部分液体通气对吸入性损伤犬血流动力学的影响

目的　将机械通气与小剂量氟碳相结合进行部分液体通气治疗犬吸入性损伤 ,对比研究确定这种通气方式对吸入性损伤犬血流动力学的影响。方法　将健康犬 16条随机分为两组。采用蒸气吸入造成吸入性损伤模型后 ,一组将氟碳缓慢注入肺内实施部分液体通气 ,作为实验组。另一组仅采用常规机械通气 ,作为对照组。结果　部分液体通气 (PLV)治疗后 30min、 6 0min、 90min、 12 0min的HR、MAP、CVP、PAWP、CO与对照组比较及与吸入性损伤后 90min实验组比较 ,上述各项参数均无明显改变 (P >0 0 5 )。PAP在PLV治疗后 30min、 6 0min比对照组高 (P <0 0 5 ) ,而与伤后 90min实验组比较差别无显著性意义。结论　部分液体通气对吸入性损伤犬的循环动力学的主要参数无不良影响。氟碳注入肺内无明显肺水肿表现 ,使用安全 ,是良好的肺内气体交换媒介。     

高频部分液体通气对吸入性损伤犬呼吸功的影响

目的　观察高频喷射通气结合小剂量氟碳 (3ml/kg)液体通气对吸入性损伤犬呼吸的功影响。方法　将 16条犬经蒸气吸入造成吸入性损伤模型 ,并随机分为两组 ,即对照组和治疗组。两组动物致伤后均行高频喷射通气 ,但治疗组动物同时经气管导管将氟碳液体 (3ml/kg)缓慢注入肺内 ,在 90min内测机械通气功 (WOBvent)。结果　治疗组在给予小剂量氟碳后的WOBvent与致伤后比较差异无显著意义 (P >0 0 5 ) ,对照组治疗后的WOBvent与致伤后比较差异亦无显著意义 (P >0 0 5 ) ,治疗组与对照组各时间点的WOBvent比较差异均无显著意义 (P >0 0 5 )。结论　高频喷射通气合并小剂量氟碳 (3ml/kg)部分液体通气并不增加动物的呼吸功。     

部分液体通气对吸入性损伤犬肺组织病理学的影响

目的 研究部分液体通气(PLV)对吸入性损伤犬肺组织病理学的影响。方法 将16只犬经蒸气吸入造成吸入性损伤模型，并随机分为对照组和治疗组。所有动物行机械通气，伤后1．5h PLV治疗组给予氟碳，剂量为12mL／kg，伤后3h放血致死动物，取肺组织分别进行光镜和电镜下的组织病理学观察。结果 与对照组比较，PLV治疗组肺组织充血、水肿、中性粒细胞浸润明显减轻，血管内皮细胞和肺泡细胞损伤轻。结论 PLV能减轻吸人性损伤的肺组织损伤，具有抗炎作用。     

高频部分液体通气治疗吸入性肺损伤的实验研究

目的：观察高频部分液体通气治疗吸入性肺损伤的效果,并与单纯高频喷射通气的疗效比较。方法：将16只犬经蒸气吸入造成吸入性肺损伤模型,并随机分为对照组和治疗组。2组动物致伤后均行高频喷射通气,治疗组动物同时经气管导管将氟碳液体（3ml/kg)缓慢注入肺内,实行高频部分液体通气治疗,于30、60及90分钟测定动脉血气、肺顺应性和气道阻力。结果：治疗组动脉血氧分压（PaO2)进行性上升,各时间点与致伤后比较均有显著性差异（P均＜0．05）,动脉血二氧化碳分压（PaCO2)也逐渐增高,于60和90分钟显著高于致伤后水平（P均＜0．05）;与对照组比较,治疗组各时间点的PaO2稍有升高,而PaCO2于90分钟显著增高（P＜0．05）。在各时间点的动、静态气道阻力和动、静态肺顺应性,2组比较均无明显差异。结论：高频部分液体通气与单纯高频喷射通气相比,更有利于动脉血氧合,但也有轻度CO2潴留现象。     

