Nε-(carboxymethyl)lysine promotes lipid uptake of macrophage via cluster of differentiation 36 and receptor for advanced glycation end products

BACKGROUND Advanced glycation end products(AGEs)are diabetic metabolic toxic products that cannot be ignored.Nε-(carboxymethyl)lysine(CML),a component of AGEs,could increase macrophage lipid uptake,promote foam cell formation,and thereby accelerate atherosclerosis.The receptor for AGEs(RAGE)and cluster of differentiation 36(CD36)were the receptors of CML.However,it is still unknown whether RAGE and CD36 play key roles in CML-promoted lipid uptake.AIM Our study aimed to explore the role of RAGE and CD36 in CML-induced macrophage lipid uptake.METHODS In this study,we examined the effect of CML on lipid uptake by Raw264.7 macrophages.After adding 10 mmol/L CML,the lipid accumulation in macrophages was confirmed by oil red O staining.Expression changes of CD36 and RAGE were detected with immunoblotting and quantitative real-time polymerase chain reaction.The interaction between CML with CD36 and RAGE was verified by immunoprecipitation.We synthesized a novel N-succinimidyl-4-18Ffluorobenzoate-CML radioactive probe.Radioactive receptor-ligand binding assays were performed to test the binding affinity between CML with CD36 and RAGE.The effects of blocking CD36 or RAGE on CML-promoting lipid uptake were also detected.RESULTS The study revealed that CML significantly promoted lipid uptake by macrophages.Immunoprecipitation and radioactive receptor-ligand binding assays indicated that CML could specifically bind to both CD36 and RAGE.CML had a higher affinity for CD36 than RAGE.ARG82,ASN71,and THR70 were the potential interacting amino acids that CD36 binds to CML Anti-CD36 and anti-RAGE could block the uptake of CML by macrophages.The lipid uptake promotion effect of CML was significantly attenuated after blocking CD36 or RAGE.CONCLUSION Our results suggest that the binding of CML with CD36 and RAGE promotes macrophage lipid uptake.

不同PEEP水平联合PCV-VG通气模式对腹腔镜大肠癌根治术老年患者呼吸力学的影响

目的探讨不同呼气末正压(PEEP)水平联合压力控制容量保证通气模式(PCV-VG)对腹腔镜大肠癌根治术老年患者呼吸力学的影响。方法选择2019年11月至2020年11月于内蒙古自治区人民医院行腹腔镜大肠癌根治术的老年患者90例,根据随机数表法将患者分为三组,每组各30例,A组PEEP为0cmH2O,B组PEEP为5cmH2O,C组为个体化PEEP。比较三组患者于插管时(T_(1))、Trendelenburg体位后30min(T_(2))、Trendelenburg体位后60 min(T_(3))及手术结束时(T_(4))的气道平台压(Pplat)和肺动态顺应性(Cdyn);于麻醉诱导前(T_(0))、T_(3)及拔管后10 min(T_(5))采集动脉血标本,记录并比较动脉氧分压(PaO_(2))、动脉二氧化碳分压(PaCO_(2))值。结果三组患者T_(2)、T_(3)、T_(4)时Cdyn低于T_(1)时,T_(4)时Cdyn高于T_(2)、T_(3)时;T_(2)、T_(3)时Pplat高于T_(1)时,T_(4)时Pplat低于T_(2)、T_(3)时,且C组T_(4)时Pplat高于T_(1);T_(3)、T_(5)时PaO_(2)显著高于T_(0)时,A组T_(5)时PaO_(2)显著低于T_(3)时;T_(3)时PaCO_(2)高于T_(0)时,差异均有统计学意义(P<0.05)。T_(2)、T_(3)和T_(4)时,C组Cdyn高于A组和B组,且T_(4)时B组Cdyn显著高于A组;T_(3)时,C组PaO_(2)显著高于A组;T_(5)时,三组患者PaO_(2)分别比较后,由高到低为C组、B组、A组,差异均有统计学意义(P<0.05)。除PaCO_(2)外,其余各指标组间比较,差异均有统计学意义(P<0.05)。结论个体化滴定的PEEP联合PCV-VG通气模式可增加腹腔镜大肠癌根治术老年患者术中Cdyn及PaO_(2),改善术中氧合,减少肺损伤。

Effect of protective lung ventilation strategy combined with lung recruitment maneuver in patients with acute respiratory distress syndrome (ARDS)

