无创通气在机械通气撤离中的作用

目的 探讨无创通气(Noninvasive positive pressure Ventilation,NNPV)在多种原因导致的急性呼吸衰竭机械通气患者撤机流程中的有效性.方法 前瞻性分析2007年1月至2008年12月浙江大学医学院附属邵逸犬医院ICU人选的71例急性呼吸衰竭机械通气患者.经气管插管机械通气治疗48 h后,达到临床撤机条件,但末能完成自主呼吸试验,排除NPPV禁忌证,将患者随机(随机数字法)分成无创通气序贯撤机(NPPV组,n=36)和传统撤机方法(IPPV组,n=35)两组.NPPV组拔管前予提高压力支持水平休息30 min,拔管后立即给予NPPV作为撤机方法;IPPV组传统方法撤机.观察两组患者自主呼吸试验前后呼吸力学参数、动脉血气、循环指标的变化,以及分组后两组机械通气2 h后的心肺参数,同时比较两组患者的转归.结果 分绀后机械通气2 h后心肺参数差异无统计学意义.与IPPV组相比,NPPV组机械通气时间、ICU住院时间、总住院时间明显缩短,分别为[(14.88 ±3.76)d vs.(20.68±2.79)d,P<0.01);(14.16±3.45)d vs.(2.57±7.71)d,P<0.01);IPPV组分别为(23.39±5.19)d vs.(33.89±8.58)d,P<0.01)],NPPV组并发症发生率明显低于IPPV组(22.9%vs.72.2%,P<0.01),特别是肺部感染发生率较低(6.1%vs.36.1%,P<0.01).结论 NPPV适用于多种原因导致的呼吸衰竭的撤机过程.把握无创通气NPPV的适应证,以及在撤机过程中及早进行NPPV干预,可以提高NPPV住序贯撤机中的成功率.     

无创正压通气与有创正压通气治疗急性呼吸衰竭的比较研究

目的　比较无创正压通气 (NPPV)和有创正压通气 (IPPV)救治急性呼吸衰竭 (ARF)的临床效果 ,评估NPPV在ARF治疗中的作用。方法　将各种原因所致ARF 5 2例患者随机分为NPPV组 (2 6例 )和IPPV组 (2 6例 ) ,在给予病因治疗同时分别实施NPPV和IPPV。观察分析两组患者在治疗过程中动脉血气变化、并发症的发生率及治疗结果。结果　NPPV组有 7例 (2 6 .9% )治疗失败转为气管插管IPPV ,其中 4例 (15 .4 % )死亡。IPPV组死亡 5例 (19.2 % ) ,两组死亡率无显著差异 (P >0 0 5 )。两组治疗有效患者在分别接受NPPV和IPPV治疗后 6h动脉血气有相似的显著改善。NPPV组患者机械通气时间和住院时间短于IPPV组 (P <0 .0 5 )。NPPV组的并发症发生率低于IPPV组 (P <0 .0 5 )。结论　在经过选择的ARF患者中 ,应用NPPV治疗的临床效果与IPPV相似。实施NPPV可缩短机械通气和住院时间 ,减少并发症。且因为无创伤性 ,NPPV可作为经过选择的ARF患者首选的通气支持治疗手段。     

应用无创通气作为急性呼吸衰竭患者撤机方法的研究

目的评价接受机械通气治疗的急性呼吸衰竭(ARF)患者应用无创通气(NIV)撤机的临床效果。方法58例ARF患者经气管插管机械通气治疗48h后病情好转,尚未完全满足撤机条件时随机分为两组,NIV组:拔管立即给予NIV作为撤机方法;有创压力支持通气(IPSV)组:继续经人工气道给予PSV实施撤机。观察比较两组患者动脉血气变化、并发症发生率、机械通气时间和住院时间、再插管率和病死率。结果NIV组有创通气时间显著短于IPSV组(P<0.05),两组总的通气支持时间相似。NIV组呼吸机相关性肺炎(VAP)的发生率显著低于IPSV组(P<0.05),住院时间显著短于IPSV组(P<0.05)。两组再插管率和病死率相似。结论NIV用于接受机械通气的ARF患者撤机可缩短有创通气时间和住院时间,降低VAP的发生率。     

