小兒體液平衡特點(diǎn)和液體療法

PAGE/r/nPAGE/r/n11/r/n小兒體液平衡特點(diǎn)及液體療法/r/n一.小兒體液平衡特點(diǎn)/r/n㈠．體液總量與分布/r/n表/r/n1 不同年齡體液總量與分布（占體重﹪）/r/n新生兒/r/n1歲/r/n2－14歲/r/n成人/r/n體液總量/r/n80/r/n70/r/n65/r/n55－60/r/n細(xì)胞內(nèi)液/r/n35/r/n40/r/n40/r/n40－45/r/n細(xì)胞外液/r/n45/r/n35/r/n25/r/n15－20/r/n間質(zhì)液/r/n40/r/n25/r/n20/r/n10－15/r/n血漿/r/n5/r/n5/r/n5/r/n5/r/n體液分細(xì)胞內(nèi)液與細(xì)胞外液，后者又分間質(zhì)液與血漿。/r/n年齡愈小，體液總量相對(duì)愈多，主要是細(xì)胞外液中的間質(zhì)液相對(duì)愈多。/r/n76﹪，/r/n10﹪。/r/n㈡．體液中電解質(zhì)的組成/r/n小兒體液中電解質(zhì)與成人相似。/r/n5～7mmol/r/n／L,/r/n104～112mmol/r/n／L，/r/n21～23/r/nmmol／L/r/n。/r/n細(xì)胞內(nèi)外液的電解質(zhì)差別較大。/r/nK/r/n﹢/r/n、Mg/r/n2+/r/n、HPO/r/n4/r/n2-/r/n和蛋白質(zhì)為主。/r/n3/r/n/r/n細(xì)胞外以/r/nNa/r/n﹢/r/n、CL/r/n﹣/r/n、/r/nHCO/r/n/r/n3/r/n/r/n3．血漿中的電解質(zhì)可精確測(cè)定，是臨床判斷電解質(zhì)正?；蛭蓙y的依據(jù)。/r/n表：血漿中電解質(zhì)組成/r/n陽離子/r/n2/r/nNa/r/n﹢/r/nK/r/n﹢/r/nCa/r/n2/r/n2/r/nMg/r/n/r/n﹢/r/n2/r/n總量/r/n

/r/nmEq/r/n142/r/n5/r/n5/r/n3/r/n155/r/n

/r/nmmol/r/n142/r/n5/r/n2.5/r/n1.5/r/n151/r/n

/r/n陰離子/r/n3/r/nHCO/r/n/r/n﹣/r/n3/r/nCL/r/n﹣/r/n4/r/nHPO/r/n/r/n4/r/n4/r/nSO/r/n/r/n2/r/n﹣/r/n4/r/n有機(jī)酸蛋白質(zhì)總量/r/n

/r/nmEq/r/n27/r/n103/r/n2/r/n1/r/n6/r/n16/r/n155/r/n

/r/nmmol/r/n／L/r/n27/r/n103/r/n1/r/n0.5/r/n6/r/n0.8/r/n138.3/r/n從上表可看出：/r/n①mEq／L/r/nmmol/r/n／L/r/n②陰陽離子以mEq／L表示均為155。/r/nmmol/r/n／L/r/n138.3=289.3/r/nmmol／L/r/n280～320/r/nmmol／L/r/n為低滲，>320/r/nmmol／L/r/nNa/r/n﹢/r/n90℅/r/nNa/r/n﹢/r/n來判斷血/r/n／L/r/n易計(jì)算公式：/r/nmmol/r/n／L＝2×（Na/r/n﹢/r/n＋10）/r/nNa/r/n/r/n∶CL/r/n＝3∶2/r/n⑥陰離子間隙（AGAnion/r/n/r/nGap）/r/nAG=Na/r/n﹢/r/n－（CL/r/n﹣/r/n＋HCO/r/n﹣/r/n）/r/n3/r/n8～16mmol／L/r/n對(duì)區(qū)別代酸的性質(zhì)和指導(dǎo)治療有一定幫助。/r/n㈢．兒童水代謝的特點(diǎn)/r/n水的生理需要量/r/n年齡愈小，需要量愈多。/r/n因?yàn)椋孩傩荷L(zhǎng)發(fā)育快，細(xì)胞組織增長(zhǎng)需積蓄水；/r/n②活動(dòng)量大；/r/n③新陳代謝旺盛；/r/n④攝入熱量、蛋白質(zhì)和腎排出的溶質(zhì)量較高；/r/n⑤體表面積大，呼吸頻率快，不顯性失水多。/r/n表：不同年齡小兒每日水的需要量/r/n年齡/r/n（歲）/r/n需水量/r/n（ml/kg）/r/n