吸入性肺损伤犬部分液体通气后一氧化氮、内皮素-1的改变

目的　研究吸入性损伤部分液体通气 (PLV)后一氧化氮 (NO)、内皮素 1 (ET 1 )的改变。方法　将 1 2条犬制成蒸汽吸入性损伤模型 ,随机分为两组 :对照组和PLV组。所有动物行机械通气 ,伤后1 5hPLV组给予全氟化碳液体 ,剂量为 6ml/kg。于PLV前 ,PLV后 1、 2h采静脉血用于测NO、ET 1。伤后 3 5h放血致死动物 ,测支气管肺泡灌洗液 (BALF)、肺匀浆NO、ET 1。结果　与对照组相比 ,PLV组PLV后 1h血NO下降明显 (P <0 0 5 ) ,但PLV 2h又后恢复至对照组水平。PLV组肺匀浆ET 1显著高于对照组 (P <0 0 5 )。结论　PLV用于吸入性损伤犬能降低血NO水平 ,提高肺匀浆ET 1 ,这是其用于吸入伤治疗中不足的一面     

高频喷射通气联合气管内吹气对急性肺损伤的治疗作用

目的　探讨高频喷射通气联合气管内吹气对急性肺损伤的治疗作用。方法　杂种犬 12条 ,随机分为两组 ,用大剂量生理盐水灌洗肺造成急性肺损伤。各组分别给予高频喷射通气 ,调整呼吸机参数使第一组实验犬PaCO2 维持在 35～ 5 0mmHg,第二组实验犬PaCO2 维持在 6 0～ 80mmHg。然后进行 4L/min和 8L/min氧气流量的气管内吹气 ,每阶段进行 30min ,观察血流动力学指标和血气指标的变化。结果　①联合通气后 ,两组PaCO2 及PetCO2 均明显下降 ,且随着吹入气氧流量的增加下降更明显。②联合通气后 ,动脉血氧分压在两组中明显上升 ,但随着吹入气氧流量的增加 ,动脉血氧分压变化无明显差异 (P >0 0 5 )。③联合通气后使各组气道压明显上升。④联合通气对各组犬血流动力学无显著影响 (P >0 0 5 )。结论　高频喷射通气联合气管内吹气能有效地降低肺损伤犬PaCO2 ,促进二氧化碳的排除 ,提高肺损伤犬的氧合且不影响实验犬的血流动力学     

肺保护性通气患者的肺动脉漂浮导管监测

目的 应用肺动脉漂浮导管研究肺保护性通气对患者的血流动力学影响.方法 24例急性呼吸衰竭患者,予机械通气治疗及肺动脉漂浮导管监测.采用自身对照研究,先予常规通气,根据潮气量(VT)及气道平台压(Pplat)的状况,分为A、B两组,A组(14例):VT 12 ml/kg,Pplat<30 cm H2O(1 cm H2O=0.098 kPa);B组(10例):VT12 ml/kg,Pplat≥30 cm H2O.监测心率(HR)、平均动脉压(MAP)、中心静脉压(CVP)、平均肺动脉压(MPAP)、肺动脉楔压(PAWP)、心排血量(CO)、心排血指数(CI).然后换用VT6 ml/kg的肺保护性通气,机械通气0.5 h后再次监测血流动力学参数.比较两组患者常规通气和肺保护性通气的血流动力学变化.结果 在常规通气更换为肺保护性通气后,A组患者的血流动力学无明显变化.而B组的HR、MAP、CI明显升高,差异有统计学意义(P<0.05);而CVP、MPAP、PAWP无明显变化.结论 为了减少机械通气时血流动力学的影响,限制Pplat比限制VT更加重要,对于血流动力学不稳定的急性呼吸衰竭患者,肺保护性通气更加安全.     

肺保护性通气对犬海水淹溺型肺水肿的治疗作用

目的 观察肺保护性通气对海水淹溺型肺水肿(PE-SWD)犬肺内气体交换、气道力学、血流动力学及外周血炎性介质的影响,并与常规机械通气进行比较.方法健康成年杂种犬15只,经气管插管灌人海水形成PE-SWD模型后,随机分为3组(n=5):阳性对照组(Ⅰ组),常规机械通气治疗组(Ⅱ组),肺保护性通气治疗组(Ⅲ组)(VT 8 mL/kg+PEEP 8 cm H2O).治疗180 min,分别观察各组治疗前后不同时间点动脉血气、呼吸力学、血流动力学以及外周血炎性介质的变化.结果肺保护性通气治疗后海水淹溺型肺水肿犬动脉血气、呼吸力学、血流动力学以及炎性介质指标均较Ⅰ、Ⅱ组明显改善(P<0.05).结论肺保护性通气可明显改善PE-SWD犬动脉血气,并能提高肺顺应性、降低气道峰压、降低肺动脉压、减少肺组织损伤.肺保护性通气模式可能是治疗PE-SWD的有效方法,值得临床实践应用.     