无创正压通气治疗慢性阻塞性肺疾病合并呼吸衰竭

目的观察无创正压通气(NPPV)在治疗慢性阻塞性肺疾病急性加重期(AECOPD)合并Ⅱ型呼吸衰竭患者中的临床疗效。方法治疗组42例AECOPD合并Ⅱ型呼吸衰竭患者在常规治疗的基础上进行NPPV治疗,对照组40例仅给予常规治疗(抗炎、解痉、吸氧等);观察血气指标、心率、血压、呼吸频率及住院时间的变化。结果治疗组和对照组在治疗后动脉血气pH值、动脉血二氧化碳分压(PaCO2)、动脉血氧分压(PaO2)、心率和呼吸频率与治疗前比较均有明显改善。治疗组在降低PaCO2、呼吸频率和提高PaO2方面比对照组效果更明显。结论NPPV治疗AECOPD合并Ⅱ型呼吸衰竭能更有效地降低PaCO2、呼吸频率,提高PaO2,缩短住院时间。     

无创正压通气对急性呼吸衰竭患者拔管后再插管率和预后影响的荟萃分析

目的 探讨无创正压通气对急性呼吸衰竭患者拔管后再插管率和预后的影响.方法 通过计算机检索和手工检索中文期刊数据库,Pubmed,Embase,Web of Science数据库,收集1995年1月1日至2010年6月30日关于无创正压通气对急性呼吸衰竭患者拔管后进行呼吸支持和治疗的随机对照研究,按Cochrane协作网推荐的方法对拔管后采用无创正压通气进行呼吸辅助治疗患者的再插管率和病死率行Meta评价.结果 共纳入6篇随机对照研究,其中拔管后无创正压通气组(治疗组)患者381例,拔管后常规氧疗组(对照组)患者379例,治疗组和对照组患者的病死率分别为18.6%(62/334)vs.21.6%(72/333)(P=0.34),再插管率分别为30.2%(115/381)vs.33.5%(127/379)(P=0.27).与常规氧疗相比,拔管后无创正压通气不能降低患者再插管率,也不能改善患者预后.对拔管后即开始进行无创正压通气的患者进行分析,结果提示治疗组患者病死率明显降低[12.2%(22/181)vs.23.9%(44/184),P=0.004],再插管率减少;但与对照组相比,差异无统计学意义[14.0%(32/228)vs.20.4%(47/230),P=0.07].结论 急性呼吸衰竭患者拔管后早期行无创正压通气有助于减少患者再插管率,可显著改善患者预后.

Abstract：

Objective To evaluate the effects of noninvasive positive pressure ventilation (NPPV)used after extubation on mortality and rate of reintubation in patients with acute respiratory failure (ARF).Method Pubmed, Embase, Web of Science databases were searched to collect data from randomized controlled trials (RCT) of the relevant subject from January 1995 to May 2010. Meta analysis of data about NPPV on mortality and rate of reintubation in patients after extubation carried out by using the methods recommended by the Cochrane Collaboration. Results Six RCTs included sample size of 381 NPPV and 379routine medical care. In total, the mortalities of patients in NPPV group and routine medical care group were 18.6% (62/334) vs. 21.6% (72/333), respectively, and the rates of reintubation of the two groups were 30.2% (115/381) vs. 33.5% (127/379), respectively. Compared with routine medical care, NPPV did not significantly reduce the mortality ( OR: 0.83, 95% CI =0.57 ～ 1.21 ,P =0.34) and rate of reintuation( OR: 0.83, 95% CI = 0.59 ～ 1.16, ( P = 0.27). When the analysis was focused to the four studies of them in which patients received NPPV as soon as extubation, the results were quite different. From these four studies, the mortalities of patients in NPPV group and routine medical care group were 12. 2% (22/181) vs.23.9% (44/184),(P=0.004), and the rate of reintubation of the two groups were 14.0% (32/228) vs.20.4% (47/230), (P =0.07). Compared with routine medical care, early application of NPPV to patients after extubation reduced the mortality. Conclusions This study suggests the favorable effects of early application of NPPV to patients after extubation on the mortality of acute respiratory failure.     