/r/n<1130～160/r/n

/r/n1～3/r/n110～140/r/n

/r/n3～9/r/n70～110/r/n

/r/n10～14/r/n50～90/r/n不顯性失水/r/n

/r/n表：機(jī)體每消耗/r/n100Kcal/r/n熱量所需水量/r/n肺/r/n /r/n14/r/n皮膚/r/n /r/n28/r/n出汗（室溫/r/n20/r/n度）/r/n /r/n20/r/n大便/r/n /r/n8/r/n小便 50～80/r/n合計(jì) 120～150/r/n水的交換：/r/n小兒水的交換率也比成人快。/r/n1/2/r/n1/7。/r/n3小兒水代謝的調(diào)節(jié)機(jī)制尚不成熟/r/n神經(jīng)內(nèi)分泌：腎、肺對(duì)水代謝的調(diào)節(jié)機(jī)制均不成熟。/r/n700mmol/r/n／L（/r/n1020/r/n，而成人可/r/n1400mmol/r/n（/r/n1035/r/n1mmol/r/n／L/r/n1～2ml/r/n0.7ml/r/n由于上述特點(diǎn)，小兒容易發(fā)生水、電解質(zhì)及酸堿平衡紊亂。/r/n二．常見的體液代謝紊亂/r/n㈠．脫水dehydration/r/n外還有鈉、鉀及其它電解質(zhì)損失。/r/n脫水程度/r/n發(fā)病后累積損失的液體量，分三度。/r/n表：脫水程度/r/n臨床表現(xiàn)/r/n輕度/r/n中度/r/n重度/r/n神志/r/n精神稍萎/r/n神萎煩躁/r/n神志不清/r/n皮膚/r/n稍干，彈性稍差/r/n干，彈性差/r/n灰白冰冷，彈性稍差/r/n前囟眼窩/r/n稍凹/r/n明顯凹陷/r/n極度凹陷/r/n唇粘膜/r/n稍干/r/n干燥/r/n干裂/r/n尿量/r/n稍減少/r/n顯著減少/r/n幾乎無尿/r/n末梢循環(huán)/r/n尚好/r/n差/r/n休克/r/n失水量（占體重℅）/r/n<5℅/r/n5～10℅/r/n>10℅/r/n損失細(xì)胞外液量1/5/r/n損失細(xì)胞外液量/r/n損失細(xì)胞外液量/r/n

/r/n

/r/n1/3/r/n

/r/n1/2約100～200/r/n脫水性質(zhì)/r/n

/r/n表：脫水性質(zhì)/r/n低滲 等滲 高滲/r/n水鹽丟失比細(xì)胞外液量細(xì)胞內(nèi)液量/r/n（mmol/r/n血鈉（mmol/r/nL）/r/n循環(huán)障礙癥狀神經(jīng)系統(tǒng)癥狀/r/n原因/r/n㈡．鉀代謝紊亂/r/n

