水电解质代谢紊乱PPT课件

(Disturbances of water and electrolyte balance),水和电解质代谢紊乱,(Normal metabolism of water and electrolyte),第一节水与电解质的正常代谢,一、体液的容量和分布(Volume and distribution of body fluid),体内的水和溶解在其中的物质。,(Water and electrolytes balance),水与电解质平衡,Total body water (TBW) 60%,Transcellular fluid(third space) 1,影响体液容量的因素,年龄、性别、胖瘦,二、体液的电解质 (Electrolyte in body fluid),ECF: Na+、Cl-、 HCO3-,ICF: K +、 Mg2 +、 HPO42- Pr-,血Na 140 mmol/L血Cl 104 mmol/L血HCO3 24 mmol/L,平均正常值,三、体液的渗透压 和水的交换(Osmotic pressure of body fluid and water movement),(一)体液的渗透压(Osmotic pressure of body fluid),280310 mmol/L (mOsm/L),血浆渗透压,(二) 水的交换(Water movement ),1.细胞内外水的运动(water movement between outside-inside of cell),水自由通过,蛋白质、Na、K、Ca2+等不能自由通过,2.血管内外水的运动(water movement between outside-inside of capillary),蛋白质等大分子物质受限,水和电解质自由交换,3. 体内外水的运动(Water movement between outside-inside of body),每日最低尿量500ml,呼吸道失水,皮肤不显性蒸发,生理需水量: 1500ml/day,(从尿排代谢废物35g/日 最大浓度68g）,三、水和钠的生理功能(Physiologic function of water and sodium),(一)水的生理功能(Function of body water),促进物质代谢 调节体温 润滑,(二)钠的生理功能(Physiologic function of sodium),维持体液的渗透压和酸碱平衡 参与细胞动作电位的形成,四、水与钠平衡的调节(Regulation of water and sodium balance),1.渴感(thirst),2.抗利尿激素(antidiuretic hormone , ADH),ECF渗透压,有效循环血量,3.醛固酮(aldosterone),有效循环血量,42岁男性，因恶心、呕吐、腹胀和腹部 绞痛3天入院。既往史：20岁做过阑尾切除术。体检： T 38.7C，脉搏104 beat/min BP 115/70 mmHg 腹胀，有压痛和反跳痛。 皮肤和舌干燥，尿量5ml/h化验：血Na152mmol/L, Cl-108mmol/L, K+ 5.4mmol/L， 尿比重1.038,Case study,woman 38 ， 2-day history of weakness and postural dizziness（直立性眩晕 ）History：laxative（泻药）abuse with multiple bowel movements each day Physical examination： BP 110/60 mmHg falls to 80/50 mmHg HR 100 beats/min and regular Skin turgor is poor The mucous membrane is dry,Case study,Laboratory testNa+ = 140 mmol/LK+ = 3.3 mmol/LCl- 116 mmol/LUrine Na+ = 9 mmol/LBUN = 40 mg/dLArterial pH = 7.25HCO3- = 12 mmol/L PaCO2 = 28 mmHg,(Disturbances of water and sodium balance),第二节 水、钠代谢紊乱,脱水(dehydration) 高渗性 低渗性 等渗性水过多(water excess) 水中毒 水 肿,类型（Classification）,低钠血症（hyponatremia) The serum sodium concentration150 mmol/L,一、脱水(Dehydration),体液容量减少(2%)。To describe water deficit,1.概念(concept),低容量性高钠血症 (hypovolemic hypernatremia),(一) 高渗性脱水(hypertonic dehydration),water losssodium loss serumNa+ 150 mmol/L plasma osmotic pressure 310 mmol/L,2.原因 (causes),(1)入量不足(decrease of intake),(2)丢失过多(lost from ECF),水源断绝 丧失口渴感 进食困难,大量出汗尿崩症和渗透性利尿呼吸道蒸发,失水失Na+,3. 影响(effects),脱水热 (dehydration fever) 因皮肤蒸发水减少引起的体温上升。,高渗性脱水的主要发病环节 ECF高渗 主要脱水部位 ICF减少,4防治的病理生理基础(pathophysiological basis of prevention and treatment),及时补水,适当补钠,1.概念(concept),低容量性低钠血症 (hypovolemic hyponatremia),(二) 低渗性脱水(Hypotonic dehydration),sodium loss water loss serumNa+ 130 mmol/L plasma osmotic pressure 失水,水移入 细胞,3. 影响(effects),脱水征：因组织间液量减少，临床 上出现皮肤弹性减退、眼 窝下陷，婴幼儿囟门凹陷 等体征。,低渗性脱水的主要脱水部位 ECF 对病人的主要威胁 循环衰竭,4防治的病理生理基础(pathophysiological basis of prevention and treatment),轻、中度补生理盐水 (机体排水量大于排Na+量),重度补少量高渗盐水 (减轻细胞水肿),1.概念(concept),(三) 等渗性脱水(Isotonic dehydration),sodium loss water loss serumNa+ 130150 mmol/L plasma osmotic pressure 280310 mmol/L,2.原因 (causes),丢失等渗液(lost isotonic fluid),胃肠道丢失(gastrointestinal losses) 肾性失钠(renal losses)皮肤丢失(skin losses)液体积聚在第三间隙(accumulate in third space),3. 影响(effects),ECF渗透压正常，血Na+正常,(1)血浆渗透压和血钠的变化？,(2)容量的变化？脱水的主要部位？,(3)激素水平的变化？