双水平无创正压通气在急性有机磷农药中毒伴呼吸衰竭中的应用

目的 探讨双水平无创正压(BiPAP)通气对急性有机磷农药中毒伴呼吸衰竭患者的疗效.方法将44例急性有机磷农药中毒伴呼吸衰竭患者随机分为治疗组和对照组,对照组给予常规治疗,治疗组在常规治疗的基础上给予BiPAP机械通气.观察治疗前及治疗2、24、48h动脉血气及呼吸频率和心率变化,并比较气管插管率、病死率、住院时间、住院费用.结果BiPAP通气对提高PaO2和降低PaCO2与对照组比较差异有统计学意义(均P<0.05),治疗组插管率、病死率、住院费用比对照组明显降低(P<0.05).结论BiPAP机械通气辅助治疗急性有机磷农药中毒伴呼吸衰竭效果好.对改善患者呼吸通气功能优于对照组,并可明显减少插管率、病死率,降低住院费用.     

Sequential use of noninvasive pressure support ventilation for acute exacerbations of COPD

Objectives: To compare the efficacy of noninvasive pressure support ventilation (NIPSV) in acute decompensation in chronic obstructive pulmonary disease (COPD) by means of a bi-level positive airway pressure support system (BiPAP) in a sequential mode with medical therapy alone; to assess the short-term physiologic effects of the device on gas exchange; and to compare patients successfully ventilated with NIPSV with those in whom NIPSV failed. Design: A prospective case series with historically matched control study. Setting: A general intensive care unit (ICU) of a university hospital. Patients: We evaluated the efficacy of administration of NIPSV in 42 COPD patients and compared this with standard treatment in 42 matched historical control COPD patients. Interventions: NIPSV was performed in a sequential mode, i. e., BiPAP in the spontaneous mode was used for at least 30 min every 3 h. Between periods of ventilation, patients could be systematically returned to BiPAP when the arterial oxygen saturation was < 0.85 or when the respiratory rate was > 30 breaths/min. Measurements and results: Success rate, mortality, duration of ventilatory assistance, and length of ICU stay were recorded. Eleven of the 42 patients (26 %) in the NIPSV group needed tracheal intubation compared with 30 of the 42 control patients (71 %). The 31 patients in whom NIPSV was successful were ventilated for a mean of 6 ± 3 days. In-hospital mortality was not significantly different in the treated versus the control group, but the duration of ventilatory assistance (7 ± 4 days vs 15 ± 10 days, p < 0.01) and the length of ICU stay (9 ± 4 days vs 21 ± 12, p < 0.01) were both shortened by NIPSV. BiPAP was effective in correcting gas exchange abnormalities. The pH values, measured after 45 min of BiPAP with optimal settings, in the success (7.38 ± 0.04) and failure (7.28 ± 0.04) patients were significantly different (p < 0.05). Conclusions: NIPSV, performed with a sequential mode, may be used in the management of patients with acute exacerbations of COPD. Received: 10 February 1997 Accepted: 14 July 1997     

Continuous positive airway pressure vs. proportional assist ventilation for noninvasive ventilation in acute cardiogenic pulmonary edema

Objective To compare continuous positive airway pressure (CPAP) and proportional assist ventilation (PAV) as modes of noninvasive ventilatory support in patients with severe cardiogenic pulmonary edema. Design and setting A prospective multicenter randomized study in the medical ICUs of three teaching hospitals. Patients Thirty-six adult patients with cardiogenic pulmonary edema (CPA) with unresolving dyspnea, respiratory rate above 30/min and/or SpO₂ above 90% with O₂ higher than 10 l/min despite conventional therapy with furosemide and nitrates. Interventions Patients were randomized to undergo either CPAP (with PEEP 10 cmH₂O) or PAV (with PEEP 5–6 cmH₂O) noninvasive ventilation through a full face mask and the same ventilator. Measurements and results The main outcome measure was the failure rate as defined by the onset of predefined intubation criteria, severe arrythmias or patient's refusal. On inclusion CPAP (n = 19) and PAV (n = 17) groups were similar with regard to age, sex ratio, type of heart disease, SAPS II, physiological parameters (mean arterial pressure, heart rate, blood gases), amount of infused nitrates and furosemide. Failure was observed in 7 (37%) CPAP and 7 (41%) PAV patients. Among these, 4 (21%) CPAP and 5 (29%) PAV patients required endotracheal intubation. Changes in physiological parameters were similar in the two groups. Myocardial infarction and ICU mortality rates were strictly similar in the two groups. Conclusions In the present study PAV was not superior to CPAP for noninvasive ventilation in severe cardiogenic pulmonary edema with regard to either efficacy and tolerance. T. Rusterholtz and P.-E. Bollaert contributed equally to this study. This work was supported in part by Respironics Inc., Murrysville, PA, USA.     

