适应性支持通气在部分支持通气中对呼吸力学和呼吸功的影响

目的探讨适应性支持通气(ASV)在部分支持通气过程中对呼吸力学和呼吸功的影响。方法30例有自主呼吸的危重症机械通气患者,在同样的分钟通气量和呼气末正压(PEEP)的设置下,先给予AC1模式通气45min后改为ASV模式通气,时间为45min,结束后改为AC2模式(参数设置与AC1一致),通气时间为45min。记录上述三个45min后的呼吸力学和呼吸做功的参数。结果ASV模式下的气道峰值压和平均气道压下降明显,P分别小于0.01和0.05。ASV下的内源性PEEP(PEEPi)发生率为23.3%,明显低于AC1的PEEPi发生率46.7%(P<0.05)。ASV的器械附加功(WOBimp)和吸气压力时间乘积(PTP)明显降低(P<0.01)。而两种呼吸模式的血气分析和血液动力学,以及前后两次AC模式的各种参数变化无统计学意义(P>0.05)。结论在危重症的部分支持机械通气过程中,ASV较常规通气模式有利于实施保护性通气策略,同时降低呼吸负荷和呼吸做功,因而能降低呼吸氧耗。     

同步间歇指令通气+压力支持通气对COPD并Ⅱ型呼吸衰竭患者呼吸力学及炎症因子的影响

目的探讨同步间歇指令通气(SIMV)+压力支持通气(PSV)对慢性阻塞性肺疾病(COPD)合并Ⅱ型呼吸衰竭患者呼吸力学及炎症因子的影响。方法选取入医院治疗的COPD并Ⅱ型呼吸衰竭患者40例作为研究对象,根据患者机械通气模式分为两组,其中20例予以同步间歇指令通气+压力支持通气作为SIMV+PSV组,20例予以单纯同步间歇指令通气作为SIMV组,观察两组呼吸力学和炎性因子的变化情况。结果 SIMV+PSV组总呼吸频率[(23.05±2.41)次/min]高于SIMV组[(17.58±2.38)次/min],差异有统计学意义(P<0.05);SIMV+PSV组C-反应蛋白、酸性蛋白、降钙素原分别为(93.26±21.56)mg/L、(1.38±0.50)g/L、(2.28±1.24)ng/ml,显著低于SIMV组,差异有统计学意义(P<0.05)。结论 SIMV+PSV能够改善COPD并Ⅱ型呼吸衰竭患者的总呼吸频率,降低机体炎性水平。     

适应性支持通气与传统通气模式在弥漫性肺出血急性呼吸衰竭中的应用比较

[目的]比较适应性支持通气（adaptive support ventilation,ASV）与同步间歇指令通气（SIMV）对弥漫性肺出血急性呼吸衰竭患者的治疗价值.[方法]将弥漫性肺出血急性呼吸衰竭机械通气患者38例,随机分为两组,分别采用ASV和SIMV模式进行治疗直至撤机,比较两组的血流动力学参数、血气分析、呼吸力学和通气参数、机械通气时间、肺出血停止时间、撤机成功率及气压伤发生率的影响.[结果]①两组的血气分析和血流动力学指标无明显差异（P〉0.05）, 但ASV组较SIMV组出血停止时间明显缩短（P＜0.05）,两组脱机成功率均100%,无气压伤发生.②ASV组较SIMV组,潮气量（VT）增加而呼吸频率（RR）明显减慢,差异有显著性（P〈0.01）;气道峰压（PIP）和平台压（Pplat）下降显著（P〈0.01或P〈0.05）,内源性呼气末正加通气（PEEPi）的发生率22.38% ,明显低于SIMV组的44.67%（P〈0.01）,ASV组的机械通气时间亦明显缩短减少（P〈0.05）.[结论]ASV模式应用于急性肺出血并呼衰患者,与传统SIMV模式相比具有相同的改善氧合的效果,但呼吸力学的改善更有利于撤机和肺保护,理论上减少机械通气加重肺出血的发生,且操作较简单,值得临床推广应用.     