压力支持通气与成比例压力支持通气模式对血流动力学状态的影响

目的　探讨压力支持通气 (PSV)与成比例压力支持通气 (PPS)不同通气模式对血流动力学的影响。方法　选择呼吸衰竭行机械通气及脉搏轮廓法持续血流动力学监护患者 2 6例。经治疗进入低辅助通气后比较在PSV、PPS两种通气模式下血流动力学及呼吸力学的差异。结果　PPS模式心输出量 (CO)、心指数 (CI)、每搏量 (SV)较PSV模式明显增加 (P <0 0 5 ) ,外周血管阻力 (SVR)无明显变化 (P >0 .0 5 ) ,气道峰压 (Ppeak)及内源性PEEP(PEEPi)明显下降 (P <0 .0 5 )。结论　PPS模式对机械通气患者的血流动力学状态影响最小 ,较适用于血流动力学不稳定患者。     

参附注射液对心源性休克犬血流动力学及氧代谢的影响

目的观察参附注射液对实验犬心源性休克血流动力学及氧代谢的影响。方法制备犬心源性休克模型，制模成功后随机分为参附组、多巴胺组和对照组。于制模前，制模成功（用药即刻），用药后30、60、90、120和180min通过Swan-Ganz导管监测血流动力学，包括心排血量（CO）、肺动脉嵌顿压（PAWP）、肺动脉压（PAP）、中心静脉压（CVP）、心率（HR）、动脉压，并计算每搏量（SV）、每搏功（SW）、平均动脉压（MAP）、全身血管阻力（SVR）、肺循环阻力（PVR）；抽取动脉血及混合静脉血测定氧代谢动力学指标，包括DO2（氧输送），VO2（氧消耗）及ERO2（氧摄取率）。结果①与用药即刻比较，对照组CO、SV、SW、HR、MAP在给药后均呈进行性下降，而PVR、PAWP、CVP呈进行性升高（P均〈0．01）。②静脉注射参附注射液后CO、SV、SW均明显增加，60min时达到最高，然后逐渐下降（P均〈0．01）；HR、MAP在用药后呈进行性下降；SVR、PVR 30min降到最低后开始逐渐升高，120min到达用药前状态；PAWP较对照组降低明显（P均〈0．01）。③静脉注射多巴胺后CO、SV、SW、MAP、HR均增加，30min达到最高，但升高幅度较参附注射液组低（P〈0．05）；SVR、PAWP较参附组明显增加（P〈0．05）。④在用药即刻3组VO2与DO2均低于用药前，ERO2代偿增高。与多巴胺组比较，参附组DO2、VO2时显著升高（P〈0．05或P〈0．01），ERO2则明显下降（P〈0．05）。结论参附注射液较多巴胺在增加CO，降低外周阻力、肺动脉阻力、PAWP和HR，以及改善组织灌注与氧代谢能力方面具有明显的优势。     

Measurement of changes in respiratory mechanics during partial liquid ventilation using jet pulses