Comparison of pressure support ventilation and assist control ventilation in patients with acute respiratory failure

We compared the effects of pressure support ventilation (PSV) with those of assist control ventilation (ACV) on the breathing pattern, work of breathing and blood gas exchange in 8 patients with acute respiratory failure. During ACV, the tidal volume was set at 10 ml/kg, and the inspiratory flow was set at 50 to 70l/min. During PSV, the pressure support level selected was 27±5 cm H₂O to make the breathing pattern regular. Tidal volume was significantly higher (908±179 ml vs. 633±96 ml) during PSV than during ACV at a lower peak airway pressure. Respiratory frequency was lower (15±4 breaths/min vs. 24±5 breaths/min) during PSV than during ACV, associated with a lower duty cycle, which improved synchrony between the patient and the ventilator. The oxygen cost of breathing, and estimate based on the inspiratory work added by a ventilator and the oxygen consumption, did not change significantly. PaO₂ was significantly higher during PSV than during ACV. We conclude that PSV using high levels of pressure support can improve the breathing pattern and oxygenation and fully sustain the patient's ventilation while matching his inspiratory efforts.     

无创正压通气治疗创伤性湿肺的临床研究

目的 观察无创正压通气（NIPPV）治疗创伤性湿肺的疗效。方法 选择30例行无创正压通气治疗的创伤性湿肺患者为治疗组，24例未用NIPPV治疗的创伤性湿肺患者为对照组，通过对2组患者进行心电监测、血氧饱和度、呼吸频率、血气分析等指标的监测，比较2组患者呼吸频率和动脉血气参数、肺部病变吸收时间、气管插管率、ICU住院时间及预后。结果 30例创伤性湿肺患者经NIPPV治疗后动脉血气指标与临床表现明显改善（P〈0．01）；与对照组相比，NIPPV治疗组患者临床症状改善时间、肺部病变吸收时间、ICU住院时间明显缩短（P〈0．01），肺实变率显著减低（P〈0．05），但2组患者气管插管率和病死率差异却无显著性。结论 NIPPV通过调节压力支持与呼吸末正压水平，早期应用可明显改善创伤性湿肺患者病情及缩短病程，但并不能改善其预后。     

无创正压通气时不同压力水平对呼吸衰竭患者呼吸生理学参数和人机同步的影响

目的 研究慢性阻塞性肺疾病急性加重期(AECOPD)呼吸衰竭患者无创机械通气时不同压力支持(PS)水平对呼吸生理学参数、人机同步性的影响.方法 入选15例住呼吸科重症监护病房(RICU)的AECOPD呼吸衰竭患者,均需无创机械通气.分别随机给予受试者5、10、15 cm H2O(1 cm H2O=0.098 kPa)水平的PS,在每个PS水平通气30 min后进行2 min的连续参数测量,取其均值.记录每个水平的生理学参数,并计算无效触发指数.结果 15例AECOPD患者,高PS水平(15 cm H2O)的无效触发指数、潮气量(VT)、分钟通气量(VE)、VT变异率、呼吸机吸气时间(TI)、呼气时间(TE)、漏气量(leak)均显著高于低PS水平[5 cm H2O,无效触发指数:(33.8±9.1)%比(8.0±6.0)%,VT(ml):626±203比339±115,VE(L/min):11.1±4.7比7.7±2.7,VT变异率:(32.6±15.5)%比(11.3±6.9)%,TI(s):1.14±0.31比0.76±0.15,TE(s):2.49±0.44比1.87±0.28,leak(L/min):8.28±4.86比2.22±1.58,均P<0.05],而高PS水平时呼吸机呼吸频率(RRvent,次/min)显著低于低PS水平(17±3比23±3,P<0.05);在低水平PS支持下,无效触发指数与TI呈显著正相关(r=0.62,P<0.05).PS水平由低至高变化时,无效触发指数变化率(Δ无效触发)的回归分析显示:Δ无效触发与ΔTI呈显著正相关,与ΔVT呈显著负相关(R2=0.88,P=0.000).结论 ①低水平PS时,患者的无效触发主要与TI延长有关.②高水平PS可显著增加患者的VE、VT,降低RRvent,同时无效触发显著升高;无效触发指数的增加可以通过患者TI的延长、VT变化的个体差异得到解释,而与leak无关.③即使使用Shape-signal切换机制,高水平无创压力支持通气下的AECOPD患者仍保持较高的无效触发指数.     

