肥胖患者单肺通气期间的通气策略

背景 肥胖人群比例不断升高,肥胖影响正常生理功能,给麻醉带来不少问题,尤其在单肺通气(one-lung ventilation,OLV)过程中. 目的 减少肥胖患者OLV过程对预后转归的影响,降低肥胖患者围手术期呼吸系统并发症的发生率. 内容 探讨肥胖患者围手术期OLV期间的通气策略,包括通气模式的选择、保护性通气策略、高碳酸血症、肺泡复张策略和吸氧浓度的选择. 趋向 肥胖患者OLV期间采用小潮气量联合呼气末正压通气(positive end-expiratory pressure, PEEP)、间断肺泡复张和低到中度Fi02等通气策略有助于改善氧合、降低肺不张发生率,高碳酸血症在无肺部疾病患者中是否具有肺保护作用尚待研究.     

不同压力的持续气道正压对化疗后病人单肺通气氧合与分流的影响

目的　探讨应用一种新的持续气道正压 (CPAP)系统在肺癌病人化疗后单肺通气(OLV)时对病人氧合和肺内分流的影响。方法　择期手术病人 30例 ,ASAⅠ～Ⅲ级 ,随机分为对照组 (A组 )、CPAP 2组 (B组 )和CPAP 5组 (C组 ) ,每组 1 0例。A组在OLV期间非通气侧肺的支气管导管直接开口于大气中 ;B组OLV期间非通气侧持续给予CPAP(压力 2cmH2 O) ,C组OLV期间非通气侧持续给予CPAP(压力 5cmH2 O) ,并在平卧双肺通气 2 0min ,仰卧OLV 2 0min ,侧卧OLV2 0、4 0min和关胸双肺通气时 ,分别采取动脉血行血气分析并计算肺内分流率 (Qs/Qt)。结果在OLV后 2 0、4 0min时 ,B、C两组氧合明显高于A组 (P <0 .0 1 ) ,B、C两组Qs/Qt明显低于A组 (P<0 .0 5 ) ,B、C两组之间氧合和Qs/Qt仅在OLV后 4 0min时差异显著。结论　化疗后病人非通气侧持续CPAP ,有助于提高氧合 ,减少肺内分流 ,减少低氧血症的发生率 ,且CPAP 2cmH2 O更易为临床所接受     

肺复张策略对健侧肺氧合及顺应性的影响

目的 评价肺复张策略(lung recruitment maneuvers,LRM)对健侧肺氧合及顺应性的影响. 方法 ASA分级Ⅱ级择期行胸腔镜辅助下肺切除术患者40例,采用随机数字表法分为对照组(C组)和实验组(L组),每组20例.C组术中常规单肺通气(one lung ventilation,OLV),L组OLV 20 min后进行1次LRM,两组均在OLV结束关闭胸腔前进行1次肺复张.分别于患者麻醉前(T0),OLV后20 min(T1),LRM后15 min(T2)、30 min(T3)、45 min(T4)及OLV结束(T5)时,采集患者生命体征数据并采集动脉血样本进行血气分析,根据公式计算肺顺应性(dynamic compliance,Cdyn). 结果 与C组相比,L组PaO2在T2[(150±11) mmHg比(204±21) mmHg,1 mmHg=0.133 kPa]、T3[(154±12) mmHg比(176±14) mmHg]、T5[(442±20) mmHg比(473±15) mmHg]时点均升高(P＜0.05),Cdyn在T2[(21±3) ml/cmH2O比(25±3) ml/cmH2O,1 cmH2O=0.098 kPa]和T5[(26±3) ml/cmH2O比(31±5)ml/cmH2O)]时点提高(P＜0.05). 结论 LRM可以有效改善OLV期间氧合及Cdyn,单次LRM提高PaO2有效时间为30 min,在15 min左右PaO2改善最为明显.     

