Intermittent positive pressure ventilation by nasal mask: Technique and applications

Intermittent positive pressure ventilation delivered non-invasively through a well-fitting nasal mask has been used to control nocturnal hypoventilation in three patients with severe, combined cardio-respiratory and skeletal disease. The advantages of this approach to domiciliary ventilation are described and the requirements of the ventilator are defined.     

气管切开与呼吸机机械通气抢救有机磷农药中毒致呼吸肌麻痹6例

目的：探讨气管切开与呼吸机机械通气抢救重度有机磷农药中毒（ＡＯＰＰ）致呼吸肌麻痹的疗效。方法：对６例重度ＡＯＰＰ致呼吸肌麻痹患者在综合治疗基础上，及时予气管切开，并使用全能呼吸机机械通气。结果：治愈５例，死亡１例。抢救成功率达８３．３％。结论：对重度ＡＯＰＰ患者及时行气管切开，并使用全能呼吸机机械通气，抢救效果良好。     

组织扩张术皮肤胶原的代谢改变

目的：研究常规扩张（ＩＴＥ）和持续快速扩张（ＣＴＥ）对皮肤胶原代谢的影响。方法用白色小家猪制作组织扩张术动物模型，用Ｇｏｒｄｅｌａｄｚｅ法测定血清和扩张组织的羟脯氨酸（ＨＰ）含量，藻酸盐印模材膜片法测量标记区面积；光镜测量真皮厚度。结果：ＩＴＥ组血清ＨＰ含量升高，０．８倍，ＣＴＥ组升高１．２倍，ＩＴＥ和ＣＴＥ组皮肤含量与正常皮肤相同，组织中ＨＰ总量均明显升高，持续扩张皮瓣组（ＣＴＥＦ）术后４ｗｋ皮     

指示肺通气不均匀性的熵变及其同其他指标的理论比较

熵代表无序的水平，作者使用通气的熵变（ＥＣＶ）指示肺通气的不均匀性，ＥＣＶ定义为当前泡潮气量趋近于零时每摩尔被吸入气体从不均匀通气到均匀通气的熵变的极限。本文从熵的基本公式民地出ＥＣＶ的计算方程。用几个数学模型肺将ＥＣＶ同其他７个洗出指标进行了比较。８个指标中，只有ＥＣＶ仅取决于通气分布，其他７个指标不仅取决于通气分布，还同潮气量和死腔的大小有关。这影响了它们评价肺通气不均匀性的效果，ＥＣＶ的另一     

机械通气并发气胸的诊断及处理

气胸是机械通气常见的并发症，在成人呼吸窘迫综合征（ＡＲＤＳ）及慢性阻塞性肺部疾病（ＣＯＰＤ）中发生率较高，分别是２９．４％和２７．８％，且多为张力性气胸。预防气胸发生的简便方法是在保证有效通气量的前提下，适当降低潮气量。机械通气过程中，患者出现血氧饱和度下降、气道压力增高、患侧呼吸音降低、心率加快及呼吸困难等临床症状均高度提示并发气胸，试穿患侧胸腔有大量气体即可诊断。安置该侧胸腔闭式引流是有效的治疗方法。     

Comparison of airway pressure-triggered and airflow-triggered ventilation in very immature infants

Failure of patient-triggered ventilation in very immature infants may be due to the use of inappropriate triggering systems. Two types of airflow trigger were therefore compared consecutively to an airway pressure (SLE) triggering system. Each comparison was made in 10 infants, ≤28 weeks of gestation. Comparison was made of the delivered volume, trigger performance and blood gases using each system for 1 h. Both comparisons showed that the airflow triggering systems performed better: one (Draeger Babylog 8000) had a higher sensitivity ( p < 0:01) and the other (Bird VIP airflow trigger), in which inflation was terminated by sensing a reduction in inspiratory flow, had a lower degree of asynchrony ( p < 0:01) and a tendency to deliver higher volumes. These results suggest that triggering systems sensing airflow changes may be superior to those sensing airway pressure changes in very immature infants. The use of a mechanism to synchronize the termination of inflation to the end of the patient's inspiration may offer further advantages.     

