超声下膈肌收缩指数与腹部大手术后脱机成功率相关性分析

目的研究超声下膈肌收缩指数与腹部大手术后脱机成功率的相关性。方法选择北京大学深圳医院2015年11月至2017年11月收治的腹部大手术患者130例,其中男性59例,女性71例;年龄40～71岁,平均年龄57.54岁;通气时间3～7 d,平均通气时间5.23 d。根据患者是否脱机成功分为2组(成功组、失败组),均65例。对比两组患者膈肌收缩指数,分析与脱机成功的相关性。结果两组患者在自主呼吸试验(SBT)0 min、10 min之间的膈肌移动度(DMM)(左侧、右侧)参数差异均无统计学意义(t=-0.112、0.480、0.753、1.036,P=0.911、0.632、0.453、0.302 0.05),但成功组SBT 30 min参数明显低于失败组,差异有显著统计学意义(t=3.692、3.341,P=0.000、0.001 0.01)。在SBT 0 min时两组患者浅快呼吸指数比较,差异无统计学意义(t=0.595,P=0.553 0.05);而在SBT 10 min、30 min时成功组低于失败组,差异有显著统计学意义(t=3.700、5.896,P=0.000、0.000 0.01)。SBT前,两组患者氧合指数差异无统计学意义(P 0.05);SBT后,成功组氧合指数在各个时间段均高于失败组,差异有显著统计学意义(t=-3.506、-4.138、-8.291,P=0.001、0.000、0.000 0.01);而两组患者左右侧的平静呼气末膈肌厚度比较,差异均无统计学意义(P 0.05)。结论通过对腹部大手术患者实施超声下膈肌检测,DMM能够明确指导患者脱机结果,图像质量较高,值得应用。     

急性呼吸衰竭患者通气治疗期间C反应蛋白/白蛋白比值变化对撤机结局的影响

目的:探讨急性呼吸衰竭患者通气治疗期间C反应蛋白(C reactive protein,CRP)/白蛋白(Albumin,ALB)比值变化情况对撤机结局的影响.方法:选择2020年11月至2021年11月安阳市第六人民医院收治的急性呼吸衰竭患者98例,Logistic回归分析通气治疗期间CRP/ALB比值变化在撤机中的预测价值.结果:撤机成功组重症加强护理病房住院时间、通气治疗第1d及自主呼吸测试前CRP/ALB值均低于撤机失败组(P<0.05);多因素Logistic回归分析显示,通气治疗期间CRP/ALB值是急性呼吸衰竭患者撤机成功的独立因素(OR>1,P<0.05);绘制ROC曲线,结果显示,通气治疗期间CRP/ALB比值预测撤机成功的曲线下面积均>0.7,具有一定的预测价值.结论:急性呼吸衰竭患者通气治疗期间CRP/ALB值变化情况是影响撤机成功的独立因素,可以有效预测机械通气撤机结局.     

流量波形触发技术在慢性阻塞性肺疾病合并撤机困难患者中的应用研究

目的 观察不同流量触发机制对撤机困难的呼吸衰竭患者在压力支持通气(PSV)时通气参数的影响.方法 呼吸衰竭患者23例,其中男性16例,女性7例,年龄(68±6)岁.基础疾病均为慢性阻塞性肺疾病(COPD).所有患者均为接受有创人工气道(气管插管/汽管造口)及机械通气支持1周以上者,在治疗过程中病情稳定准备进行自主呼吸试验(spontaneous breathing trial,SBT).分别在标准流量触发(2L/min)和流量波形触发机制下通气支持30min(PS10cmH2),监测患者的呼吸力学参数[包括潮气量(VT)、呼吸频率(RR)、分钟通气量(MV)、气道闭合压(Pα1)、浅快呼吸指数(RSBI)和压力时间乘积(PTPt)等]及动脉血气分析,并观察流量波形触发技术对撤机的影响.结果 2例患者因生理学参数不稳定而终止SBT试验.其余21例在采用流量波形触发PSV支持30 min后,RR、MV和RSBI均出现显著增加(P＜0.05),但VT、Pα1却无明显变化.继续通气支持24h后,RR、MV和RSBI与采用流量波形触发PSV支持30 min时相比无显著改变,PTPt和Pα1却呈显著降低,动脉血二氧化碳分压(PaCO2)也逐渐降低.采用流量波形触发PSV支持3～7 d后,21例患者成功撤机.结论 流量波形触发技术能显著减少COPD呼吸衰竭患者的自主吸气做功,改善人机同步性,提高撤机成功率.     

