外科手术的水电解质平衡课件.ppt

1、1FLUID AND ELECTROLYTE FLUID AND ELECTROLYTE MANAGEMENTMANAGEMENT2For surgical patients:Diseases,injuries,operative trauma,lack of alimentation metabolism of salt,water,other electrolytes3Total Body Water 60%of body weigh 50%of body weight 75%to 80%lean individual obese person 6Composition of UrineW

2、aterNitrogen-containing material：urea、uric acid、creatine、creatinine、amino acid and amonia。Organic compound：hippuric acid、glucuronate、lactic acid、ethanedioic.Electrolyte：Cl-、Na、K and phosphate。Little protein and sugar，positive in urine pathology。7Three functional compartments of the body waterintrace

3、llular water 40%extracellular water 20%body weight 60%plasma 5%interstitial fluid 15%8Total blood volume of human bodyGenerally 8of body weight，About 5000 ml for an adult。increase2325 in pregnancy women。About 80 of total volume in circulationOther 20%stored in liver and spleen 9154mEq/l 154mEq/l153m

4、Eq/l 153mEq/l200 mEq/l 200 mEq/l Cation Anions Na+142 Cl-103 HCO3-27 SO4=PO4 3K+4Ca+5Mg+3 Protein 16 Organic acid 5Cation AnionsNa+144 Cl-114 HCO3-30 SO4=PO4 3K+4Ca+3Mg+2 Protein 1 Organic acid 5Cation AnionsK+150 HPO4=SO4=150 HCO3-10 Na+10Mg+40 Protein 40 Plasma Intestitial fluid Intracellular flui

5、dChemical composition of body fluid compartment:10Osmotic Pressure Depends on the number of particles present per unit volume.1 mM NaCl=sodium+chloride,contributes 2 mM,1 mM Na2SO4=3 particles,contributes 3 mM.1 mM glucose is equal to 1 mM of the substance.Normal Osmotic Pressure Cations(151)Anions(

6、139)non electrolyte(10)300mmol/L(280 310mmol/L)11semipermeable membrane The cell wall maintained the differences in ionic composition between ICF and ECF.The cell membranes are completely permeable to water12colloid osmotic pressureThe dissolved proteins in the plasma are primarily responsible for e

7、ffective osmotic pressure between the plasma and the interstitial fluid compartments.13The effective osmotic pressureintracellular extracellular dissolved proteins plasma interstitial fluid 14The effective osmotic pressure The difference of pressure between the ECF and ICF compartments induced by an

8、y substance that does not traverse the cell membranes freely.15CLASSIFICATION OF BODY FLUID CHANGESThe disorders in fluid balance：volume deficit or Excessconcentration composition16Volume DeficitThe most common disorders leading to an ECF volume deficit include:losses of gastrointestinal fluids due

9、to vomiting,nasogastric suction,diarrhea,fistula drainage.1.sequestration of fluid in soft tissue injuries and infections,intra-abdominal and peritonitis,intestinal obstruction,and burns.17Volume Excess Generally secondary to renal insufficiency.Both the plasma and the interstitial fluid volumes are

10、 increased.18CONCENTRATION CHANGESECF:Na+represent 90%of particles concentration.Hyponatremia and hypernatremia can be diagnosed by clinical manifestations,laboratory tests.19Mechanism of HyponatremiaWater intake excessSodium intake deficientRenal inadequacyVomite,suction20Hyponatremia Asymptomatic

11、until the serum sodium level falls 120 mmol per liter.Acute symptomatic hyponatremia:CNS signs:Increased intracranial pressure;tissue signs of excessive intracellular water.21Hyponatremia:(Water intoxication)serum sodium level less than 120 mmol/LCNS:Moderate severe Muscle twitching Convulsions Hype

12、ractive tendon reflexes Loss of reflexes increased intracranial pressureCardioVascular:Bp change Tissue:increased salivation Watery diarrhea Renal:Oliguria progressing to anuria Metabolic:None 22Mechanism of HypernatremiaWater intake deficientDiseases of digestive tractExcess loss waterexcess perspi

13、rationVomite,diarrhea,suction23Hypernatremia:(Water deficit)serum sodium level greater than 150 mmol/LCNS:Moderate severe Restlessness Delirium Weakness Maniacal behavior CardioVascular:Tachycardia,HypotensionTissue:Decreased saliva and tears Dry and sticky mucous membranes Renal:OliguriaMetabolic:F

14、ever 24MIXED VOLUME AND CONCENTRATION ABNORMALITIESConsequence of the disease state or occasionally from inappropriate parenteral fluid therapy.1.The more common is an ECF deficit and hyponatremia(Hypotonic dehydration).2.ECF volume deficit+hypernatremia(Hypotonic dehydration).:glucosuria 3.ECF volu

15、me excess and hypernatremia:excessive quantities of sodium salts 4.ECF volume excess and hyponatremia(Water intoxication):oliguric renal failure 25COMPOSITION CHANGESCompositional abnormalities include:concentration changes of potassium,calcium,magnesium1.changes in acid-base balance 26Potassium The