适应性支持通气在急性呼吸衰竭中对人机相互作用的影响

目的：探讨适应性支持通气（ASV）在急性呼吸衰竭中对人机相互作用的影响。方法：20例有自主呼吸的急性呼吸衰竭患者,在同样的分钟通气量和呼气末正压的设置下,先予以AC1（辅助-控制通气）模式通气,45min后改为ASV模式通气,时间为45min,结束后再次回到AC2模式（参数设置与AC1一致）,通气时间为45min。记录上述三个45min后的呼吸力学和呼吸做功指标等参数。结果：ASV模式下的气道峰值压、气道闭合内压（P0.1）、呼吸频率下降显著,而顺应性增加明显,P值小于0.05或0.01;同时内源性呼气末正压（PEEPi）的发生率（25%）低于AC模式（45%）,P值小于0.05;而二种呼吸模式下的血气分析和血液动力学参数无明显变化,P值﹥0.05,同时前后二次AC模式的各种参数变化无统计学意义,P值﹥0.05。结论：在急性呼吸衰竭患者的机械通气过程中,ASV相对于常规通气模式,能明显改善机械通气中的人机相互作用。     

严重多发伤后急性呼吸窘迫综合征的呼吸机治疗

目的:探讨严重多发伤后急性呼吸窘迫综合征(ARDS)机械通气治疗的同步间歇指令通气(SIMV)+压力支持通气(PSV)+呼气末正压(PEEP)呼吸模式应用。方法:总结12例严重多发伤后ARDS的机械通气措施。结果:3例因并发多脏器功能衰竭(MSOF)死亡,9例呼吸功能改善存活,平均使用呼吸机时间3±2.4天。结论:严重多发伤供氧仍持续低氧血症,PaO_2<60mmHg(8kPa)或PaO_2/FiO_2<300,应机械通气治疗。SIMV+PSV+PEEP是一种可选用的呼吸模式,早期诊断、早实施机械通气、早撤机为ARDS呼吸治疗原则。     

应用机械通气模式改善婴幼儿心脏手术后低氧血症的护理

目的研究应用压力控制型同步间歇指令（SIMV＋PC）加压力支持（PSV）加呼气末正压（PEEP）通气模式改善婴幼儿心脏手术后并发低氧血症的护理方法。方法对62例心脏手术后并发低氧血症患儿分为治疗组和对照组,治疗组（32例）给予SIMV（PC）＋PSV＋PEEP通气,随时调整呼吸机参数,加强呼吸道的护理。对照组（30例）采用同步间歇指令（SIMV）通气模式和常规护理。结果治疗组血氧改善快,呼吸机使用时间短,并发症少;住ICU时间缩短。治疗组1例、对照组3例死于多器官功能衰竭。结论婴幼儿心脏手术后并发低氧血症时,应用SIMV（PC）＋PSV＋PEEP模式通气,能有效改善低氧血症,减少肺部并发症,缩短呼吸机使用时间。     

慢性阻塞性肺疾病伴呼吸衰竭患者两种通气模式应用效果比较

目的探讨两种不同呼吸机通气模式对慢性阻塞性肺疾病伴呼吸衰竭患者的影响。方法 85例COPD合并呼吸衰竭患者分为2组,观察组(n=41)患者采用适用性支持通气模式(ASV),对照组(n=44)患者采用压力支持通气模式(PSV)和同步间歇指令通气模式(SIMV)。结果 2组患者HR、呼吸频率、MAP、pH、SpO_2、p(O_2)、p(CO_2)及p(A-a)O_2指标比较无显著差异(P0.05)。观察组MRV显著高于对照组(P0.01),潮气量(VT)显著低于对照组(P0.01)。观察组患者吸气流量显著高于对照组(P0.01),呼吸比、气道闭合压显著低于对照组(P0.05)。观察组患者并发症发生率显著低于对照组(P0.05)。结论相比SIMV+PSV模式,ASV通气模式可以维持COPD伴呼衰患者自主呼吸功能。     