单肺通气时机械通气模式的研究进展

背景 单肺通气(one lung ventilation,OLV)实施过程中最常见的并发症是低氧血症,也是麻醉医师遇到的最严重的挑战. 目的 近来研究表明OLV本身能够引起低氧血症和急性肺损伤(acute lung injury,ALI).因此,如何实施OLV时机械通气模式,降低肺内分流率(pulmonary shunt fraction,Qs/Qt)、预防低氧血症一直是临床研究的热点. 内容 综述提高吸入氧分数(fraction of inspiration O2,FiO2)、控制通气模式、高频通气(high frequency ventilation,HFV)、潮气量(tidal volume,Vt)、反比通气、部分液体通气(partial liquid ventilation,PLV)、持续气道正压通气(continuous positive airway pressure,CPAP)、呼气末正压通气(positive end-expiratory pressure,PEEP)等通气模式,以及实施联合多种模式的保护性肺通气策略. 趋向 综合运用多种预防OLV期间低氧血症的通气模式取得良好的效果,但应针对患者和手术情况制定OLV时机械通气模式.     

单肺通气萎陷肺损伤机制的研究

背景 单肺通气(one lung ventilation,OLV)常用于胸科手术中,OLV不仅导致通气侧肺损伤,缺氧、低灌注状态也会导致萎陷侧肺出现严重的炎症反应,甚至造成远端器官的损伤,严重影响患者的预后及生存率. 目的 简要归纳总结OLV期间萎陷肺损伤可能的发生机制. 内容 OLV期间萎陷肺损伤可能的机制包括氧化应激反应、炎症反应、免疫反应、肺泡表面活性物质的减少及萎陷肺水肿. 趋向 通过探讨OLV萎陷肺损伤的机制为临床中预防和治疗OLV萎陷肺损伤提供理论依据.     

单肺通气时肺泡征募对呼吸动力学的影响

目的研究单肺通气时肺泡征募技术对肺机械力学的影响。方法选择20例侧卧位行肺切除患者。单肺通气（OLV）时,肺泡征募（ARM）持续1分钟后紧接着对通气肺给予5cmH2O呼气末正压。在下列各时点记录血流动力学参数、气体交换和呼吸力学改变数据：双肺通气时（TLVbaseline）、单肺通气前（OLVpre-ARM）、ARM后20分钟（OLVpost-ARM）以及双肺通气结束时TLVend。结果 TLVbaseline时PaO2/FiO2为358±126,OLVpre-ARM降为235±113（P〈0.01）,OLVpost-ARM上升到351±120（P〈0.01）。在ARM期间,心指数从3.04±0.71/m2OLVpre-ARM下降到2.4±0.61/m2（P〈0.05）,OLVpost-ARM时恢复到3.1±0.71/m2（P〉0.05）。ARM能够肺泡开放且引起通气侧肺静弹性阻力明显下降（16.6±8.9 cmH2O/ml OLVpost-ARM vs 22.3±8.1 cmH2O/ml OLVpre-ARM）（P〈0.01）。结论胸科手术侧卧位OLV时,对通气肺实行ARM能够使肺泡开放,改善氧合和呼吸机械力学。但应注意ARM引起的短暂血流动力学变化。     