Interruption of pulmonary arterial flow with inadequate ventilation leads to pulmonary infarction

We examined the effect of interruption of pulmonary arterial flow and inadequate ventilation on the development of pulmonary infarction in rats. Pulmonary arterial flow was blocked by the injection of agar into the inferior vena cava and inadequate ventilation was produced by obstructing the left main bronchus with a polypropylene tip. Histological and angiographic examination of the lung demonstrated that: pulmonary artery embolism alone does not induce pulmonary infarction; obstruction of a bronchus does not induce significant changes, but that pulmonary infarction develops when pulmonary artery embolism and obstruction of a bronchus occur simultaneously. It has been thought that pulmonary infarction is caused by acute obstruction of a pulmonary artery, however, the alveolar walls are supplied with oxygen by both the pulmonary circulation and by ventilation. Interruption of pulmonary arterial flow alone is probably not sufficient to induce pulmonary infarction, which is probably caused by deficiency of oxygen supply to the alveolar walls by a synergy between interruption of pulmonary arterial flow and inadequate ventilation.     

左双腔支气管导管管端位置与吸气峰压变化的关系

目的 观测无隆突钩双腔支气管导管(DLT)管端位置与吸气峰压(Ppeak)以及肺顺应性环形状改变的关系，探讨用Ppeak和顺应性环的变化评估DLT管端位置的可行性。方法 拟行右侧剖胸手术的成年患者32例，静脉诱导后插入左Mallinckrodt DLT，吸入氧化亚氮和地氟醚维持麻醉。按纤维支气管镜(FOB)确认DLT管端位置和通气方式将观测过程分为四个阶段：第一阶段(S1)，管端位置正确的双肺通气；第二阶段(S2)，管端位置正确的左侧单肺通气；第三阶段(S3)，管端插入左下支气管(置管过深)的左侧单肺通气；第四阶段(S。)，管端处在左支气管开口(置管偏浅)的左侧单肺通气。每阶段均机械通气15min。结果 回归方程预计插管深度与FOB检查符合者占71．9％。S2时Ppeak值比S1时增加50．8％，肺顺应性(Cdyn)值减少36．2％；S3时Ppeak值比S1时增加87．4％，Cdyn值减少56．8％。PV环曲线斜率向右明显移位，环体显著延长。结论 用无隆突钩DLT行肺隔离，在无FOB定位的条件时，联合应用听诊法、回归方程预计插管深度、动态监测气道峰压和P-V环的变化综合评估，可提高DLT管端的正确到位率。单肺通气的气道峰压超过双肺通气时的1．65倍，且气道峰压超过25cm H2O．应高度怀疑DLT管端发生过深移位。     

人工心肺机血液泵监测系统的研制

为避免人工心肺机血液泵转速失控现像的发生，特研制人工心肺机监测系统，通过对血泵转速的实时监测，判断系统是否正常，自动进行相应的处理，提高现有系统的安全性。     

胃减容术3种机械通气对患者氧合情况的比较

目的：探讨病态肥胖患者行腹腔镜胃减容术时，3种机械通气参数对患者氧合情况的影响。方法：选择行腹腔镜胃减容术的病态肥胖24例，按手术时间顺序分为3组，每组8例。A组：潮气量12ml／kg，呼吸频率10次／min；B组：潮气量20ml／kg，呼吸频率10次／min；C组：潮气量12ml／kg，呼吸频率20次／min。分别于气腹前（T1）、气腹后（T2）抽取动脉血测量pH、PO2、PCO2、Plat（平台压）、Peak（峰压）、AaDO2（肺泡-动脉氧分压差）。结果：气腹后B组Plat（33．2±1．8）cmH2O、Peak（36．3±1．6）cmH2O显著高于A组Plat（29．5±3．9）cmH2O（q=3．053，P〈0．05）、Peak（33．0±2．9）cmH2O（q：2．823，P〈0．05）和C组Plat（28．0±4，1）cmH2O（q：4．290，P〈0．05）、Peak（31．8±2．8）cmH2O（q：4．704，P〈0．05）。其他观察指标无统计学差异。结论：病态肥胖患者在腹腔镜下施行胃减容术时，加大潮气量20ml／kg或加快呼吸频率20次／min不能改善患者的氧合情况。