慢性阻塞型肺疾病伴Ⅱ型呼吸衰竭患者实施无创通气最佳时机的探讨

目的探讨无创通气(NIPPV)用于治疗慢性阻塞性肺疾病(COPD)伴Ⅱ型呼吸衰竭患者的最佳时机。方法120例COPD患者随机分为NIPPV组和常规治疗组(对照组),在治疗前及治疗2 h、第3天观察两组血气、临床症状、肺功能和预后的变化。根据病情将患者分为轻、中、重三组,评价NIPPV的效果,选择应用NIPPV的最佳时机。结果NIPPV组在治疗2h后迅速改善了患者的心率、呼吸频率、呼吸困难评分、辅助呼吸肌动用评分和血气(P<0.05)。实施NIPPV后,患者的住院时间由20.6±28.9 d缩短至12.4±9.9 d,插管率由26.7%降至11.7%,病死率由13.3%降至3.3%(P<0.05)。轻、中度患者实施NIPPV的成功率较高,而重度患者的疗效不佳。结论COPD伴Ⅱ型呼吸衰竭患者应尽早使用NIPPV,应用NIPPV的最佳时机为50 mmHg相似文献   

神经电活动辅助通气和压力支持通气对呼吸衰竭患者呼吸形式的影响

目的观察神经电活动辅助通气（NAVA）和压力支持通气（PSV）对急性呼吸衰竭患者呼吸形式的影响。 方法以2018年1月至2019年6月入住苏北人民医院ICU的12例急性呼吸衰竭行机械通气患者为研究对象，随机选择NAVA或PSV模式进行通气，NAVA和PSV通气支持水平均从5 cmH₂O（1 cmH₂O=0.098 kPa）开始，分4步递增，每10 min增加1次。PSV压力支持水平分别为5、10、15、20 cmH₂O，分别记为PSV1~4组。NAVA组的支持水平每10 min增加1倍，分别为起始NAVA支持水平的1、2、3、4倍，分别记为HAVA1~4组。观察不同支持条件下（PSV1~4组及NAVA1~4组）潮气量（V_T）、气道峰压（Ppeak）、呼吸机通气频率（VRR）、中枢呼吸频率（NRR）、膈肌电活动峰值（EAdipeak）、动脉血二氧化碳分压（PaCO₂）、无效触发发生情况、呼吸机送气时间（T_i-flow）、呼吸机呼气时间（T_e-flow）、神经吸气时间（T_i-neu）、神经呼气时间（T_e-neu）、总体V_T变异度等指标。 结果（1）随着通气支持水平的增加，PSV1~4组V_T、无效触发显著增加，VRR、NRR均明显减慢，组内比较差异均有统计学意义（F=13.471，F=30.521，F=13.672，F=9.357，P＜0.05）；PSV3~4组的V_T较同时点NAVA3~4组均显著增加，PSV4组无效触发显著高于NAVA4组，差异均有统计学意义（P＜0.05）；NAVA1~4组组内各时点的V_T比较，差异无统计学意义（P＞0.05）。（2）随着通气支持水平的增加，PSV1~4组组内各时点的T_i-neu，以及NAVA1~4组组内各时点的T_i-flow、T_e-flow、T_i-neu、T_e-neu均无显著增加，差异无统计学意义（P＞0.05）；PSV1~4组T_i-flow、T_e-flow、T_e-neu显著增加，组内比较差异均有统计学意义（F=9.564，F=13.431，F=21.126，P＜0.05）；PSV4组T_i-flow、T_e-flow、T_e-neu分别显著高于NAVA4组，差异均有统计学意义（P均＜0.05）。（3）NAVA组总体V_T变异度显著高于PSV组，差异有统计学意义（P＜0.05）；NAVA组Ppeak和EAdi显著相关（r=0.96±0.14，P＜0.05）。（4）PSV4组的PaCO₂较PSV1组显著降低，差异有统计学意义（P＜0.05）。 结论与PSV相比，NAVA通气支持时间、通气支持水平与自身呼吸形式更加匹配，对呼吸形式影响更小，一定程度上避免通气不足和过度通气。     

