水电解质代谢与酸碱平衡失调

FluidsandElectrolytesManagementoftheSurgicalPatient*和谐社会*旱灾*水灾*Case1：王某，女，23岁。以“呕吐、腹泻36小时”入院患者于36小时前，吃剩饭后即感上腹不适，继则腹痛、呕吐频繁，呕吐出大量食物和胃液，并腹泻十余次，为大量黄色稀水便。逐渐出现口渴、尿少、恶心、厌食、软弱无力。半小时前便后起立时，突然晕倒在厕所，救醒后速送医院求治。入院查体：体温37.8℃,脉搏120次/分.呼吸深快(28次/分),血压90/70mmHg，体重50Kg，神志淡漠，面色苍白，皮肤弹性差，眼眶凹陷。肢端湿泠，腹部轻度深压痛。化验：①血常规：RBC550万/mm3，Hb12g%，WBC15000/mm3，N80%；②尿常规：比重1.030,强酸性；③粪常规：黄色稀水便，WBC(＋)；④血清Na+138mEg/L、K+3.5mEg/L、CO2CP30VOL%，BUN39mg/ml。Diagnosis:?Prescription:?*Case2赵××，男性，60岁，体重65Kg“胆囊切除，胆总管探查术后第一天”术后从胃管内共抽出液体600ml。T管引流出胆汁400ml。烟卷引流出渗液约240ml体温持续在38.2℃ Prescriptionoffluidreplacement:?*BodyFluid&ItsCompartments Composition:Water＋Electrolytes Volume:50%（female）～60%（male）80%（infant）ofbodyweightFACTOR：sex、age、lean&fat Distribution(figure1):ExtracellularFluid（20%）Plasma5%、InterstitialFluid15%IntracellularFluid（35%～40%）Skeletalmuscle35% Electrolyte：ECF：Na＋/CI－、HCO3－、proteinICF：K＋、Mg＋＋/P3－、proteinTheeffectiveosmoticpressureinthetwocompartmentsareconsideredequal,about290-310mOsm／L.以上的稳定持机体新陈代谢正常进行的保证*FunctionofWaterWaterisoneofthemostimportantmaterialtomaintainthemormalfunctionsofhumanbody.人只饮水可生存十日之久，无水只能生存数日 ①调节体温Regulatebodyheat②促进物质代谢Facilitatemetabolism:溶解dissolve,、运输transportation③润滑作用lubrication*FunctionofElectrolytes ①MaintainingtheOsmoticPressureandthebalanceofwater：K＋/HPO4－；Na＋/CI－ ②MaintainingAcid-baseBalance：Buffersysteminbodyfluids. ③Maintainingtheexcitabilityofnerveandmuscle：[Na＋]＋[K＋]theexcitability∝[Ca＋＋]＋[Mg＋＋]＋[H+] ④K＋istheactivatorofmanyenzymesinhumanbody：K＋takepartinthebiosynthesisofglycogenandprotein.*水的摄入与排出Watergainandloss每天代谢产生固体废物35～40g，每g至少需尿15ml将它排出。因此，每天尿量不应少于500ml（1.030）.但每天尿量1500ml±（1.012）时肾脏负担最轻。∴Anormaladultneedatleast1500mlwatereveryday,but2500mlismorereasonable. H2OGain（ml） H2OLoss Oralfluids1000～1500 Urine1000～1500 Solidfoods700 Stool150 endogeny300 InsensibleSkin500Lungs350 Total2000～2500 Total2000～2500*ElectrolyteContentofBodyFluid1 正常人血浆or血清中的电解质浓度 positiveionmEg/LnegativeionmEg/L Na＋142CI－103K＋5HCO3－27Ca＋＋HPO4-22SO4-21Mg＋＋organicacid5Protein16 Total154Total154*ElectrolyteContentofBodyFluid2各种消化液每日分泌量（ml）及其电解质浓（mEg/L）TotalVolume>8000,Only150mlfluidexcretethroughdejectainnormalstate.Duringvomitinganddiarrhea,thebodyfluidwillchange.Lossofanydigestivejuicewillleadtospecificsequent. Digestivejuice