钾代谢障碍酸碱平衡紊乱.pptx

DisordersofPotassiumMetabolism钾代谢障碍酸碱平衡紊乱第1页Outline I.Normal potassium metabolism and regulationII.HypokalemiaIII.HyperlalemiaIV.Case discussion钾代谢障碍酸碱平衡紊乱第2页1.thetotalpotassiumofbody:intracellular:98（140-160mmol/L）extracellular：2（3.5-4.5mmol/L）I.Normalpotassiummetabolism钾代谢障碍酸碱平衡紊乱第3页2.potassiumpresentsinthefood,suchasmilk,peanutpotatoes,saltsubstitute.Potassium excrete pathway:kidney through urine:90 Stool(feces):10Sweatnormal serum potassium:3.5-5.5mmol/Lbalance between intra-and extracellular K+normal:15 h钾代谢障碍酸碱平衡紊乱第4页3.regulationofpotassiumhomeostasisTranscellulartransferRenalregulation钾代谢障碍酸碱平衡紊乱第5页(1)PotassiumtranscellulartransferPump-leakmechanismfactors:PotassiumconcentrationinECFAcid-basebalanceInsulinCatecholamineOsmolarityExerciseTotalbodypotassium钾代谢障碍酸碱平衡紊乱第6页(2).RenalregulationforpotassiumexcretionGlomerular filtrationReabsorption by the proximal tubule and the loop of HenleRegulation of potassium excretion in the distal and collecting tubules钾代谢障碍酸碱平衡紊乱第7页Sodium-potassium ATP ase Permeability of luminal membrane for potassiumReabsorption in collecting tubules Hydrogen-potassium ATP ase-proton pumpMechanismofpotassiumexcretionindistalandcollectingtubules:钾代谢障碍酸碱平衡紊乱第8页Influencing factors of potassium excretion in distal and collecting tubules:Potassium concentration in ECFAldosteroneDistal flow rateAcid-base balance(3)Potassium excretion in colon The same as the excretion in kidney钾代谢障碍酸碱平衡紊乱第9页4.physiologicalfunctionofpotassium maintain cellular metabolism maintain cellular resting membrane potential regulate the osmolarity and acid-base balance钾代谢障碍酸碱平衡紊乱第10页DisorderofpotassiummetabolismNormal serum potassium:3.5-5.5mmol/LHypokalemiaHyperkalemia钾代谢障碍酸碱平衡紊乱第11页 5.influencing facter of potassium homeostasis acidosis alkalosis hypoxia serum insulin serum damage of cells K+ADS K+catabolism anabolism distal flow rate distal flow rate钾代谢障碍酸碱平衡紊乱第12页1.Definition:Hypokalemiaisdefinedasadecreaseinserumpotassiumlevellessthan3.5mmol/L.hypokalemia钾代谢障碍酸碱平衡紊乱第13页2.causes(1).intake(2).dischargedigestivetractkidneys：skin钾代谢障碍酸碱平衡紊乱第14页 GI:vomiting;diarrhea;Gastrointestinal suction Skin:excessive sweats furosemide diuretic losses diamox diuretic phase of ARF renal:primary hyperaldosteronism lack of magnesium renal tubular acidosis osmotic diuresis 钾代谢障碍酸碱平衡紊乱第15页(3).Abnormalitydistributionofpotassiummoveintocellsacute alkalosis insulin overdose Barium poisoningBeta-receptor excitomotoryhypokalemic periodic paralysis钾代谢障碍酸碱平衡紊乱第16页3.alterationsofmetabolismandfunctionNerve cellsskeletal muscles gastrointestinal smooth muscleMyocardial cells 钾代谢障碍酸碱平衡紊乱第17页 Effects on body (1).nerves and muscles acute hypokalemia excitability 0 mv serumK+-30mv AP -60mv TP(Et)-90mv RP(Em)hyperpolarization钾代谢障碍酸碱平衡紊乱第18页(2).Heart arrhythmia 0 mv serumK+-30mv -60mv -90mv depolarization 钾代谢障碍酸碱平衡紊乱第19页Excitability:K+ECF K+permeability depolarization repolarization excitability ECG T wave Conductivity:RP 0 phase of AP conductivity conductive block unidirectional block ECG P-R 钾代谢障碍酸碱平衡紊乱第20页 Autorhythmicity:Contractility:acute ;chronic effects on heart cardiac excitability cardiac conductivity cardiac automaticity cardiac contractibility 钾代谢障碍酸碱平衡紊乱第21页(3).Renal polyuria (sensitivity of ADH)(4).GI smooth muscles Hyperpolarization(5).acid-base balancemetabolic alkalosis paradoxical aciduria钾代谢障碍酸碱平衡紊乱第22页4.principlesofpreventionandtreatment1.treatmentofprimarydisease2.principlesofpotassiumcompensationoral