无创呼吸机治疗冠心病致急性左心衰竭疗效观察

目的观察无创正压通气治疗冠心病致急性左心衰竭的疗效。方法观察27例冠心病致急性左心衰竭患者在常规治疗不能有效改善低氧血症时使用双水平正压通气（BiPAP）治疗，观察治疗前后临床症状，体征及动脉血气的变化。结果24例患者临床症状，血气分析结果明显改善。结论无创双水平正压通气（BiPAP）可明显改善冠心病致急性左心衰竭患者低氧血症，可提高冠心病致急性左心衰竭的抢救成功率。     

Noninvasive pressure support ventilation vs. continuous positive airway pressure in acute hypercapnic pulmonary edema

Objective This study compared noninvasive pressure support ventilation (NIPSV) and continuous positive airway pressure (CPAP) in patients with acute hypercapnic pulmonary edema with regard to resolution time.Design and setting Randomized prospective study in an emergency department.Patients and participants We randomly assigned 36 patients with respiratory failure due to acute pulmonary edema and arterial hypercapnia (PaCO₂ >45 mmHg) to NIPSV (n=18) or CPAP through a face mask (n=18).Measurements and results Electrocardiographic and physiological measurements were made over 36 h. There was no difference in resolution time defined as clinical improvement with a respiratory rate of fewer than 30 breaths/min and SpO₂ of 96% or more between CPAP and NIPSV groups. Arterial carbon dioxide tension was significantly decreased after 1 h of ventilation (CPAP, 60.5±13.6 to 42.8±4.9 mmHg; NIPSV, 65.7±13.6 to 44.0±5.5 mmHg); respective improvements were seen in pH (CPAP, 7.22±0.11 to 7.37±0.04; NIPSV, 7.19±0.11 to 7.38±0.04), SpO₂ (CPAP, 86.9±3.7% to 95.1±2.6%; NIPSV, 83.7±6.6% to 96.0±2.9%), and respiratory rate (CPAP, 37.9±4.5 to 21.3±5.1 breaths/min; NIPSV, 39.8±4.4 to 21.2±4.6 breaths/min). No significant differences were seen with regards to endotracheal intubation and in-hospital mortality.Conclusions NIPSV proved as effective as CPAP in the treatment of patients with acute pulmonary edema and hypercapnia but did not improve resolution time.     

Comparison of invasive and noninvasive positive pressure ventilation delivered by means of a helmet for weaning of patients from mechanical ventilation

Purpose

The effectiveness of noninvasive positive pressure ventilation delivered by helmet (H-NPPV) as a weaning approach in patients with acute respiratory failure is unclear.

Patients and methods

We randomly and evenly assigned 64 patients intubated for acute respiratory failure to conventional weaning with invasive mechanical ventilation (IMV) or H-NPPV. The primary end point was a reduction in IMV duration by 6 days between the 2 groups. Secondary end points were the occurrence of ventilator-associated pneumonia and major complications, duration of mechanical ventilation and weaning, intensive care unit and hospital length of stay, and survival.