Volumeofsecretion(ml/day) H+(mEq/l) Na+(mEq/l) K+(mEq/l) Cl-(mEq/l) HCO3-(mEq/l) saliva 1500 9 25 10 12~18 Gastricjuice 2000 0~90 40~100 10~45 50~140 0~5 Bilejuice 700 135~145 5 80~110 35 Pancreaticjuice 800 135~185 5 50~70 90 Smallintestinaljuice >3000 105~135 5~20 100~120 20~30*MetabolizeofElectrolytesElectrolytesisingestedfromfood,comeintoeverytissuethroughblood,andexcretedfromkidneymostly.Theurineofadultcontains:natrium(≈NaCI6～9g)andkalium(2～3g).TheexcretionofNa+andK+fromkidneyNa+:themoreingested,themoreexcreted,viceversa.noingested,noexcreted.K+:themoreingested,themoreexcreted,viceversa.noingested,stillexcerted.*AdjustofBodyFluidBalance1可以分为:出入量的调节；细胞内外的调节；血管内外的调节。 晶体渗透压 血浆胶渗压 毛细管通透性 毛细管静水压 饮水and排尿主要通过肾脏，其调节功能受神经、内分泌反应影响首先：Hypothalamus—neurohypophysis—ADHsystemosmoticpressure然后：Rein–angiotensin–aldosteronesystemvolume 但当血容量↓↓↓时，机体优先保持和恢复血容量，→使重要生命器官的灌流得以保证，维护生命。*AdjustofBodyFluidBalance2下丘脑、垂体后叶、抗利尿激素S体内水份丧失，细胞外液渗透压↑（灵敏度2%） 口渴、饮水增加下丘脑、垂体后叶分泌ADH远曲肾小管、集合管上皮细胞吸收水、尿量保留水份于体内细胞外液渗透压↓细胞外液渗透压*细胞外液↓（血容量↓）BP↓ 肾素醛固酮S交感神经兴奋压力感受器（肾小球入球小动脉）肾小球滤过率↓经远曲肾小管的Na+↓钠感受器（远曲肾小管致密斑）肾小球旁细胞分泌肾素血管紧张素原血管紧张素Ⅰ血管紧张素Ⅱ肾上腺皮质球状带醛固酮合成分泌↑血浆中远曲肾小管再吸收Na＋↑→CI－↑→H2O↑（排泌K＋、H＋↑）细胞外液↑循环血量↑BP↑AdjustofBodyFluidBalance3*神经-内分泌对细胞外液的调节细胞外液变化渗透压↑容量↓下丘脑肾素↑口喝ＡＤＨ↑血管紧张素Ⅰ饮水↑保水（尿量↓）血管紧张素Ⅱ醛固酮↑保Na（尿Na↓）渗透压↓容量↑细胞外液恢复AdjustofBodyFluidBalance4*BodyFluidAbnormalitiesTotalBodyWaterLossDehydration=saltdeficient+waterdeficientInsurgicalpatients,waterandsaltdeficitsmoreoftenoccurtogether.Dehydrationcanbeclassifiedintothreecategories:hypertonic,hypotonic,isotonic.* 高渗性脱水.1Hypertonicdehydration Definition:waterdeficient>sodiumdeficientPNa+>150mEq/L(hypertonia) Cause:Intakedeficient--unabletoregulateintake,fountaindiscontinuityOverabundantloss–profusesweatingfromardentfever,excessivediuresisIt’salsocalledprimarywaterdeficits. Pathophysiology:ECFvolumedeficitaccompaniedbyhypernatremia,ADH↑，aldostenrone↑* 高渗性脱水.2HypertonicdehydrationLaboratoryInvestigation:WBC↑、Concentratedblood,increasedurinespecificgravity(spgr≻1.035).Plasmaprotein,Potassium,Natrium,Chlorine,BUN,andOsmoticpressureareallincreased. Extent Weight↓% Clinicalfinding Light 2 Thirsty Moderate 3~4 Severethirsty,Ligulaxeransis,Flexibilityofskindecerase,Sunkeneyes,Apathy,Xeransisinaxillaandinguen,Oliguria,increasedurinespecificgravity Severe Above5~6 Severethirsty+obvioussymptomofcentralnervoussystem,Mania,Hallucination,Phrenitis,Hyperpyrexia,Eclampsia,coma,DecreasedBP,Shock*2.