OBJECTIVE: To compare the changes in respiratory mechanics within the breathing cycle in healthy lungs between gas ventilation and partial liquid ventilation using a special forced-oscillation technique. DESIGN: Prospective animal trial. SETTINGS: Animal laboratory in a university setting. SUBJECTS: A total of 12 newborn piglets (age, <12 hrs; mean weight, 725 g). INTERVENTIONS: After intubation and instrumentation, lung mechanics of the anesthetized piglets were measured by forced-oscillation technique at the end of inspiration and the end of expiration. The measurements were performed during gas ventilation and 80 mins after instillation of 30 mL/kg perfluorocarbon PF 5080. MEASUREMENTS AND MAIN RESULTS: Brief flow pulses (width, 10 msec; peak flow, 16 L/min) were generated by a jet generator to measure the end-inspiratory and the end-expiratory respiratory input impedance in the frequency range of 4-32 Hz. The mechanical variables resistance, inertance, and compliance were determined by model fitting, using the method of least squares. At least in the lower frequency range, respiratory mechanics could be described adequately by an RIC single-compartment model in all piglets. During gas ventilation, the respiratory variables resistance and inertance did not differ significantly between end-inspiratory and end-expiratory measurements (mean [sd]: 4.2 [0.7] vs. 4.1 [0.6] kPa x L(-1) x sec, 30.0 [3.2] vs. 30.7 [3.1] Pa x L(-1) x sec2, respectively), whereas compliance decreased during inspiration from 14.8 (2.0) to 10.2 (2.4) mL x kPa(-1) x kg(-1) due to a slight lung overdistension. During partial liquid ventilation, the end-inspiratory respiratory mechanics was not different from the end-inspiratory respiratory mechanics measured during gas ventilation. However, in contrast to gas ventilation during partial liquid ventilation, compliance rose from 8.2 (1.0) to 13.0 (3.0) mL x kPa(-1) x kg(-1) during inspiration. During expiration, when perfluorocarbon came into the upper airways, both resistance and inertance increased considerably (mean with 95% confidence interval) by 34.3% (23.1%-45.8%) and 104.1% (96.0%-112.1%), respectively. CONCLUSIONS: The changes in the respiratory mechanics within the breathing cycle are considerably higher during partial liquid ventilation compared with gas ventilation. This dependence of lung mechanics from the pulmonary gas volume hampers the comparability of dynamic measurements during partial liquid ventilation, and the magnitude of these changes cannot be detected by conventional respiratory-mechanical analysis using time-averaged variables.     

High-frequency oscillatory ventilation of the perfluorocarbon-filled lung: dose-response relationships in an animal model of acute lung injury

OBJECTIVE: To examine dose-response relationships regarding the efficiency of gas exchange and hemodynamic function during high-frequency oscillation and partial liquid ventilation (HFO-PLV) of the perfluorocarbon (PFC)-treated lung in a model of acute lung injury. SETTING: An animal research laboratory in a university medical center. DESIGN: A prospective, randomized study comparing animals receiving varying doses (0, 5, 15, and 20 mL/kg) of perflubron during high-frequency oscillatory ventilation (HFOV) with mean airway pressure (Paw) optimized to achieve a minimal percutaneous oxygen saturation (Spo2). SUBJECTS: Nineteen healthy swine (mean weight 28.9 kg) with saline lavage-induced acute lung injury. METHODS: Animals were treated with repetitive saline lavage to achieve a uniform degree of acute lung injury (Spo2 < or =90% on an Fio2 of 1.0). After lung injury, subjects were converted to HFOV, and lung volume was optimized. HFO-PLV was initiated by instillation of perflubron at a rate of 0.5 mL.kg-1.min-1 to achieve total doses of 5, 15, and 20 mL/kg. After PFC dosing, the only experimental manipulation consisted of adjustment of Paw to achieve an Spo2 of 90% +/- 2% with Fio2 of 0.6. Gas exchange, hemodynamic variables, and pulmonary mechanics data were collected over a 1-hr period. Five control animals were not dosed with perflubron and remained on HFOV for the 1-hr period of data collection. MEASUREMENTS AND MAIN RESULTS: After lung volume recruitment with HFOV, the initiation of HFO-PLV was best tolerated with the two lower doses in our protocol. There were essentially no changes in Paco2 or pH between groups over the dosing interval. After dosing, analysis of variance demonstrated a PFC dose-dependent effect for oxygenation index (p =.01) only; the lowest oxygenation index was found in the 15 mL/kg group (p =.01). In the 15 mL/kg group, the Paw decreased steadily from 20.6 +/- 3.4 cm H2O at the end of dosing to 18.0 +/- 4.9 cm H2O at 60 mins. The Pao2 increased from 113 +/- 51 torr (15.06 +/- 6.79 kPa) to 134 +/- 49 torr (17.86 +/- 6.53 kPa) during this period and was associated with a decreasing oxygenation index (from 11.4 +/- 2.0 to 9.3 +/- 1.5). The cardiac index and pulmonary vascular resistance did not change significantly during the dosing period and were relatively stable after the completion of dosing. CONCLUSIONS: The combination of HFOV and perflubron administration was well tolerated hemodynamically and was not associated with deterioration of gas exchange during dosing. Our data suggest that the optimal dose of perflubron to achieve the lowest oxygenation index during HFO-PLV is between 5 and 15 mL/kg. The combination of HFOV and perflubron administration is a novel strategy in the treatment of acute lung injury that shows some promise and merits additional investigation. We hope in future studies to address the histopathologic effects of varying perflubron doses during HFOV in a long-term study of the lung-protective effects of HFO-PLV.     

