部分液体通气对急性肺损伤兔肺表面活性物质的影响

目的 研究部分液体通气(PLV)对油酸诱导的急性肺损伤肺表面活性物质的影响。方法 24只健康成年日本大白兔随机分成三组,每组8只:正常对照单纯机械通气组(C组);油酸肺损伤机械通气组(MV组)和油酸肺损伤部分液体通气组(PLV组)。中心静脉滴注油酸150μg/kg诱导急性肺损伤(ALI)模型,1h后当PaO_2/FiO_2<300时,认为造模成功,再连续通气4h,用多导生理监测仪连续记录血压和心率的变化,并测定基础、肺损伤及治疗后1、2、4h动脉血气。治疗4h立即处死动物,描记肺的压力-容积曲线,行右肺支气管灌洗,测量灌洗液中双饱和磷脂酰胆碱(DPPC)、肺表面活性物质相关蛋白A(SP-A)、总蛋白(TP)的浓度。结果 PLC组经PLV治疗后,PaO_2提高(P<0.01),各时段PaO_2高于MV组(P<0.01);PLV组PaCO_2逐渐降低,治疗后4h,PaCO_2与MV组差异有显著性(P<0.05)。PLV组灌洗液中DPPC、SP-A的含量高于MV组(P<0.01),而TP的含量低于MV组(P<0.01)。PLV组肺的顺应性较MV组提高。结论 PLV可增加油酸性急性肺损伤肺泡Ⅱ型上皮细胞分泌肺泡表面活性物质,改善肺功能。     

Combining partial liquid ventilation and prone position in experimental acute lung injury.

BACKGROUND: Partial liquid ventilation (PLV) and prone position can improve arterial oxygen tension (PaO2) in acute lung injury (ALI). The authors evaluated additive effects of these techniques in a saline lung lavage model of ALI. METHODS: ALI was induced in 20 medium-sized pigs (29.2+/-2.5 kg body weight). Gas exchange and hemodynamic parameters were determined in both supine and prone position in all animals. Thereafter, one group was assigned to PLV with two sequential doses of 15 ml/kg of perfluorocarbon (n = 10); the second group was assigned to gaseous ventilation (n = 10). Gas-exchange and hemodynamic parameters were determined at corresponding time points in both groups in prone and supine position. RESULTS: In the PLV group, positioning the animals prone resulted in an increase of PaO2 prior to PLV and during PLV with both doses of perfluorocarbon when compared to ALI. PLV in supine position was only effective if 30 ml/kg of perfluorocarbon was applied. In the gaseous ventilation group, PaO2 increased reproducibly compared with ALI when the animals were turned prone. A significant additive improvement of arterial oxygenation was observed during combined therapy with 30 ml/kg of perfluorocarbon and prone position in the PLV group compared with either therapy alone. CONCLUSIONS: The authors conclude that combining PLV with prone position exerts additive effects on pulmonary gas exchange in a saline lung lavage model of ALI in medium-sized pigs.     

Real-time visualization of partial liquid ventilation in a model of acute lung injury

BACKGROUND: To clarify the effects of partial liquid ventilation, we visualized and morphologically analyzed real-time alveolar recruitment in a model of acute lung injury. METHODS: Male Wistar rats were divided into 3 groups: a group that underwent hydrochloric acid aspiration and mechanical gas ventilation (ALI group, n = 15), a group that underwent acid aspiration and partial liquid ventilation beginning 90 minutes after acid aspiration (PLV group, n = 15), and a group that underwent mechanical ventilation without acid aspiration (control group, n = 5). The number of ventilated alveoli and the diameter of the largest ventilated alveolus in each of 10 high-power fields observed on fluorescence micrographs with a tracer of labeled albumin were determined and averaged from 90 to 210 minutes after acid aspiration. RESULTS: The number of alveoli in the PLV group significantly increased in comparison to that in the ALI group. The diameter of the largest alveolus in the PLV group decreased from 103.7 +/- 16.3 microm to 76.3 +/- 6.5 microm until the end of the experiment. This diameter was equivalent to that in the control group. CONCLUSIONS: The excellent alveolar recruitment suggests that liquid ventilation ameliorates ventilator-associated lung injury.     

