張小明 李雪芬 劉偉 任姜汶 田福華
終末期腎病維持性血液透析患者不同液體超負(fù)荷水平與心率變異性關(guān)系的研究
張小明 李雪芬 劉偉 任姜汶 田福華
目的探討終末期腎病維持性血液透析(maintenance hemodialysis, MHD)患者不同液體超負(fù)荷水平與心率變異性(heart rate variability, HRV)的關(guān)系。方法終末期腎病MHD患者60例, 根據(jù)透析期間患者體重增長(zhǎng)情況, 將入選患者透析期間體重增長(zhǎng)不超過(guò)5%的歸入對(duì)照組, 共47例;因患者自身原因(透析不充分、飲水過(guò)多及氣候變化等)透析期間體重增長(zhǎng)超過(guò)5%的歸入實(shí)驗(yàn)組, 共13例, 分析同一MHD患者透析后不同液體超負(fù)荷水平與HRV的關(guān)系。結(jié)果兩組比較, 高頻功率(high frequency, HF)差異無(wú)統(tǒng)計(jì)學(xué)意義(P>0.05), 低頻功率(low frequency, LF)及R-R間期功率變異比值(LF/ HF)差異有統(tǒng)計(jì)學(xué)意義(P<0.05)。近似熵(ApEn)在透析前差異無(wú)統(tǒng)計(jì)學(xué)意義(P>0.05), 透析后差異有統(tǒng)計(jì)學(xué)意義(P<0.05)。結(jié)論透析期間控制液體負(fù)荷水平可能有助于心臟自主神經(jīng)功能的改善。
血液透析;液體超負(fù)荷水平;心率變異性
血液透析是終末期腎病患者賴(lài)以生存的重要手段, 患者體內(nèi)液體超負(fù)荷現(xiàn)象是MHD患者透析后的常見(jiàn)并發(fā)癥之一,對(duì)患者的愈后及生存率密切相關(guān)[1-3]。臨床觀(guān)察發(fā)現(xiàn), 透析患者體內(nèi)液體超負(fù)荷水平與心率變異性有密切關(guān)系, 但目前尚沒(méi)有相關(guān)文獻(xiàn)報(bào)道。心率變異性是近年來(lái)比較受關(guān)注的無(wú)創(chuàng)性心電監(jiān)測(cè)指標(biāo)之一, 可用來(lái)預(yù)測(cè)心臟性猝死、評(píng)價(jià)心臟自主神經(jīng)的活動(dòng)性、均衡性及相關(guān)的病理狀態(tài)[3-7]。本文旨在通過(guò)研究透析患者心率變異性中的頻域指標(biāo), 探討透析患者不同體液超負(fù)荷水平與心率變異性的關(guān)系。
1.1一般資料 選擇2011年1月~2012年1月在九龍坡區(qū)第一人民醫(yī)院腎內(nèi)科血液凈化中心透析治療≥3個(gè)月, 年齡≥18歲的終末期腎病患者, 所有患者均簽署知情同意書(shū)均病情穩(wěn)定, 無(wú)急性心腦血管疾病, 3個(gè)月內(nèi)未接受外科手術(shù),無(wú)嚴(yán)重肝功能受損。
1.2研究方法
1.2.1分組 選擇入組患者連續(xù)3個(gè)月記錄每次血液透析中的體重, 并根據(jù)體重增長(zhǎng)情況進(jìn)行分組, 透析期間體重增長(zhǎng)不超過(guò)5%的歸入對(duì)照組, 透析期間體重增長(zhǎng)超過(guò)5%的歸入實(shí)驗(yàn)組。血液透析2~3次/周, 透析時(shí)間3.5~4 h/次,血流速度200~250 ml/min。普通肝素或低分子肝素抗凝。透析液配方:Na+138 mmol/L, K+2.0 mmol/L, Ca2+1.5 mmol/L, Mg2+1.5 mmol/L, 碳酸氫鹽34 mmol/L。兩組一般資料比較, 差異無(wú)統(tǒng)計(jì)學(xué)意義(P>0.05), 具有可比性。血樣本在透析前抽取,以測(cè)定血色素(HGB)、血細(xì)胞比容(Hct)、尿素氮(BUN)和肌酐(Cr)水平。
1.2.2心率變異性檢測(cè) 按照文獻(xiàn)報(bào)道的標(biāo)準(zhǔn)方法進(jìn)行[8]。采用美國(guó)GEMarquette公司生產(chǎn)的配備Holter-Star分析軟件的Holter心電圖掃描儀及三通道模擬V5、V1、avF 導(dǎo)聯(lián)記錄器進(jìn)行24 h動(dòng)態(tài)心電圖分析, 于透析開(kāi)始前監(jiān)測(cè)所有患者的24 h動(dòng)態(tài)心電圖變化, 運(yùn)用Holter-Star分析軟件對(duì)HRV進(jìn)行分析。瞬間R-R間期的突然變化視為干擾所致, 予以剔除。透析前30 min囑患者平躺靜臥, 分別在透析開(kāi)始時(shí)、結(jié)束時(shí)以及透析過(guò)程中每30 min記錄患者血壓及心率。動(dòng)態(tài)心電圖自動(dòng)記錄整個(gè)血液透析過(guò)程中HRV的各個(gè)指標(biāo)。對(duì)每一入選患者透析前后共24 h(以透析4 h為中心時(shí)間段)進(jìn)行24 h動(dòng)態(tài)心電圖監(jiān)測(cè), 并分析主要的時(shí)域(SDNN、NN50)和頻域HRV(VLF、LF/HF)指標(biāo), 每一入選患者觀(guān)察連續(xù)3次血液透析的24 h動(dòng)態(tài)心電圖, 每3個(gè)月對(duì)所有入選患者按上述方法重復(fù)檢測(cè), 連續(xù)檢測(cè)18個(gè)月。其中, 分析LF和HF需要使用標(biāo)準(zhǔn)化后的結(jié)果, 標(biāo)準(zhǔn)化LF和HF用LFn和HFn表示,由如下公式計(jì)算得出:LFn=LF/(TP-VLF)×100%;HFn=HF/ (TP-VLF)×100%;[TP=總功率(單位為ms2);VLF=極低頻功率(單位為ms2)]。比較透析前后5 min兩組非線(xiàn)性分析指標(biāo)近似熵(ApEn), 計(jì)算公式為ApEn(r, m, n)=Φm(r)-Φm+1(r)。