重症机械通气患者Th17/Treg细胞平衡与困难撤机结局的相关性

目的 观察重症机械通气(MV)患者辅助性T细胞17(Th17)/调节性T细胞(Treg)因子失衡与困难撤机结局的关系,以指导未来重症机械通气患者困难撤机结局的评估与干预.方法 选择我院2018年1月至2020年1月收治的214例重症患者作为研究对象,患者有不同程度的自主呼吸困难,均接受MV治疗,对达到撤机标准的患者进行自主呼吸试验(SBT),通过试验者行拔管,观察48h,记录撤机结局.比较不同撤机结局患者的炎症因子[降钙素原(PCT)、C反应蛋白(CRP)、肿瘤坏死因子(TNF-α)、白细胞介素-1β(IL-1β)]水平,Th17细胞因子[白细胞介素-6(IL-6)、白细胞介素-17(IL-17)及γ-干扰素(IFN-γ)]水平及Treg细胞因子[转化生长因子-β(TGF-β)、白细胞介素-4(IL-4)及白细胞介素-10(IL-10)]水平,并探讨Th17/Treg细胞平衡状况,分析Th17/Treg细胞失衡对撤机结局的预测价值.结果 214例重症MV患者,有89例发生困难撤机结局,发生率为41.59％;困难撤机组IL-6、IL-17及IFN-γ水平均高于撤机成功组,TGF-β、IL-4及IL-10水平均低于撤机成功组(P<0.05);撤机困难组Th17细胞比例、Th17/Treg高于撤机成功组,Treg细胞比例低于撤机成功组(P<0.05);经Logistic回归分析结果 显示,IL-6、IL-17及IFN-γ高水平,TGF-β、IL-4及IL-10低水平,Th17细胞高比例,Treg细胞低比例及Th17/Treg高比值是重症MV患者困难撤机结局发生的危险因素(OR>1,P<0.05);绘制ROC曲线发现,Th17细胞比例、Treg细胞比例、Th17/Treg比值用于重症MV患者困难撤机结局风险预测的AUC均>0.80,有一定预测价值,且以Th17/Treg比值的预测价值高;当各细胞cut-off值取分别取4.180％、4.860％、0.779％时,可得到最佳预测价值.结论 重症MV患者Th17/Treg细胞平衡与困难撤机结局密切相关,Th17/Treg细胞高比例可导致困难撤机发生,可将Th17/Treg细胞作为困难撤机结局的有效预测因子.     

ICU呼吸衰竭患者呼吸机依赖原因和护理研究进展

机械通气是救治重症病房呼吸衰竭患者的重要手段,能控制或替代自主呼吸、提高通气量、改善肺通气,使患者度过危险期,因此在临床得到了广泛的应用。但长期使用机械通气会造成依赖性,导致反复撤机失败,不利于预后。本文对近年来关于重症监护病房呼吸机撤机失败影响因素的相关研究进行总结,为今后该类患者呼吸机依赖和撤机失败的有效预防提供参考。     

