反比通氣和PEEP對(duì)肺損傷TNF(一)

1、反比通氣和PEEP對(duì)肺損傷TNF(一)    作者：秦鑫，劉又寧，陳良安，陳天獅 【關(guān)鍵詞】 急性病；肺/損傷;反比通氣;正壓呼吸;腫瘤壞死因子【Abstract】 AIM: To investigate the effects of inverse ratio ventilation(IRV) and positive endexpiratory pressure(PEEP) on TNF, IL8 and ET1 in oleic acidinduced lung injury. METHODS: Sixteen New Zealand rabbit

2、s were randomly divided into 2 groups, IRV group(n=8) and PEEP group (n=8). The IRV group were ventilated with a tidal volume(VT) of 12 mL/kg, respiratory rate of 30 breaths/min, IE=31 and PEEP of 0 cmH2O; in PEEP group, VT was 10 mL/kg and respiratory rate 40 breaths/min, IE=12 and PEEP=20 cmH2O; F

3、iO2=0.5 in both groups. Mixed venous blood 3 mL was taken via right ercernal jugular vein respectively at 0, 30, 60, 90 and 120 min during ventilating. The animals were sacrificed by draining artery blood at the end of experiment. Right lung was cut off for wet/dry weighing and left was lavaged. Con

4、centrations of TNF, IL8 and ET1 in blood plasma and bronchoalveolar lavage fluid(BALF) were measured by radioimmune assay. RESULTS: Levels of TNF，IL8 and ET1 in BALF in IRV group were higher than those in PEEP group (P0.05). Serum levels of TNF，IL8 and ET1 in both groups after 30 min ventilation wer

5、e significantly higher than those at base points (P0.05). Additionally, with the proceeding of ventilation, TNF, ET1 and IL8 in both groups were increasing gradually (P0.05). Levels of TNF, IL8 and ET1 in serum in PEEP group were lower significantly than those in IRV group (P0.05) at the similar tim

6、e points. In IRV vs PEEP, the ratio of wet to dry lung (%) surging(79±1 vs 62±1, P0.01). Levels of TNF，IL8 and ET1 in BALF were correlated with the ratio of wet to dry lung（r1=0.8972, r2=0.9518, r3=0.8978）. CONCLUSION: Lung inflammatory response of acute lung injury may be alleviated more

7、effectively in the setting of PEEP than IRV.【Keywords】 acute disease; lung/injuries; inverse ratio ventilation; positive pressure respivetion; tumornecrosisfactoralpha; interleukin8; endothelin1【摘要】 目的： 探討反比通氣（IRV）和呼氣末正壓通氣（PEEP）對(duì)油酸所致急性肺損傷肺泡灌洗液及外周血中TNF, IL8, ET1的影響. 方法： 將16只新西蘭大白兔隨機(jī)分為兩組,每組8只. IRV組，呼吸

8、頻率30次/min，IE=31，潮氣量12 mL/kg，PEEP=0；PEEP組，呼吸頻率40次/min，IE=12，潮氣量10 mL/kg，PEEP=20 cmH2O（1 cmH2O=0.098 kPa）. 兩組均以容量控制通氣. 吸氧濃度(FiO2)=0.5. 在0, 30, 60, 90及120 min由右頸外靜脈導(dǎo)管采集混合靜脈血各3 mL,放免法測(cè)定血漿及肺泡灌洗液中腫瘤壞死因子(TNF)、白細(xì)胞介素8(IL8)、內(nèi)皮素1（ET1）的含量. 實(shí)驗(yàn)結(jié)束后放血處死動(dòng)物,右肺用于肺濕質(zhì)量/干質(zhì)量比率測(cè)定. 結(jié)果： 兩組BALF中TNF，IL8，ET1濃度，IRV組明顯高于PEEP組(P均0

9、.05)；兩組血清中TNF，IL8，ET1濃度，在肺損傷后30 min均顯著升高,明顯高于肺損傷前(P0.05). 各組隨著時(shí)間延長(zhǎng)，三種細(xì)胞因子逐漸增加. PEEP組三種細(xì)胞因子濃度均明顯低于對(duì)應(yīng)時(shí)間點(diǎn)的IRV組(P均0.05)；PEEP組肺干質(zhì)量占肺濕質(zhì)量(62±1)%,顯著低于IRV組的(79±1)%(P0.01). BALF中三種因子含量也與肺水質(zhì)量分?jǐn)?shù)呈顯著正相關(guān)（r1=0.8972, r2=0.9518, r3=0.8978）. 結(jié)論： PEEP比IRV能更好地減少急性肺損傷的肺部炎癥反應(yīng).【關(guān)鍵詞】 急性病；肺/損傷;反比通氣;正壓呼吸;腫瘤壞死因子; 白細(xì)胞