1.3統(tǒng)計(jì)學(xué)方法 采用SPSS17.0統(tǒng)計(jì)軟件進(jìn)行統(tǒng)計(jì)學(xué)分析。計(jì)量資料以均數(shù)±標(biāo)準(zhǔn)差表示, 采用t檢驗(yàn);計(jì)數(shù)資料采用χ2檢驗(yàn)。P<0.05為差異具有統(tǒng)計(jì)學(xué)意義。
HF兩組比較差異無(wú)統(tǒng)計(jì)學(xué)意義(P>0.05);但LF及LF/HF透析實(shí)驗(yàn)組較對(duì)照組顯著降低(P<0.05);ApEn在透析前兩組比較差異無(wú)統(tǒng)計(jì)學(xué)意義(P>0.05), 透析后差異有統(tǒng)計(jì)學(xué)意義(P<0.05)。見(jiàn)表1。
表1血液透析過(guò)程中平均心率變異性頻域指標(biāo)、非線(xiàn)性分析指標(biāo)變化
表1血液透析過(guò)程中平均心率變異性頻域指標(biāo)、非線(xiàn)性分析指標(biāo)變化
注:與對(duì)照組比較,aP<0.05,bP>0.05
組別例數(shù)LFn(nu)HFn(nu)LF/HFApEn透析前透析后實(shí)驗(yàn)組1356.01±2.33a39.55±1.88b2.12±0.33a1.07±0.14b0.90±0.17a對(duì)照組4761.13±1.6741.23±1.543.60±0.621.05±0.111.07±0.13 t 6.940.512.590.163.46 P 0.0080.610.0140.8760.001
HRV是反映自主神經(jīng)系統(tǒng)活性和定量評(píng)估心臟交感神經(jīng)與迷走神經(jīng)張力及其平衡性, 從而判斷其對(duì)心血管疾病的病情及預(yù)防的, 可能是預(yù)測(cè)心臟性猝死和心律失常性事件的一個(gè)有價(jià)值的指標(biāo)。致命性的心律失常與交感神經(jīng)的興奮性增加、迷走神經(jīng)的興奮性減少有關(guān), 自主神經(jīng)系統(tǒng)活動(dòng)的量化可以通過(guò)心率變化的程度表現(xiàn)出來(lái), HRV代表了這樣一種量化標(biāo)測(cè)。即通過(guò)測(cè)量連續(xù)正常P-P間期變化的變異性來(lái)反映心率變化程度、規(guī)律, 從而用以判斷其對(duì)心血管活動(dòng)的影響。HRV降低為交感神經(jīng)張力增高, 可降低室顫閾, 屬不利因素;HRV升高為副交感神經(jīng)張力增高, 提高室顫閾,屬保護(hù)因素[3,7,8]。國(guó)內(nèi)外報(bào)道, 終末期腎病患者的心血管疾病的發(fā)生率和由此導(dǎo)致的死亡率明顯高于普通人群。隨著腎功能的進(jìn)行性損害, 慢性腎衰竭患者血肌酐和尿素氮亦進(jìn)行性升高, 由此引起HRV不同程度的下降, 提示該類(lèi)患者自主神經(jīng)功能遭受不同程度的損傷[9-13]。然而, 維持性血液透析患者不同體液超負(fù)荷水平對(duì)HRV的影響, 目前尚不完全清楚。
眾所周知, 維持性血液透析患者極易合并心血管疾病,主要是因?yàn)樵擃?lèi)患者大多存在不同程度的自主神經(jīng)系統(tǒng)功能紊亂, 尤其以交感神經(jīng)系統(tǒng)功能亢進(jìn)為主。透析過(guò)程中, 由于血管內(nèi)進(jìn)行脫水的原因, 會(huì)出現(xiàn)循環(huán)血容量減少和血壓下降, 進(jìn)而引起人體代償機(jī)制。而外周血容量的減少會(huì)刺激頸動(dòng)脈竇和主動(dòng)脈弓壓力感受器, 進(jìn)而增強(qiáng)交感神經(jīng)的興奮性,使心率加快, 心肌收縮力增強(qiáng), 同時(shí)使小動(dòng)脈和容量血管收縮,防止垮血壓的發(fā)生, 以此來(lái)維持正常的血流動(dòng)力學(xué)狀態(tài)[12-16]。另一方面, 由于血液透析患者自主神經(jīng)調(diào)節(jié)功能存在不同程度的損害, 不能及時(shí)對(duì)快速體液丟失作出反應(yīng), 所有血液透析患者極易發(fā)生垮血壓。國(guó)內(nèi)外學(xué)者認(rèn)為, HRV可較好的反映交感和副交感神經(jīng)的功能水平以及相互間的平衡, 是評(píng)估自主神經(jīng)功能的有效指標(biāo), 對(duì)患者的愈合也有一定的評(píng)估作用[3-7]。