低钾血症学习全面版课件

1、1低钾血症学习PPT第1页/共20页1低钾血症学习PPT第1页/共20页 K+ Balance DiagramLungsIntercellularIntracellularKidneysLost in urinePlasmaNormal Values:Major Functions:MouthStomachSmall IntestineLargeIntestineLost in FecesIngestedLost in sweatK+3.5-5.0 mEq/LMaintains intracellular osmolarity, controls resting potential of ne

2、rve and muscle, exchanged for H+ to correct pH, exchanged for Na+ when distal tubules reabsorb Na+ Passive diffusionActive transportFiltered into glomerulus,depending on blood pressureand GFRSecreted by aldosterone-controlled Na+/K+ ATPasein distal tubuleNa+/K+ ATPase activated by insulin, epinephri

3、ne; inhibitedby digitalis, beta blockersPassive diffusionK+/H+ exchangeRepolarization(exercise, seizures)Reabsorbed in proximal tubule and loop of HenleK+/H+ exchange第2页/共20页 K+ Balance DiagramLungsIntercK+ 3.5-5.5 mEq/L, Total: 60 mEqK+ channelNa+K+K+Na+Na-K ATPaseNa-K ATPase+_ _ _ _ _ _ _ K+Distri

4、bution of potassium K+ 150 mEq/L, Total: 4000 mEq第3页/共20页K+ 3.5-5.5 mEq/L, Total: 60 m1、Factors that modify transcellular K+ distribution（钾的肾外调节）Modifying factorsAcid-base status Blood PH( Acidosis/alkalosis ) Plasma HCO3- ( Low/high )Pancreatic hormone Insulin/GlucagonCatecholamine -adrenergic/ -ad

5、renergicAlkalosisGlucagonAcidosisa-adrenergicInsulinb-adrenergicCELL K+第4页/共20页1、Factors that modify transcelPotassium Homeostasis第5页/共20页Potassium Homeostasis第5页/共20页2、肾脏的调节血钾在肾小球自由滤过约50-55%在近端肾小管重吸收约30-35%在髓袢重吸收远端小管和集合管泌钾第6页/共20页2、肾脏的调节血钾在肾小球自由滤过第6页/共20页Renal Handling of K+ in PCTK+(Paracellular r

6、oute)K+Cl-X-第7页/共20页Renal Handling of K+ in PCTK+(Reabsorption of Sodium Chloride Lessons from the Chloride Channels, NEJM,2004,350(13):1282Renal Handling of K+ in TALCaSR第8页/共20页Reabsorption of Sodium ChloridK reabsorption byH-K exchanger in intercalated cellsK secretion by Na-K exchanger in Princi

7、pal cellsRenal Handling of K+ in DCT and CT第9页/共20页K reabsorption byK secretion b二、引起低钾血症的原因 Insufficient potassium intake: Deficient dietary intakeTranscellular shift of K (no depletion): Hypokalaemic periodic paralysis Thyrotoxic periodic paralysis Barium poisoning Alkalosis Insulin excess第10页/共20

8、页二、引起低钾血症的原因 Insufficient potas Potassium depletion: Extra-renal losses: (1) Diarrhea (2) Rectal villous adenoma (3) Fistulas, Ureterosigmoidostomy (4) Laxative abuse Renal losses: (1) Excessive mineralocorticoids (primary& secondary aldosteronism, licorice，ingestion, glucocorticoid excess) (2) Rena

9、l tubular diseases (RTAs,leukaemia, Liddles syndrome,antibiotics, carbonic anhydrase inhibitors) (3) Diuretics (4) Magnesium depletion第11页/共20页 Potassium depletion: Extra-三、低钾血症的诊断思路第12页/共20页三、低钾血症的诊断思路第12页/共20页Differential Diagnosis of HypokalemiaHypokalemiaMetabolic alkalosisHypertensionGI wasting

10、YNUrine KUrine ClInsufficent intakeIntracellular transitionRTANHighLowHighPlasma reninLaxativesRenal wastingDiureticsBartter/Gitelman synUrine Ca/CrDiureticsRASRenin secretCushing synPlasma AldoHyperaldosteronismYHighHighNormalLowLowCongenital adrenal hyperplasiaChronic liguorice ingestionApparent m

11、ineralocorticoid excessLiddles synCarbenoxoloneHighLowBartters synGitelmans synInsulin-adrenergichyperthyroidismPeriodic Hypok-alemic Paralysis第13页/共20页Differential Diagnosis of HypoBarium poisoning约50-55%在近端肾小管重吸收Renal wastingIntercellularReabsorbed in proximal tubuleExtra-renal losses:depending on

12、 blood pressureLost in sweatK+/H+ exchangePancreatic hormone低血钾测尿钾尿钾正常高尿钾摄入少或吸收不良胃肠道丢失测PH碱中毒不定酸中毒测尿氯20mmol/L测血压正常高血压测Ald高低低肾素高肾素低肾素正常或高肾素肾间质小管疾病、低血镁、锂盐肾小管酸中毒、糖尿病酸中毒、乙酰唑胺呕吐、腹泻、高碳酸血症原醛利尿药、Batter或Gitelman、低血钾软病肾素瘤、肾动脉狭窄、恶性高血压Liddle、CAHCushing、ACTH分泌过多第14页/共20页Barium poisoning低血钾测尿钾尿钾正常高尿钾摄Metabolic alk

13、alosis(1) DiarrheaBarium poisoningTranscellular shift of K (no depletion):(1) DiarrheaSecreted by肾小管酸中毒、糖尿病酸中毒、乙酰唑胺b-adrenergicInsulin/GlucagonLost in urineNa-K ATPaseLost in urineMaintains intracellular osmolarity, controls resting potential of nerve and muscle, exchanged for H+ to correct pH, exch

14、anged for Na+ when distal tubules reabsorb Na+原发性钾缺失时，肌肉的细胞内镁缺失而无低镁血症b-adrenergic-adrenergic/ -adrenergicUrine Ca/CrThank you！第15页/共20页Metabolic alkalosisThank you！第Barium poisoning抑制钾在集合管管腔侧的传导第16页/共20页Barium poisoning抑制钾在集合管管腔侧的传导第Thyrotoxic periodic paralysis作用在细胞的NaK-ATPase上，促进能量代谢和物质代谢引起严重的恶心、呕吐，最终导致电解质紊乱第17页/共20页Thyrotoxic periodic paralysis作低镁血症40的低镁血症患者伴有低钾血症原发性钾缺失时，肌肉的细胞内镁缺失而无低镁血症第18页/共20页低镁血症40的低镁血症患者伴有低钾血症第18页/共20页1、Factors that modify transcellular K+ distribution（钾的肾外调节）Modifying factorsAcid-base status Blood PH( Acidosis/alkalosis ) Plasma HCO3- ( Low/high )Pancreatic