Objective:To evaluate the efficacy and safety of protective lung ventilation strategy combined with lung recruitment maneuver (RM) in the treatment patients with acute respiratory distress syndrome (ARDS).Methods:Totally 74 patients with ARDS admitted to the Department of Intensive Care Unit, Changshu Second People's Hospital in Jiangsu Province between September 2010 and June 2013 were selected and randomly divided into lung recruitment group and non-lung recruitment group, and the initial ventilation solution for both groups was synchronized intermittent mandatory ventilation (SIMV). For RM, SIMV mode (pressure control and pressure support) was adopted. Positive end expiratory pressure (PEEP) was increased by 5 cm H2O every time and maintained for 40-50 s before entering the next increasing period, and the peak airway pressure was kept below 45 cm H2O. After PEEP reached the maximum value, it was gradually reduced by 5 cm H2O every time and finally maintained at 15 cm H2O for 10 min.Results:A total of 74 patients with mean age of (49.0±18.6) years old were enrolled, 36 patients were enrolled in lung recruitment maneuver (RM) group and 38 patients were enrolled into non-lung recruitment maneuver (non-RM) group. 44 were male and accounted for 59.5% of all the patients. For the indicators such as PEEP, pressure support (PS), plateau airway pressure (Pplat), peak airway pressure (Ppeak), vital capacity (VC) and fraction of inspired oxygen (FiO2), no statistical differences in the indicators were found between the RM group and non-RM group on D1, D3 and D7 (P>0.05), except that only FiO2 of RM group on D7 was significantly lower than that of non-RM group (47.2±10.0) vs. (52.2±10.5),P<0.05]. For the indicators of blood gas analysis, including pH, arterial oxygen pressure (PaO2), arterial carbon dioxide pressure (PaCO2) and oxygenation index (PaO2/FiO2), PaO2 and PaO2/FiO2 of RM group were significantly higher than those of non-RM group on D7, and the values were [(90.2±16.1) mmHg vs. (76.4±11.3) mmHg,P<0.05] and [(196.5±40.7) mmHg vs. (151.7±37.3) mmHg,P<0.05] respectively. There was no statistical difference in heart rate (HR), cardiac index (CI), central venous pressure (CVP) or mean arterial pressure (MAP) between RM group and non-RM group on D1, D3 and D7 (P>0.05). 28-day mortality, ICU mortality and in-hospital mortality were 25% vs. 28.9%, 25% vs. 26.3% and 36.1% vs. 39.5% respectively between RM group and non-RM group (allP>0.05).Conclusion:Protective lung ventilation strategy combined with lung recruitment maneuver can improve the indicators such as PaO2, FiO2 and PaO2/FiO2 on D7, but failed to improve the final outcomes such as 28-day mortality, ICU mortality and in-hospital mortality.

Endozepine-4 levels are increased in hepatic coma

AIM:To evaluate the serum levels of endozepine-4,their relation with ammonia serum levels,the grading of coma and the severity of cirrhosis,in patients with hepatic coma. METHODS:In this study we included 20 subjects with Hepatic coma,20 subjects with minimal hepatic encephalopathy(MHE) and 20 subjects control. All subjects underwent blood analysis,Child Pugh and Model for End- stage liver disease(MELD) assessment,endozepine-4 analysis. RESULTS:Subjects with hepatic coma showed significant difference in endozepine-4(P < 0.001) and NH3 levels(P < 0.001) compared both to MHE and controls patients. Between NH3 and endozepine-4 we observed a significant correlation(P = 0.009; Pearson correlation 0.570). There was a significant correlation between endozepine-4 and MELD(P = 0.017; Pearsoncorrelation = 0.529). In our study blood ammonia concentration was noted to be raised in patients with hepatic coma,with the highest ammonia levels being found in those who were comatose. We also found a high correlation between endozepine-4 and ammonia(P < 0.001). In patients with grade Ⅳ hepatic coma,endozepine levels were significantly higher compared to other groups. CONCLUSION:This study suggests that an increased level of endozepine in subjects with higher levels of MELD was observed. In conclusion,data concerning involvement of the GABA-ergic system in HE coma could be explained by stage-specific alterations.

Expiratory flow-limitation in mechanically ventilated patients: A risk for ventilator-induced lung injury?