在本研究中, LF和HF分別反映交感神經(jīng)和迷走神經(jīng)的活性, LF/HF則代表交感和副交感神經(jīng)的平衡。而計(jì)算出來(lái)的近似熵的大小反映系統(tǒng)復(fù)雜性的高低, 近似熵越大, 說(shuō)明系統(tǒng)越趨近于隨機(jī)狀態(tài), 包含頻率成分越豐富, 具有較強(qiáng)的適應(yīng)性;近似熵越低, 則信號(hào)越趨于周期性, 信號(hào)包含的頻譜較窄, 系統(tǒng)的適應(yīng)能力越低[17-20]。在心血管系統(tǒng)中, 心血管調(diào)節(jié)的模式常用近似熵表示, 近似熵的高低與心血管系統(tǒng)的復(fù)雜性呈正相關(guān)。國(guó)內(nèi)外文獻(xiàn)表明, MHD患者的HRV的所有參數(shù)均較正常值低[19,20]。本研究中, 觀(guān)察到透析實(shí)驗(yàn)組較對(duì)照組LF、LF/HF值均降低, 說(shuō)明MHD患者透析期間嚴(yán)格控制液體負(fù)荷水平可能有助于心臟自主神經(jīng)功能的改善。
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Study of the relation between liquid overload level and heart rate variability in end-stage renal disease patients undergone maintenance hemodialysis
ZHANG Xiao-ming, LI Xue-fen, LIU Wei, et al.
Department
of Nephrology, Chongqing Jiulongpo First People’s Hospital, Chongqing 410000, China
ObjectiveTo investigate the relationship between liquid overload level and heart rate variability (HRV) in end-stage renal disease patients undergone maintenance hemodialysis (MHD).MethodsThere were 60 cases of end-stage renal disease with MHD.According to ponderal growth of patients during hemodialysis, 47 cases with ponderal growth less than 5% were divided into the control group, and 13 cases with ponderal growth more than 5% due to personal reasons (inadequate hemodialysis, too much drinking and climate change) were divided into experimental group.The relationship between different liquid overload level and HRV was analyzed in the same MHD patients.ResultsThe comparison showed that the difference of high frequency (HF) had no statistical significance (P>0.05), while the differences of low frequency (LF) and the R-R interphase variation ratio (LF/HF) between the experimental group and the control group were statistically significant (P<0.05).The difference of approximate entropy (ApEn) before hemodialysis had no statistical significance (P>0.05), the difference after hemodialysis was statistically significant (P<0.05).ConclusionControl of liquid overload level during hemodialysis may promote the improvement of cardiac autonomic nervous system.
Hemodialysis; Liquid overload level; Heart rate variability
2014-07-01]
重慶市衛(wèi)生局2012年醫(yī)學(xué)科研項(xiàng)目(面上項(xiàng)目)基金(項(xiàng)目編號(hào):2012-2-448)
410000 重慶市九龍坡區(qū)第一人民醫(yī)院腎內(nèi)科
田福華