16、 normal dietary intake of potassium is approximately 50 to 100 mmol.daily.98%of the potassium is located in the IC compartment at a concentration of 150 mmol.per liter.Extracellular potassium is 3.55.5 mmol/L.1.Most of this is excreted in the urine.27Potassium Abnormalilies HyperkalemiaExtracellular

17、 potassium 5.5 mmol/L.HypokalemiaExtracellular potassium 3.5 mmol/L.28Hyperkalemia Significant quantities of intracellular potassium are released into the extracellular space.Cause:severe injury or surgical stress Acidosis the catabolic state.1.oliguric or anuric renal failure 29Hyperkalemia Signs:T

18、he gastrointestinal symptoms include nausea,vomiting,intermittent intestinal colic,and diarrhea.The cardiovascular signs are apparent on the ECG initially,with high peaked T waves,widened QRS complex,and depressed S-T segments.Disappearance of T waves,heart block,and diastolic cardiac arrest may dev

19、elop with increasing levels of potassium.30HyperkalemiaTreatment:intravenous administration of 1 gm.of 10%calcium gluconate under ECG monitoring administration of bicarbonate and glucose with insulin(1/4gG)Rapid alkalinization of the ECF with either sodium lactate or bicarbonate promotes transfer of

20、 potassium into cells 1.definitive removal of excess potassium by cation-exchange resins,peritoneal dialysis,or hemodialysis.31HypokalemiaA more common problem in the surgical patient may occur as a result of:excessive renal excretion(1g/500ml)movement of potassium into cells prolonged administratio

21、n of potassium-free parenteral fluids with continued obligatory renal loss of potassium parenteral nutrition with inadequate potassium replacement,1.loss of gastrointestinal secretions.32Hypokalemia The signs of potassium deficit:failure of normal contractility of skeletal,smooth,and cardiac muscle

22、weakness to flaccid paralysis,diminished to absent tendon reflexes,and paralytic ileus.1.Sensitivity to digitalis with cardiac arrhythmias and ECG signs of low voltage,flattening of T waves,and depression of S-T segments33Normal Hypokalemia Hyperkalemia34Hypokalemia Treatment of hypokalemia involves

23、:First prevention of these state.Intravenous administration of potassium No more than 40 mmol should be added to 1 liter of intravenous fluid The rate of administration should not exceed 20 mmol/hour unless the ECG is being monitored.Administration of potassium is about 3-6 g/day1.1 gram of KCl=13.4

24、mmol of potassium 35Composition of Gastrointestinal Secretions Volume Na K Cl HCO3 (ml/24hr)mmol/L mmol/L mmol/L mmol/LSalivary 1500 10 26 10 30 Stomach 1500 60 10 130 -Duodenum100-2000 140 5 104 -Ileum 3000 140 5 104 30 Colon -60 30 40 -Pancreas 100-800 140 5 75 115 Bile 50-800 145 5 100 35 36Calci

25、um Abnormalities Most of body calcium(99%)is found in the bone in the form of phosphate and carbonate.Normal daily intake of calcium is between 1 and 3 gm.Most of this is excreted via the gastrointestinal tract,and 200 mg.or less is excreted in the urine daily.The normal serum level is between 2.25

26、2.75 mmol/L1.The 45%is the ionized portion that is responsible for neuromuscular stability.37Hypocalcemia The common causes:Acute pancreatitis Massive soft tissue infections Acute and chronic renal failure Pancreatic and small intestinal fistulas 1.Hypoparathyroidism 38Hypocalcemia The symptoms(seru

27、m level less than 2.25 mmol/L):Numbness and tingling of the circumoral region and the tips of the fingers and toes.Hyperactive tendon reflexes,Muscle and abdominal cramps,convulsions(with severe deficit),1.Chvosteks sign and Trousseausign positive39Hypocalcemia Treatment:correction of the underlying

28、 cause with concomitant repletion of the deficit.Intravenous administration of calcium gluconate or calcium chloride Calcium lactate may be given orally,1.With or without supplemental vitamin D,in a patient requiring prolonged replacement.40Hypercalcemia The two major causes:Hyperparathyroidism Canc

29、er with bony metastasis.1.The latter is most frequently seen in a patient with metastatic breast cancer.41Hypercalcemia The manifestations of hypercalcemia include:Easy fatigue,lassitude,weakness of varying degree,Anorexia,nausea,vomiting,and weight loss.Lassitude,stupor,and finally coma.1.Severe he

30、adaches,pains in the back and extremities,thirst.42Hypercalcemia Treatment:vigorous volume repletion with salt solutions lowers the calcium level by dilution and increased urinary calcium excretion.Concomitant use of large doses of intravenous furosemide to increase urinary calcium excretion.Oral or

31、 intravenous inorganic phosphates 1.Intravenous sodium sulfate also lowers serum calcium 43Magnesium Abnormalities The total body content of magnesium is approximately 1000 mmol.,About half of which is in bone and the major other portion being intracellular Serum magnesium concentration normally ran