Prevention of ventilator-induced lung injury with partial liquid ventilation

BACKGROUND/PURPOSE: Pulmonary injury from mechanical ventilation has been attributed to application of excess alveolar pressure (barotrauma) or volume (volutrauma). The authors questioned whether partial liquid ventilation (gas ventilation of the perfluorocarbon filled lung, PLV) would reduce ventilator-induced lung injury. METHODS: A tracheostomy tube and carotid artery catheter were placed in anesthetized Sprague-Dawley rats (500 +/- 50 g). Bovine serum albumin (BSA) labeled with Iodine (I) 125 was administered intraarterially. Ventilation with tidal volume (TV) of 5 mL/kg was initiated. The rats were then selected randomly to a 30-minute experimental period of one of the following ventilation protocols: continued atraumatic gas ventilation (GV, TV, 5 mL/kg; n = 10); atraumatic gas ventilation combined with intratracheal administration of 10 mL/kg perfluorocarbon (GV-PLV, TV, 5 mL/kg, n = 10); barotrauma (BT, peak inspiratory pressure [PIP], 45 cm H(2)O; n = 10); barotrauma with PLV (BT-PLV, PIP, 45 cm H(2)O; n = 8); volutrauma (VT, TV, 30 mL/kg; n = 8); or volutrauma with PLV (VT-PLV, TV, 30 mL/kg; n = 10). Animals were killed and the amount of radiolabeled BSA in both lungs was measured and normalized to the counts in 1 mL of blood from that animal (injury index). Data were analyzed by analysis of variance (ANOVA) with post-hoc t test comparison between groups. RESULTS: There was a significant difference in the (125)I-BSA injury index when all groups were compared (P <.001 by ANOVA). Post-hoc analysis showed a significant decrease in the injury index when comparing BT versus BT-PLV (P =.024) and VT versus VT-PLV (P =.014). CONCLUSION: (125)I-BSA leak produced during high-pressure or high-volume mechanical ventilation is reduced by partial liquid ventilation.     

Effect of increasing perfluorocarbon dose on VA/Q distribution during partial liquid ventilation in acute lung injury

BACKGROUND: Although gas exchange during partial liquid ventilation (PLV) depends on perfluorocarbon liquid, the effect of perfluorocarbon dose on the ventilation-perfusion (VA/Q) distribution is not known. This study investigated how VA/Q distribution of an acutely injured lung is affected during PLV at increasing perfluorocarbon dose. METHODS: In eight rabbits (3.2 +/- 0.1 kg), acute lung injury (ALI) was created by repeated saline lavage (arterial oxygen partial pressure/fraction of inspired oxygen, 37 +/- 11 mm Hg). Three different doses of perfluorodecalin (9 ml/kg = low dose; 13.5 ml/kg = medium dose; 18 ml/kg = functional residual capacity [FRC] dose) were applied in random order during PLV. VA/Q distribution at different doses was evaluated by multiple inert gas elimination technique. RESULTS: Inert gas shunt (63 +/- 21% at ALI) decreased with increasing perfluorocarbon dose (43 +/- 21% at low dose, 29 +/- 10% at medium dose, 11 +/- 9% at FRC dose; P = 0.022). Compared with ALI (0%), the proportion of low VA/Q units was higher at all tested doses (19 +/- 10, 25 +/- 12, and 34 +/- 18%, respectively; all P < 0.05). Compared with ALI (27 +/- 14%), the proportion of normal VA/Q units was not increased at low or medium doses but was increased only at the FRC dose (45 +/- 13%; P = 0.027). CONCLUSIONS: With increasing perfluorocarbon dose during PLV, shunt was reduced from a small dose. The majority shunt units were converted to units showing low VA/Q ratios rather than normal VA/Q ratios. The presence of considerable amount of low VA/Q units across the varying doses of perfluorocarbon suggested that additional measures are necessary during PLV to augment its effect on gas exchange.     