Expiratory flow limitation(EFL), that is the inability of expiratory flow to increase in spite of an increase of the driving pressure, is a common and unrecognized occurrence during mechanical ventilation in a variety of intensive care unit conditions. Recent evidence suggests that the presence of EFL is associated with an increase in mortality, at least in acute respiratory distress syndrome(ARDS) patients, and in pulmonary complications in patients undergoing surgery. EFL is a major cause of intrinsic positive end-expiratory pressure(PEEPi), which in ARDS patients is heterogeneously distributed, with a consequent increase of ventilation/perfusion mismatch and reduction of arterial oxygenation. Airway collapse is frequently concomitant to the presence of EFL.When airways close and reopen during tidal ventilation, abnormally high stresses are generated that can damage the bronchiolar epithelium and uncouple small airways from the alveolar septa, possibly generating the small airways abnormalities detected at autopsy in ARDS. Finally, the high stresses and airway distortion generated downstream the choke points may contribute to parenchymal injury, but this possibility is still unproven. PEEP application can abolish EFL, decrease PEEPi heterogeneity, and limit recruitment/derecruitment.Whether increasing PEEP up to EFL disappearance is a useful criterion for PEEP titration can only be determined by future studies.

Preliminary Validation of Transcutaneous CO₂Monitoring in Patients Undergoing Cardiac Ablation Using Jet Ventilation

Objectives: There is no data in the current medical literature on efficacy or accuracy of transcutaneous (tcPCO2) monitoring during jet ventilation for cardiac ablation. The use of tcPCO2 during cardiac ablation procedures offers the opportunity to compare end-tidal and transcutaneous methods of CO2 measurement before and after the use of the jet ventilation. Comparison of these measurements with arterial blood gas CO2 levels allows evaluation of the accuracy of the tcPCO2 technique for use during jet ventilation. Design: Observational study;patients served as their own controls. Setting: Cardiac electrophysiology laboratory. Participants: 15 adult patients (9 M), ASA III-IV, aged 26 to 82 years (median 66 years) undergoing radiofrequency ablation for atrial fibrillation. Interventions: Jet ventilation (JV) versus conventional ventilation. Measurements and Main Results: Paired measurements of end-tidal CO2 (EtCO2) and transcutaneous CO2 (tcPCO2) were recorded during periods of conventional ventilation. Paired measurements of arterial blood CO2 (PaCO2) levels and tcPCO2 were recorded during JV. ABG samples were drawn at the anesthesiologist’s discretion to assess the patient’s respiratory status. The level of agreement between the three methods was compared using the Bland Altman plot. We found that tcPCO2 values consistently provided a close approximation to PaCO2 levels. The mean difference between tcPCO2 and EtCO2 values in baseline and post-JV was on the order of 3 - 5 mmHg, with standard deviation of 4 - 6 mmHg. This is well within the range of variability that is accepted in clinical practice. Conclusions: These preliminary results suggest that tcPCO2 provides an acceptable estimate of CO2 concentration in arterial blood during JV, as well as prior to and following JV.

Appraisal of Existing HIV/AIDs Prevention and Control Measures and Presentation of Innovative Strategies to End HIV/AIDS Epidemic by 2030

