The CO₂ reactivity increased with age from 6.5% kPa⁻'(< 1 day) to adult levels of 25% kPa⁻¹ for piglets over 4 days old. The mean arterial blood pressure reactivity was reduced from 1.3% mmHg⁻¹ (< 1 day old) to 0.0%/ mmHg (> 4 days old). The reactivities were similar with two different anesthetics: chloralose/urethane or pentobarbital. To validate the cerebral blood flow velocity data, both electromagnetic flow and precerebral Doppler ultrasound velocity were recorded from the same common carotid artery with extracranial branches tied off. There were no differences between the results with these two methods nor between these results and those obtained when the cerebral blood flow velocities were recorded from an intracerebral artery and the electromagnetic flowmeter recorded from the carotid artery. The vessel diameter appears stable during these interventions. In conclusion, the autoregulatory response and the reaction to P _aCO₂ appear poorly developed in the newborn piglet, but rapidly mature during the first 4 days of life.     

Peak expiratory flow rate of rural school children from Wardha district,Maharashtra in India

Background  Peak expiratory flow rate (PEFR) recording is an essential measure in the management and evaluation of asthmatic children. The PEFR can be measured by a simple instrument—peak expiratory flow meter. The aim of this study was to determine the normal PEFR in rural school children from Wardha district of Maharashtra state, India. Methods  The PEFR was measured in 1078 healthy rural school children, living in Wardha district, Maharashtra using the Mini-Wright peak flow meter. All measurements were obtained in a standing position and the best out of three trials was recorded. Anthropometric measurements, weight, height, and mid-upper-arm circumference (MAC) were recorded, and body surface area (BSA) and body mass index (BMI) were calculated. Results  Positive correlation was seen between age, height, weight and PEFR. The regression equations for PEFR were determined for boys and girls separately. The boys had higher values than the girls at all heights. The prediction equation for PEFR based on height was PEFR = 3.64 height (cm) − 257.86 (R=0.47, R ²=0.22) for female; PEFR = 4.7 height (cm) − 346.51 (R=0.62, R ²=0.38) for male. Conclusion  PEFR is a reliable measurement, which can be used routinely and regularly in rural areas for assessment of airway obstruction and prediction formula derived for use in this population.     

To investigate the effects of CO2 pneumoperitoneum pressure in neonates and younger infants undergoing laparoscopy

目的 探讨新生儿及小婴儿腹腔镜手术适宜气腹压力与基本生理指标间的函数关系.方法 A组20例腹腔镜手术患儿,在气腹前,气腹压力5mmHg和10mmHg时,分别记录患儿腹围,心率(HR)、平均动脉压(MAP),血氧饱和度(SiO2),呼气末二氧化碳分压(PETC2).B组30例腹腔镜手术患儿,气腹压力由6 mmHg逐步增加,当PETCO2达到或超过50 mmHg时,记录上一气腹压力值,即为适宜该患儿的气腹压力.结果 A组:5 mmHg气腹压力可使腹腔容积增加约35％,且PETCO2均小于50 mmHg.10 mmHg气腹压仅可使腹腔容积再增加约11％.B组:实验得到的个体化气腹压力与身长、体重、年龄、Kaup指数均存在相关.经逐步回归法的多元线性回归,得到回归方程为气腹压力(mmHg)=3.926+1.468×体重(kg).结论 该函数关系适于预判3个月以内且心肺功能基本正常患儿的适宜气腹压力,术中根据PETCO2监测可对气腹压做进一步调整.