自动导管阻力补偿技术联合压力支持通气对撤机患者呼吸力学参数的影响

目的观察自动导管阻力补偿技术（ATC）联合压力支持通气（PSV）对接受机械通气支持的撤机患者在自主呼吸试验（SBT）时通气参数的影响。方法呼吸衰竭患者16例．其中男性9例,女性7例,年龄（65±6）岁,基础疾病均为慢性阻塞性肺疾病急性加重期（AECOPD）．所有入选患者均为接受气管插管（导管直径7．0～8．0mm）并机械通气支持至少24h以上,在治疗过程中病情稳定进入撤机阶段者。患者随机接受不同辅助通气模式（ATC、PSV或ATC＋PSV）进行SBT,持续时间均为60min。预置持续气道正压（CPAP）／呼气末气道正压（PEEP）为0．49kPa（5cmH2O）,ATC时根据气管导管类型与直径将补偿比例设置为100％,PSV的吸气压力支持（PS）水平则为0．78kPa（8cmH2O）,吸气触发灵敏度为2L／min。结果ATC＋PSV时的气道峰压（PIP）明显高于标准PSV时,且出现在吸气早期;吸气峰流速（PIFR）与呼气峰流速（PEFR）也均显著增高,达峰容积比（VPEFR/VTE）则由PSV时的7．9％±0．4％降至3．7％±0．3％（P〈0．05）;但潮气量（VT）、呼吸频率（RR）、分钟通气量（MV）和浅快呼吸指数（RSBI）等参数差异则无统计学意义（P〈0．05）。ATC时患者的PIP最低,VT与ATC＋PSV相比略减小,但差异无统计学意义;RR和RSBI则明显增高。ATC时的PIFR低于PSV和ATC＋PSV时,PEFR则与ATC＋PSV时相近．而较PSV增高。结论ATC技术与PSV一样均通过提供一定的预置压力,以帮助患者在自主呼吸状态克服人工气道所引起的阻力。但与PSV的固定水平压力补偿所不同．ATC时呼吸机所提供的压力补偿是根据实际气流变化而相应改变,且对呼气也有效。     

健康教育对机械通气患者顺利撤机的影响

目的探讨给予机械通气患者健康教育对ICU患者护理的影响。方法60例机械通气患者,随机分为实施健康教育组、对照组,每组30例,观察撤机时间、依从性、呼吸机相关性肺炎（VAP）的发生率、死亡率。结果实施健康教育组撤机时间明显早于一般治疗组（P〈0.05）,依从性较低,呼吸机相关性肺炎（VAP）的发生率、死亡率均较对照组低。结论机械通气患者应尽早实施健康教育。     

AECOPD伴呼吸衰竭患者短期内撤机拔管的影响因素分析

目的 研究慢性阻塞性肺疾病急性加重期伴呼吸衰竭患者短期内撤机拔管的影响因素。方法 回顾性分析AECOPD伴呼吸衰竭并经有创机械通气治疗成功撤机拔管的患者总共34例。入选患者根据有创机械通气的时间分为两组,即通气时间≤3 d组及通气时间＞3 d组。分别记录两组患者的性别、年龄、入科时的病程、APACHEⅡ评分、白蛋白、血红蛋白、红细胞分布宽度、C反应蛋白、降钙素原、乳酸等指标。将所有的指标进行单因素分析和多因素Logistic回归分析。结果 两组患者之间的性别、年龄、病程及APACHEⅡ评分比较,差异均无统计学意义（P＞0.05）。而通气时间≤3 d组患者血清白蛋白＜30 g/L、血红蛋白＜130 g/L患者数均少于通气时间＞3 d组,差异均有统计学意义（P＜0.05）。两组患者入科时红细胞分布宽度、C反应蛋白、降钙素原水平比较,差异无统计学意义（P＞0.05）。通气时间≤3 d组患者血乳酸＞2 mmol/L患者数少于通气时间＞3 d组,差异有统计学意义（P＜0.05）。多因素Logistic回归分析示入科时血乳酸水平是慢性阻塞性肺疾病急性加重期患者有创机械通气时间＞3 d独立的危险因素（P＜0.05）。结论 白蛋白、血红蛋白、乳酸均是AECOPD伴呼吸衰竭患者短期内撤机拔管的影响因素,其中患者入科时的血乳酸水平是慢性阻塞性肺疾病急性加重期患者有创机械通气时间＞3 d独立的危险因素,积极干预处理影响因素,对患者尽早撤机拔管有重要意义。     

表面肌电信号评价呼吸电刺激治疗功能性便秘的疗效

目的　利用表面肌电测量腹肌、膈肌和盆底肌肌电改变,评价呼吸电刺激治疗功能性便秘的疗效。 方法　共31例功能性便秘患者纳入研究,按随机数字表法分为对照组和治疗组,对照组采用单纯盆底生物反馈治疗（16例）,治疗组在盆底生物反馈治疗基础上进行呼吸电刺激训练（15例）。分别于治疗前以及治疗后对两组选用便秘评分系统进行评估,采用表面肌电图技术检测膈肌和下腹肌表面肌电均方根,Glazer法评估盆底肌肌电参数。 结果　治疗2周后,两组患者便秘评分系统评估较治疗前下降（P<0.05）,且治疗组评分低于对照组（P<0.05）;两组患者的膈肌和腹直肌均方根值较治疗前改善（P<0.05）,且治疗组膈肌肌电均方根值改善程度与对照组比较有统计学差异（P<0.05）。治疗后,Glazer法评估两组患者前基线、后基线波幅值较治疗前降低（P＜0.05）,且治疗组前基线波幅值较对照组降低,差异有统计学意义（P<0.05）。 结论　呼吸电刺激训练可有效提高膈肌、腹肌收缩力,降低盆底肌的过度活动,增强盆底生物反馈治疗改善功能性便秘的治疗效果。     