选择性肺叶隔离通气用于COPD老年患者开胸手术时的通气效果

目的 评价选择性肺叶隔离通气用于慢性阻塞性肺病(COPD)老年患者开胸手术时的通气效果.方法 择期拟行食管癌根治术合并COPD的老年患者30例,年龄65～80岁,体重指数16～ 28 kg/m2,ASA分级Ⅱ或Ⅲ级,采用随机数字表法,将其随机分为2组(n=15):单肺通气组(OLV组)和选择性肺叶隔离通气组(SLC组).OLV组患者采用双腔气管导管实施单肺通气,SLC组患者使用支气管堵塞器堵塞肺叶支气管,实施选择性肺叶隔离通气.于平卧位双肺通气10 min(T0)、侧卧位单肺通气或选择性肺叶隔离通气5 min(T1)、45 min(T2)、90 min(T3)、术毕侧卧位双肺通气10 min(T4)时测定气道峰压(Ppeak)、气道平台压(Pplat)、气道阻力(Raw)和动态肺顺应性(Cd).于T0、T3、T4时采集动脉血样,行血气分析,计算氧合指数(OI)、肺泡-动脉血氧分压差[P(A-a)Q2]和呼吸指数(RI).结果 与OLV组比较,SLC组T2～4时Peak、Pplat及Raw降低,T1～4时Cd升高,T3,4时0I升高、P(A-a)O2和RI降低(P＜ 0.05或0.01).结论 COPD老年患者胸科手术时,单肺通气和选择性肺叶隔离通气均可安全完成手术,实施肺叶隔离通气能改善氧合,具有更好的通气效果.     

利用动态肺顺应性设定呼气末正压在胸腔镜肺叶切除术中的运用

目的 探讨单肺通气利用动态肺顺应性设定呼气末正压通气(positive end-expiratory pressure,PEEP)的优势及可行性. 方法 选择预行右侧肺叶切除患者80例,完全随机分为A组和B组,每组40例:A组,单肺通气实施肺膨胀(sustained inflation,SI)复张后加用20 cmH2O(1 cmH2O=0.098 kPa)的PEEP并递减滴定,随后以得到最大肺顺应性的PEEP值通气,直到恢复双肺通气;B组,通气PEEP值固定为5 cmH2O,其他通气方法同A组.记录患者血气、呼吸等参数. 结果 两组设定的PEEP值[A组(9.2±1.2) cmH2O,B组5 cmH2O]差异有统计学意义(P＜0.05);在单肺通气1 h(T3)、手术结束(T4)时,两组动脉血氧分压(partial pressure of oxygen,PaO2)比较,差异有统计学意义(P＜0.05);B组的PaO2在T3～T4逐步降低,差异有统计学意义(P＜0.05),而A组则维持较好(P＞0.05);T3、T4时刻A组的动态肺顺应性[(30.8±5.9)、(30.7±6.4) ml/cmH2O]与B组[(26.6±5.5)、(26.4±5.2) ml/cmH2O]比较,差异有统计学意义(P＜0.05). 结论 胸腔镜肺叶切除术中的单肺通气,利用动态肺顺应性设定的PEEP值通气能够得到更好的氧合及呼吸参数,并且维持较好.     

单肺通气时炎性反应机制及预防的研究进展

背景 开胸手术需要长时间维持单肺通气(one-lung ventilation,OLV),这一过程可激活炎性细胞并释放大量炎性因子,导致肺部炎症反应及并发症. 目的 着重探讨OLV所致炎性因子释放的机制,保护性通气策略,促炎症消退等相关进展.内容 OLV时,过度机械牵张刺激作用于肺细胞膜表面机械感受器,激活细胞内各种传导通路,导致各种致炎因子及炎症介质的上调表达.术中小潮气量、低气道压、低呼气末正压通气(end-expiratory positive pressure,PEEP)为策略的保护性通气模式的应用及吸入麻醉药、局部麻醉药、糖皮质激素等药物的使用可显著减少炎性因子的释放,减少胸科患者术后肺损伤的发病率.趋向 内源性炎症消退机制及基因和生物靶向治疗已成为近年来研究炎症的新的热点.     