SIMV+PSV、ASV无创呼吸机治疗模式对慢阻肺合并呼吸衰竭的治疗效果

目的对比分析SIMV+PSV、ASV无创呼吸机治疗模式对慢阻肺合并呼吸衰竭的治疗效果。方法选取我院收治的110例慢阻肺合并呼吸衰竭患者,按通气模式分为对照组和观察组各55例。对照组以同步间歇指令通气+压力支持通气(SIMV+PSV)模式行机械通气;观察组采用适应性支持通气(ASV);对两组通气效果进行比较。结果潮气量、指令呼吸频率、总通气时间比较,观察组均优于对照组(P0.05);治疗后,两组各项血气指标对比均无较大差异(P0.05);两组治疗后各项炎症反应指标比较差异明显(P0.05);观察组呼吸机相关性肺炎发生率明显低于对照组(P0.05)。结论 ASV通气模式在慢阻肺合并呼吸衰竭中的应用效果更加理想,有利于缩短机械通气时间,减少并发症,可推广应用。     

机械通气治疗重症支气管哮喘16例体会

目的:探讨同步间歇指令通气和呼气未正压(SIMV PEEP治疗重症支气管哮喘的疗效。方法:对16 例重症支气管哮喘采用同步间歇指令通气和呼气未正压机械通气模式,观察上机前和上机后2 h,12 h,24 h,平均动脉血压,PH,PO2,PaCO2,SaO2 指标变化。结果:机械通气后PaO2,SaO2 均明显升高,PaCO2 明显降低,PH明显改善,差异均有显著性(P<0.01)。结论使用机械通气治疗重症哮喘疗效满意。     

危重支气管哮喘的机械通气治疗探讨

目的 :探讨危重支气管哮喘的机械通气方法及适应证。方法 :对符合指征的患者分别予无创性正压通气 (NPPV)或气管插管机械通气 ,采用容量控制性低通气 ,模式为同步间歇指令通气 (SIMV ) +压力支持通气(PSV ) +呼气末正压 (PEEP)。结果 :15例危重哮喘患者均抢救成功 ,治疗前后动脉血气分析明显改善 (P <0 0 1)。结论 :控制性低通气、PEEP和PSV的有机结合是抢救危重支气管哮喘安全有效的通气方法     

Patient-ventilator interactions during partial ventilatory support: a preliminary study comparing the effects of adaptive support ventilation with synchronized intermittent mandatory ventilation plus inspiratory pressure support