10、介素8; 內(nèi)皮縮血管肽1近年來(lái)機(jī)械通氣相關(guān)肺損傷（ventilatorinduced lung injury, VILI）越來(lái)越引起人們的重視，針對(duì)這一問(wèn)題而進(jìn)行的各種肺保護(hù)策略的研究已成為機(jī)械通氣研究領(lǐng)域的熱點(diǎn)1-2. 反比通氣（inverse ratio ventilation, IRV）和呼氣末正壓通氣（positive endexpiratory pressure, PEEP）是兩種重要的肺保護(hù)策略，其主要機(jī)制是通過(guò)減小呼吸過(guò)程中萎陷肺泡與膨脹或正常肺泡之間的剪切力來(lái)減小肺損傷3-4. 我們通過(guò)比較兩種肺保護(hù)策略對(duì)油酸肺損傷兔肺泡灌洗液及外周血中炎癥因子的不同影響，探討兩種肺保護(hù)通氣策

11、略的優(yōu)劣.1材料和方法1.1材料健康成年雄性新西蘭白兔16只，體質(zhì)量2.33.0（平均2.6）kg，均由解放軍總醫(yī)院動(dòng)物中心許可證號(hào)SCXK（京）20020005提供，動(dòng)物飼養(yǎng)環(huán)境，溫度18 22，濕度40%70%.1.2方法將動(dòng)物隨機(jī)分為兩組,每組8只. IRV組，呼吸頻率30次/min，IE=31，潮氣量12 mL/kg，PEEP=0；PEEP組，呼吸頻率40次/min，IE=12，潮氣量10 mL/kg，PEEP=20 cmH2O. 兩組均以容量控制通氣. 吸氧濃度(FiO2)=0.5. 調(diào)整潮氣量維持PCO2 40 cmH2O，MAP維持在50 mmHg(1 mmHg=0.133 kP

12、a)以上. 在0, 30, 60, 90及120 min抽動(dòng)脈血監(jiān)測(cè)血?dú)庵笜?biāo).各組動(dòng)物在實(shí)驗(yàn)前均禁食12 h,用30 g/L戊巴比妥鈉(1 mL/kg)經(jīng)耳緣靜脈麻醉后, 取仰臥位固定于手術(shù)臺(tái)上,分別行右頸總動(dòng)脈和頸外靜脈插管及氣管切開(kāi)、氣管內(nèi)插管, 連接PB840呼吸機(jī)（PuritonBenett公司，美國(guó)）,靜脈注射潘庫(kù)溴銨0.2 mg/kg抑制自主呼吸,整個(gè)實(shí)驗(yàn)過(guò)程中以0.1 mg/(kg?h)的劑量持續(xù)靜脈滴注維持肌松, 30 min內(nèi)iv油酸(0.06 mL/kg),建立油酸ALI模型. 用Spacelabs多功能監(jiān)護(hù)儀（Spacelabs Nedical公司，美國(guó)）持續(xù)監(jiān)測(cè)動(dòng)脈平均

13、血壓、心率.實(shí)驗(yàn)后0, 30, 60和120 min，由右頸外靜脈導(dǎo)管采集混合靜脈血各3 mL,分置于含有100 g/L EDTA的試管中,4 3000 r/min離心15 min,分離血漿或血清,-20保存待測(cè)血漿TNF，IL8和ET1含量. 各組動(dòng)物均于實(shí)驗(yàn)完成后120 min時(shí)放血處死,立即開(kāi)胸取肺,左肺生理鹽水灌洗3次，每次10 mL,將灌洗液混合，3000 r/min離心15 min,取上清，-20保存待測(cè)BALF中TNF, IL8, ET1含量. 上述用放免法檢測(cè)，試劑盒均由解放軍總醫(yī)院放免所提供，將右肺稱濕質(zhì)量后置于75烤箱72 h取出稱干質(zhì)量. 肺水含量按下列公式計(jì)算： 肺水質(zhì)