低渗性脱水.1Hypotonicdehydration Definition:waterdeficient<sodiumdeficient PNa+<135mEq/L(hypotonia) Cause:Chronicbodyfluidlossorbodyfluidlossarereplacedwithonlywithnoly5%dextroseinwaterorahypotonicsodiumsolution. It’salsocalledChronicwaterdeficits. Pathophysiology:ECFvolumedeficitandhyponatremia,Circulationfailurepresentsintheearlystage.ADHdecreasesinearlystageandincreasesinterminalstage,Increasedaldostenrone*2.低渗性脱水.2HypotonicdehydrationLaboratoryInvestigation:Concentratedblood,increasedMCV,MCHC,Oliguria,non-increasedurinespecificgravity,SeverelydecreasedNatriumandChlorineinurine.IncreasedplasmaproteinandBUN,DecreasedplasmaNatriumandChlorine,DecreasedOsmoticpressure. Extent ΔNaCl/kgBW PNa(meq/L) Clinicalfinding Light 0.5g 130~135 Tired,Apathy,Faint,extremeanaesthesia,Withoutthirsty,decreasedurineNa,normalurinevolume Moderate 0.6~0.8g 120~130 Theabovesymptomaggravate,Anorexia,Nausea,Vomiting,Sleepiness,Collapsedveinsandpulse,UnsteadyordecreasedBP,illegibleeyesight,Orthostaticfaint,Oliguria,withoutchlorideinurine Severe Above0.8g below120 CNSsymptom:Dottiness,Jerk,Decreasedtendonreflexes,Anesthsiaofdistalextremities,shock.*3.等渗性脱水.1Isotonicdehydration Definition:ThelossoffluidiswaterandelectrolytesinapproximatelythesameproportionasthatinthichtheyexistinnormalECF. PlasmaNa+isnormal.(isotonia) Cause:Acutelossesofgastrointestinalfluidsduetovomiting,diarrhea.Ponderosusascitedrainage,Earlystageoflargeareaempyrosis(exudation). It’salsocalledacutewaterdeficits. Pathophysiology:DecreasedECF,Severevolumedepletion,Increasedaldostenrone * Clinicalfinding:Hydropeniasyndrome:Thirsty,Oliguria,Withthesodiumdeficit:Anorexia,nausea,adynamia.Above4%ofweight:Symptomofseverevolumedepletion.Absentperipheralpulses,Coldextremities,unsteadyordecreasedBP.Above6%ofweight:peripheralcirculatoryfailure,ShockItisoftenaccompaniedwithmetabolicacidosis.Whenthegastricjuicelostseverely,itwillbeaccompaniedwithmetabolicalkalosis. LaboratoryInvestigation:Concentratedblood,NormalMCV,MCHC,Increasedurinespecificgravity,DecreasedNatriumandChlorineinurine.IncreasedplasmaproteinandBUN,NormalplasmaNatrium,Chlorine,andOsmoticpressure3.