/r/n失水<失鹽/r/n↓↓↓/r/n↑/r/n↓<280/r/n↓<130/r/n血壓下降/r/n可昏迷/r/n①嚴(yán)重或長(zhǎng)期腹瀉/r/n②營(yíng)養(yǎng)不良并腹瀉/r/n③慢性心腎疾病長(zhǎng)期忌鹽/r/n④大量利尿劑應(yīng)用/r/n⑤補(bǔ)充非電解質(zhì)液量多/r/n

/r/n失水=失鹽/r/n↓↓/r/n↓280～320/r/n130～150/r/n可有/r/n(中度以上脫水時(shí))重者，萎靡、嗜睡/r/n①嘔吐、腹瀉/r/n②胃腸引流/r/n③進(jìn)食不足/r/n

/r/n失水>失鹽/r/n↓/r/n↓↓/r/n↑>320/r/n↑>150/r/n輕/r/n明顯，煩躁激惹、口渴高熱驚厥，肌張力增高/r/n① 腹瀉伴高熱/r/n② 不顯性失水增多/r/n③ /r/n3.5～5.5mmol/r/n／L/r/n低鉀血癥hypokalemia/r/n/r/n血鉀<3.5mmol/r/n原因： ①攝入不足/r/n②損失過多：胃腸道丟失（吐瀉、胃腸引流）/r/n③鉀轉(zhuǎn)移到細(xì)胞內(nèi)/r/n家族性周期性麻痹/r/n堿中毒/r/n臨床表現(xiàn)：①神經(jīng)肌肉興奮性降低：神萎，全身軟弱無力，肌張力降低，腱反射減弱或消失。弛緩性癱瘓/r/n②胃腸平滑肌興奮性降低：腹脹、腸鳴減弱或消失，腸麻痹。/r/n③心肌張力降低：心音低鈍，心率增快，心律紊亂，心電圖：/r/nS－T/r/n長(zhǎng)，U/r/nK/r/n﹢/r/nNa/r/n﹢/r/n、/r/nH/r/n+/r/nH/r/n+/r/n降低，遠(yuǎn)曲小管/r/nK/r/n﹢/r/nH/r/n+/r/n診斷：/r/n

/r/n合分析。/r/n血鉀濃度可正?；蛏愿摺?r/n治療： ①治療原發(fā)病/r/n②補(bǔ)鉀見尿補(bǔ)鉀，多次監(jiān)測(cè)?？诜a(bǔ)鉀/r/n靜脈補(bǔ)鉀：濃度<40mmol／L(<0.3℅)/r/n速度<0.3mmol/r/n／kg.h./r/n靜脈注射。/r/n3/r/nmmol／kg.d/r/nmmol/r/n／kg.d./r/n高鉀血癥hyperkalemia/r/n原因： ①排出減少：腎功能衰竭、休克、嚴(yán)重脫水。/r/n②產(chǎn)生或進(jìn)入過多：溶血、嚴(yán)重?cái)D壓傷、酸中毒、輸入含鉀溶/r/n液濃度過高、速度過快。/r/n臨床表現(xiàn)：①神經(jīng)肌肉系統(tǒng)：血鉀/r/n>7mmol/r/nL/r/n全身軟弱，嗜睡，腱反射降低或消失。/r/n②心臟：心肌應(yīng)激性下降，心率緩慢，傳導(dǎo)阻滯，心/r/n室纖顫。心電圖可見/r/nT/r/n長(zhǎng)，傳導(dǎo)阻滯，室性心律不齊。/r/n治療：停止含鉀液體及一切隱性的鉀來源。/r/n積極降低血鉀：①快速靜脈應(yīng)用碳酸氫鈉1～2mmol／kg/r/n②輸入葡萄糖（3g）＋胰島素（1U）溶液/r/n③10℅葡萄糖酸鈣0.5ml／kg緩慢靜注/r/n④離子交換樹脂、血液或腹膜透析/r/n㈢.酸堿平衡紊亂/r/npH/r/n7.35～7.45。pH<7.30/r/n；pH>7.45/r/nCO/r/n2/r/n排出過少或過多，使血漿中/r/nH/r/n2/r/nCO/r/n3/r/n減少，引起的酸堿平衡紊亂稱為呼吸性酸中毒或堿中毒。/r/npH/r/n圍時(shí)稱為代償性酸中毒或堿中毒，否則為失代償酸或堿中毒。/r/n代謝性酸中毒metabolicacidosis/r/nAG/r/nAG/r/n（AG＝8～16mmo/r/nl/r/n／L/r/n產(chǎn)物堆積等。/r/nAG/r/n（AG>16mmol/r/nL）/r/n酮癥酸中毒，饑餓性酮癥。/r/n臨床表現(xiàn)：根據(jù)血漿中CO/r/n2/r/nCP測(cè)定分為輕中重三度。（見下表）/r/n代謝性酸中毒的臨床表現(xiàn)/r/n輕度/r/n中度/r/n重度/r/n精神狀態(tài)/r/n正?；蛏詿┰?r/n煩躁或萎靡/r/n昏睡或昏迷/r/n口唇顏色/r/n正常/r/n櫻桃紅色/r/n暗紅或紫紺/r/n呼吸改變/r/n深而慢/r/n深而快/r/n不規(guī)則/r/n周圍循環(huán)衰竭/r/n無/r/n無/r/n有/r/n面色/r/n蒼白/r/n蒼白或灰白/r/n灰白或紫紺/r/nmmol／L/r/n18～13/r/n13～9/r/n<9/r/nCO2CP/r/n

