Evaluation of high-frequency jet ventilation in oxygenation through an artificial membrane lung

The membrane oxygenator often develops impaired gas exchange after prolonged use because plasma proteins adhere to the membrane's surface and leak through its micropores. This study was performed to examine the efficacy of high-frequency jet ventilation (HFJV) in minimizing these problems in a "flat plate" type of membrane oxygenator. We first vibrated the membrane of the oxygenator by HFJV from 1 to 10 Hz to find the frequency most effective for optimal gas exchange in animals with partial extracorporeal circulation. These studies suggested that 6 Hz HFJV was preferable in our model. We subsequently performed in vivo extracorporeal oxygenation in dogs for 8 h using the membrane oxygenator with or without 6 Hz HFJV. Although the gas exchange capacity within the first 8 h was similar in the two groups, after 6 h a significant decrease in the red blood cell count and in the hematocrit was found in the group not receiving HFJV. Scanning electron microscopic examination of the membranes after 8 h of use disclosed that the membrane from the group receiving HFJV had less plasma protein and fibrin adhesion than that from the group not receiving HFJV. Moreover, it appears that with prolonged extracorporeal oxygenation, 6 Hz HFJV also protects against a decrease in the hematocrit of the passed blood and might lead to enhanced gas exchange. Our data suggest that good gas exchange can be maintained for periods even longer than 8 h if HFJV is used in conjunction with the membrane oxygenator.     

Plasma catecholamines and oxygen consumption during weaning from mechanical ventilation

Previous studies on oxygen consumption ( ) during weaning from mechanical ventilation assumed that an increase in ( ) reflected oxygen consumption by respiratory muscles ( ), and proposed as a weaning predictor. We measured CO₂ production ( ) and plasma catecholamines in 20 short-term ventilated patients during weaning by SIMV and CPAP. as a percentage of during spontaneous ventilation ( %) ranged from 4.8% to 41.5%. also increased and correlated with . Plasma adrenaline and noradrenaline increased significantly to levels known to produce considerable increases in metabolic rate. Mean arterial pressure and heart rate concomitantly increased, but spontaneous minute ventilation decreased. Thus, since the increased plasma catecholamines are calorigenic, the assumption that represents is incorrect. Although mean % of successfully weaned patients was significantly less than that of failure-to-wean patients, the wide scatter of individual values in the latter group excludes % as an accurate weaning predictor.     

机械通气治疗新生儿呼吸衰竭疗效观察

目的 观察机械通气治疗新生儿呼吸衰竭的疗效。方法 对96例呼吸衰竭的新生儿上呼吸机行机械通气治疗。结果 平均上机时间68．8h，存活75例，死亡9例，自动出院12例。结论 对呼吸衰竭的新生儿应及时行机械通气治疗，并掌握好呼吸机参数的调节，及时安全撤机，防治呼吸和相关肺炎的发生。     

纳洛酮治疗肺性脑病45例临床观察

目的：研究纳洛酮对肺性脑病患者的治疗效果。方法：68例出现肺性脑病的患者被随机分成两组。治疗组45例采用纳洛酮治疗，对照组23例采用尼可刹米和洛贝林治疗。结果：治疗组在8h内较对照组有较高的苏醒率，且苏醒所需时间短。8h后治疗组的心率、呼吸频率以及PaCO2的平均水平较对照组低，而PaO2较对照组高。结论：纳洛酮能有效地改善患者的通气，明显地加快肺性脑病患者的苏醒。     

高频振荡通气治疗新生儿肺透明膜病文献的Meta分析

目的　综合比较高频振荡通气 (HFOV)与传统机械通气 (CMV)对新生儿肺透明膜病的治疗作用及其潜在危害性。方法　通过数据库检索出符合纳入分析条件的相关文献 12篇 ,采用Meta分析方法进行定性、定量综合分析 ,得出合并OR值及其 95 %可信区间。结果　与CMV相比 ,HFOV能明显改善肺透明膜病患儿的呼吸功能 (P <0 0 0 5 )以及降低慢性肺部疾病的发生率 (P <0 0 1) ,但增加新生儿颅内出血的危险性 (P <0 0 5 ) ;在两种通气方式引起的气漏方面 ,无明显差异 (P >0 0 5 )。结论　应用HFOV治疗新生儿肺透明膜病的效果优于CMV ,并可减少慢性肺部疾病的发生 ,但应注意其它并发症的出现。     

儿科重症监护病房中影响机械通气成功的相关因素

目的 探讨儿科重症监护病房(PICU)中影响机械通气成功的相关因素。方法 将lll例行机械通气的危重病儿分成治疗成功组与失败组，对其相关因素进行回顾性分析。结果两组患儿在上机前危重病例评分、是否伴有心跳呼吸骤停和(或)休克及并发多系统器官功能衰竭(MODS)等方面差异有权显著意义(P＜0．001)；超过48h的机械通气患儿是否继发呼吸机相关肺炎(VAP)亦有显著意义(P＜0.05)。结论 PICU中影响机械通气成功率的因素主要是原发病的性质及严重程度，并与MODS与VAP有密切关系。     