application is better Give potassium according to the urine concentration 40mmol/L，slowly 10-20mmol/htoobserve：heart rate cardiac rhythm consciousness acid base钾代谢障碍酸碱平衡紊乱第23页1.definition:hyperkalemia is defined as serum potassium exceeding 5.5mmol/L.hyperkalemia钾代谢障碍酸碱平衡紊乱第24页2.causes(1).increased intake of potassium(2).Impaired renal potassium excretion：renal dysfunction ALD potassium-sparing diuretics钾代谢障碍酸碱平衡紊乱第25页(3).abnormalpotassiumtranscellularditributionacuteacidosishypoxiaATPtissuedamagehyperkalemicperiodicparalysisDiabetesBeta-receptorinhibbitor钾代谢障碍酸碱平衡紊乱第26页3.alterationsofmetabolismandfunction(1).effect on neuromuscular excitability:(2).effects on heart cardiac excitability cardiac conductivity cardiac automaticity cardiac contractibility (3).effect on the acid-base balance acidosis paradoxical alkaline urine钾代谢障碍酸碱平衡紊乱第27页 skeletal muscle 8mmol/L RP (depolarization)excitability stabbing;tremor 8mmol/L RP inactivation of Na+channel depolarization paralysis钾代谢障碍酸碱平衡紊乱第28页 heart(hyperkalemia K+permeability )5.5-7mmol/L RP E excitability 7-9mmol/L RP E 7-9mmol/L RP E T wave ;QT shortcardiac arrestPR QT钾代谢障碍酸碱平衡紊乱第29页 Autorhythmicity:K+out ward of phase 4 Spontaneous depolarization heart rate Conductivity:RP Na+inward of phase 0 conductivity conductive block unidirectional block Contractility:inhibition of Ca2+inward flow contractilityacid-base balanceacidosis paradoxical alkaline urine钾代谢障碍酸碱平衡紊乱第30页4.principlesofpreventionandtreatmenta)treatment of primary disease b)decrease uptake of K+c)cut down total amount of body potassium dialysis ion-exchange resind)induce K+uptake by cells.e)application of calcium and sodium钾代谢障碍酸碱平衡紊乱第31页SummaryI.NormalpotassiummetabolismandregulationII.HypokalemiaIII.hyperkalemiadefinitioncausesalterationsofmetabolismandfunctionprinciplesofpreventionandtreatmentIV.Casepresentation钾代谢障碍酸碱平衡紊乱第32页 The pH of the ECF is maintained within the narrow range of 7.357.45 7.8 !钾代谢障碍酸碱平衡紊乱第33页I.Acid-base homeostasis 1.The acids and bases in the blood 1)Acids钾代谢障碍酸碱平衡紊乱第34页Respiratory acid(Volatile acid)H2CO3 CO2+H2O H2CO3 H+HCO3-钾代谢障碍酸碱平衡紊乱第35页 Metabolic acid The product of metabolism of amino acid:phosphophoryn,nucleric acid phosphoric acid methionine,cysteine sulfuric acid purine uric acid (gout)Lactic acid(The liver removes and converts to G)Ketoacids(pyruvic acid,acetoacetic acid,hydroxybutyric acid)钾代谢障碍酸碱平衡紊乱第36页2)Base The fruits and vegetables are rich in alkali salt,e.g.sodium citrate,potassium citrate.钾代谢障碍酸碱平衡紊乱第37页2.Control of pH 1)The buffer systems Buffers are the first defense against pH disorders,and act immediately.Alkali salt of the acid Buffer system:Weak acid钾代谢障碍酸碱平衡紊乱第38页 NaHCO3 Bicarbonate buffer pair H2CO3 To buffer metabolic acid and base in ECF Hb buffer pairs in RBC to buffer respiratory acid.HPO42-Phosphate buffer pair H2PO4-To buffer in ICF 钾代谢障碍酸碱平衡紊乱第39页2)Respiratory contribution The respiratory system is the second defense against pH disorders,and needs several minutes.H2CO3 The rate and depth H2CO3 H+But when PaCO2 80mmHg,the rate and depth.H2CO3 The rate and depth H2CO3 H+钾代谢障碍酸碱平衡紊乱第40页3)Renal contribution The kidney is the third defense against acid-base disorders.Metabolic acid Excretion of acid Reabsorption of baseMetabolic acid Excretion of acid Reabsorption of base Base Excretion of acid Excretion of base钾代谢障碍酸碱平衡紊乱第41页The kidneys can compensate for respiratory acid imbalances by excretion of metabolic acids.