等渗性脱水.2Isotonicdehydration*Thetreatmentoftheprimarydiease.Restoringvolumeandthedeficientelectrolytes.Thecontentsoffluidreplacementcontain:thevolumeofphysiologicalrequirements,Preexistingdeficits,andongoinglosses.Thereplacementofexistingdeficitsofvolume:theextentandcategoryofdehydrationdecidethevolumeandthetypeofsolution(G/N),respectively.Hypertonicdehydration----5-10%GlucoseSolution.Hypotonicdehydration----normalsalineor3~5％saline(Hypertonic)Isotonicdehydration---5%GNSTakeorallyasfaraspossible,supplyfromveinswhenthepatientcannottakeorally.2.脱水的处理原则Thetherapicprincipleofdehydration*ElectrolyteDisordersHypokalemia*①Transportationbetweenextra-andintracellular: Physiologicfactor:Na＋－K＋ATPenzyme,Digitaloiddrugs，Catecholamine,Insulin,Bloodglucoseconcentration,BloodPotassiumconcentration,Heavyexercise. Pathologicfactor:PlasmapH(inorganicacid),Hypertonia,histoclasia,excessivegrowth. ②Regulationofbody： IntakeandexcretedofPotassium： Kidney：aldosterone(actatcollectingtubuletopromotethesecretionofPotassium) glucocorticosteroid(keepnatriumandexcretePotassium)AdjustofSerumPotassium*Definition:SerumPotassium<3.5mmol/L.体内缺钾300mmol以上时，血清钾才下降。Cause:①钾摄入量不足：禁食、厌食、拒食时间较久②钾损失过多：大量出汗、呕吐、腹泻、胃肠减压、肠瘘；利尿药、肾小管酸中毒、棉酚中毒Conn综合征et.al.③体内分布异常：糖元、蛋白合成，碱中毒，低钾性周期性麻痹，儿茶酚胺制剂，细胞生长过速，钾进入细胞内Hypokalemia1*Clinicalfinding：钾的丢失主要来自细胞内，C内含钾很丰富，故机体丢钾350mmol以下时，无临床表现；临床表现的严重与否、取决于钾丢失的多少及丢失的速度。临床表现包括以下6个方面：①循环系统；②神经肌肉系统；③CN系统；④泌尿系统；⑤消化系统；⑥肌纤维溶解；⑦酸碱平衡失调。Hypokalemia2*①Circulationsystemcardiacdamage：坏死、细胞侵润、瘢痕－心衰arhythmia：期前收缩、阵发性心动过速、室扑或室颤、猝死Susceptibletodigitalisintoxication：ECG：K＋﹤3.0，U波出现、TU融合K＋﹤2.5，ST段下移、T波倒置U波出现，体内缺钾400mmol以上hypopiesia：植物N功能紊乱、血管扩张引起Hypokalemia3临床表现：*②neuromuscularsystem骨骼肌：肌无力(K＋﹤3.0)、肌痛、肌麻痹、软瘫(K＋﹤2.5)平滑肌：腹胀、便秘、麻痹性肠梗阻、尿潴留K＋是许多酶的激活剂,与三羧循环.乙酰胆碱合成有关③centralnervoussystem神志淡漠、目光呆滞、疲乏；烦躁不安、情绪激动、精神不振；嗜睡、定向力障碍、昏迷(K＋﹤2.0)与糖代谢障碍、能量生成及乙酰胆碱生成减少有关Hypokalemia4临床表现：*④urinarysystem多尿、夜尿增多、甚至肾衰－煩渴、多饮缺钾可引起肾小管上皮细胞损害；体内缺钾200mmol时肾小管浓缩功能↓⑤digestivesystem食欲不振、恶心、呕吐、腹胀、便秘⑥musclefibrolysisK＋﹤2.5，肌红蛋白尿、甚至急性肾衰Hypokalemia5临床表现：*Hypokalemia6临床表现：⑦cid-basedisturbancemetabolicalkalosisparadoxicalaciduria低钾时，①C内K＋与C外H＋交换↑，C内H＋↑→C内酸中毒；C外H＋→C外液碱中毒。