肺部超声对重症肺部感染患者肺通气的评估价值

目的:探讨肺部超声评价重症肺部感染患者通气情况的应用价值。方法:选取88例重症肺部感染患者,采用半定量方法对肺部超声征象进行评分,以CT检查结果为金标准,分析肺部超声评分与患者肺通气的关系;同时分析存活和死亡患者临床资料、肺部超声评分的差异,以及肺部超声评分预测患者死亡的价值。结果:88例患者全肺超声评分平均为（18.50±2.12）分,全肺CT值平均为（-620.50±88.13） HU,不通气/低通气肺组织比例平均为（10.41±3.35）%,正常通气肺组织比例平均为（71.54±6.69）%,过度通气肺组织比例平均为（17.65±4.11）%;患者肺部超声评分与全肺CT值、不通气/低通气肺组织比例呈正相关（r=0.775、0.648, P<0.05）,与正常通气肺组织比例、过度通气肺组织比例无明显相关性（r=-0.170、0.046, P>0.05）;死亡组患者年龄、糖尿病比例、APACHEⅡ评分、肺泡-动脉氧分压差、机械通气治疗和肺部超声评分分别为（59.28±8.12）岁、44.83%、（22.19±2.40）分、（344.40±82.29） mmHg、72.41%和（20.20±1.72）分,明显高于存活组（P<0.05）,而氧合指数为（104.42±21.18）,明显低于存活组（P<0.05）;Logistic回归分析结果显示:年龄、APACHEⅡ、肺部超声评分是重症肺部感染患者死亡的影响因素（OR=1.758、2.841、2.440, P<0.05）;肺部超声评分预测重症肺部感染患者死亡的ROC曲线下面积为0.901（95%CI:0.836~0.966）,截断值为20分,灵敏性和特异性分别为82.80%和84.70%。结论:肺部超声可以作为重症肺部感染患者肺通气的评估指标,同时其在预测患者预后方面有一定应用价值。     

和肽素水平对大鼠心肾综合征的早期预测价值

目的:研究和肽素(CPP)水平对部分肾切除术(SNX)合并心肌梗死(MI)大鼠心肾综合征(CRS)的预测价值。方法:60只雄性SD大鼠采用SNX+MI建立CRS模型,随机分成空白对照(Con)组、SNX组、MI组和CRS组,造模后1~5周检测大鼠血清与尿液中CPP浓度的变化及血液动力学、血压与肾功能的水平。采用受试者工作特征(ROC)曲线评价CPP对大鼠发生CRS的预测价值。结果:与Con组比,CRS组大鼠在造模后9 d的左心室收缩压(LVSP)显著降低(P0.05),左心室舒张末压(LVEDP)显著升高(P0.05),而血压在各时点的差异无统计学显著性;CRS组大鼠的血尿素氮(BUN)和尿肌酐(UCr)在1周和3周均显著升高(P0.05)。与Con组比,CRS组在造模后1、3和5周血清中的CPP显著升高(P0.05),造模后3周尿液中的CPP显著升高(P0.05);在造模后1和3周血清中脑钠肽(BNP)显著升高(P0.05),造模后5周尿液中BNP显著升高(P0.05);CRS组在造模后1周血清和尿液中CPP与BNP和BUN无相关性。ROC曲线分析显示,血清CPP在1周时预测CRS的曲线下面积(AUC)为0.908(95%CI为0.789~1.028),以56.59 ng/L为阈值,其诊断敏感度为87.5%,特异性为80.0%。结论:SNX+MI合并术式能建立心肾共损的CRS大鼠模型,血清CPP可以作为CRS早期预测较为敏感和特异的生物标志物。     

The development of a novel knowledge-based weaning algorithm using pulmonary parameters: a simulation study