急性肺损伤时胃黏膜pH值和肺微循环相关性研究

目的 探讨急性肺损伤(acute lung injury,ALI)时胃黏膜pH值(gastric intramucosal pH,pHi)与肺微循环的相关性. 方法 健康家兔24只,体重2.6～3.2 kg,采用随机数字表法分为3组(每组8只):对照组(C组)、模型组(M组)和治疗组(T组).麻醉稳定后30 min (T0),M组和T组制备兔ALI模型,模型制备成功后(T1),T组静脉输注前列腺素E1(prostaglandin E1,PGE1)30 ng·kg-1· min-1.分别于T0、T1及模型成功后30 min(T2)、60 min(T3)、90min(T4)、120min(T5)、150min(T6)、180min(T7),记录平均肺动脉压(mean pulmonary artery pressure,MPAP)、动脉血氧分压(pressure of artery oxygen,PaO2)、气道峰压(peakinspiratory pressure,PIP)及测量肺微循环和pHi.T7时记录支气管肺泡灌洗液(bronchoalveolar lavage fluid,BALF)中中性粒细胞(polymorphonuclear neutrophils,PMN)及总细胞计数,计算肺湿/干重比(wet/dry,W/D).应用线性混合效应模型分析肺微循环和pHi的相关性. 结果 与C组比较,M组与T组T1～T7时PaO2降低,MPAP及PIP升高(P＜0.05);M组和T组BALF中PMN百分比和肺W/D升高(P＜0.05);M组T2～T7时pHi降低,T3～T7肺微循环血流量减少(P＜0.05).与M组比较,T组T3～T7时PaO2升高,T4～T7时PIP降低,T5～T7时MPAP降低(P＜0.05);T组BALF中PMN百分比[(20.341±0.033)比(40.232±0.054)]和肺W/D[(0.191±0.020)比(0.472±0.061)]降低(P＜0.05),T2～T7时pHi升高,T3～T7肺微循环血流量增加(P＜0.05).C组、M组和T组肺微循环的变化与pHi的变化相关(P＜0.05). 结论 随着肺损伤的产生和改善,肺微循环和pHi也发生相应的改变,二者具有相关性,可以通过pHi来预测肺损伤的情况.     

Effects of spontaneous breathing during airway pressure release ventilation on intestinal blood flow in experimental lung injury

BACKGROUND: In critical illness, the gut is susceptible to hypoperfusion and hypoxia. Positive-pressure ventilation can affect systemic hemodynamics and regional blood flow distribution, with potentially deleterious effects on the intestinal circulation. The authors hypothesized that spontaneous breathing (SB) with airway pressure release ventilation (APRV) provides better systemic and intestinal blood flow than APRV without SB. METHODS: Twelve pigs with oleic acid-induced lung injury received APRV with and without SB. When SB was abolished, either the tidal volume or the ventilator rate was increased to maintain pH and arterial carbon dioxide tension constant as compared to APRV with SB. Systemic hemodynamics were determined by double indicator dilution. Blood flow to the intestinal mucosa-submucosa and muscularis-serosa was measured using colored microspheres. RESULTS: Systemic blood flow increased during APRV with SB. During APRV with SB, mucosal-submucosal blood flow (ml. g-1. min-1) was 0.39 +/- 0.21 in the stomach, 0.76 +/- 0.35 in the duodenum, 0.71 +/- 0.35 in the jejunum, 0.71 +/- 0.59 in the ileum, and 0.63 +/- 0.21 in the colon. During APRV without SB and high tidal volumes, it decreased to 0.19 +/- 0.03 in the stomach, 0.42 +/- 0.21 in the duodenum, 0.37 +/- 0.10 in the jejunum, 0.3 +/- 0.14 in the ileum, and 0.41 +/- 0.14 in the colon (P < 0.001, respectively). During APRV without SB and low tidal volumes, the respective mucosal-submucosal blood flows decreased to 0.24 +/- 0.10 (P < 0.01), 0.54 +/- 0.21 (P < 0.05), 0.48 +/- 0.17 (P < 0.01), 0.43 +/- 0.21 (P < 0.01), and 0.50 +/- 0.17 (P < 0.001) as compared to APRV with SB. Muscularis-serosal perfusion decreased during full ventilatory support with high tidal volumes in comparison with APRV with SB. CONCLUSION: Maintaining SB during APRV was associated with better systemic and intestinal blood flows. Improvements were more pronounced in the mucosal-submucosal layer.     

