BiPAP通气对慢性充血性心力衰竭患者心肺功能的影响

【目的】了解经面罩双水平气道正压（BiPAP）通气对慢性严重充血性心力衰竭（CHF）心肺功能和血液动力学的影响。【方法】对34例多种病因的CHF患者在常规治疗的基础上采用经面罩BiPAP,以流速触发、压力支持同步呼吸。同时与另34例常规药物治疗心衰组进行对照,观察其动脉血气和心功能的变化。【结果】BiPAP组患者的呼吸频率减慢,心率下降,PaO2、SaO2和CaO2和射血分数显著提高（P〈0.05）,而血压、心输出量、心脏指数无明显变化（P〉0.05）,BiPAP组心肺功能的有效改善率为94.16%,而对照组仅为85.29%（P〈0.05）。【结论】BiPAP压力支持通气能有效纠正低氧血症,改善心肺功能和部分血液动力学指标,是CHF患者有效的辅助治疗措施。     

儿童反复呼吸道感染的支气管黏膜免疫和气道高反应性变化

反复呼吸道感染(recurrent respiration tract infection,RRTI)是儿童常见的呼吸道疾病,常见的原因有免疫功能低下、先天畸形、营养物质缺乏、慢性疾病以及感染疾病治疗不彻底等。RRTI与呼吸道黏膜免疫改变、气道高反应性及过敏有关。     

Sensory afferent and hypoxia-mediated activation of nucleus tractus solitarius neurons that project to the rostral ventrolateral medulla

The nucleus tractus solitarius (nTS) of the brainstem receives sensory afferent inputs, processes that information, and sends projections to a variety of brain regions responsible for influencing autonomic and respiratory output. The nTS sends direct projections to the rostral ventrolateral medulla (RVLM), an area important for cardiorespiratory reflexes and homeostasis. Since the net reflex effect of nTS processing ultimately depends on the properties of output neurons, we determined the characteristics of these RVLM-projecting nTS neurons using electrophysiological and immunohistochemical techniques. RVLM-projecting nTS neurons were identified by retrograde tracers. Patch clamp analysis in the horizontal brainstem nTS slice demonstrated that RVLM-projecting nTS cells exhibit constant latency solitary tract evoked excitatory postsynaptic currents (EPSCs), suggesting they receive strong monosynaptic contacts from visceral afferents. Three distinct patterns of action potential firing, associated with different underlying potassium currents, were observed in RVLM-projecting cells. Following activation of the chemoreflex in conscious animals by 3 h of acute hypoxia, 11.2±1.9% of the RVLM-projecting nTS neurons were activated, as indicated by positive Fos-immunoreactivity. Very few RVLM-projecting nTS cells were catecholaminergic. Taken together, these data suggest that RVLM projecting nTS neurons receive strong monosynaptic inputs from sensory afferents and a subpopulation participates in the chemoreflex pathway.     

Evolutionary and comparative aspects of nitric oxide,carbon monoxide and hydrogen sulfide

The concept that non-respiratory gases, such as nitric oxide (NO), carbon monoxide (CO) and hydrogen sulfide (H₂S) functioned as signaling moieties is a relatively recent development, due in part to their ephemeral existence in biological tissues. However, from an evolutionary perspective these gases dominated the prebiotic and anoxic Earth and were major contributors to the origin of life and the advent of eukaryotic animals. As Earth's oxygen levels rose, NO, CO and H₂S disappeared from the environment and cells began to utilize their now well-developed metabolic pathways to compartmentalize and regulate these three gases for signaling purposes. Ironically, many of the signaling pathways have become now intimately involved in regulating oxygen delivery and their evolution has continued well into the vertebrates. This review examines the role NO, CO and H₂S played in early life and their regulatory roles in oxygen delivery during the course of vertebrate evolution.     

双水平气道正压无创通气应用于腹腔镜胆囊切除术全身麻醉用药费用评价

目的 通过计算比较全身麻醉采用不同机械通气模式:双水平气道正压(BiPAP)面罩无创通气与气管内插管间歇正压通气(IPPV)(静脉麻醉与吸入麻醉)下的麻醉用药费用,探讨BiPAP通气在临床麻醉中的应用价值.方法 择期行腹腔镜胆囊切除手术成年患者60例,完全随机分为3组,Ⅰ组(BiPAP无创通气组),术中输注丙泊酚维持麻醉;Ⅱ组(气管内插管机械通气组),术中输注丙泊酚维持麻醉;Ⅲ组(气管内插管机械通气组),术中吸入七氟醚维持麻醉.3组患者术中均应用舒芬太尼镇痛,顺式阿曲库铵维持肌松,根据麻醉深度指数(NI)监测镇静深度,将NI控制在50～60(脑电图分级NTS为DI级).记录麻醉药消耗量、拔管时间以及恢复室停留时间.结果 3组患者一般情况、麻醉时间、手术时间差异均无统计学意义.麻醉用药费用3组分别为Ⅰ组(360.5±90.7)元、Ⅱ组(502.4±81.2)元、Ⅲ组(441.0±99.3)元,3组间比较差异有统计学意义(P＜0.05).各时间点生命体征及血气分析监测3组间差异均无统计学意义.结论 BiPAP无创通气应用于腹腔镜胆囊切除术的全身麻醉下达到和气管内插管IPPV同样的通气效果,前者显著减少了麻醉的用药量,降低了麻醉用药费用.     