保护性通气策略对单肺通气患儿局部脑氧饱和度和S100β蛋白的影响

目的评价保护性通气策略对单肺通气(OLV)患儿局部脑氧饱和度(rScO_2)和S100β的影响。方法选择2018年2月至2020年3月择期行胸科手术OLV患儿70例,男47例,女23例,年龄2个月至11岁,ASAⅡ或Ⅲ级。采用随机数字表法将患儿分为两组:常规通气组(CV组)和保护性通气组(PV组),每组35例。CV组双肺通气和OLV期间V_T均为10 ml/kg; PV组双肺通气和OLV期间V_T均为7 ml/kg, PEEP 5 cmH_2O。两组均在麻醉诱导后纤维支气管镜明视下插入支气管封堵器。记录OLV前(T_1)、OLV 30 min(T_2)、OLV结束后10 min(T_3)的MAP、Ppeak、rScO_2、PaO_2和血浆S100β蛋白浓度。结果与T_1时比较,T_2时两组MAP、PaO_2、rScO_2均明显降低,Ppeak明显升高(P0.05)。T_2时PV组rScO_2明显高于CV组(P0.05)。与T_1时比较,T_2和T_3时两组患儿S100β蛋白浓度明显升高,且PV组明显低于CV组(P0.05)。结论保护性通气策略可通过降低S100β蛋白浓度改善OLV期间的脑氧合,具有一定的脑保护作用。     

Comparison between conventional and protective one-lung ventilation for ventilator-assisted thoracic surgery

Recent papers suggest protective ventilation (PV) as a primary ventilation strategy during one-lung ventilation (OLV) to reduce postoperative pulmonary morbidity. However, data regarding the advantage of the PV strategy in patients with normal preoperative pulmonary function are inconsistent, especially in the case of minimally invasive thoracic surgery. Therefore we compared conventional OLV (VT 10 ml/kg, FiO2 1.0, zero PEEP) to protective OLV (VT 6 ml/kg, FiO2 0.5, PEEP 5 cmH2O) in patients with normal preoperative pulmonary function tests undergoing video-assisted thoracic surgery. Oxygenation, respiratory mechanics, plasma interleukin-6 and malondialdehyde levels were measured at baseline, 15 and 60 minutes after OLV and 15 minutes after restoration of two-lung ventilation. PaO2 and PaO2/FiO2 were higher in conventional OLV than in protective OLV (P<0.001). Interleukin-6 and malondialdehyde increased over time in both groups (P<0.05); however, the magnitudes of increase were not different between the groups. Postoperatively there were no differences in the number of patients with PaO2/FiO2<300 mmHg or abnormalities on chest radiography. Protective ventilation did not provide advantages over conventional ventilation for video-assisted thoracic surgery in this group of patients with normal lung function.     

双肺通气时混合吸入空气可延迟单肺通气时的肺萎陷

背景 一侧肺萎陷有助于显露胸外科手术的手术野.双肺通气时吸入不同的混合气体可通过加速或延迟肺萎陷过程,从而改善或影响单肺通气时的手术条件.我们观察了双肺通气时吸入3种不同的混合气体对单肺通气时肺萎陷和氧合的影响:空气/氧气(FiO2=0.4)、氧化亚氮(N2O)/氧气(FiO2=0.4)、氧气(FiO2=1.0).方法...     

Lung recruitment improves the efficiency of ventilation and gas exchange during one-lung ventilation anesthesia

Atelectasis in the dependent lung during one-lung ventilation (OLV) impairs arterial oxygenation and increases dead space. We studied the effect of an alveolar recruitment strategy (ARS) on gas exchange and lung efficiency during OLV by using the single-breath test of CO(2) (SBT-CO(2)). Twelve patients undergoing thoracic surgery were studied at three points in time: (a) during two-lung ventilation and (b) during OLV before and (c) after an ARS. The ARS was applied selectively to the dependent lung and consisted of an increase in peak inspiratory pressure up to 40 cm H(2)O combined with a peak end-expiratory pressure level of 20 cm H(2)O for 10 consecutive breaths. The ARS took approximately 3 min. Arterial blood gases, SBT-CO(2), and metabolic and hemodynamic variables were recorded at the end of each study period. Arterial oxygenation and dead space were better during two-lung ventilation compared with OLV. PaO(2) increased during OLV after lung recruitment (244 +/- 89 mm Hg) when compared with OLV without recruitment (144 +/- 73 mm Hg; P < 0.001). The SBT-CO(2) analysis showed a significant decrease in dead-space variables and an increase in the variables related to the efficiency of ventilation during OLV after an ARS when compared with OLV alone. In conclusion, ARS improves gas exchange and ventilation efficiency during OLV. IMPLICATIONS: In this article, we showed how a pulmonary ventilatory maneuver performed in the dependent lung during one-lung ventilation anesthesia improved arterial oxygenation and dead space.     