Partial liquid ventilation in severely surfactant-depleted, spontaneously breathing rabbits supported by proportional assist ventilation

OBJECTIVE: We hypothesized that partial liquid ventilation (PLV) would improve oxygenation in nonparalyzed, surfactant-deficient rabbits breathing spontaneously while supported by proportional assist ventilation (PAV). This ventilation mode compensates for low pulmonary compliance and high resistance and thereby facilitates spontaneous breathing. DESIGN: Randomized trial. SETTING: University animal research facility. SUBJECTS: Twenty-six anesthetized New Zealand white rabbits weighing 2592 +/- 237g (mean +/- sd). INTERVENTIONS: After pulmonary lavage (target Pao2 <100 mm Hg on mechanical ventilation with 6 cm H2O of positive end-expiratory pressure [PEEP] and an Fio2 of 1.0), rabbits were randomized to PAV (PEEP of 8 cm H2O) with or without PLV. PLV rabbits received 25 mL/kg of perfluorocarbon by intratracheal infusion (1 mL/kg/min). Pao2, Paco2, tidal volume, respiratory rate, minute ventilation, mean airway pressure, arterial blood pressure, heart rate, pulmonary compliance, and airway resistance were measured. Evaporated perfluorocarbon was refilled every 30 mins in PLV animals. After 5 hrs, animals were killed and lungs were removed. Lung injury was evaluated using a histologic score. MAIN RESULTS: Pao2 and compliance were significantly higher in PLV rabbits compared with controls (p <.05, analysis of variance for repeated measures). All other parameters were similar in both groups. CONCLUSIONS: PLV improved oxygenation and pulmonary compliance in spontaneously breathing, severely surfactant-depleted rabbits supported by PAV. The severity of lung injury by histology was unaffected.     

Partial liquid ventilation decreases serum tumor necrosis factor-alpha concentrations in a rat acid aspiration lung injury model

OBJECTIVE: To examine the hypothesis that partial liquid ventilation (PLV) with perfluorocarbon would decrease serum tumor necrosis factor-alpha concentrations in a rat acid aspiration lung injury model. DESIGN: Prospective, controlled animal study. SETTINGS: Research laboratory in a university setting. SUBJECTS: Male Sprague-Dawley rats. INTERVENTIONS: Treatment with intratracheal perflubron or control mechanical ventilation beginning 30 mins after acid aspiration. MEASUREMENTS AND MAIN RESULTS: PLV with perfluorocarbon compared with control ventilation resulted in significantly greater mean arterial blood pressures at 3 and 4 hrs and greater arterial Po2 at all times. Serum tumor necrosis factor-alpha at 2, 3, and 4 hrs was significantly less than that observed in the control group (4-hr values: 80+/-64 pg/mL vs. 658+/-688 pg/mL; p<.05), although no significant difference in tracheal fluid tumor necrosis factor-alpha concentrations (1425+/-1347 pg/mL vs. 2219+/-1933 pg/mL) was found. CONCLUSION: We conclude that the effects of PLV with perfluorocarbon can extend beyond improvements in pulmonary physiology and that PLV may be beneficial in reducing systemic sequelae of acute lung injury and inflammation.     

Effects of partial liquid ventilation on regional pulmonary blood flow distribution of isolated rabbit lungs