(Indirectly)H2CO3 Excretion of metabolic acid H2CO3 Excretion of metabolic acid钾代谢障碍酸碱平衡紊乱第42页 The renal compensation requires several days to be fully effective.钾代谢障碍酸碱平衡紊乱第43页4)Effects of K+and Cl-on pH regulation Acidosis can cause hyperkalemia,and alkalosis can cause hypokalemia.H+K+HCO3-Cl-钾代谢障碍酸碱平衡紊乱第44页3.The determination of pH pH=pKa+logHCO3-/H2CO3 If the ratio is 20:1,the pH will be 7.4钾代谢障碍酸碱平衡紊乱第45页4.The main indicators of laboratory about acid-base balance 1)pH:The normal range is 7.357.45 A normal range of pH represents No disturbance in acid-base balance Acid-base imbalance with complete compensation A mixed acidosis and alkalosis which have opposite effect on pH and offset each other.3 situations:钾代谢障碍酸碱平衡紊乱第46页2)PaCO2:Normal range is 3842mmHg(40mmHg).(3346mmHg)PaCO2 is an indicator of the effectiveness of respiratory excreting of carbonic acid.If PaCO2,means hypoventilation or metabolic alkalosis after compensation PaCO2,means hyperventilation or metabolic acidosis after compensation钾代谢障碍酸碱平衡紊乱第47页3)HCO3-:The normal range is 24 33mmol/L.It is an indicator of the renal excretion of metabolic acid.HCO3-means an excess of metabolic acids(metabolic acidosis or respiratory alkalosis after compensation).HCO3-means a deficit of metabolic acids or an excess of base(metabolic alkalosis or respiratory acidosis after compensation).钾代谢障碍酸碱平衡紊乱第48页 Standard bicarbonate SB(2227mmol/L)Actual bicarbonate AB ABSB,hypoventilation;ABSB,hyperventilation Buffer base BB Base excess BE CO2 combine power（CO2CP）钾代谢障碍酸碱平衡紊乱第49页4)AG(aniongap):AG describes the difference between unmeasured anion(UA)and unmeasured cation(UC).AG=Na+-(Cl-+HCO3-).The normal range is 10 14 mmol/L(12 mmol/L).钾代谢障碍酸碱平衡紊乱第50页II.Acid-baseimbalances1.Metabolicacidosis1)Concept:Metabolic acidosis refers to a primary deficit in base bicarbonate,the pH falls.钾代谢障碍酸碱平衡紊乱第51页2)Causes:(1)Increaseinmetabolicacids Excess production of metabolic acids E.g.fasting and starvation,diabetic ketoacidosis,lactic acidosis(shock,hypoxia,heart failure,anemia).Decreased loss of metabolic acids E.g.renal failure,renal tubular acidosis-I Over dose of acidic medicine(aspirin).AG is increased.钾代谢障碍酸碱平衡紊乱第52页 (2)Increase in bicarbonate loss E.g.Severe diarrhea,intestinal fistulas Renal tubular acidosis-II.Over dose of NH4+,releases HCl AG is normal.钾代谢障碍酸碱平衡紊乱第53页3)Compensation:(1)Buffer system and cell (2)Signs of compensation Kussmaul breathing Acid urine钾代谢障碍酸碱平衡紊乱第54页4)Manifestations (1)Heart failure:Hyperkalemia _cardiac arrhythmia Impair myocardial contraction (2)Decreased response of capillary to catecholamines _Shock (3)Depression of neural function Lethargy,disorder of consciousness,coma.(4)Changes of osseous system Renal rickets肾性佝偻病,osteomalacia骨软化症钾代谢障碍酸碱平衡紊乱第55页4)Laboratory findings pH,HCO3-,PaCO2 if there is compensation of respiratory system.钾代谢障碍酸碱平衡紊乱第56页Case study:Arterial blood:pH 7.21 PaCO2 26 mmHg PaO2 108 mmHg HCO3-12 mmol/L Na+135 mmol/L K+2.0 mmol/L Cl-110 mmol/L Urine:pH 5.0钾代谢障碍酸碱平衡紊乱第57页(1)A 36-year-old man was hospitalized with a 3-day history of fever and watery diarrhea.The blood pressure is 90/60 mmHg,the pulse is 112/minute,the respiratory rate is 24/minute,and the temperature is 37.5C.The laboratory results were obtained.钾代谢障碍酸碱平衡紊乱第58页2.Respiratory acidosis 1)Concept:Respiratory acidosis is defined as a decrease of pH induced by primary increase in plasma H2CO3.