《水电酸碱紊乱诊治》由会员分享，可在线阅读，更多相关《水电酸碱紊乱诊治（95页珍藏版）》请在金锄头文库上搜索。
1、FLUID, ELECTROLYTE, AND ACID-BASE DISORDERS外科水电紊乱与酸碱失衡Case Report 78 ys, female 平时一般状态良好，自行料理家务，活动 近月来纳差，近5天进食后呕吐，乏力、懒言、 嗜睡，入院前一天未排尿 入院Bp 96/58 mmHg, P 106 bpm, R 28 tpm 心肺查体无明显异常；腹部稍隆，未见胃肠型 及逆蠕动波，胃区振水音未闻及；肝、胆、脾未 触及，全腹未及肿物，无压痛、反跳痛区；膀胱 区叩浊，移动性浊音阴性。留置导尿，膀胱潴留 尿液3200 ml，导尿后尿量30 ml/hrs。Case Report (cont)
2、 Blood RTuHb 152 g/LuRBC 4521012/LuHct 45.2%uWBC 107109/LuN 71% ElectrolytesuNa 128 mEq/LuK 2.8 mEq/LuCa 1.83 mEq/LuCl 87 mEq/LuTCO2 32.8 mEq/L Liver FunctionuAlb 28 g/LuGlu 26 g/LuOthers normal Kidney FunctionuBUN 7.1 mg/LuCr 218 mg/L Blood Sugar 4.6 mEq/L Urine RTuDensity 1.030uKET +uOthers normal
3、 Outline Introduction Physiology & Pathophysiology Dehydration Disorders of Composition Acidosis and AlkalosisBody Fluids Total body water is contained in 2 compartments. uIntracellularuExtracellular Extracellular is divided into 2 spaces.uIntravascularuInterstitial The intravascular space contains
4、the plasma volume. u25% of the extracellular fluid u8% of the total body water u5% of body weight These compartments are in dynamic equilibrium, and alterations in one ultimately leads to compensatory changes in the others.体液的构成Body WaterTotal Body WaterBody WeightMaleFemaleTotal1006050Intracellular
5、67 (2/3)4030Extracellular33 (1/3)2020Intravascular(plasma) 8 5 5Interstitial 251515BODY FLUID CONSTITUTION (%)Lean Body Weight体液的成份BODY FLUID COMPOSITION (mEq/L) Extracellular FluidIntracellular fluidPlasmaInterstitial Fluid CATIONS Na+140146 12 K+ 4 4150 Ca2+ 5 3 10-7 Mg2+ 2 1 7 ANIONS Cl-103114 3
6、HCO3- 24 27 10 SO42- 1 1 HPO43- 2 2116 Protein 16 5 40 Organic Anions 5 5 Water Transcompartmental Movement晶体渗透压CELLBLOOD VESSELINTERSTITIAL SPACE胶 体 渗 透 压细胞膜半透作用Osmolality crystal colloid细胞间紧密连接semipermeable membraneHomeostasis The Third Space An additional ECF compartment, the transcellular compar
7、tment, consists of water that is poorly exchangeable under normal circumstances. This fluid is separated from other compartments by both endothelial and epithelial barriers. Included in this category are cerebrospinal fluid, synovial fluid, water in cartilage and bone, fluids of the eye, and the lub
8、ricating fluids of the serous membranes. Gastrointestinal juice also belongs to this category. Together, these fluids constitute approximately 4% of TBW. (1%-2%BW)Non-functional ECFELECTROLYTE CONCENTRATION & QUANTITY IN GASTROINTESTINAL SECRETIONSMaintenance of Fluid Homeostasis 机体通过肾来维持体液平衡，保持内环境稳