OBJECTIVE: Partial liquid ventilation with perfluorocarbons may increase alveolar hydrostatic transmural pressure and may result in a redistribution of pulmonary blood flow from dependent to nondependent lung regions. To test this hypothesis under controlled study conditions, we determined intrapulmonary blood flow distributions during gas and perfluorocarbon ventilation in isolated rabbit lungs. DESIGN: Controlled animal study with an ex vivo isolated lung preparation. SETTING: Research laboratory for Experimental Anesthesiology at the Heinrich-Heine-University of Düsseldorf. SUBJECTS: New Zealand White rabbits. INTERVENTIONS: The lungs were perfused with autologous blood at constant flow (150 mL/min) and ventilated with 5% C(O2) in air (positive end-expiratory pressure, 2 cm H2O; tidal volume, 10 mL/kg body weight; respiratory rate, 30 breaths/ min) without and with perfluorocarbon administered intratracheally (15 mL/kg). MEASUREMENTS AND MAIN RESULTS: Regional lung perfusion was measured with colored microspheres in apical, central, peripheral, and basal samples before and after bronchial instillation of perfluorocarbons. Compared with gas ventilation, intrapulmonary blood flow during perfluorocarbon ventilation was higher in apical samples (49.4+/-8.6 mL/min/g vs. 38.3+/-6.8 mL/min/g dry weight; p = .03) and lower in basal samples (22.2+/-5.1 mL/min/g vs. 39.9+/-8.2 mL/min/g; p = .04). CONCLUSIONS: Our findings suggest that during partial liquid ventilation, intrapulmonary blood flow is redistributed toward less-dependent lung regions. (Crit Care Med 2000; 28:1522-1525) KEY WORDS: partial liquid ventilation; perfluorocarbons; isolated rabbit lungs; pulmonary circulation; regional blood-flow distribution; colored microspheres     

Effects of exogenous surfactant supplementation and partial liquid ventilation on acute lung injury induced by wood smoke inhalation in newborn piglets

OBJECTIVE: To investigate the beneficial effects of exogenous surfactant supplementation (ESS) and partial liquid ventilation (PLV) in treating acute lung injury induced by wood smoke inhalation. DESIGN: A prospective, randomized, controlled, multigroup study. SETTING: An animal research laboratory at a medical center. SUBJECTS: Newborn piglets (n = 29; 1.80 +/- 0.06 kg) of either sex. INTERVENTIONS: Animals were ventilated with a tidal volume of 15 mL/kg, a rate of 30 breaths/min, a positive end-expiratory pressure of 5 cm H(2)O, and an Fio(2) of 1.0. After the induction of acute lung injury by wood smoke inhalation, animals were randomly assigned to receive either conventional mechanical ventilation (CMV) or PLV with or without ESS pretreatment. Animals were grouped as CMV, ESS-CMV, PLV, and ESS-PLV. MEASUREMENTS AND MAIN RESULTS: Arterial blood gases, cardiovascular hemodynamics, dynamic lung compliance, and total lung injury scores were measured. After smoke inhalation, all four groups displayed similar high arterial carboxyhemoglobin levels, low Pao(2) (<150 mm Hg), and low dynamic lung compliance (<66% of its baseline). In the CMV group, these deleterious conditions remained during the 4-hr observation period, and severe lung injury was noted histologically. All treatment groups demonstrated a significant increase in Pao(2) compared with the CMV group. In addition, both the PLV and ESS-PLV groups displayed significant improvements in dynamic lung compliance and in their histologic outcomes. Nevertheless, none of the variables measured in the PLV group differed from those measured in the ESS-PLV group. CONCLUSIONS: In a newborn piglet model of smoke inhalation injury, PLV or ESS improved oxygenation. PLV compared favorably with ESS in its greater improvements in lung compliance and lung pathology. However, the combined therapy of ESS and PLV was not clearly superior to PLV alone during the observation period.     

高频振荡通气及肺泡表面活性物质对吸入性损伤兔肺组织的影响

目的 比较高频振荡通气(HFOV)与HFOV联合肺泡表面活性物质(PS)对重度蒸汽吸入性肺损伤兔肺组织的保护作用.方法 将24只新西兰大白兔制成重度蒸汽吸入性肺损伤模型后,按随机数字表法分为3组,每组8只.分别给予常规机械通气(CMV)、HFOV、HFOV+气管内滴入外源性PS(100 mg/kg)治疗;通气4 h后处死动物,取肺组织观察组织病理变化,并行肺组织损伤评分.结果 肺大体标本、光镜下及电镜下均观察到HFOV后肺损伤程度较CMV明显减轻,3组中以HFOV+PS组损伤最轻,CMV组损伤最重;肺组织损伤评分也显示CMV组最高[(3.71±0.43)分],HFOV+PS组最低[(2.08±0.28)分],HFOV组居中[(2.87±0.26)分],两两比较差异均有统计学意义(P<0.05或P<0.01).结论 与CMV比较,HFOV通过减少肺组织内炎性细胞浸润及水肿液的渗出,可减轻吸入性肺损伤,且HFOV联合PS作用最明显.