Weaning is important for patients and clinicians who have to determine correct weaning time so that patients do not become addicted to the ventilator. There are already some predictors developed, such as the rapid shallow breathing index (RSBI), the pressure time index (PTI), and Jabour weaning index. Many important dimensions of weaning are sometimes ignored by these predictors. This is an attempt to develop a knowledge-based weaning process via fuzzy logic that eliminates the disadvantages of the present predictors. Sixteen vital parameters listed in published literature have been used to determine the weaning decisions in the developed system. Since there are considered to be too many individual parameters in it, related parameters were grouped together to determine acid-base balance, adequate oxygenation, adequate pulmonary function, hemodynamic stability, and the psychological status of the patients. To test the performance of the developed algorithm, 20 clinical scenarios were generated using Monte Carlo simulations and the Gaussian distribution method. The developed knowledge-based algorithm and RSBI predictor were applied to the generated scenarios. Finally, a clinician evaluated each clinical scenario independently. The Student?s t test was used to show the statistical differences between the developed weaning algorithm, RSBI, and the clinician’s evaluation. According to the results obtained, there were no statistical differences between the proposed methods and the clinician evaluations.     

糖尿病大鼠膈肌功能和形态学变化

目的:观察四氧嘧啶诱导的糖尿病4周大鼠膈肌收缩功能和形态结构的改变。方法:应用体外大鼠膈肌肌条,对其单收缩动力学、最大强直张力(P₀)、张力-频率曲线、疲劳指数(FI)的变化以及应用H.E、Heidenhain铁矾苏木素法和标准脱氢酶染色法对膈肌组织的形态学变化进行观察。结果:糖尿病大鼠膈肌最大颤搐张力(Pt)、收缩时间(CT)、半舒张时间(RT_1/2)及FI均明显低于对照组,而两组P₀无明显变化。予25、50、75、100、125Hz频率刺激膈肌时,糖尿病大鼠膈肌张力明显低于对照组。在膈肌疲劳后予氨茶碱浸浴膈肌,再予25、50、75、100和125Hz频率分别刺激膈肌,糖尿病大鼠膈肌张力均明显低于对照组。H.E及Heidenhain法染色可见糖尿病大鼠膈肌萎缩,肌横纹模糊。标准脱氢酶染色法显示糖尿病大鼠膈肌α-甘油磷酸脱氢酶呈弱阳性,光密度明显低于对照组(P＜0.01)。结论:糖尿病4周大鼠膈肌出现收缩功能减弱、易疲劳和结构破坏。     

D-二聚体、NT-proBNP对慢性阻塞性肺疾病并肺动脉高压的诊断价值

目的 分析血浆D-二聚体(DD)及N端脑钠肽前体(NT-proBNP)对慢性阻塞性肺疾病(COPD)并肺动脉高压(PH)的诊断价值.方法 选择自2013年1月至2016年1月我院呼吸内科住院并确诊为COPD的500名患者,根据有无合并PH分为PH组(n=236)和非PH组(n=264),并对COPD并PH的相关危险因素进行多因素Logistic回归分析,利用ROC曲线分析相关指标的诊断价值.结果 ①单因素分析示,PH组和非PH组两组间DD(t=9.912,P<0.05)、NT-proBNP(t=5.592,P<0.05)、LDH(t=7.592,P<0.05)、HCO3-(t=6.471,P<0.05)、PO2(t=5.461,P<0.05)、PCO2(t=6.618,P<0.05)、年龄>65岁(χ2=10.307,P<0.05)、慢性心功能不全(χ2=8.307,P<0.05)差异有统计学意义;②多因素Logistic回归分析示,DD、NT-proBNP、HCO3-、慢性心功能不全是COPD并PH的独立危险因素(P<0.05);③ROC曲线示,DD曲线下面积为0.830,最佳阈值为2.18mg/L,灵敏度为0.816,特异性为0.712;NT-proBNP曲线下面积为0.794,最佳阈值为3225ng/L,灵敏度为0.820,特异性为0.782.结论 联合DD及NT-proBNP水平对COPD并PH具有较高的诊断价值.     