②肾保Cl-↓，尿Cl-↑，Na＋重吸收时不能与Cl-而与HCO3-→HCO3-重吸收↑低钾时，代谢性碱中毒肾小管上皮细胞内K＋↓，K＋与肾小管管腔中的Na＋交换↓，H＋与Na＋交换↑，尿呈酸性，肾排H＋↑*Diagnosis：主要依靠病史＋表现血清Ｋ＋<3.5mEg/L,EKG特征改变→确诊注意:酸中毒、脱水时，重症才出现Therapy：积极治疗原发病，必要时补充钾盐。注意：尽量口服，不能口服者V补给（常用10％KCl）；尿少不补K；浓度不宜过高（≤0.3%）；速度不宜过快(<80d/分)；总量不宜过多(6g左右)最好加入NS，加入GS有可能使血钾更低；丢正糖尿病酮症酸中毒时，应特别注意低钾可能。Hypokalemia7*Acid-baseBalance*Theph(thenegativelogarithmofthehydrogenionconcentrationPH=7.35~7.45)ofthebodyfluidsisnormallymaintainedwithinnarrowlimitsdespitetheratherlargeloadofacidproducedendogenouslyasaby-productofbodymetabolism.包括四个方面:A.buffersystem（作用快,仅能应付急需）HCO3－27mmol/L20==(PH7.4)H2CO31.351mmol/L1B.CO2excretedviathelungs（体内挥发性酸H2CO3）调节血液中的呼吸性成分，即H2CO3（PCO3）1.MaintainofAcid-baseBalance1*1.MaintainofAcid-baseBalance2C.Kidney—排出固定酸和过多的碱性物质维持血中HCO3－浓度的稳定机理：H＋—Na+交换；HCO3－重吸收；正常尿液PH值6，最低4.4—肾有强排酸功能D.Bufferingeffectofcell细胞内每进入1个H＋＋2个Na＋→3个K＋替换出碱中毒：H＋出细胞内→K＋入细胞内—低血钾酸中毒：H＋入细胞内→K＋出细胞内—高血钾*2.DisturbancesofAcid-baseBalanceMetabolicacidosis（CO2CP↓，PH↓）Metabolicalkalosis（CO2CP↑，PH↑）Respiratoryacidosis（PCO2↑、CO2CP↑、PH↓）Respiratoryalkalosis（PCO2↓、CO2CP↓、PH↑）HCO3－H2CO3增多减少增多减少*Metabolicacidosis1  Retentionoffixedacidsorlossofbasebicarbonate. Thecausesofmetabolicacidosiscanbedividedintotwomanageablegroupsbydeterminingtheaniongap：高AG代酸-常见于尿毒症、糖尿病酮症酸中毒、乳酸中毒正常AG代酸—常见于HCO-3丢失过多及应用含有Cl-的药物Aniongap,AG:Amountoftheunmeasuredanions(i.e.sulfateandphosphatepluslactateandotherorganicanions).正常值：10～15mmol/L.AG=（Na++K+）-(HCO-3+Cl-)均以mEq/L为单位145/155134/155（95%）（85%）=未测定阴离子-未测定阳离子因K+很低，所以AG=Na+-(HCO-3+Cl-)*Metabolicacidosis2  Cause：Excessivelossesofbicarbonate—见于消化道瘘、呕吐、腹泻Retentionofacids—腹膜炎、休克、高热、长期未进食者ExcretionofH+andresorptionofHCO3-decrease—肾衰*Metabolicacidosis3  Clinicalfinding：轻者：常被原发病所遮盖重者：疲乏、眩晕、嗜睡、迟钝、烦躁不安呼吸深快、带酮味（烂苹果味）面部潮红、心率↑、BP↓、神态不清-昏迷常伴严重脱水、休克、尿少、尿酸性反应。Diagnosis：病史＋临床表现＋血气分析*Metabolicacidosis4  Therapy：严重者，才需V补碱性药物5%NaHCO3ml=（50-CO2CP）×Kg×0.5(作用快、效确切最常用)11.2乳酸钠ml=（50-CO2CP）×Kg×0.3(休克、肝功不良禁用)3.6%THAMml=（50-CO2CP）×Kg×1(细胞内外均能起作用,但副作用多,一般不用)※公式计算量易偏多，实际中常先输入计算量1/2～2/3※也可先按提示10vol%的CO2CP补给，再据测得的CO2CP值调整。45vol%以上、尿碱性、即停补。尿量↑、注意补钾。*PrinciplesofFluid&ElectrolyteTherapyFluid&ElectrolyteAbnormalitiesPreventDisease*Prevent1.Thevolumeofphysiologicalrequirements(2000～2500ml):5-10%GS1500ml等渗盐500～1000ml10%KCI30ml2.Recruitthesensiblelossesintime体温每增加1℃，每公斤体重需增补液体3～5ml汗湿-衬衣、裤-增补1000ml气管切开-增补1000ml/日3.Perioperativefluidreplacement小手术—不需大手术—术日清晨开始急症手术、有紊乱者术前尽可能部分纠正，术后继续术后胃肠功能未恢复补生理需要量有胃肠减压者—酌情↑术后1-2日不补K＋，3日后仍不能进食、补钾3-4g/日*Therapy11．