The effect of timing of application of positive end-expiratory pressure on oxygenation during one-lung ventilation

Many studies have confirmed that applying positive end-expiratory pressure (PEEP) to the dependent lung during one-lung ventilation (OLV) improves oxygenation. Our purpose was to investigate the best time and level of PEEP application. Thirty patients undergoing thoracic surgery were randomised into three groups. After 20 minutes of two-lung ventilation (TLV) in the lateral position, all patients received OLV for one hour During OLV, 0, 5, 10 cmH2O PEEP were applied in order in group A, with each level sustained for 20 minutes. Group B had 5 cmH2O PEEP applied and maintained for one hour Patients in group C received PEEP with levels set in the opposite order to that of group A. The ventilation model was then converted to TLV. PaO2, PaCO2 and respiratory mechanical variables were compared at five different time points among groups, 20 minutes after TLV (T1), 20 (T2), 40 (T3) and 60 minutes (T4) after OLV and 20 minutes after conversion to TLV (T5). We found that PaO2 was lower in group A than the other two groups at T2 (P <0.05). PaO2 decreased significantly at T5 compared with T1 (P <0.05) in group A only. When PEEP was set to 10 cmH2O, the airway pressure increased significantly (P <0.05). These findings indicate that PEEP applied at the initial time of OLV improves oxygenation most beneficially. Five cmH2O PEEP may produce this beneficial effect without the increase in airway pressure associated with 10 cmH2O PEEP.     

单肺通气期间PEEP对血流动力学的影响

目的：观察２６例胸科手术病人单肺通气期间ＰＥＥＰ对血流动力学的影响。方法：Ａ组１２例,单肺通气期间采用５ｃｍＨ２ＯＰＥＥＰ;Ｂ组１４例,单肺通气期间未用ＰＥＥＰ。结果：两组病人单肺通气后ＳＶ、ＣＯ、ＣＩ均呈下降趋势。Ａ组下降幅度略大于Ｂ组,Ａ组在ＰＥＥＰ后４５ｍｉｎ降至最低。但两组之间比较无显著差异。恢复双肺通气后ＳＶ、ＣＯ、ＣＩ即回升。其余参数无明显变化。单肺通气后动脉血氧分压下降,但均有安全范     

经胸腔镜肺大泡切除术中应用单肺通气对血气及血液动力学的影响

目的　观察胸腔镜手术中单肺通气时应用不同水平的呼气末正压通气 (PEEP)对血气及血液动力学的影响。方法　随机选择胸腔镜肺大泡切除术病人 36例 ,均分为三组 :A组为单肺间歇正压通气 (IPPV)通气 ;B组为单肺IPPV加PEEP 5cmH2 O通气 ;C组为单肺IPPV加PEEP10cmH2 O通气。分别记录平卧位双肺通气、侧卧位双肺通气、单肺通气 10min和 30min四个时点的血气和血液动力学参数。结果　各组病人SpO2 始终维持在 99%～ 10 0 %。动脉血氧分压 (PaO2 )也在正常范围 ,但B、C组明显高于A组 (P <0 .0 5 )。其余血气指标无明显变化。三组病人HR、MAP、左心室射血时间 (LVET)及体循环血管阻力 (SVR)均无明显变化。B、C组在单肺通气 10min及 30min后 ,每搏量 (SV)及心输出量 (CO)下降明显 ,但均在正常范围 ,且无组间差异。体位改变时血液动力学稳定。结论　经胸腔镜肺大泡切除术中单肺IPPV、PEEP 5cmH2 O均能维持满意的PaO2 和动脉血二氧化碳分压 (PaCO2 ) ,血液动力学变化不显著 ;但PEEP 5cmH2 O较IPPV能进一步提高PaO2 ,PEEP 10cmH2 O不能较PEEP 5cmH2 O进一步提高PaO2 。     