Background: Globally, UNAIDS report 2022 shows, there are 84.2 million people affected by HIV/AIDS and 40.1 million deaths from AIDS since the start of epidemic. In sub-Saharan Africa, women and girls accounted for 63% of all new HIV infections in 2021 with, six in seven new HIV infections among adolescents aged 15 - 19 years being girls. Key populations accounted for 70% of HIV infections globally in 2021, with 51% of these new HIV infections in sub-Saharan Africa. Reflecting on the 4 decades’ journey of HIV epidemic amidst local, national and international efforts, the UN target of ending AIDS as a public health threat by 2030 remains questionable unless new innovative ways are used. This study aimed at analyzing existing HIV/AIDS interventions, discuss UN interventions in line with ending HIV/AIDS by 2030 then, suggest and discuss new innovative ways of ending HIV scourge by 2030. Methods: Systematic literature review methodology was used to extract existing published information on HIV prevention strategies from 1981 to 2023. The articles were previewed by 2 experts for quality and grouped by intervention. Of the 637 articles accessed, on HIV prevention/control only 45 met the inclusion criteria. Data were synthesized using a narrative synthesis approach following standard guidelines on synthesis without meta-analysis. Descriptive analysis was done, strength and limitations were identified. UNAIDS recommendations for ending HIV/AIDS by 2030 identified and analyzed. New Innovations in HIV/AIDS were presented and discussed. The scope of the reviewed literature was limited to HIV preventive strategies practiced between 1981 and 2023. Results: Findings show that, Uganda’s HIV prevalence was at a peak in 1991 of 15% (30% among pregnant women in urban areas). ABC strategy is claimed to have turned sharply downward the prevalence through the mid-1990s and reached 5% (14% for pregnant urban women) by 2001. Analysis of the strategy showed that the achievements of the strategy could not be sustained, subsequently HIV prevalence rose again. This is because none of the ABC components can independently reduce HIV problem. In the real world, 100% abstinence has failed, condom use only reduces infection by 90% (WHO), and lifelong monogamy is impractical. Such limitations weaken ABC strategy. The study established that Post-exposure prophylaxis (PEP) i.e. taking HIV medicines within 72 hours (3 days) after a possible exposure to HIV infection is a safe, effective and a globally practiced HIV preventive intervention in emergency situations of HIV exposure. However, PEP is limited to care sought within 72 hours after exposure and yet timely access especially in rural areas and for key populations remains a big challenge. Oral PrEP was also identified as effective HIV preventive measure that can reduce HIV risk from sex by about 99% and from injection drug users by 74%. However, like PEP, timely access especially in rural areas and for key populations remains a big challenge. The UNAIDS 95-95-95 strategy (i.e. 95% of people know their HIV status, 95% with +HIV status be on sustained ART and 95% on ART get viral load suppression) formed the basis for setting the target of ending HIV/AIDS epidemic by 2030. However, our analysis shows that this target is unrealistic given the above highlighted limitations/ barriers in preventive measures and the unlikely perfect adherence (100%) to ART by all enrolled HIV positive persons. Conclusion: Ending HIV/AIDS by 2030 cannot be achieved by implementing the current preventing strategies and control measures. This study established that most of the existing HIV preventive strategies and control measures have a number of limitations. However, with sustained UN 95-95-95 strategy supplemented with additional innovative ways, there is hope that the UN dream of ending HIV/AIDS though not necessarily by 2030, can in the long run be achieved.

HMGB1-TLR4/RAGE信号通路在呼吸机相关性肺炎中的研究进展

呼吸机相关性肺炎(VAP)是一种医源性肺部感染,其发病机制复杂,缺乏诊断标志物和治疗靶点。高迁移率蛋白1(HMGB1)主要在真核细胞内表达,当细胞坏死后被动释放,晚期糖基化终末产物受体(RAGE)和Toll样受体(TLR)是HMGB1的主要受体,介导炎症因子的释放。目前针对呼吸机肺功能损害发生发展机制的研究较少,现对HMGB1参与呼吸机相关性肺炎的发病机制进行阐述,以期进一步为呼吸机相关性肺炎提供一种新的研究思路。

基于驱动压的肺保护性通气策略在婴儿单肺通气中的应用效果

目的探讨基于驱动压(Pd)个体化调节呼气末正压(PEEP)的保护性通气策略在婴儿单肺通气(OLV)中的临床效果。方法60例择期胸腔镜手术婴儿随机分成对照组(C组)和驱动压力组(DP组),每组30例。于OLV期间,比较两组婴儿人工气胸前(T0)、人工气胸后10 min(T_(1))、人工气胸后30 min(T_(2))、人工气胸后60 min(T_(3))和人工气胸结束(T4)时的MAP、HR、潮气量(Vt)、PEEP、Pd、气道峰压(Ppeak),肺静态顺应性(Cs),以及人工气胸前后的动脉血气分析结果。结果两组患儿在各时间点上的MAP、HR和Vt均差异无统计学意义(P>0.05)。与T0相比,两组患儿在T_(1)、T_(2)和T_(3)时的Pd和Ppeak均升高,Cs降低(P<0.05),在T_(2)时的Pa O_(2)和OI降低,Pa CO_(2)升高(P<0.05)。与C组相比,DP组在T_(1)、T_(2)和T_(3)时的Pd和Ppeak更低,PEEP和Cs更高(P<0.05),在T_(2)时Pa O_(2)和OI更高(P<0.05),Pa CO_(2)和FiO_(2)无明显差异(P>0.05)。OLV期间,DP组需要通气补救2例(6.9%)低于C组9例(32.4%)(P<0.05)。两组患儿术后并发症差异无统计学意义(P>0.05)。结论基于驱动压的肺保护性通气策略可个体优化婴儿OLV中PEEP设置,改善通气侧肺部顺应性和氧合。