Quantitative and qualitative adaptation of human skeletal muscle mitochondria to hypoxic compared with normoxic training at the same relative work rate

Aim: To investigate if training during hypoxia (H) improves the adaptation of muscle oxidative function compared with normoxic (N) training performed at the same relative intensity. Method: Eight untrained volunteers performed one‐legged cycle training during 4 weeks in a low‐pressure chamber. One leg was trained under N conditions and the other leg under hypobaric hypoxia (526 mmHg) at the same relative intensity as during N (65% of maximal power output, W_max). Muscle biopsies were taken from vastus lateralis before and after the training period. Muscle samples were analysed for the activities of oxidative enzymes [citrate synthase (CS) and cytochrome c oxidase (COX)] and mitochondrial respiratory function. Results: W _max increased with more than 30% over the training period during both N and H. CS activity increased significantly after training during N conditions (+20.8%, P < 0.05) but remained unchanged after H training (+4.5%, ns) with a significant difference between conditions (P < 0.05 H vs. N). COX activity was not significantly changed by training and was not different between exercise conditions [+14.6 (N) vs. ?2.3% (H), ns]. Maximal ADP stimulated respiration (state 3) expressed per weight of muscle tended to increase after N (+31.2%, P < 0.08) but not after H training (+3.2%, ns). No changes were found in state four respiration, respiratory control index, P/O ratio, mitochondrial Ca²⁺ resistance and apparent Km for oxygen. Conclusion: The training‐induced increase in muscle oxidative function observed during N was abolished during H. Altitude training may thus be disadvantageous for adaptation of muscle oxidative function.     

Approximate Entropy of Respiratory Movements in Human Newborns during Different Sleep States

Previous studies have reported that the respiratory cycle of healthy newborns is more irregular during active sleep. This study aimed to apply non-linear analysis to examine the irregularity of respiratory movement in newborns at different sleep states. The respiratory movement signals from an abdominal band during quiet and active sleep were analyzed using approximate entropy (ApEn). The breathing interval of active sleep was significantly shorter than that of quiet sleep [1.30 (0.17) s vs. 1.58 (0.11) s; (P < 0.03)]. The ApEn of respiratory movements during active sleep were significantly larger than that during quiet sleep [0.785 (0.135) s vs. 0.678 (0.083) s; (P < 0.05)]. We found that the ApEn of respiratory movement in healthy newborns could detect irregularities in respiration during sleep.     

Effect of mother's voice on neonatal respiratory activity and EEG delta amplitude

While the influence of the mother's voice on neonatal heart‐rate response and its relevant activity on cerebral cortex and the autonomic nervous system (ANS) are well known, few studies have assessed its influence on respiratory activity. We investigated the relationship among the respiration rate, the delta wave amplitudes through electroencephalography, and the basal state of ANS through the respiratory variability index while 22 full‐term neonates hear their mother's voice and an unknown voice. It was found that when respiratory variability was large, a transient (<5 s) change in respiration rates was observed in response to an unknown voice, while a greater increase in the delta wave amplitude was observed in the frontal lobe than the parietal one in response to the mother's voice. Conversely, when respiratory variability was small, a sustained increase (>10 s) in respiration rates was observed in response to the mother's voice, while a greater increase in the delta wave amplitude was found in both the frontal and parietal lobes. These results suggest that the basal state of ANS influences the latency of increases in respiration rates. Furthermore, induced by the mother's voice, transient increases in respiration rates are reduced in association with frontal lobe activity, and sustained increases in respiration rates are promoted in association with frontal and parietal lobe activities.     

基于电阻抗技术的多通道呼吸监测系统

目的为及时检测到早期呼吸系统疾病引起的呼吸功能的改变,本研究开发了一套采用生物电阻抗技术同时监测胸部和腹部的呼吸电阻抗信号的多通道呼吸监测系统。方法本系统主要分为3个单元：电阻抗数据采集单元、多通道开关单元和控制单元。电阻抗数据采集单元完成生物电阻抗数据高精度的检测,多通道开关单元完成不同部位数据采集通道之间的转换,控制单元采用LabVIEW编程实现对电阻抗数据采集单元和多通道开关单元的控制、同步采集、数据的显示及存储。利用本系统采集5名健康人长跑5000m前后胸部和腹部的同步呼吸电阻抗信号,采用一种新的参数定量描述胸部和腹部的呼吸电阻抗信号的同步程度。结果长跑前后胸部和腹部同步呼吸电阻抗信号的同步程度具有显著差异（P〈0．01）。结论基于电阻抗技术的多通道呼吸监测系统能够有效用于多个部位呼吸电阻抗信号的同步监测,为早期呼吸系统疾病的检测提供辅助诊断信息。     

Physiological measures of mother–infant interactional synchrony

Mother–infant interactional synchrony has been hypothesized to be crucial for the development of many key neurodevelopmental behaviors in infants, including speech and language. Assessing synchrony is challenging because many interactive behaviors may be subtlety, if at all, observable in overt behaviors. Physiological measures, therefore, may provide valuable physiological/biological markers of mother–infant synchrony. We have developed a multilevel measurement platform to assess physiological synchrony, attention, and vocal congruency during dynamic face-to-face mother–infant interactions. The present investigation was designed to provide preliminary data on its application in a group of 10 mother–infant dyads (20 subjects) ranging in age from 7 to 8.5 months at the time of the experimentation. Respiratory kinematics, heart rate, and vocalization were recorded simultaneously from mothers and infants during nonstructured, face-to-face interactions. Novel statistical methods were used to identify reliable moments of synchrony from cross-correlated, mother–infant respiration and to tag infant attention from heart rate deceleration. Results revealed that attention, vocal contingency, and respiratory synchrony are temporally clustered within the dyad interaction. This temporal alignment is consistent with the notion that biological synchrony provides a supportive platform for infant attention and mother–infant contingent vocalization.