Partial liquid ventilation in acute salt water-induced lung injury

BACKGROUND AND OBJECTIVES: Salt-water aspiration results in pulmonary oedema and hypoxia. We tested the hypothesis that partial liquid ventilation has beneficial effects on gas exchange and rate of survival in acute and extended salt water-induced lung injury. METHODS: Anaesthetized, ventilated rats (tidal volume 6 mL kg(-1), PEEP 5 cmH2O) received a tracheal salt-water instillation (3%, 8 mL kg(-1) body weight) and were randomly assigned to three groups (n = 10 per group). While lungs of Group 1 were gas-ventilated, lungs of Group 2 received a single perfluorocarbon instillation (30 min after the injury, 5 mL kg(-1) perfluorocarbon) and lungs of Group 3 received an additional continuous perfluorocarbon application into the treachea (5 mL kg(-1) h(-1)) Arterial blood gases were measured with an intravascular blood gas sensor. RESULTS: Salt-water instillation resulted in a marked decrease in PaO2 values within 30 min (from 432 +/- 65 to 83 +/- 40 mmHg, FiO2 = 1.0, P < 0.01). Arterial oxygenation improved in all three groups irrespective of treatment. We observed no significant differences between groups in peak PaO2 and PaCO2 values. CONCLUSIONS: Our results suggest that partial liquid ventilation has no additional beneficial effects on gas exchange after life-threatening salt water-induced lung injury when compared to conventional gas ventilation with positive end-expiratory pressure.     

Small dose of exogenous surfactant combined with partial liquid ventilation in experimental acute lung injury: effects on gas exchange, haemodynamics, lung mechanics, and lung pathology

A combination of exogenous surfactant and partial liquid ventilation(PLV) with perfluorocarbons should enhance gas exchange, improverespiratory mechanics and reduce tissue damage of the lung inacute lung injury (ALI). We used a small dose of exogenous surfactantwith and without PLV in an experimental model of ALI and studiedthe effects on gas exchange, haemodynamics, lung mechanics,and lung pathology. ALI was induced by repeated lavages (Pa_O2/FI_O2less than 13 kPa) in 24 anaesthesized, tracheotomized and mechanicallyventilated (FI_O2 1.0) juvenile pigs. They were treated randomlywith either a single intratracheal dose of surfactant (50 mgkg^–1, Curosurf^®, Serono AG, München, Germany)(SURF-group, n=8), a single intratracheal dose of surfactant(50 mg kg^–1, Curosurf^®) followed by PLV with 30 mlkg^–1 of perfluorocarbon (PF 5080, 3M, Germany) (SURF-PLV-group,n=8) or no further intervention (controls, n=8). Pulmonary gasexchange, respiratory mechanics, and haemodynamics were measuredhourly for a 6 h period. In the SURF-group, the intrapulmonaryright-to-left shunt (Q^·S/Q^·T) decreased significantlyfrom mean 51 (SEM 5)% after lavage to 12 (2)%, and Pa_O2 increasedsignificantly from 8.1 (0.7) to 61.2 (4.7) kPa compared withcontrols and compared with the SURF-PLV-group (P<0.05). Inthe SURF-PLV-group, Q^·S/Q^·T decreased significantlyfrom 54 (3)% after induction of ALI to 26 (3)% and Pa_O2 increasedsignificantly from 7.2 (0.5) to 30.8 (5.0) kPa compared withcontrols (P<0.05). Static compliance of the respiratory system(C_RS), significantly improved in the SURF-PLV-group comparedwith controls (P<0.05). Upon histological examination, theSURF-group revealed the lowest total injury score compared withcontrols and the SURF-PLV-group (P<0.05). We conclude thatin this experimental model of ALI, treatment with a small doseof exogenous surfactant improves pulmonary gas exchange andreduces the lung injury more effectively than the combined treatmentof a small dose of exogenous surfactant and PLV. Br J Anaesth 2001; 87: 593–601     