个体化PEEP通气策略对围手术期肺保护、肺不张及血流动力学的影响:系统性评价及荟萃分析

目的 在全麻患者术中使用不同的方法(电阻抗断层成像、肺部超声、动/静态肺顺应性、驱动压、跨肺压)确定个体化呼吸末正压(PEEP),与传统的固定PEEP相比是否引起肺损伤、肺不张及血流动力学不稳定。方法 计算机检索PubMed、clinicaltrials.gov、Web of Science、Cochrane Library及中国知网,并筛选所有选定文章的参考列表和类似文献,搜索截至2023年1月的所有中英文出版物,使用Revman 5.3软件进行Meta分析。结果 研究了45篇文献,共3 767患者。Meta分析显示个体化PEEP组CC-16浓度、肺部超声评分及肺部并发症发生率与传统PEEP组相比明显降低(P<0.05)。个体化PEEP与术中更高的动态肺顺应性和更低的驱动压有关(P<0.000 01)。同时,个体化PEEP组相较于传统PEEP组对MAP(P=0.13)和HR(P=0.94)差异无统计学意义。结论 与传统PEEP相比,术中使用个体化PEEP增加了患者围手术期肺保护效应,降低了围手术期肺不张的发生率和严重程度。同时,并不引起围手术期血流动力学紊乱。

家蚕3-羟基异丁酸脱氢酶基因克隆及其在模拟失重环境中的表达模式分析

采用RT-PCR和RACE技术克隆了家蚕3-羟基异丁酸脱氢酶(hibadh)基因全长cDNA(GenBank登录号EU719652)并对其序列进行了分析,用RT-PCR方法检测了hibadh基因在家蚕5龄幼虫不同组织中的分布,最后用real-timeRT-PCR方法分析了整个胚胎期家蚕hibadh基因在模拟失重环境中的表达模式。克隆的hibadh基因cDNA全长1074bp,包含1个能编码完整Hibadh长度为969bp的开放阅读框。家蚕hibadh基因与伯霍尔德杆菌、果蝇、蜜蜂、热带爪蟾、小鼠、人类等6个物种hibadh基因推导的氨基酸序列同源性分别达到46%、43%、48%、44%、45%、45%。Hibadh蛋白为分泌蛋白,不存在糖基磷脂酰肌醇锚定位点,分子量和等电点分别为34.1kD和9.14。hibadh基因在家蚕5龄幼虫的头、丝腺、中肠、皮肤、血液、脂肪体、马氏管等组织中稳定表达。模拟失重环境中家蚕hibadh基因在胚胎发育的不同时期表达量不同,胚体突起发生期和反转期hibadh基因表达量分别上调2.3倍(P<0.05)和4.6倍(P<0.01),气管形成期hibadh基因表达量下调7.6倍(P<0.01),其余时间段hibadh基因表达量没有明显变化。整个胚胎发育期内,模拟失重组与对照组相比较hibadh基因总表达量下调2.6倍(P<0.05)。在模拟失重环境中,家蚕hibadh基因的表达模式与家蚕整体的响应模式有相似之处但不尽相同。基因对环境反应的灵敏度高于有机体整体对环境反应的灵敏度。该研究有利于进一步探讨hibadh基因的重力生物学机制。

阿司匹林抵抗联合血小板-白细胞聚集体检测对急性脑梗死患者早期神经功能恶化的预测价值

目的 探讨阿司匹林抵抗（AR）联合血小板-白细胞聚集体（PLA）检测对急性脑梗死（ACI）患者早期神经功能恶化（END）的预测价值，旨在为早期识别END及临床干预提供参考。方法 选取ACI患者197例，均于患者入院当天行AR检测、PLA检测，于入院时以及入院后24、48、72 h采用美国国立卫生研究院卒中量表（NIHSS）评估患者的神经功能情况，记录END发生情况，据此分为END组、非END组。依次对两组的可能相关影响因素进行单因素分析和多因素Logistic回归分析。结果 197例ACI患者中，发生END者49例，END发生率为24.87%。根据AR的判定标准，END组AR 23例、阿司匹林半抵抗（ASR） 15例、阿司匹林敏感（AS） 11例，非END组AR 17例、ASR 29例、AS 102例。经单因素分析，END组AR、ASR及PLA、血小板粒细胞聚集体（PNA）、血小板单核细胞聚集体（PMA）、血小板淋巴细胞聚集体（PLyA）均高于非END组（P＜0.05或P＜0.01）。多因素Logistic回归分析显示，AR及PLA、PMA、PNA、PLyA均为发生END的独立危险因素，存在AR及PLA、PMA、PNA、PLyA水平越高的患者，发生END的风险越高（P＜0.05）。结论AR和血小板活化可能都是ACI患者发生END的重要危险因素，AR联合PLA检测对于预测END的发生可能具有积极的临床意义，据此及时调整抗血小板策略，有望减少END的发生。