小剂量芬太尼在机械通气中的应用

目的　 了解机械通气患儿以小剂量芬太尼持续静脉滴注的作用。 方法 　观察用药前后呼吸顺应性 (Cdyn)、气道阻力 (Raw)及呼气末二氧化碳分压 (PetCO2 )的变化。 结果 　 1个月～ 3岁患儿用药前后Raw及PetCO2 明显下降 ,肺部感染患儿指标变化显著大于非感染患儿 ,Cdyn用药前后均未发现显著差异。 结论 　提示机械通气中用小剂量芬太尼可以减轻人机对抗 ,降低气道压 ,改善肺气体交换及肺功能 ,有利于患儿顺利地渡过危险期     

气道闭合压P0.1在小儿机械通气中的临床价值

目的探讨气道闭合压(P0.1)在小儿机械通气中的临床价值.方法对收住儿童ICU的呼吸衰竭上呼吸机的患儿,分别于上呼吸机第一天和撤机时(中枢性呼吸衰竭放弃治疗的那一天)测气道闭合压(P0.1).结果在外周型呼吸衰竭患儿,0～1岁组、1～3岁组和3岁以上组,P0.1在撒机时与上呼吸机第一天比较均有显著的统计学差异(P＜0.001或0.001＜P＜0.05).结论在机械通气中,检测Po.1的动态变化,可了解患儿的病情变化,指导呼吸机参数的调节,为临床小儿呼吸机的成功撤离提供了有关肺功能的预测指标.     

高频振荡通气在新生儿重症肺疾病中的应用

目的　 为观察高频振荡通气 (HFOV)治疗新生儿重症肺疾病的应用价值及安全性。 方法 　 2 7例新生儿重症肺疾病 ,15例应用HFOV治疗 ,12例应用常频机械通气 (CMV)治疗 ,观察治疗前后 2 4h内氧合参数及呼吸机参数的变化。 结果 　HFOV组 2 4h内氧浓度 (FiO2 )迅速从 ( 0 85± 0 11)降至 ( 0 5 3± 0 0 8) ,P <0 0 1;平均气道压 (MAP)从 ( 15 3± 1 8)cmH2 O降至( 11 2± 2 1)cmH2 O(P <0 0 1) ,氧合指数 (OI)从 ( 3 4± 10 )降至 ( 2 0± 4) (P <0 0 1) ,二氧化碳分压 (PCO2 )从 ( 6 9± 0 8)kPa迅速降至 ( 5 4± 0 9)kPa(P <0 0 1)。HFOV期间血压、心率无明显变化。 结论 　HFOV治疗新生儿重症肺疾病 ,通气效果优于CMV ,氧合改善快 ,短时间内氧浓度、MAP下降更快 ,是一种疗效肯定、安全性好的新型机械通气方法。     

高频振荡通气及联合硫酸镁治疗新生猪重症胎粪吸入综合征的实验研究

目的　探讨高频振荡通气 (HFOV)及联合硫酸镁 (Mg SO4 )治疗合并持续肺动脉高压(PPH)的重症胎粪吸入综合征 (MAS)模型氧合、循环功能 ,血镁浓度及肺组织病理改变。　方法　以2 0 %胎粪混悬液制备重症 MAS模型 ,健康新生猪随机分为 3组 ,即模型 HFOV治疗组 (HFOV组 ,n= 6 ) ,HFOV+Mg SO4 治疗组 (HFOV+Mg SO4 组 ,n=7) ,HFOV对照组 (对照组 ,n=5 ) ,HFOV+Mg SO4 组同时静脉持续泵入 Mg SO4 。监测生命体征、血气、血镁浓度。　结果　 (1) HFOV和 HFOV+Mg SO4 治疗均使 MAS模型动脉血氧分压 (Pa O2 )、动脉血氧 /肺泡血氧分压比 (a/ APO2 )增加 ,肺泡-动脉血氧分压差 (A- a DO2 )、肺内分流 (Qs/ Qt)降低 ,治疗 30 min与治疗前比差异有非常显著性 (P<0 .0 1)。HFOV组各时间点 Pa O2 、a/ APO2 低于对照组 ,A- a DO2 、Qs/ Qt高于对照组 (P<0 .0 5 )。HFOV+Mg SO4 组治疗 12 0 m in后上述指标与对照组差异无显著性 (P>0 .0 5 )。 (2 )尽管氧合功能改善 ,单独 HFOV对重症 MAS的 PPH无降低作用 ,联合 Mg SO4 治疗 30 min即可有效降低 PPH(P<0 .0 5 ) ,并保持疗效。(3) HFOV组较 HFOV+Mg SO4 组有明显肺出血 ,出血沿肺段、小叶分布 ,两组病理评分差异有显著性 (P<0 .0 5 )。 (4) HFOV+Mg SO4 组血镁浓度较治疗