Effect of partial liquid ventilation and nebulized perfluorocarbon on CT lung density distribution: randomized controlled study of experimental lung injury

Background. Perfluorocarbon (PFC) liquid can improve gas exchangein acute lung injury. How PFC aerosol is distributed in thelung is unknown. Methods. We induced lung injury in rabbits with saline lavage,followed by mechanical ventilation in the supine position. Theanimals were divided into three groups: a control group, a grouptreated with partial liquid ventilation and a group given nebulizedperfluorocarbon (PF 5080). We made CT image slices of the excisedlungs. In the apical, middle and caudal slices we defined threeregions of interest, from anterior to posterior, and noted themean attenuation of each area. We also studied two rabbits whichhad not received lung injury or mechanical ventilation. Results. Group means were different between the normal rabbitsand all three study groups. There was a difference between thecontrol and partial liquid ventilation groups, and between thepartial liquid ventilation and nebulized groups, but no differencebetween the nebulized and control groups. Within each treatmentgroup, there was no regional difference in the distributionof density. Conclusions. PF 5080 is not deposited in large amounts by aerosol.Less PFC was found in the lungs after partial liquid ventilationthan expected. Within treatment groups, lung densities indicateless gravitational and regional differences than found in otherstudies.     

Comparative effects of vaporized perfluorohexane and partial liquid ventilation in oleic acid-induced lung injury

BACKGROUND: It is currently not known whether vaporized perfluorohexane is superior to partial liquid ventilation (PLV) for therapy of acute lung injury. In this study, the authors compared the effects of both therapies in oleic acid-induced lung injury. METHODS: Lung injury was induced in 30 anesthetized and mechanically ventilated pigs by means of central venous infusion of oleic acid. Animals were assigned to one of the following groups: (1) control or gas ventilation (GV), (2) 2.5% perfluorohexane vapor, (3) 5% perfluorohexane vapor, (4) 10% perfluorohexane vapor, or (5) PLV with perfluorooctane (30 ml/kg). Two hours after randomization, lungs were recruited and positive end-expiratory pressure was adjusted to obtain minimal elastance. Ventilation was continued during 4 additional hours, when animals were killed for lung histologic examination. RESULTS: Gas exchange and elastance were comparable among vaporized perfluorohexane, PLV, and GV before the open lung approach was used and improved in a similar fashion in all groups after positive end-expiratory pressure was adjusted to optimal elastance (P < 0.05). A similar behavior was observed in functional residual capacity (FRC) in animals treated with vaporized perfluorohexane and GV. Lung resistance improved after recruitment (P < 0.05), but values were higher in the 10% perfluorohexane and PLV groups as compared with GV (P < 0.05). Interestingly, positive end-expiratory pressure values required to obtain minimal elastance were lower with 5% perfluorohexane than with PLV and GV (P < 0.05). In addition, diffuse alveolar damage was significantly lower in the 5% and 10% perfluorohexane vapor groups as compared with PLV and GV (P < 0.05). CONCLUSIONS: Although the use of 5% vaporized perfluorohexane permitted the authors to reduce pressures needed to stabilize the lungs and was associated with better histologic findings than were PLV and GV, none of these perfluorocarbon therapies improved gas exchange or lung mechanics as compared with GV.     