肺动态顺应性指导个体化PEEP滴定对颅面重建术患儿术后肺不张的影响

目的探讨肺动态顺应性(Cdyn)指导个体化PEEP滴定对颅面重建术患儿术后肺不张的影响。方法选择全麻下行颅面重建术患儿80例,男52例,女28例,年龄≤1岁,ASAⅠ或Ⅱ级,麻醉时间≥2 h。采用随机数字表法将患儿分为两组:Cdyn导向个体化PEEP组(I组)和固定PEEP组(P组),每组40例。I组在插管后5 min肺部超声评分(LUS)后进行PEEP滴定,Cdyn最高值对应的PEEP为个体化PEEP;P组PEEP固定为6 cmH_(2)O。记录插管后5 min和手术结束时胸膜旁实变评分、B线评分、LUS总评分和肺不张发生情况。记录插管后5 min和PEEP建立后Cdyn、气道峰压(Ppeak)、HR、MAP。记录插管后5 min和手术结束时氧合指数(OI)和术后72 h肺部并发症的发生情况。结果I组滴定过程中Cdyn最高值时对应个体化PEEP滴定值中位数为9 cmH_(2)O。与插管后5 min比较,两组手术结束时胸膜旁实变总评分、后胸部胸膜旁实变评分、B线总评分和前、侧、后胸部B线评分、LUS总评分均明显降低(P<0.05)。与P组比较,I组手术结束时胸膜旁实变评分、后胸部胸膜旁实变总评分、B线总评分、后胸部B线评分、LUS总评分、肺不张发生率明显降低(P<0.05),I组PEEP建立后Cdyn和Ppeak明显升高(P<0.05),手术结束时OI明显升高(P<0.05),术后72 h肺部并发症总发生率明显降低(P<0.05)。结论术中应用Cdyn指导个体化PEEP滴定能有效降低颅面重建术患儿手术结束时LUS评分和肺不张发生率,改善氧合功能,降低术后肺部并发症发生率。

肺动态顺应性指导个体化呼气末正压通气对老年患者腹腔镜结直肠癌术中肺功能的影响

目的观察肺动态顺应性(Cdyn)指导个体化呼气末正压通气(PEEP)对老年患者腹腔镜结直肠癌术中肺功能的影响。方法选择择期行腹腔镜结直肠癌根治术的老年患者68例,男37例,女31例,年龄65~79岁,BMI<30 kg/m^(2),ASAⅡ或Ⅲ级。采用随机数字表法将患者分为两组:个体化PEEP组(P组)和对照组(C组),每组34例。P组在插管完成即刻、气腹-屈氏体位建立即刻、气腹结束即刻行肺复张及PEEP滴定试验,C组设置固定PEEP 5 cmH_(2)O。记录P组3次滴定时最佳PEEP和实际VT。记录气管插管完成后10 min(T_(1))、气腹-屈氏体位建立后10 min(T_(2))、60 min(T_(3))、手术结束拔管前(T_(4))PaO_(2)、PaCO_(2)、PETCO_(2),计算氧合指数(OI)、死腔/潮气量比值(Vd/VT)、肺泡-动脉血氧分压差(A-aDO_(2))、驱动压和Cdyn。采用ELISA法测定麻醉诱导前(T0)、拔管后10 min(T5)的白细胞介素-8(IL-8)、肿瘤坏死因子-α(TNF-α)、肺Clara细胞分泌蛋白(CC16)及肺泡表面活性物质-D(SP-D)的浓度。记录术后肺部并发症(PPCs)的发生情况。结果P组滴定最佳PEEP的中位数为4 cmH_(2)O。与C组比较,P组T_(4)时PaO_(2)、OI明显升高,T_(1)、T_(3)、T_(4)时Cdyn明显升高,T_(1)—T_(4)时驱动压明显降低,T5时CC16血清浓度明显降低(P<0.05)。两组T_(1)—T_(4)时PaCO_(2)、PETCO_(2)、A-aDO_(2)、Vd/VT差异无统计学意义。两组术后3 d均未发生严重PPCs。结论在老年患者腹腔镜结直肠癌根治术中,采用压力控制通气下肺动态顺应性指导个体化PEEP的肺保护通气策略,可提高患者术中肺动态顺应性,降低驱动压,改善手术结束时氧合,降低术后CC16血清浓度,改善术中肺功能。

