低钾血症学习全面版课件.pptx
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 Diagram,Lungs,Intercellular,Intracellular,Kidneys,Lost in urine,PlasmaNormal Values:Major Functions:,Mouth,Stomach,Small Intestine,LargeIntestine,Lost in Feces,Ingested,Lost in sweat,K+,3.5-5.0 mEq/L,Maintains intracellular osmolarity, controls resting potential of nerve and muscle, exchanged for H+ to correct pH, exchanged for Na+ when distal tubules reabsorb Na+,Passive diffusion,Active transport,Filtered into glomerulus,depending on blood pressureand GFR,Secreted by aldosterone-controlled Na+/K+ ATPasein distal tubule,Na+/K+ ATPase activated by insulin, epinephrine; inhibitedby digitalis, beta blockers,Passive diffusionK+/H+ exchange,Repolarization(exercise, seizures),Reabsorbed in proximal tubule and loop of Henle,K+/H+ exchange,第2页/共20页,K+ Balance DiagramLungsInterc,K+ 3.5-5.5 mEq/L, Total: 60 mEq,K+ channel,Na+,K+,K+,Na+,Na-K ATPase,Na-K ATPase,+,+,+,+,+,+,+,_,_,_,_,_,_,_,K+,Distribution of potassium,K+ 150 mEq/L, Total: 4000 mEq,第3页/共20页,K+ 3.5-5.5 mEq/L, Total: 60 m,1、Factors that modify transcellular K+ distribution（钾的肾外调节）,Alkalosis,Glucagon,Acidosis,a-adrenergic,Insulin,b-adrenergic,CELL K+,第4页/共20页,1、Factors that modify transcel,Potassium 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 PCT,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):1282,Renal Handling of K+ in TAL,第8页/共20页,Reabsorption of Sodium Chlorid,K reabsorption byH-K exchanger in intercalated cells,K secretion by Na-K exchanger in Principal cells,Renal 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) Renal 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 Hypokalemia,Hypokalemia,Metabolic alkalosis,Hypertension,GI wasting,Y,N,Urine K,Urine Cl,N,High,Low,High,Plasma renin,Laxatives,Renal wasting,Diuretics,Bartter/Gitelman syn,Urine Ca/Cr,Cushing syn,Plasma Aldo,Hyperaldosteronism,Y,High,High,Normal,Low,Low,High,Low,Bartters syn,Gitelmans syn,Insulin,-adrenergic,hyperthyroidism,Periodic Hypok-alemic Paralysis,第13页/共20页,Differential Diagnosis of Hypo,Barium poisoning约50-55%在近端肾小管重吸收Renal wastingIntercellularReabsorbed in proximal tubuleExtra-renal losses:depending on 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,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、CAH,Cushing、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 alkalosis(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, exchanged 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/Cr,Thank 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）,Alkalosis,Glucagon,Acidosis,a-adrenergic,Insulin,b-adrenergic,CELL K+,第19页/共20页,1、Factors that modify transcel,Potassium Homeostasis,第20页/共20页,Potassium Homeostasis第20页/共20页,低钾血症学习全面版课件,