钾代谢障碍酸碱平衡紊乱第59页2)Causes Respiratory acidosis can occur as an acute or a chronic disorder.(1)Acute respiratory acidosis E.g.acute respiratory infections,chest injuries,pulmonary edema.(2)Chronic respiratory acidosis E.g.chronic obstructive lung disease,chronic bronchitis.钾代谢障碍酸碱平衡紊乱第60页3)Compensation:Buffer system and cell4)Manifestations:Headache,cardiac arrhythmias and neurologic abnormalities.Neurologic manifestations may be more prominent in respiratory acidosis than in metabolic acidosis.“CO2 narcosis”The mechanism:钾代谢障碍酸碱平衡紊乱第61页 (1)CO2 crosses the blood-brain barrier relatively easily,and can dilate the blood vessels in the brain and lead to brain edema.(2)CO2 can also decrease the pH of the cerebrospinal fluid,and make depression of neural function,like weakness,confusion,paralysis,stupor and coma.钾代谢障碍酸碱平衡紊乱第62页5)Laboratory findings pH,PaCO2,HCO3-if there is compensation of kidneys(chronic).钾代谢障碍酸碱平衡紊乱第63页3.Metabolic alkalosis 1)Concept:Metabolic alkalosis refers to a primary increase in base bicarbonate,the pH elevates.2)Causes:(1)Decrease of acid E.g.vomiting (Ileus:intestinal obstruction).(2)Increase of base E.g.antacids,transfusion with citrated blood,hyperaldosteronism.Saline-responsive alkalosis and saline-resistant alkalosis钾代谢障碍酸碱平衡紊乱第64页3)Compensation4)Manifestations Alkalosis can cause increased excitability of nervous system,like hyperactive reflexes,muscle hypertonicity,tetany etc.钾代谢障碍酸碱平衡紊乱第65页5)Laboratory findings pH,HCO3-,PaCO2 if there is compensation of respiratory system.钾代谢障碍酸碱平衡紊乱第66页4.Respiratory alkalosis 1)Concept:Respiratory alkalosis is defined as an increase of pH induced by primary decrease in plasma H2CO3.2)Causes:Hyperventilation E.g.anxiety,hysteria,fever,early salicylate(aspirin)toxicity,misuse of mechanical ventilation.钾代谢障碍酸碱平衡紊乱第67页3)Compensation4)Manifestations Tetany 5)Laboratory findings pH,PaCO2,HCO3-(depend on the normal renal function).钾代谢障碍酸碱平衡紊乱第68页5.Mixed acid-base imbalancesConcept:Two or more primary acid-base imbalances exist at the same time.钾代谢障碍酸碱平衡紊乱第69页BacterialpneumoniarespiratoryacidosisPatientDiarrheametabolicacidosisIn this mixed imbalance,the pH is likely to be very low.PneumoniarespiratoryacidosisPatientVomitingmetabolicalkalosisIn this mixed imbalance,the pH will change slightly or in normal range.钾代谢障碍酸碱平衡紊乱第70页 Acidosis+acidosis,or alkalosis+alkalosis,the pH will change a lot;acidosis+alkalosis,the pH will change slightly or in normal range.Respiratory acidosis and respiratory alkalosis can not exist at the same time.钾代谢障碍酸碱平衡紊乱第71页(2)A 32-year-old male presented with vomiting of one weeks duration.On examination,he had a blood pressure of 90/60 mmHg and a pulse of 116/minute.See the laboratory results.钾代谢障碍酸碱平衡紊乱第72页Arterial blood:pH 7.55 PaCO2 46 mmHg HCO3-39 mmol/L Na+143 mmol/L K+2.7 mmol/L Cl-72 mmol/L Urine pH 5.0钾代谢障碍酸碱平衡紊乱第73页(3)A 52-year-old man with chronic obstructive lung disease is admitted to the hospital with worsening dyspnea.He appears cyanosis and in respiratory distress.The laboratory data follow.钾代谢障碍酸碱平衡紊乱第74页Arterial blood pH 7.34 PaCO2 60 mmHg PaO2 50 mm Hg HCO3-35 mmol/L Na+136mmol/L K+4.9 mmol/L Cl-96 mmol/L 钾代谢障碍酸碱平衡紊乱第75页(4)A 48-year-old female presented with severe vomiting.On examination,T 38,HR 89/min,R 26/min,Bp 150/100 mmHg.She appears general edema.The laboratory results 钾代谢障碍酸碱平衡紊乱第76页Arterial blood pH 7.39 PaCO2 43 mmHg PaO2 95 mm Hg HCO3-26 mmol/L Na+142mmol/L K+3.6 mmol/L Cl-98 mmol/L 钾代谢障碍酸碱平衡紊乱第77页