不同通气模式对Trendelenburg体位腹腔镜手术患者PaO_2和PaCO_2的影响

目的探讨压力控制通气（PCV）联合呼气末正压（PEEP）在Trendelenburg体位腹腔镜手术中对PaO_2和PaCO_2的影响。方法腹腔镜直肠癌根治术患者40例,年龄35~55岁,随机分为两组,每组20例。A组采用容量控制通气模式（VCV）通气[VT=体重（kg）×10ml]20min后,改用PCV模式通气20min,返回VCV模式继续通气20min后,采用PCV＋低PEEP（5cm H_2O）模式通气20min。B组则将PCV与PCV＋PEEP的顺序调换。在切换通气模式时行动脉血气分析。结果两组VCV模式时PaO_2均明显低于PCV模式及PCV＋PEEP模式（P〈0.05）。PCV模式时PaO_2明显低于PCV＋PEEP模式（P〈0.05）;VCV模式时PaCO_2明显高于PCV模式和PCV＋PEEP模式（P〈0.05）,而PCV模式和PCV＋PEEP模式时PaCO_2差异无统计学意义。VCV模式时动脉血pH值明显低于PCV和PCV＋PEEP模式（P〈0.05）,PCV和PCV＋PEEP模式时动脉血pH值差异无统计学意义。结论 Trendelenburg体位腹腔镜手术时采用PCV＋PEEP通气模式,与单纯VCV或单纯PCV模式比较,在提高PaO_2以及降低PaCO_2方面更具优势。

压力-容积曲线指导个体化保护性单肺通气在开胸术中的应用

目的:应用动态压力-容积曲线设定全身麻醉单肺通气时个体化的潮气量和呼气末正压(PEEP)。方法:42例ASAⅠ～Ⅱ级择期行肺叶切除术患者,常规双肺通气30min后(T0)行单肺通气,按照患者单肺通气即刻动态压力-容积曲线低位拐点对应的压力(PLIP)+0.196kPa设定PEEP值,依次按照100%、80%、60%高位拐点对应的容量(VUIP)设定潮气量,分别通气30min(T1、T2、T3)。记录各时点血流动力学和呼吸力学参数,并采集动脉和混合静脉血行血气分析,根据公式计算肺内分流率。结果:T1、T2、T3的PEEP值均为(0.64±0.13)kPa,潮气量分别为(10.1±1.2)mL/kg、(7.2±1.1)mL/kg、(5.6±0.7)mL/kg,与T1相比,T2的气道峰压、气道阻力、分流率降低;动脉氧分压、胸肺顺应性增加;T3的平均动脉压、动脉二氧化碳分压增高,差异有统计学意义(P<0.05)。结论:根据动态压力-容积曲线,80%VUIP联合PLIP+0.196kPa水平的PEEP有助于改善单肺通气氧合,降低分流,对血流动力学影响轻微。

高水平呼气末正压通气联合肺复张在肥胖患者全麻俯卧位手术中的应用研究

目的评价高水平呼末正压通气(PEEP)联合肺复张(RM)在肥胖患者全麻俯卧位手术中的应用效果。方法选择60例BMI≥28 kg/m^(2)择期拟行全麻下腰骶椎手术的肥胖患者,采用随机数字表法分为两组:对照组(A组)和实验组(B组),每组30例。A组设置PEEP=5 cmH_(2)O,B组设置PEEP=10 cmH_(2)O联合肺复张手法。观察并记录两组患者麻醉前(T0)、气管插管后仰卧位机械通气10 min(T1)、气管插管后俯卧位机械通气10 min(T2)、俯卧位机械通气1 h(T3)和气管拔管后脱氧30 min(T4)的血流动力学指标、呼吸力学指标、动脉血气分析指标、T0、T4和术后1 d(T5)时肺部超声评分(LUS)总分以及术后5 d内呼吸系统并发症的发生情况。结果两组患者心率(HR)、平均动脉压(MAP)比较差异无统计学意义;B组在T2、T3、T4时刻的氧合指数(OI)均显著高于A组,肺泡动脉氧分压差(A-aDO_(2))均低于A组(P<0.05);与T1时刻相比,T2、T3时刻两组患者的气道峰压(Ppeak)和驱动压(ΔP)呈上升趋势,肺动态顺应性(Cdyn)呈下降趋势(P<0.05)。B组术中的Ppeak、Cdyn相比于A组明显升高,而ΔP均低于A组(P<0.05);B组LUS评分在T4和T5时刻低于A组(P<0.05);两组术后5 d内呼吸系统并发症发生率比较差异无统计学意义。结论对于需行全麻俯卧位手术的肥胖患者,高水平PEEP联合肺复张有助于改善肺顺应性和氧合状态,提高患者氧储备和肺功能的恢复能力,但并未发现能够降低患者术后呼吸系统并发症的发生率。