Results

The mean duration of IMV was significantly reduced in the H-NPPV group compared with the IMV group (P < .0001), without significant difference in duration of weaning (P = .26) and total ventilatory support (P = .45). In the H-NPPV group, the incidence of major complications was less than the IMV group (P = .032). Compared with the H-NPPV group, the IMV group was associated with a greater incidence of VAP (P = .018) and an increased risk of nosocomial pneumonia (P = .049). The mortality rate was similar between the groups, with no significant difference in overall intensive care unit (P = .47) or hospital length of stay (P = .37).

Conclusions

H-NPPV was well tolerated and effective in patients who were difficult to wean.     

Outcome of reintubated patients after scheduled extubation

Purpose

The main objective of study was to evaluate the outcome of patients who require reintubation after elective extubation.

Materials and Methods

This is an observational, prospective cohort study including mechanically ventilated patients who passed successfully a spontaneous breathing trial. Patients were observed for 48 hours after extubation. During this time, reintubation or use of noninvasive positive pressure ventilation was considered as a failure. Reintubated patients were followed after the reintubation to register complications and outcome.

Results

A total of 1,152 extubated patients were included in the analysis. Three hundred thirty-six patients (29%) met the criteria for extubation failure. Extubation failure was independently associated with mortality (odds ratio, 3.29; 95% confidence interval, 2.19-4.93). One hundred eighty patients (16% of overall cohort) required reintubation within 48 hours after extubation. Median time from extubation to reintubation was 13 hours (interquartile range, 6-24 hours). Reintubation was independently associated with mortality (odds ratio, 5.18; 95% confidence interval, 3.38-7.94; P < .001). Higher mortality of reintubated patients was due to the development of complications after the reintubation.

Conclusions

In a large cohort of scheduled extubated patients, one third of patients developed extubation failure, of whom half needed reintubation. Reintubation was associated with increased mortality due to the development of new complications after reintubation.     

无创正压通气对急性呼吸衰竭患者拔管后再插管率和预后影响的荟萃分析

Objective To evaluate the effects of noninvasive positive pressure ventilation (NPPV)used after extubation on mortality and rate of reintubation in patients with acute respiratory failure (ARF).Method Pubmed, Embase, Web of Science databases were searched to collect data from randomized controlled trials (RCT) of the relevant subject from January 1995 to May 2010. Meta analysis of data about NPPV on mortality and rate of reintubation in patients after extubation carried out by using the methods recommended by the Cochrane Collaboration. Results Six RCTs included sample size of 381 NPPV and 379routine medical care. In total, the mortalities of patients in NPPV group and routine medical care group were 18.6% (62/334) vs. 21.6% (72/333), respectively, and the rates of reintubation of the two groups were 30.2% (115/381) vs. 33.5% (127/379), respectively. Compared with routine medical care, NPPV did not significantly reduce the mortality ( OR: 0.83, 95% CI =0.57 ～ 1.21 ,P =0.34) and rate of reintuation( OR: 0.83, 95% CI = 0.59 ～ 1.16, ( P = 0.27). When the analysis was focused to the four studies of them in which patients received NPPV as soon as extubation, the results were quite different. From these four studies, the mortalities of patients in NPPV group and routine medical care group were 12. 2% (22/181) vs.23.9% (44/184),(P=0.004), and the rate of reintubation of the two groups were 14.0% (32/228) vs.20.4% (47/230), (P =0.07). Compared with routine medical care, early application of NPPV to patients after extubation reduced the mortality. Conclusions This study suggests the favorable effects of early application of NPPV to patients after extubation on the mortality of acute respiratory failure.     

Physiological effects of noninvasive positive ventilation during acute moderate hypercapnic respiratory insufficiency in children