14、量分?jǐn)?shù)(g/kg)=(肺濕質(zhì)量-肺干質(zhì)量)/肺濕質(zhì)量×100%.統(tǒng)計(jì)學(xué)處理:各組數(shù)據(jù)以x±s表示,用SPSS10.0統(tǒng)計(jì)軟件進(jìn)行數(shù)據(jù)分析,重復(fù)測(cè)量方差分析及LSDt檢驗(yàn).2結(jié)果兩組BALF中TNF，IL8，ET1濃度IRV組明顯高于PEEP組(P均0.05，表1). 表1BALF中細(xì)胞因子濃度兩組血清中TNF， IL8， ET1濃度在肺損傷后30 min均顯著升高,明顯高于肺損傷前(P0.05). 各組隨著時(shí)間延長(zhǎng)，三種細(xì)胞因子逐漸增加. PEEP組三種細(xì)胞因子濃度均明顯低于對(duì)應(yīng)時(shí)間點(diǎn)的IRV組(P均0.05,表2).表2油酸肺損傷兔IRV和PEEP通氣條件下外周血三種細(xì)胞

15、因子變化PEEP組肺干質(zhì)量占肺濕質(zhì)量（62±1）%,顯著低于IRV組的（79±1）%(P0.01). 中三種因子含量均與肺水質(zhì)量分?jǐn)?shù)呈正相關(guān)（r1=0.8972, r2=0.9518, r3=0.8978）.3討論IRV和PEEP是兩種重要的肺保護(hù)策略，其主要機(jī)制都是通過(guò)減小呼吸過(guò)程中萎陷肺泡與膨脹或正常肺泡之間的剪切力來(lái)減小肺損傷. PEEP大于20 cmH2O，IRV吸呼時(shí)間比大于31時(shí)，呼氣末肺泡全部處于開(kāi)放狀態(tài). Neumann等5通過(guò)對(duì)油酸致豬肺損傷模型分別行IRV和PEEP 3 h后，做胸部CT掃描，發(fā)現(xiàn)IRV組肺充氣不均，而PEEP組則肺通氣較均勻. TNF,

16、 IL8是急性肺損傷肺內(nèi)炎癥的啟動(dòng)和放大因子，它們可通過(guò)多種途徑直接或間接損傷細(xì)胞毛細(xì)血管膜,使其通透性增高,產(chǎn)生滲透性肺水腫6. 本研究提示，機(jī)械通氣2 h后，IRV組BALF及血中炎癥因子均高于PEEP組，可能因?yàn)镮RV時(shí)，由于受到肺局部順應(yīng)性和阻力的影響，PEEP在肺的不同區(qū)域分布不同，因而使得不同區(qū)域的肺充氣程度不同. 肺毛細(xì)血管血流向充氣不佳的區(qū)域，充氣好的區(qū)域血流反而不足，因此加重了通氣血流失衡，局部肺組織缺氧，毛細(xì)血管通透性增加，炎癥因子滲出增加. 本研究還提示，IRV過(guò)程中，隨著通氣時(shí)間的延長(zhǎng)，血中炎癥因子有上升趨勢(shì)，進(jìn)一步證實(shí)，IRV對(duì)急性肺損傷可能沒(méi)有逆轉(zhuǎn)作用. PEEP組

17、隨著時(shí)間延長(zhǎng)，血中炎癥因子雖然也有上升，但升高的程度和幅度均低于相應(yīng)時(shí)間點(diǎn)的IRV組，且BALF中炎癥因子及肺濕干比明顯低于IRV組，因此PEEP可能減輕急性肺損傷炎癥反應(yīng)方面優(yōu)于IRV.【參考文獻(xiàn)】1 Laffey JG, O'Croinin D, McLoughlin P, et al. Permissive hypercapniarole in protective lung ventilatory strategiesJ. Intensive Care Med, 2004,30(3):347-356.2 趙衛(wèi)國(guó)，劉又寧，曹德森，等. 死腔內(nèi)氣體吸出技術(shù)對(duì)急性高碳酸血癥犬呼吸功能

18、及血流動(dòng)力學(xué)的影響J. 中華結(jié)核和呼吸雜志，2001,24（11）:643-647.3 Mutch WAC, Eschun GM, Kowalski SE, et al. Biologically variable ventilation prevents deterioration of gas exchange during prolonged anaesthesiaJ. Br J Anaesth, 2000,84:197-203. 4 Pelosi P, Goldner M, McKibben A, et al. Recruitment and derecruitment during acute respiratory failure: An experimental studyJ. Am J Respir Crit Ca