急性呼吸窘迫综合征肺压力-容积曲线及其在通气设置中的应用

肺压力-容积曲线反映肺的机械力学特性,急性呼吸窘迫综合征时描记肺压力-容积曲线不仅可以监测肺机械力学受损情况,而且可以指导机械通气参数的设置,从而降低呼吸机相关性肺损伤发生的可能性。现就肺压力-容积曲线的各种描记方法、对其含义的新阐述以及利用肺压力-容积曲线来调整急性呼吸窘迫综合征通气参数等方面进行综述,为急性呼吸窘迫综合征的机械通气设置提供参考。目前文献提示应用肺压力-容积曲线的呼气支最大曲率拐点来设置急性呼吸窘迫综合征通气时的呼气末正压可能更合理。尽管如此,如何便捷准确地描记、理解急性呼吸综合征时肺压力-容积曲线并指导机械通气参数的设置仍需依靠更进一步的实验、临床研究。

呼气相压力-容积曲线在急性呼吸窘迫综合征犬肺开放策略中的应用价值

目的研究急性呼吸窘迫综合征(ARDS)犬呼气相压力-容积(P-V)曲线的特点及其在实施肺开放策略中的应用价值。方法采用大注射器法绘制ARDS犬呼气相和吸气相P-V曲线,根据曲线转折点选择不同水平的呼气末正压(PEEP),分析动脉血气、肺呼吸力学和血流动力学变化规律。结果①ARDS犬P-V曲线吸气相有两个转折点:低位拐点(LIP)及高位拐点(UIP),压力分别为(8.77±0.88)cm H2O和(13.75±0.66)cm H2O;呼气相曲线仅一个拐点(PPMC,d),压力为(10.67±0.83)cm H2O。②当PEEP从0逐渐增加到PPMC,d+2 cm H2O时,PaO2逐渐升高,静动脉分流/总血流量比值.Qs/.Qt逐渐降低;气道平台压、峰压、平均气道压逐渐升高;心排出量(CO)逐渐下降,肺循环阻力(PVR)、体循环阻力(SVR)逐渐升高。与PLIP比较,PEEP在PPMC,d及PPMC,d+2 cm H2O时PaO2显著升高[(366.67±33.00)cm H2O和(431.30±19.23)cm H2O比(309.40±30.71)cm H2O,P<0.05],Q.s/.Qt显著降低[14.38±1.48)%和(12.14±0.94)%比(17.35±1.29)%,P<0.05]。PPMC,d和PPMC,d+2 cm H2O时PaO2和.Qs/.Qt水平均与健康犬的PaO2[(446.78±49.80)cm H2O]和.Qs/.Qt[(12.25±1.08)%]水平接近,其中.Qs/.Qt变化与健康犬比较差异无统计学意义,但对循环的抑制作用却明显增强。结论对病变早期的犬ARDS采用“肺开放策略”是可行的,适当水平的通气压力可使损伤肺组织基本开放,PEEP可选择在PPMC,d或稍高于PPMC,d的水平。

电阻抗断层成像技术用于呼气末正压滴定的研究进展

适当的呼气末正压(PEEP)是保护性肺通气策略的重要组成部分,PEEP可以保持肺泡开放,减少肺萎陷伤。尽管个体化PEEP已被越来越多的临床医师认可,但最佳的PEEP滴定方法尚存争议。电阻抗断层成像(EIT)是一种无创、无辐射的成像技术,可在床边实时动态评估肺功能,将肺通气过程中的阻抗变化以动态图像呈现,能够反映PEEP调整前后肺内通气及气体分布变化,因此,EIT可用于滴定个体化PEEP。本文简要概括EIT的基本原理及监测指标,阐述临床应用EIT指导下的PEEP(PEEP_(EIT))滴定方法,旨在加强对EIT的优点和局限性的理解,为优化个体化PEEP的设置提供参考。