CalculationoffluidreplacementPhysiologicalrequirements：2000～2500ml，其中NS500mlPreexistingdeficits：On-goinglosses：胃肠道继续丢失；内在性失液；发热出汗酌情于当天or次日补给,丢失什么,补什么*Therapy2已丧失量的估计方法◎缺水的日数：脱水1日丧失体重的2%◎体重的减轻数：◎临床表现：◎血清Na＋浓度：高渗：降1mmol/L的Na＋需补男4ml、女3ml/Kg体重低渗：缺Na＋量mmol/L=体重Kg×0.6×(140－[Na＋])∵1LNaCI=154mol.∴NS量(L)=缺Na量／154*Therapy3根据临床表现估计Preexistingdeficits 程度 高渗脱水缺水占体重 需补液量ml/Kg体重 低渗缺水缺NaCI量（g/Kg体重） 补NS量ml/Kg体重 轻度 2～4% 20 0.5 25 中度 4%～6% 20～40 0.75 20～40 重度 7～% 40～60 1.0 40～60*Therapy4常用溶液的电解质含量(mEg/L) Solution Na＋ CI－ K＋ Ca＋＋ Mg＋＋ HCO3－ lactate Plasma 142 103 5 5 2 27 5 Balancedsaline 154 154 5％saline 850 850 Ringer'ssolution 147 157 4 6 SodiumLactate 170 170 LactatedRinger's 130 102 4 4 27 63 5%NaHCO3 595 595 10%KCI 1340 1340 intradex 153 153*Therapy5注意事项1.managementforprimarydisease2.Identifytheextentandtypeofdehydration3.Takenoticeofthefunctionofpatient’sheart,lung,kidney,especiallyforagedpeople.4.Thedisturbanceofwater,electrolytes,acid-basebalancemayoccuratthesametime.5.Closelymonitorthechangeofpathogeneticcondition.6.Makinglaboratoryinvestigationorientedtotimetoguidethetreatment.7．总的程序：先浓后淡，先快后慢，先晶体后胶体，见尿补钾，灵活掌握。 应据病人情况和化验、合理安排补液，随时调整量、速度、性质。对于各种公式计量，只能做参考。从临床实践中进一步提高。*Case1:1王某，女，23岁。以“呕吐、腹泻36小时”入院患者于36小时前，吃剩饭后即感上腹不适，继则腹痛、呕吐频繁，呕吐出大量食物和胃液，并腹泻十余次，为大量黄色稀水便。逐渐出现口渴、尿少、恶心、厌食、软弱无力。半小时前便后起立时，突然晕倒在厕所，救醒后速送医院求治。入院查体：体温37.8℃,脉搏120次/分.呼吸深快(28次/分),血压90/70mmHg，体重50Kg，神志淡漠，面色苍白，皮肤弹性差，眼眶凹陷。肢端湿泠，腹部轻度深压痛。化验：①血常规：RBC550万/mm3，Hb12g%，WBC15000/mm3，N80%；②尿常规：比重1.030,强酸性；③粪常规：黄色稀水便，WBC(＋)；④血清Na+138mEg/L、K+3.5mEg/L、CO2CP30VOL%，BUN39mg/ml。诊断：？处方：？*Case1:2 Diagnosis：① Isotonicdehydration（midrange）； ② metabolicacidosis 补液计算： ①已丧失量的计算：失液量=体重×5%=50×5%=2500ml 即已丧失量=2500ml,第一天只补1/2即只补1250ml ②生理需要量：2000ml（NS500ml） 故补液总量=①＋②=3250ml ③纠正酸中毒:5%碳酸氢钠量=（50－30）×50×0.5=500ml 先输1/2=250ml*Case1:3physicianorder:①NS500ml平衡盐1000ml5～10%GS1500ml5%NaHCO3250mlivdrop②尿量增至40ml/h以上，液体中加入10%KCL40ml③酌情补充继续丢失量④严密观察:BP、P、R、尿量、尿比重、神志…*Case2:1 赵××，男性，60岁，体重65Kg “胆囊切除，胆总管探查术后第一天” 术后从胃管内共抽出液体600ml。 T管引流出胆汁400ml。 烟卷引流出渗液约240ml 体温持续在38.2℃ prescription：？*Case2:1计算：已丧失量600＋400＋240＋4×65=1500ml，补1/2=750ml生理需要量2500ml（NS750ml）处方：NS500ml平衡盐1000ml10%GS1000ml5%GS750ml10%kCI？ivdrop*