Experimental study in partial liquid ventilation for acute respiratory failure after ischemia reperfusion pulmonary injury in a rabbit model

Partial liquid ventilation (PLV) using perfluorooctylbromide (PFOB) was studied for use in treating experimental animal models in which acute respiratory failure was caused by hypoxia, oleic acid lung injury, or saline lung lavage. Clinical trials are currently being conducted in the United States. We studied the effectiveness of PLV with PFOB in treating acute respiratory failure after ischemia reperfusion pulmonary injury in a rabbit model; left lung ischemia was induced with a hilar clamp. Ninety minute later, the clamp was removed for reperfusion. Fifteen Japanese white rabbits weighing from 2.5 to 3.2 kg were divided into three groups-conventional mechanical ventilation (CMV) after reperfusion, PLV after reperfusion and controls (conventional mechanical ventilation without ischemia reperfusion injury). In the PLV group, a dose of 7 ml/kg PFOB was administered through an endotracheal tube. In the CMV group, PaO₂ value decreased to 79 ± 13 mmHg 120 min after reperfusion, significantly lower than in the PLV group-404 ± 70-or controls ?494 ± 61?. PaCO₂ was significantly higher in the CMV group ?61.9 ± 14.4 mmHg- than in the PLV group-45.7 ± 6.1? or controls-32.1 ±2.2. Peak airway pressure was slightly higher in the CMV group-19.0 ± 4.9-than in the PLV group-18.2 ± 5.4-or controls-16.2 ± 1.8. mPAP/mSAP did not differ significantly among groups. The heart rate decreased in the CMV and PLV groups, but was unchanged in controls. Microscopic studies revealed markedly reduced alveolar hemorrhage, lung fluid accumulation, and inflammatory infiltration in the PLV group, compared to the CMV group. PLV thus is effective in improving gas exchange and preventing pulmonary injury in acute respiratory failure after ischemia reperfusion injury in a rabbit model.     

Comparison of exogenous surfactant therapy, mechanical ventilation with high end-expiratory pressure and partial liquid ventilation in a model of acute lung injury

We have compared three treatment strategies, that aim to prevent repetitive alveolar collapse, for their effect on gas exchange, lung mechanics, lung injury, protein transfer into the alveoli and surfactant system, in a model of acute lung injury. In adult rats, the lungs were ventilated mechanically with 100% oxygen and a PEEP of 6 cm H2O, and acute lung injury was induced by repeated lung lavage to obtain a PaO2 value < 13 kPa. Animals were then allocated randomly (n = 12 in each group) to receive exogenous surfactant therapy, ventilation with high PEEP (18 cm H2O), partial liquid ventilation or ventilation with low PEEP (8 cm H2O) (ventilated controls). Blood-gas values were measured hourly. At the end of the 4-h study, in six animals per group, pressure-volume curves were constructed and bronchoalveolar lavage (BAL) was performed, whereas in the remaining animals lung injury was assessed. In the ventilated control group, arterial oxygenation did not improve and protein concentration of BAL and conversion of active to non-active surfactant components increased significantly. In the three treatment groups, PaO2 increased rapidly to > 50 kPa and remained stable over the next 4 h. The protein concentration of BAL fluid increased significantly only in the partial liquid ventilation group. Conversion of active to non-active surfactant components increased significantly in the partial liquid ventilation group and in the group ventilated with high PEEP. In the surfactant group and partial liquid ventilation groups, less lung injury was found compared with the ventilated control group and the group ventilated with high PEEP. We conclude that although all three strategies improved PaO2 to > 50 kPa, the impact on protein transfer into the alveoli, surfactant system and lung injury differed markedly.      

Effect of PEEP and inhaled nitric oxide on pulmonary gas exchange during gaseous and partial liquid ventilation with small volumes of perfluorocarbon

BACKGROUND: Partial liquid ventilation, positive end-expiratory pressure (PEEP) and inhaled nitric oxide (NO) can improve ventilation/perfusion mismatch in acute lung injury (ALI). The aim of the present study was to compare gas exchange and hemodynamics in experimental ALI during gaseous and partial liquid ventilation at two different levels of PEEP, with and without the inhalation of nitric oxide. METHODS: Seven pigs (24+/-2 kg BW) were surfactant-depleted by repeated lung lavage with saline. Gas exchange and hemodynamic parameters were assessed in all animals during gaseous and subsequent partial liquid ventilation at two levels of PEEP (5 and 15 cmH2O) and intermittent inhalation of 10 ppm NO. RESULTS: Arterial oxygenation increased significantly with a simultaneous decrease in cardiac output when PEEP 15 cmH2O was applied during gaseous and partial liquid ventilation. All other hemodynamic parameters revealed no relevant changes. Inhalation of NO and instillation of perfluorocarbon had no additive effects on pulmonary gas exchange when compared to PEEP 15 cmH2O alone. CONCLUSION: In experimental lung injury, improvements in gas exchange are most distinct during mechanical ventilation with PEEP 15 cmH2O without significantly impairing hemodynamics. Partial liquid ventilation and inhaled NO did not cause an additive increase of PaO2.     