9、定。 肾调节功能受神经和内分泌反应的影响。 肾调节功能的实现u先通过下丘脑垂体后叶抗利尿激素系统来恢 复和维持体液的正常渗透压u后通过肾素醛固酮系统来恢复和维持血容量 血容量锐减时，机体将以牺牲体液渗透压的维持 为代价，优先保持和恢复血容量，使重要生命器官 的灌流得到保证。 Maintenance of Acid-Base Balance 血液中的HCO3-和H2CO3最重要的缓冲物质 肺的呼吸是排出CO2以调节血液中的呼吸性成分，即 调节血中的H2CO3 u呼吸频率和呼吸深度 肾的调节作用是最主要的酸碱平衡调节系统，以维持 血浆HCO3-浓度的稳定uH+Na+的交换uHCO3-的重吸收u分泌
10、NH3与H+结合成NH4+排出u尿的酸化排出H+维持水电代谢和酸碱平衡 Consume 正常成人每天消耗2500ml电解质液 Administration 禁食者为维持体液平衡每日静脉滴注u510 Dextrose 15002000mlu5 Dextrose in Normal Saline 500mlu10% KCl 3040ml Increase 在某些情况下机体需要量增加 Risk Factor of disturbance 原发病的伴发现象或结果 Prophylaxis 及时采取措施以预防这类失调的发生FeverSweatHypermetabolismHyperventilationD
11、AILY FLUID PHYSIOLOGIC LOSS维持水电代谢和酸碱平衡 Fever：从皮肤隐性丧失低渗体液u体温每升高1按 35 ml/kg 的标准增加补给量 Sweet：含NaCl 1.252.50g/Lu中度：丧失体液约 5001000ml/du大量：丧失体液约 10001500ml/d Tracheotomy：自呼吸蒸发水分比正常多2倍u每日增加1000ml左右 尽早发现尽早发现 尽快纠正尽快纠正Niagara Falls in Buffalo, NY, USFluids and Electrolytes Disorders Water DisorderuVOLUMEWater D
12、eficit (dehydration)Water Excess (overhydration) Electrolytes DisturbanceuTONICITYSodium (isotonic, hypertonic or hypotonic state)uCOMPOSITIONPotassiumCalciumMagnesiumTonicityconcentration of natriumDehydration(A) Isotonic dehydration. Extracellular fluid is lost, but sodium concentration and osmola
13、lity remain unchanged. There is no change in intracellular volume. (B) Hypotonic dehydration caused by an extracellular fluid deficit with hyponatremia. Water moves into the intracellular space, causing further extracellular depletion and intracellular fluid expansion. (C) Hypertonic dehydration cau
14、sed by loss of extracellular free water, resulting in hypernatremia. Water from the intracellular fluid shifts to the extracellular space, resulting in contraction of both intracellular fluid and extracellular fluid compartments.Isotonic Dehydration 急性缺水或混合性缺水 外科病人最易生 水和钠成比例丧失 血清钠仍在正常范围 细胞外液渗透压正常，容量
15、（包括循环血量）迅速减少 细胞内液量在早期不发生变化 代偿机制：u入球小动脉壁压力感受器u小球滤过率下降所致远曲肾小管液内Na+的减少u肾素醛固酮系统的兴奋，醛固酮的分泌增加Etiology 消化液的急性外在丧失u大量呕吐u急剧腹泻u肠瘘 体液丧失在感染区或软组织内u腹腔内或腹膜后感染区渗出u肠梗阻 烧伤创面急性渗出这些丧失的液体有着与细胞外液基本相同的成分Clinical Manifestation 渗透压变化表现：口渴不明显 容量不足表现：u厌食、恶心、 乏力等u舌干，眼球内陷，皮肤松驰、粘膜干燥，尿少等 休克表现：u体重的5 （细胞外液的25）：脉博细速、肢端湿冷、 血压不稳定、心率加快u体重的67（细胞外液的30 35%）：血压下降 ，出现重要脏器供血不全 酸碱失衡表现：u微循环障碍造成酸性物质产生和积聚引发代谢性酸中毒u胃液丢失可伴发代谢性碱中毒u肠液丢失可伴发代谢性酸中毒 Diagnosis Approach 病史和临床表现u消化液或其他体液的大量丧失u持续较长时间不能进食 实验室检查u红细胞计数、血红蛋白含量和红细胞压积明显增 高，表示有血液浓缩u血清Na和CI一般无明显降低u尿比重增高u必要时作血气分析或二氧化碳结合力测定Management Strategy 尽早处理引起等渗性缺水的原因。 针对细胞外液量减少用平衡盐溶液或等渗盐水尽快补充 血