血清PCT、D-D及BNP水平与AECOPD合并呼吸衰竭患者病情严重程度的相关性

目的探究血清降钙素原(PCT)、D-二聚体(D-D)及脑钠肽(BNP)水平与慢性阻塞性肺疾病急性加重(AECOPD)合并呼吸衰竭患者病情严重程度的相关性。方法选择2016年1月至2019年2月我院收治的122例AECOPD合并呼吸衰竭患者及50例未并发呼吸衰竭的AECOPD患者作为研究对象,分别纳入呼吸衰竭组及非呼吸衰竭组。收集患者入院时肺功能、血气指标、急性生理及慢性健康状态(APACHEII)评分,测定血清PCT、D-D、BNP水平,随访患者预后。结果呼吸衰竭组患者第一秒用力呼气容积占预计值的百分比(FEV1%)、第一秒用力呼气容积/用力肺活量(FEV1/FVC)等肺功能指标及动脉氧分压(PO2)等血气指标显著低于非呼吸衰竭组(P<0.05);动脉二氧化碳分压(PCO2)、APACHEII评分显著高于非呼吸衰竭组(P<0.05);呼吸衰竭组患者血清PCT、D-D、BNP水平显著高于非呼吸衰竭组(P<0.05);相关性分析示,呼吸衰竭组患者血清PCT、D-D、BNP水平与FEV1%、FEV1/FVC、PO2呈负相关(P<0.05),与PCO2、APACHEII评分呈正相关(P<0.05);呼吸衰竭组患者存活96例,死亡26例,死亡组患者血清PCT、D-D、BNP水平显著高于存活组(P<0.05);血清PCT、D-D、BNP水平预测AECOPD并发呼吸衰竭患者预后的ROC曲线下面积为0.685、0.812、0.771,血清D-D水平对其预测价值最高。结论血清PCT、D-D及BNP水平与AECOPD合并呼吸衰竭患者病情严重程度相关,可一定程度反映患者预后。     

Logistic回归和ROC曲线分析多种肿瘤标志物在结直肠癌中的诊断价值

目的:应用Logistic回归和ROC曲线探讨CEA、CA199及CA50在结直肠癌诊断中的应用价值.方法:结直肠癌患者75例,良性结直肠病患者35例,正常人49例,分别应用化学发光免疫分析测定CEA,电化学发光免疫分析测定CA199,免疫放射分析测定CA50,通过ROC曲线分析CEA、CA199、CA50及各种Logistic回归结果的ROC曲线下面积(AUC).结果:结直肠癌-良性结直肠病中,CA50的AUC要高于CA199的AUC,而CEA、CA50两项联合诊断结直肠癌的AUC(0.875)要高于CEA、CA199、CA50三项联合诊断的AUC(0.604),且CEA、CA50两项联检诊断的AUC高于CEA、CA199或CA50任意单一检查的AUC.在结直肠癌-正常对照组中,三项肿瘤标志物联检的AUC(0.866)均高于三项肿瘤标志物单一检查的AUC,无论在结直肠癌-正常对照组中还是结直肠癌-良性结直肠病中CEA的AUC都高要于CA199或CA50.结论:CEA在诊断结直肠癌有一定的临床应用价值,CA50联合CEA检测可为临床鉴别良恶性结直肠病提供有效的参考,而CEA、CA199及CA50三者联检对鉴别良恶性结直肠病的意义不大.作为一种统计手段,Logistic回归可改善诊断的灵敏度和特异性.     

支气管哮喘患者FeNO的表达及临床意义

目的:探讨不同呼出气一氧化氮(Fractional exhaled nitric oxide,FeNO)水平下支气管哮喘患者痰液、血液、肺功能检测等多个观察指标的表达特点,并分析在气道高反应性中的预测价值。方法:选取2017年1月至2019年5月于我院就诊的120例疑似支气管哮喘患者作为研究对象进行前瞻性分析,根据FeNO水平不同,将FeNO>49 ppb的42例患者列为高水平组,FeNO为26~49 ppb的33例患者为低水平组,FeNO≤25 ppb的45例患者为正常组。比较三组患者的基本临床资料、痰嗜酸性粒细胞、痰中性粒细胞、血嗜酸性粒细胞阳离子蛋白(Eosinophilic cationic protein,ECP)和免疫球蛋白E(Immunoglobulin E,IgE)以及第1s用力呼气容积(Forced expiratory volume at 1s,FEV1)、FEV1占预测值百分比(FEV1%Pred)、用力肺活量(Forced vital capacity,FVC)以及FEV1与FVC比值(FEV1/FVC)等肺功能检测结果进行统计分析。结果:经Spearman相关性分析显示,血IgE、ECP水平与FeNO水平呈正相关(r=0.615/0.629,P>0.01),FEV1%pred、FEV1/FVC与FeNO水平呈负相关(r=-0.494/0.789,P>0.01)。其中血IgE、ECP、FEV1%pred、FEV1/FVC对于预测支气管哮喘有一定的价值,而联合上述指标对于预测支气管哮喘的准确性最佳(AUC=0.920,P>0.01)。结论:不同FeNO水平支气管哮喘患者在临床表现中具有显著差异,在血IgE、ECP和肺功能FEV1%pred、FEV1/FVC指标检测的基础上增加FeNO可大大增加预测支气管哮喘的准确性。     