/r/nVol℅/r/n

/r/n40～30/r/n

/r/n30～20/r/n

/r/n<20/r/nAG/r/nHCO/r/n﹣/r/n的損失和補(bǔ)/r/n3/r/n充堿劑；高AG型原則為改善循環(huán)和機(jī)體缺氧狀況。/r/n⑵.補(bǔ)堿：①輕度酸中毒經(jīng)原發(fā)病治療后通過機(jī)體代償可自行恢復(fù)。/r/npH<7.3/r/n酸氫鈉。/r/n③在無條件測(cè)定血?dú)饣蜓獨(dú)饨Y(jié)果尚為出來前可先按提高/r/nHCO/r/n﹣/r/n5/r/nmmol／L/r/n3/r/n有血?dú)鉁y(cè)定結(jié)果時(shí)可按公式計(jì)算：/r/n堿劑需要量（mmol／L）＝（22-測(cè)得的HCO/r/n3/r/n﹣/r/n）×0.6×體重（Kg）或堿劑需要量（mmol／L）＝∣－BE∣×0.3×體重（Kg）/r/n1/2，/r/n缺氧、休克和肝功能不全時(shí)不宜使用乳酸鈉。/r/n⑶.在糾正過程中應(yīng)注意補(bǔ)鉀和補(bǔ)鈣。2．代謝性堿中毒metabolicalkalosis/r/n由于體內(nèi)H/r/n﹢/r/n丟失或HCO/r/n3/r/n﹣/r/n蓄積所致。/r/n見于嚴(yán)重嘔吐，嚴(yán)重低鉀血癥，先天性失氯性腹瀉，應(yīng)用大劑量皮質(zhì)/r/n激素，使用過多堿性藥物等。臨床表現(xiàn)：/r/n典型表現(xiàn)為呼吸慢而淺，頭痛、煩躁、手足麻木，低鉀血癥和血清游離鈣降低而導(dǎo)致的手足抽溺。/r/n治療:/r/n①去除病因，停用堿性藥物。/r/n②輕癥給于0.9℅氯化鈉溶液靜脈滴注。/r/n③/r/n（pH>7.6;/r/nHC/r/n3/r/n﹣/r/n>4/r/nmmol/r/n／L;C/r/n﹣/r/n<85/r/n/r/nmmo/r/nl/r/n／/r/nL/r/n可給予氯化銨。/r/n需補(bǔ)充的氯化銨（mmol／L）＝（測(cè)得的HCO/r/n3/r/n-/r/n22）mmol／L×0.3×體重（kg）./r/n1/2/r/n1/3，/r/n0.9℅氯化銨靜脈滴注。/r/n（0.9%/r/n3ml/kg/r/nHCO/r/n﹣/r/n1mmol/r/n／L/r/n。/r/n3/r/n呼吸性酸中毒respiratoryacidosis/r/nCO/r/n2/r/nH/r/n2/r/nCO/r/n3/r/n增多。/r/n見于呼吸道堵塞；肺和胸腔疾?。缓粑袠幸种?；呼吸肌麻痹以及呼/r/nCO/r/n2/r/n臨床表現(xiàn)：/r/n除原發(fā)病表現(xiàn)以外，缺氧為突出癥狀。