胸科手术中单肺通气期间不同通气方式的比较

目的 观察胸科手术病人麻醉中单肺通气（ＯＬＶ）期间不同通气方式的效果。方法 １０例择期胸科手术成年病人,ＡＳＡⅠ～Ⅱ级,在ＯＬＶ期间首先采用全潮气量（１０ｍｌ／ｋｇ）不加ＰＥＥＰ,随后采用半潮气量（５ｍｌ／ｋｇ）同时施加７ｃｍＨ２Ｏ ＰＥＥＰ两种通气方式,保持每分通气量不变。在开胸后ＯＬＶ前,ＯＬＶ时采用敏种通气方式后３０ｍｉｎ,以及恢复双肺通气（ＴＬＶ）后３０ｍｉｎ分别进行血气分析,同时监测气道     

Intracuff pressure during one-lung ventilation in infants and children

ObjectiveWe prospectively evaluated intracuff pressure (IP) during one-lung ventilation (OLV) to characterize potential risk associated with overinflation of the cuff used for OLV.DesignProspective observational study over a 2-year period, in infants and children undergoing thoracic surgery. The IPs of the tracheal and bronchial balloon were measured using a manometer and compared to a previously recommended threshold of 30 cmH2O. Data were compared by the device type used to achieve OLV.SettingFreestanding tertiary-care pediatric hospital.ParticipantsPatients ≤ 18 years of age undergoing thoracic procedures requiring OLV.InterventionsMeasurement of IP.Measurements and main resultsThirty patients were enrolled (age 5 months–18 years) with a median weight of 28 kg. Median tracheal and bronchial IPs were 32 cmH2O (range: 11, 90) and 44 cmH2O (range: 10, 100), respectively. The tracheal and bronchial IPs exceeded 30 cmH2O in 13 of 20 patients (65%) and 21 of 30 patients (70%), respectively.ConclusionsIP was high and in excess of recommended levels in most children undergoing OLV. Continuous monitoring of IP may be indicated during OLV to address the risks involved and ensure the prevention of complications related to high IP.Type of studyProspective comparative study.Level of evidenceLevel II.     

The effects of remifentanil and thoracic epidural on oxygenation and pulmonary shunt fraction during one-lung ventilation

OBJECTIVE: To compare the effects of remifentanil and thoracic epidural analgesia on the hemodynamic changes and pulmonary shunt fraction during one-lung ventilation (OLV) for thoracotomy. DESIGN: Prospective, single crossover design. SETTING: Tertiary care hospital. PARTICIPANTS: Thirty-four patients undergoing OLV for thoracic surgery. INTERVENTIONS: During general anesthesia with 2-lung ventilation, one-lung ventilation with remifentanil infusion, and one-lung ventilation with thoracic epidural anesthesia (TEA), hemodynamic parameters and arterial and mixed venous blood gases were taken from the radial and pulmonary artery catheters. During these 3 study periods, cardiac index (CI) was measured using thermodilution technique while shunt fraction (Qs/Qt), alveolar arterial oxygen gradient (A-a O(2)), and systemic (SVRI) and pulmonary vascular resistances indices (PVRI) were calculated. A p value <0.05 was taken to be statistically significant. MEASUREMENTS AND MAIN RESULTS: When OLV was instituted, there was a significant decrease in mean arterial blood pressure. Arterial oxygenation decreased, whereas CI and Qs/Qt increased during OLV, but there was no significant difference between remifentanil infusion and thoracic epidural analgesia. CONCLUSIONS: Both remifentanil infusion and TEA are suitable for analgesia during thoracic surgery when OLV is used. There was no significant difference in PaO(2) and Qs/Qt during each administration.