Weaning from Mechanical Ventilation in Children: Are We Getting It Right?

How to cite this article: Baalaaji ARM. Weaning from Mechanical Ventilation in Children: Are We Getting It Right? Indian J Crit Care Med 2021;25(9):974–975.

Respiratory disorders are one of the major reasons for admission into the Pediatric Intensive Care Unit (PICU), and mechanical ventilation is a major intervention carried out to save lives in these children. Although mechanical ventilation is lifesaving, it is not free of complications. Airway injury, ventilator-induced lung injury, ventilator-associated pneumonia (VAP), need for sedatives, and their resultant effects can all lead to prolonged morbidity in children. Hence, it becomes imperative to identify the patient''s readiness to sustain spontaneous breathing independent of a ventilator and liberate them from mechanical ventilation promptly. On the contrary, premature extubation exposes the child to risks of extubation failure, reintubation, aspiration, higher risks of VAP, and mortality. Both delayed and premature extubation result in higher complication rates, increased morbidity and mortality, and also escalating the costs involved.The phase of transition from complete ventilatory support to complete spontaneous breathing while maintaining adequate gas exchange is referred to as “weaning from ventilation.” It should be distinguished from extubation that refers to the physical removal of an endotracheal tube. Approximately 40–50% of the total ventilation duration is occupied by this weaning phase.¹ The clinical decision to wean from ventilation has been traditionally based on physician''s judgment and clinical experience. The steps involved in weaning and subsequent extubation include (1) assessment of the readiness to wean; (2) spontaneous breathing trial (SBT) while monitoring the child for possible weaning failure; and (3) extubation. Readiness to wean is assessed once the child is stabilized and the primary indication for initiating ventilation is reversed. The parameters considered are (i) reversal of the primary reason for ventilation; (ii) ability to maintain oxygenation and ventilation with low FiO₂ and positive end-expiratory pressure (PEEP); (iii) hemodynamic stability; (iv) acceptable consciousness level and airway protective reflexes; (v) adequate spontaneous respiratory efforts; (vi) sedation level; and (vii) fluid balance. This assessment is done daily, and eligible children are then weaned from ventilation.²Once it is decided that the child is ready to be weaned, the most common approach is a gradual decrease in ventilatory support and assessing the readiness to extubate once they tolerate a low level of ventilator support. The alternative approach is to assess the readiness to extubate as soon as the patient meets the criteria to initiate the ventilator weaning process. SBT is used to assess the ability of a patient to maintain acceptable gas exchange with minimal/no ventilator assistance. Pressure support (PS) with PEEP, Continuous Positive Airway Pressure (CPAP), or a T-piece trial are the various accepted SBTs. Once the child is able to tolerate one of the three SBTs without any increase in effort of breathing, they can be extubated, provided, protective airway reflexes are intact and are able to handle tracheal secretions. It was previously believed that breathing through a narrow endotracheal tube by infants imposes additional work of breathing and PS is needed to overcome this presumed additional work, although it has been proven to be not the case.^3,4 It is also important to realize that provision of “minimal PS” offers substantial ventilatory assistance to the child and does not truly represent complete spontaneous breathing. A T-piece or CPAP ≤5 cm H₂O provides the best assessment of unassisted effort of breathing.^5,6This entire process of weaning assessment and subsequent extubation could be protocolized or driven by individual physician. Protocolized weaning aims at having a uniform set of rules to reduce unwanted variability in the clinical practice. The use of protocols may also have the potential to enable nonmedical healthcare personnel, namely the nurses and respiratory therapists to take up the responsibility in weaning, thus initiate the weaning process at an appropriate time and potentially reduce the risks and costs associated with unnecessary prolongation of ventilation duration.⁷In the current study, the authors have compared the duration of mechanical ventilation and extubation failure rates using two different approaches: protocolized weaning using PS SBT followed by T-piece vs nonprotocolized physician-driven weaning, which was synchronized intermittent mandatory ventilation followed by the T-piece trial.⁸ The children were randomized once they met the eligibility criteria for SBT. Prior to extubation, children in both the groups were given a T-piece trial of 2 hours duration. A majority of children (38/40) in both the groups could be extubated, and no significant difference could be demonstrated between the two groups. Also, the ventilation duration was similar between the two groups.Previous studies in children gave conflicting results with respect to protocolized weaning. In the study by Foronda et al., children randomized to SBT protocol using PS with PEEP had a significant reduction in average ventilation duration compared to standard care.⁹ In another study conducted by Ferreira et al, during the postoperative period following cardiac surgery, the SBT group had a greater extubation success and shorter PICU length of stay compared to the control group.¹⁰ A few other randomized controlled trials did not find significant differences in the duration of ventilation or reintubation rates between protocolized and control groups.^11,12 The results of these studies are not generalizable due to the heterogeneous study population, varying practices of weaning protocol, and different end points chosen as primary outcome measures.While comparing the different modalities that assess weaning and extubation in children, it is essential to understand the differences in the terminologies—extubation failure and weaning failure. Extubation failure is defined as a requirement for reintubation within 48 hours of extubation. In children, one of the major reasons for reintubation is upper airway obstruction due to injury or edema and while, it denotes extubation failure, it cannot be termed as weaning failure. On similar grounds, patients who are electively initiated on noninvasive ventilation postextubation cannot be termed as successful weaning or “complete liberation from ventilator” but they might have been successfully extubated.The current study has demonstrated that PS SBT could be utilized to assess readiness to extubate; however, the authors have also performed additional T-piece trials following PS SBT prior to extubation. Also, the shorter weaning duration in the control group could be due to decisions being taken by the Pediatric Intensivist in the unit. Although data in adults support the use of a dedicated weaning protocol that results in faster weaning, the data are still less clear in children.¹³ The reasons for this disparity could be due to shorter duration of mechanical ventilation and lower extubation failure rates in children.¹⁴Thus, the process of weaning of children from mechanical ventilation continues to involve as much an art as science. Consistent and daily application of practice such as sedation holidays, assessing readiness to wean, and SBTs would be needed to liberate them from mechanical ventilation at appropriate time point. The exact way of conducting the various SBTs, the relation with weaning success, and the effect on ventilator-free days or length of stay still remain unanswered.     