OBJECTIVE: To compare the effects of adaptive support ventilation (ASV) and synchronized intermittent mandatory ventilation plus pressure support (SIMV-PS) on patient-ventilator interactions in patients undergoing partial ventilatory support. DESIGN: Prospective, crossover interventional study. SETTING: Medical intensive care unit, university tertiary care center. PATIENTS: Ten patients, intubated and mechanically ventilated for acute respiratory failure of diverse causes, in the early weaning period, ventilated with SIMV-PS and clinically detectable sternocleidomastoid activity suggesting increased inspiratory load and patient-ventilator dyssynchrony. INTERVENTIONS: Measurement of respiratory mechanics, P0.1, sternocleidomastoid electromyographic activity, arterial blood gases, and systemic hemodynamics in three conditions: 1) after 45 mins with SIMV-PS (SIMV-PS 1); 2) after 45 mins with ASV, set to deliver the same minute-ventilation as during SIMV-PS; 3) 45 mins after return to SIMV-PS (SIMV-PS 2), with settings identical to those of the first SIMV-PS period. MAIN RESULTS: The same minute ventilation was observed during ASV (11.4 +/- 3.1 l/min [mean +/- sd]) as during SIMV-PS 1 (11.6 +/- 3.5 L/min) and SIMV-PS 2 (10.8 +/- 3.4 L/min). No parameter was significantly different between SIMV-PS 1 and 2, hence subsequent results refer to ASV vs. SIMV-PS 1. During ASV, tidal volume increased (538 +/- 91 vs. 671 +/- 100 mL, p <.05) and total respiratory rate decreased (22 +/- 7 vs. 17 +/- 3 breaths/min, p <.05) vs. SIMV-PS. However, spontaneous respiratory rate increased in six patients, decreased in four, and remained unchanged in one. P0.1 decreased during ASV in all patients except three in whom no change was noted (1.8 +/- 0.9 vs. 1.1 +/- 1 cm H2O, p <.05). During ASV, sternocleidomastoid electromyogram activity was markedly reduced (electromyogram index, where SIMV-PS 1 = 100, ASV 34 +/- 41, SIMV-PS 2 89 +/- 36, p <.02) as was palpable muscle activity. No changes were noted in arterial blood gases, pH, or mean systemic pressure during the trial. CONCLUSION: In patients undergoing partial ventilatory support, with clinical and electromyographic signs of increased respiratory muscle loading, ASV provided levels of minute ventilation comparable to those of SIMV-PS. However, with ASV, central respiratory drive and sternocleidomastoid activity were markedly reduced, suggesting decreased inspiratory load and improved patient-ventilator interactions. These preliminary results warrant further testing of ASV for partial ventilatory support.     

有创-无创序贯性机械通气治疗老年肺内源性急性呼吸窘迫综合征随机对照临床研究

目的 评价有创-无创序贯性机械通气治疗老年肺内源性急性呼吸窘迫综合征(ARDS)患者的疗效及可行性.方法 32例老年肺内源性ARDS患者被随机分为序贯治疗组及常规治疗对照组,每组16例.两组均建立人工气道,以辅助/控制模式+呼气末正压(PEEP)+间隙性控制性肺膨胀(SI)方式通气24 h,随病情改善改用同步间歇指令通气(SIMV)+压力支持通气(PSV)+PEEP的方式.待"ARDS控制窗"出现,序贯组改换为无创正压通气(NIPPV),以持续气道正压(CPAP)方式通气并逐渐脱离呼吸机;对照组以SIMV+PSV+PEEP常规方式脱机.动态观察两组患者的通气及氧合指标,记录有创和总机械通气时间、呼吸机相关性肺炎(VAP)发生情况及住呼吸重症监护病房(RICU)的天数.结果 两组患者治疗前血气分析结果相仿(P均>0.05);序贯组有创通气时间[(4.6±1.0)d]、总机械通气时间[(12.7±4.0)d]、住RICU时间[(16±7)d]较对照组[分别为(21.9±9.0)d、(21.9±9.0)d、(29±13)d]明显缩短,VAP发生率[6.25%(1/16)]和病死率[25.00%(4/16)]也较对照组[分别为75.00%(12/16)、56.25%(9/16)]明显降低,差异均有统计学意义(P<0.05或P<0.01).结论 对老年肺内源性ARDS插管机械通气以ARDS控制窗为时机及时改用无创通气可显著改善其疗效.     

Influence of respiratory rate on gas trapping during low volume ventilation of patients with acute lung injury