Introduction  A prospective physiological study was performed in 12 paediatric patients with acute moderate hypercapnic respiratory insufficiency to assess the ability of noninvasive positive pressure ventilation (NPPV) to unload the respiratory muscles and improve gas exchange. Materials and methods  Breathing pattern, gas exchange, and inspiratory muscle effort were measured during spontaneous breathing and NPPV. Results  NPPV was associated with a significant improvement in breathing pattern, gas exchange and respiratory muscle output. Tidal volume and minute ventilation increased by 33 and 17%, and oesophageal and diaphragmatic pressure time product decreased by 49 and 56%, respectively. This improvement in alveolar ventilation translated into a reduction in mean partial pressure in carbon dioxide from 48 to 40 mmHg (P = 0.01) and in respiratory rate from 48 to 41 breaths/min (P = 0.01). No difference between a clinical setting and a physiological setting of NPPV was observed. In conclusion, this study shows that NPPV is able to unload the respiratory muscles and improve clinical outcome in young patients admitted to the paediatric intensive care unit for acute moderate hypercapnic respiratory insufficiency. Electronic supplementary material  The online version of this article (doi:) contains supplementary material, which is available to authorized users.     

无创正压通气治疗急性左心衰竭合并低氧血症患者的效果观察

目的 观察无创正压通气治疗急性左心衰竭合并低氧血症患者的疗效.方法 将62例急性左心衰竭合并低氧血症患者随机分为治疗组31例和对照组31例,两组均给予常规内科治疗,治疗组应用无创正压通气治疗,分别监测两组患者治疗前、后的血气分析指标、B型脑钠肽（BNP）、临床表现等变化.结果 治疗组临床症状缓解时间[（33.7 ±7.9） min]明显短于对照组[（55.9±12.1） min],两组比较差异有统计学意义（t=8.554,P ＜0.01）.治疗组治疗前心率、呼吸频率、平均动脉压（MAP）、pH值、血氧饱和度（SaO2）、动脉血氧分压（PaO2）、动脉血二氧化碳分压（PaCO2）、B型脑钠肽（BNP）分别为（133.89 ±5.45）次/min、（34.25±5.67）次/min、（104.52 ±7.25） mmHg、7.29 ±0.06、（81.52 ±5.01）％、（55.30 ±7.14） mmHg、（46.23±10.30） mmHg和（831.59 ±292.65） ng/L,治疗3h后上述8项指标均有明显改善,心率、呼吸频率、MAP、pH值、SaO2、PaO2、PaCO2和BNP分别为（87.27 ±5.74）次/min（t=32.794,P ＜0.01）、（20.15 ±2.54）次/min（t=12.636,P＜0.01）、（76.57±3.76） mmHg（t=19.055,P＜0.01） 、7.40 ±0.06（t =7.218,P ＜0.01）、（97.16±1.27）％（t=16.848,P ＜0.01）、（92.80 ±6.24）mmHg（t=22.019,P＜0.01）、（40.56±5.19） mmHg（t=2.737,JP＜0.05）和（265.52±65.39） ng/L（t=10.511,P＜0.01）.对照组治疗前心率、呼吸频率、MAP、PH值、SaO2、PaO2、PaCO2和BNP分别为（132.13 ±5.31）次/min、（34.96±4.78）次/min、（102.56 ±7.14） mmHg、7.30 ±0.06、（82.15 ±5.24）％、（54.56±6.27） mmHg、（44.30±9.27） mmHg和（823.15±277.26） ng/L,治疗后心率[（92.15 ±4.28）次/min,t=32.638 、P＜0.01]、呼吸频率[（23.91 ±3.27）次/min,t=10.634、P＜0.01]、MAP[（82.83±3.52） mmHg,t =13.800 、P＜0.01]、SaO2[（93.16±2.59）％,t=10.488、P＜0.01）]、PaO2[（75.19±3.52） mmHg,t=15.974、P ＜0.01]和BNP[（371.15±87.55） ng/L,t=8.656 、P＜0.01]比较差异均有统计学意义;pH值、PaCO2较前无明显改变,分别为7.32 ±0.05（t=1.426,P =0.159） 、（43.78 ±6.74）mmHg（t =0.253,P=0.801）.治疗组治疗后心率、呼吸频率、MAP、pH值、SaO2、PaO2、PaCO2和BNP较对照组改善更明显,差异均有统计学差异（t值分别为3.795、5.056、6.767、5.703、7.721、13.686、2.107、5.382,P ＜0.01或P＜0.05）.结论 应用无创正压通气能迅速改善急性左心衰竭并低氧血症患者心功能,纠正低氧血症,降低血浆BNP水平.