,4防治的病理生理基础(pathophysiological basis of prevention and treatment),补水量多于补Na+量,42岁男性，因恶心、呕吐、腹胀和腹部 绞痛3天入院。既往史：20岁做过阑尾切除术。体检： T 38.7C，脉搏104 beat/min BP 115/70 mmHg 腹胀，有压痛和反跳痛。 皮肤和舌干燥，尿量5ml/h化验：血Na 152 Cl- 108 K+ 5.4 尿比重 1.038,Case study,急性肠梗阻， hypertonic dehydration,woman 38 ， 2-day history of weakness and postural dizziness（直立性眩晕 ）History：laxative（泻药）abuse with multiple bowel movements each day Physical examination： BP 110/60 mmHg falls to 80/50 mmHg HR 100 beats/min and regular Skin turgor is poor The mucous membrane is dry,Case study,Laboratory test：Na+ = 140 mmol/LK+ = 3.3 mmol/LCl- 116 mmol/LUrine Na+ = 9 mmol/LBUN = 40 mg/dLArterial pH = 7.25HCO3- = 12 mmol/L PaCO2 = 28 mmHg,Case study,病史：62岁男性，嵌顿性腹股沟疝入院。体检：消瘦、虚弱、舌干、组织充盈差治疗：术前 NS 1L 术中 NS 1.5L 术后 NS 1L GS 2L昏昏欲睡、躁动，血Na+133 mmol/L GS 1L昏迷、抽搐、死亡,What happened in the patient?,二、水过多(Water excess),体液容量增多。,1.概念(concept),高容量性低钠血症 (hypervolemic hyponatremia),(一)水中毒(water intoxication),低渗性液体在体内潴留的病理过程 serumNa+ 130 mmol/L plasma osmotic pressure 回流,Alteration in capillary hemodynamics that favors the movement of fluid from the vascular space into interstitium.,毛细血管流体静压增高(increased capillary hydrostatic pressure),血浆胶体渗透压降低(decreased plasma colloid osmotic pressure) 摄入； 合成； 丢失,微血管壁通透性(increased capillary permeability),漏出液(transudate)蛋白质含量低，比重低，细胞数少渗出液(exudate)蛋白质含量高，比重高， 白细胞多,淋巴回流障碍(lymphatic obstruction),(2) 体内外液体交换平衡失调(imbalance of exchange between intra- and extra-body fluid),肾小球滤出钠、水9999.5 肾小管重吸收6570 近曲小管吸收0.51 滤出液排出,(decreased glomerular filtration rate),滤过面积有效循环血量,肾小球滤过率下降,肾小管重吸收增加,(Increased tubular reabsorption),肾内血流重新分布,肾小球滤过分数增高(滤过分数肾小球滤过率/肾血浆流量),球-管平衡失调的机制,(net filtration pressure),肾小球有效滤过压,Blood hydrostatic pressure(BHP) 60 mmHg out,Colloid osmotic pressure(COP) -32 mmHg in,Capsular pressure(CP) -18 mmHg in,Net filtration pressure(NFP) 10 mmHg out,NFP,BHP,60 out,COP,32 in,CP,循环血量减少:出球小动脉收缩入球小动脉收缩肾小球滤过率/肾血浆流量 滤过分数增加,血浆从肾小球滤出增多管周血管中胶体渗透压相对增高血流量减少，流体静压相对降低近曲小管重吸收钠水增多,3.常见全身性水肿的 发病机制及特点,心性水肿(cardiac edema)左心衰心源性肺水肿 右心衰心性水肿,特点:因重力作用先发于下垂部位,机制,右心功能,(Potassium homeostasis and its disorders),第三节 钾代谢及钾代谢障碍,病理生理教研室 吴立玲,病史： 男41岁，呕吐4天， 不能进食食物和水。既往史：胃溃疡，服用抗酸药治疗。体检：重病容。血压100/60mmHg 心率90 beats/min 皮肤干燥、弹性差， 腱反射减弱。,Case study,化验：血Na+145mmol/L Cl-92mmol/L K+2.6mmol/L HCO3-34mmol/L BUN35mg/dl EKG:T波低平，ST段降低 抽出3升胃内容物,一、正常钾代谢(Normal metabolism of potassium),1. 摄入(intake)： 食物,2. 吸收(absorption): 肠道,3. 分布(distribution)： 98% 细胞内(ICF) 2% 细胞外(ECF) serum K+ 3.55.5mmol/L,4. 排泄(excretion) : 肾（urine 80%90） 肠 (feces 10) 皮肤 (sweat),体内钾(50mmol/Kg体重),Distribution and content of potassium within body,5. 功能(function),参与细胞代谢(Promoting the cell metabolism),维持细胞膜静息电位 (Maintenance of the resting membrane potential),调节渗透压和酸碱平衡 (Regulating the osmotic pressure and acid-base balance),6. 钾平衡的调节(Regulation of potassium balance),跨细胞转移,肾调节,1. 激素：胰岛素，儿茶酚胺2. 细胞外液的K+浓度3. 酸碱平衡,影响钾在细胞内外转移的因素,醛固酮: Na- K+泵活性细胞外液的K+浓度酸碱平衡: H使Na-K泵活性远曲小管液流速加快,影响肾排钾的因素,二、低钾血症(Hypokalemia),概念 (concept) Serum K+ 5.5mmol/L,(一)原因和机制(Causes and mechanisms),1. 排钾减少(decreased K+ excretion),少尿(oliguria),潴钾性利尿剂,醛固酮,2. K+从细胞内逸出(K+ shifts out of cells),细胞损伤(cell injury),酸中毒(acidosis),高钾性周期性麻痹 (hyperkalemic periodic paralysis),3. 入钾过多(increased K+ intake),酸中毒(acidosis),