OBJECTIVE: Reduction in tidal volume (Vt) associated with increase in respiratory rate to limit hypercapnia is now proposed in patients with acute lung injury (ALI). The aim of this study was to test whether a high respiratory rate induces significant intrinsic positive end-expiratory pressure (PEEPi) in these patients. DESIGN: Prospective crossover study. SETTING: A medical intensive care unit. INTERVENTIONS AND MEASUREMENTS: Ten consecutive patients fulfilling criteria for severe ALI were ventilated with a 6 ml/kg Vt, a total PEEP level at 13+/-3 cmH(2)O and a plateau pressure kept at 23+/-4 cmH(2)O. The respiratory rate was randomly set below 20 breaths/min (17+/-3 breaths/min) and increased to 30 breaths/min (30+/-3 breaths/min) to compensate for hypercapnia. External PEEP was adjusted to keep the total PEEP and the plateau pressure constant. PEEPi was computed as the difference between total PEEP and external PEEP. The lung volume retained by PEEPi was then measured. RESULTS: Increase in respiratory rate resulted in significantly higher PEEPi (1.3+/-0.4 versus 3.9+/-1.1 cmH(2)O, p<0.01) and trapped volume (70+/-43 versus 244+/-127 ml, p<0.01). External PEEP needed to be reduced from 11.9+/-3.4 to 9.7+/-2.9 cmH(2)O ( p<0.01). PaO(2) was not affected but the alveolar-arterial oxygen tension difference slightly worsened with the high respiratory rate (p<0.05). CONCLUSIONS: An increase in respiratory rate used to avoid Vt reduction-induced hypercapnia may induce substantial gas trapping and PEEPi in patients with ALI.     

压力与容量控制通气模式对危重症患者心排血指数和胸腔内血容量指数影响的比较研究

目的 比较在机械通气过程中双水平气道正压(BIPAP)与同步间歇指令通气(SIMV)两种模式对患者心排血指数(CI)、胸腔内血容量指数(ITBVI)的影响.方法 选择24例因各种原因需行有创机械通气和脉搏指示连续心排血量(PiCCO)技术监测血流动力学的患者,根据CI分为心功能正常组(9例)和心功能低下组(15例).在BIPAP模式下,调整吸气压使潮气量(VT)分别维持于6、10、15ml/kg,其他参数不变,呼吸机模式改为SIMV后,VT调节同前.以上各种条件维持20 min后测量呼吸力学及中心静脉压(CVP)、CI、ITBVI指标,试验过程中上述参数随机选择进行.结果 在心功能正常组,两种呼吸模式间CI、ITBVI、心率(HR)、平均动脉压(MAP)、平均气道压(Pmean)、内源性呼气末正压(PEEPi)的变化均无明显差异(P值分别为0.067、0.124、0.348、0.328、0.110、0.187);而外周循环阻力指数(SVRI)在10 ml/kg VT时,BIPAP模式下高于SIMV模式(P=0.030).在心功能低下组,CI、ITBVI在SIMV模式下降明显,仅在10ml/kgVT时CI差异有统计学意义(P<0.05);在6、10、15 ml/kg VT时BIPAP模式下Pmean均较SIMV模式低(P值分别为0.003、0.000、0.004);而SVRI、HR、MAP及PEEPi在不同VT水平两种呼吸模式间差异均无统计学意义.结论 两种通气模式随VT增加均可使CI、ITBVI降低.在相同VT时,压力控制模式(BIPAP)较容量控制模式(SIMV)Pmean相对低,对CI、ITBVI影响相对较小,因此,应用PiCCO监测容量变化时通气模式可影响CI、ITBVI.     