部分液体通气与吸入NO对急性肺损伤动物疗效的对比研究

目的对肺灌洗(Lavage)诱导的急性肺损伤(ALI)家猪实施以氟碳(PFC)为媒介的部分液体通气(PLV)及吸入20ppm的一氧化氮(NO),比较二者对肺气体交换及血液动力学的影响.方法24头健康家猪,麻醉后经气管导管肺内以生理盐水反复灌洗,直至动脉氧分压(PaO2)<100mmHg达1h,记录气体交换及血液动力学各参数作为急性肺损伤的基础值.随机分为PLV组、NO组及对照组,PLV组肺内灌以相当于肺功能余气量(30ml/kg)的PFC,然后以普通呼吸机行常规气体通气,补充PFC4ml·kg-1·h-1以弥补蒸发损失;NO组吸入20ppmNO,对照组不给予其它治疗,各组每小时记录气体交换及血液动力学各参数的变化.结果PLV组实施PLV1h后,PaO2即从ALI时的(53±11)mmHg升高至(142±133)mmHg,4h后达(318±109)mmHg,与ALI时比较差异有显著性(P＜0.01),亦显著高于对照组(P＜0.05).实施PLV1h后Qs/Qt从ALI时的(57±9)%降至(42±13)%,4h后降至(26±10)%,较ALI时差异有显著性(P＜0.01),并于2h后显著低于对照组(P＜0.05).NO组的MPAP在整个实验过程中显著低于对照组(P＜0.01).NO组吸入NO1h后,PaO2即呈上升趋势,4h后从ALI时的65±14升至(114±36)mmHg,与对照组比较差异有显著性(P＜0.05).同时肺内分流(Qs/Qt)及肺泡-动脉氧压差(AaDO2)降低.MAP及体循环血管阻力(SVR)与对照组比较无显著性改变.结论以氟碳为媒介的部分液体通气及吸入20ppm的NO均能有效的改善ALI动物肺气体交换.吸入NO能显著降低MPAP,而PLV更能显著的升高PaO2.     

部分液体通气用于家猪肺灌洗诱导的急性肺损伤的疗效观察

目的 对肺灌洗诱导的急性肺损伤家猪实施以氟碳（PFC）为媒介的部分液体通气（PLV）,观察其对肺气体交换及血液动力学的影响。方法 16头体重为（25±3）kg的健康幼猪,麻醉后经气管导管注入生理盐水反复肺内灌洗,直致动脉氧分压（PaO2）<100 mm Hg达1h,记录肺气体交换及血液动力学各参数作为肺损伤基值。随机分为PLV组及对照组。对照组以呼吸机仅行常规机械通气,PLV组动物经气管导管肺内灌以30ml/kgPFC,然后以与对照组同样的呼吸参数行机械通气,每小时补充4ml/kg的PFC以弥补蒸发损失量。每小时记录各肺气体交换及血液动力学参数的变化。结果 实施PLV1h后,PaO2即从 ALI的（53.2±10.81）mm Hg升高至（14.07±133.42）mmHg,4h后高达（318.51±108.97）mm Hg,显著高于对照组。实施PLV1h后Qs/Qt从ALI的57.10％±8.88％降至42.3％±12.78％,4h后降至26.05％±10.56,并于2h后显著低于对照组。与对照组比较,PLV组血液动力学无显著性的改变。结论 以PFC为媒介的PLC可明显地改善急性肺损伤的肺气体交换,对血液动力学无明显影响。