uIL-18、ET-1、persepsin联合检测在肾结石患者术后急性肾损伤诊断中的应用

目的分析尿液uIL-18及血中ET-1、persepsin联合检测在肾结石患者术后急性肾损伤诊断中的应用价值。方法将我院2016年1月至2019年1月间收治的100例肾结石术后急性肾损伤(acute kindey injury,AKI)患者作为观察组,100例肾结石术后非AKI患者作为对照组;采用酶联免疫吸附法检测受试者血中ET-1、persepsin及尿中uIL-18水平;绘制ROC曲线分析各指标单独及联合应用在诊断肾结石术后急性肾损伤诊断中的应用。结果观察组患者血中ET-1及persepsin水平明显高于对照组,尿中uIL-18水平明显高于对照组,且差异有统计学意义(P<0.05);以不同指标作为鉴别诊断的金标准,uIL-18作为诊断指标时AKI共98例,ET-1作为诊断指标时AKI共90例,persepsin作为诊断指标时AKI共99例,三指标联合应用作为诊断指标时AKI共96例;uIL-18、ET-1、persepsin三指标联合应用评估肾结石术后AKI的灵敏度、特异性、阳性预测值、阴性预测值及AUC均明显高于三指标单独应用,且差异有统计学意义(P<0.05)。结论uIL-18、ET-1、persepsin水平联合检测有效提高肾结石术后急性肾损伤诊断价值。