慢性阻塞性肺疾病机械通气患者两种不同通气模式的比较

目的探讨适应性支持通气（ASV）在慢性阻塞性肺疾病（COPD）机械通气患者中的应用。方法24例存在自主呼吸行机械通气的COPD患者随机分成两组,一组先使用辅助／控制通气（A／C）模式后改为ASV模式,另一组先使用A／C模式后改为同步间歇指令通气联合压力支持通气（SIMV＋PSV）模式,采用对照性研究方法,比较前后两种通气模式对患者的呼吸力学、血流动力学和血气分析的影响,以及两组间的有创通气时间、机械通气总时间、撤机成功率及调机次数。结果从A／C模式改为ASV后患者的呼吸频率（RR）、气道峰压（Pp）、平均气道压（Pro）、气道闭合压（P0．1）和浅快呼吸指数（RSB）下降,潮气量（VT）和肺顺应性（C）上升（P〈0．01）;从A／C模式改为SIMV＋PSV后RR、Pp、Pm、P0.1和RSB下降（P〈0．01）。两组其余呼吸力学、血流动力学及血气分析指标变更模式前后差异均无统计学意义,两组之间的有创通气时间、机械通气总时间、撤机成功率差异无统计学意义,但是ASV组的调机次数明显少于SIMV＋PSV组（8．5±2．2vs13．1±3．1,P〈0．01）。结论ASV和SIMV＋PSV与A／C比较能在一定程度上降低呼吸负荷,保护肺组织。运用于撤机时两种模式效果无明显差别,但ASV操作相对简单,适合于临床医师使用。     

Dead-space reduction and tracheal pressure measurements using a coaxial inner tube in an endotracheal tube

OBJECTIVE: To evaluate the effects on CO(2) washout of the coaxial double lumen tube (DLT) as compared to a standard endotracheal tube (ETT) and tracheal gas insufflation (TGI). Precision of tracheal pressure monitoring through the DLT and safety issues, including intrinsic PEEP (PEEPi) formation during DLT ventilation, were also evaluated. DESIGN: Lung model study. SETTING: University research laboratory. MEASUREMENTS AND RESULTS: CO(2) washout was analysed in a lung model by measuring single alveolar CO(2) concentration during DLT ventilation as compared to standard ETT ventilation, at different minute ventilation (6-14 l/min) and different CO(2)-output levels (180 ml/min, 240 ml/min, and 300 ml/min). At a CO(2) output level of 240 ml/min the CO(2) washout was also compared to tidal volume-adjusted continuous TGI and expiratory synchronised TGI. Precision of tracheal pressure monitoring and PEEPi formation during DLT ventilation was evaluated by comparing pressure in each limb above the tube to reference tracheal pressure, varying I:E ratios (1:2, 1:1, and 2:1), tidal volumes (300-700 ml), breathing frequencies (15-25), and compliance (20-50 ml/cmH(2)O). DLT ventilation had the same efficacy in removing CO(2) as continuous and expiratory synchronised TGI, reducing single alveolar CO(2) concentration by 9-21% compared to normal ventilation. Tracheal pressure could be measured through the DLT with high precision. There was only marginal formation of PEEPi at tidal volumes 相似文献   

Pulse and Systolic Pressure Variation Assessment in Partially Assisted Ventilatory Support

OBJECTIVE: The use of pulse pressure variation (PPV) and systolic pressure variation (SPV) is possible during controlled ventilation (MV). Even in acute respiratory failure, controlled MV tends to be replaced by assisted ventilatory support. We tested if PPV and SPV during flow triggered synchronized intermittent mechanical ventilation (SIMV) could be as accurate as in controlled MV. METHODS: Prospective case-controlled study. Thirty patients who met criteria of weaning from controlled MV. Twenty minutes pressure support ventilation with 3 min(-1) flow triggered SIMV breathes (10 ml kg(-1)) T1, then three consecutive breaths in controlled MV (respiratory rate 12 min(-1),10 ml kg(-1)) T2. PPV and SPV were measured in T1 and T2. Correlation and Bland-Altman analysis were used to compare respective values of PPV and SPV in the two modes of ventilation. RESULTS: Significant correlations were found between dynamic indices in SIMV during pressure support ventilation and those in controlled MV mode. The mean differences between two measurements were: PPV 0.6+/-2.8% (limit of agreement: -5.0 and 6.2), SPV 0.5+/-2.3 mmHg (limit of agreement: -4.0 and 5.1). CONCLUSIONS: PPV and SPV measured during SIMV fitted with the findings in controlled MV. Dynamic indexes could be accurately monitored in patients breathing with assisted respiratory assistance adding an imposed large enough SIMV breath.