治療：/r/n積極治療原發(fā)病，改善通氣和換氣功能，解除呼吸道阻塞。重癥可作氣管插管或氣管切開，人工輔助呼吸。/r/n呼吸性堿中毒respiratoryalkalosis/r/nCO/r/n2/r/nH/r/n2/r/nCO/r/n3/r/n降低。/r/n見于神經(jīng)系統(tǒng)疾??；嚴(yán)重貧血、肺炎；過度通氣；水楊酸中毒；CO/r/n中毒。臨床表現(xiàn)：/r/n突出癥狀為呼吸深快；其它與代謝性堿中毒相似。治療：/r/n主要是病因治療，改善呼吸。/r/n三．液體療法時(shí)常用的溶液/r/n㈠．非電解質(zhì)溶液/r/n：/r/n常用5℅和10℅葡萄糖溶液。/r/n特點(diǎn)：葡萄糖進(jìn)入體內(nèi)后代謝變?yōu)镃O/r/n2/r/n和水，不能起到維持血漿滲透壓的作用。/r/n用途：①供給水份②稀釋電解質(zhì)溶液③供給部分熱量。/r/n㈡．電解質(zhì)溶液/r/n（1）0.9℅氯化鈉溶液（生理鹽水）特點(diǎn)：①等張液（308/r/n/r/nmmol/r/n／L/r/n/r/n②Na:Cl=1:1(/r/n154/r/n/r/nmmol/r/n／L)/r/n③中性溶液，對(duì)血漿來說偏酸。/r/nNa/r/nCl/r/n②可用于擴(kuò)容/r/n③糾正部分低氯性堿中毒/r/n（2）3℅/r/n1ml/r/nNa/r/n﹢/r/n0.5/r/nmmol/r/n／L/r/n（3）10℅氯化鉀溶液：用于補(bǔ)鉀。靜脈滴注一般用/r/n0.2℅（/r/n27/r/nmmol/r/n／/r/nL/r/n0./r/n℅（/r/n40/r/nmmol/r/n／L/r/n不能靜脈直接推注。/r/n堿性溶液：用于糾正酸中毒。/r/n①/r/n5℅/r/n（1190/r/nmmol／L）/r/n3.5/r/n）可直接緩沖堿，故可迅速糾正酸中毒。/r/n（NaHCO/r/n3/r/n→/r/nNa/r/n﹢/r/n+/r/nHCO/r/n3/r/n﹣/r/n+/r/nH/r/n﹢/r/n→/r/nH/r/n2/r/nCO/r/n3/r/n→/r/nCO/r/n2/r/n+H/r/n2/r/nO）/r/nCO/r/n2/r/n②11.2℅乳酸鈉溶液:高張液（2000/r/nmmo/r/nl/r/n／/r/n，/r/n1.87℅為等張液/r/n（11.2℅/r/n6/r/n）/r/n后才有糾酸作用，故發(fā)揮作用緩慢。/r/n4 /r/n0.9℅等張液。NH/r/n﹢/r/nCO/r/n4 /r/nH/r/n﹢/r/nPH/r/n㈢.混合溶液：/r/nNa/r/nCL/r/n其增加HCO/r/n3/r/n﹣/r/n。/r/n常用溶液成分/r/n100ml/r/n溶液/r/n

/r/nNa/r/n﹢ /r/n

/r/nCl/r/n-/r/n

/r/n

/r/nNa/r/n﹢/r/n質(zhì)或液量/r/n乳酸根/r/n質(zhì)或液量/r/n乳酸根/r/n/Cl/r/n血漿/r/n142/r/n5/r/n103/r/n24/r/n3:2/r/n1/r/n①0.9℅氯化鈉/r/n0.9g/r/n154/r/n154/r/n1：1/r/n1/r/n②/r/n5℅或10℅葡萄糖/r/n5或10g/r/n0/r/n③5℅碳酸氫鈉/r/n5g/r/n595/r/n595/r/n3.5/r/n④1.4℅碳酸氫鈉/r/n1.4g/r/n167/r/n167/r/n1/r/n⑤11.2℅乳酸鈉/r/n11.2g/r/n1000/r/n1000/r/n6/r/n⑥1.87℅乳酸鈉/r/n1.87g/r/n167/r/n167/r/n1/r/n⑦10℅氯化鉀/r/n10g/r/n1342/r/n1342/r/n8.9/r/n⑧0.9℅氯化銨/r/n0.9g/r/nNH/r/n+/r/n167/r/n4/r/n167/r/n1/r/n1：1含鈉液/r/n①50ml②50ml/r/n77/r/n77/r/n1：1/r/n1/2/r/n1：2含鈉液/r/n①35ml②65ml/r/n54/r/n54/r/n1：1/r/n1/3/r/n1：4含鈉液/r/n①20ml②80ml/r/n30/r/n30/r/n1：1/r/n1/5/r/n①65ml④或⑥/r/n2：1/r/n含鈉液/r/n /r/n158/r/n100/r/n58/r/n3:2/r/n1/r/n①33ml②50ml/r/n2：3：1/r/n含鈉液/r/n /r/n79/r/n51/r/n28/r/n3:2/r/n1/2/r/n①45ml②33ml/r/n4:3：2/r/n含鈉液/r/n /r/n106/r/n69/r/n37/r/n3:2/r/n1/3/r/n35ml/r/n④或⑥17ml/r/n④或⑥22ml/r/n表/r/n幾種混合液的簡(jiǎn)要配制/r/n加入溶液/r/n5%碳酸氫鈉/r/n溶液種類/r/n張力/r/n(ml)5%/r/n葡萄糖/r/n10%氯化鈉/r/n（11.2%乳酸鈉）/r/n2:1/r/n1/r/n加至500/r/n30/r/n47（30）/r/n1:1/r/n1/2/r/n加至500/r/n20/r/n——/r/n1:2/r/n1/3/r/n加至500/r/n15/r/n——/r/n1:4/r/n1/5/r/n加至500/r/n10/r/n——/r/n2:3:1/r/n1/2/r/n加至500/r/n15/r/n24(15)/r/n4:3:2/r/n2/3/r/n加至500/r/n20/r/n33(20)/r/n㈣．口服補(bǔ)液鹽/r/n（ORSoralrehydrationsalts）/r/n80/r/nWHO/r/nORS/r/nORS/r/n2003/r/nWHO/r/nUNICEF/r/nORS/r/n表 新的/r/nORS/r/n配方組成及滲透壓比較/r/n舊ORS/r/n新ORS/r/n舊ORS/r/n新ORS/r/n氯化鈉/r/n3.5/r/n2.6/r/n鈉/r/n90/r/n75/r/n無水葡萄糖/r/n20.0/r/n13.5/r/n氯/r/n80/r/n45/r/n氯化鉀/r/n1.5/r/n1.5/r/n無水葡萄糖/r/n111/r/n75/r/n枸櫞酸鈉/r/n2.9/r/n2.9/r/n鉀/r/n20/r/n20/r/n總重量/r/n27.9/r/n20.5