32、ges between 0.71.1mmol/L.The normal dietary intake of magnesium is approximately 20 mmol.(240 mg.)daily.1.The larger part is excreted in the feces and the remainder in the urine.The kidneys have a remarkable ability to conserve magnesium.44Magnesium DeficiencyCause:starvation,malabsorption syndromes

33、,protracted losses of gastrointestinal fluid,prolonged parenteral fluid therapy with magnesium-free solutions.Acute pancreatitis,diabetic acidosis during treatment.primary aldosteronism,1.chronic alcoholism.45Magnesium Deficiency The signs and symptomsThe magnesium ion is essential for proper functi

34、on of most enzyme systems,and depletion is characterized by neuromuscular and CNS hyperactivity,which are quite similar to those of calcium deficiency.46Magnesium Deficiency Treamient In asymptomatic patients:oral replacement.Severe symptomatic deficit:The intravenous route is preferable for the ini

35、tial treatment.1.When large doses are given intravenously,the heart rate,blood pressure,respiration,and ECG should be monitored closely for signs of magnesium toxicity,which could lead to cardiac arrest.47Magnesium ExcessCause:1,Patients with impaired renal function 2,Early-stage burns3,Massive trau

36、ma or surgical stress4,Severe ECF volume deficit5,Severe acidosis.48Magnesium Excess signs and symptoms include:lethargy and weakness with progressive loss of deep tendon reflexes.Interference with cardiac conduction ECG changes(increased P-R interval,widened QRS complex,and elevated T waves)resembl

37、e those seen with hyperkalemia.1.Somnolence leading to coma and muscular paralysis occurs in the later stages,and death is usually caused by respiratory or cardiac arrest.49Magnesium Excess Treatment Correcting any acidosis,Replenishing any preexisting ECF volume deficit Stop exogenously administere

38、d magnesium.Acute symptoms may be controlled by slow intravenous administration of 2.5 to 5 mmol.of calcium gluconate.(about 10%calcium gluconate 1020ml)1.If elevated levels or symptoms persist,peritoneal dialysis or hemodialysis is indicated.50Phosphonium AbnormalitiesPhosphonium AbnormalitiesAbout

39、 85%of phosphonium exite in boneNormal serum phosphonium level:0.961.62mmol/LParticipate phosphorate of protein,cell membrain and acid-base balance 51HypophosphatemiaCause:Hyperparathyroidism,severe burn or infectionSyptom:manifestation in nervous-muscle.Treatment:administration of sodium glyceropho

40、sphate 10 ml52HyperphosphatemiaCause:acute renal failure,Hypoparathyroidism,acidosisSyptom:like hypocalcemia,ectopic calcificationTreatment:treatment of hypocalcemia,dialysis53Acid-base BalanceAcid-base BalanceAcidAcidvolatile（H H2 2COCO3 3）fixed acidMaterial release H+Resp.regul.Renal regul54Alkali

41、saltamoniaAcid-base BalanceAcid-base BalanceSth receive H+55Asid and Alkali in bodyAsid and Alkali in bodyvolatile acid:carbonic acid（H H2 2COCO3 3）fixed acid：H H2 2SOSO4 4、H H2 2POPO4 4、ketobodiesAcid:Alkali：HCO3-、Hb-、Na2HPO4、NH356Acid-base BalanceAcid-base BalanceIntracellular PH:proteins and phos

42、phates,ECF space:bicarbonate-carbonic acid system red cell hemoglobin PH of body fluids maintained by several buffer systems and subsequently excreted by the lungs and kidneys.57HPr PrH2PO 4HPO42-22HHbOHbOHHbHb58H2ORegulation by lung and kidney59Excrete H+and reuptake NaHCO3H2OProximal nephronCO2H2O

43、CA60Acid-base BalanceAcid-base Balance1、PH：Normal blood PH:7.357.452、PCO2：Normal:35-45mmHg,(40mmHg)3、Buffuer excess（BE）:Represent ascidosis or alkolosis,Normal:+3-3 mmol/L,(0)4、Actual bicarbonate radical（AB）：）：actual HCO3-in plasma5、Standard bicarbonate radical（SB）：）：HCO3-content measured when PaCO2

44、=40mmHg,HbO2=100%，T=37.0 Normal AB=S B=2227mmol/L,average 24mmol/L61pH Conception：Negative logarithm of H+concentration in solutionNormal value：Artery blood 7.357.45Meaning：To distinguish acidosis or alkalosis7.35 7.45Acidosis6.8Alkalosis7.8deathdeathpH16 nmol/L40160【H+】62Hendeison-Hasselbalch equat

45、ionpH=pK+log BHCO3/H2CO3 =6.1+log HCO3/0.03 PaCO2 =6.1+log 24/0.03 40 =6.1+log20/1=7.4PK represents the dissociation constant of carbonic acid in the presence of base bicarbonate HCO3 represent the factor of metabolismPaCO2 represent the factor of respiration63Six-Step to the Interpretation of Arter

46、ial Blood Gas With Serum Sodium,Potassium,and Chloride ConcentrationsOBSERVATIONINTERPRETATIONINTERVENTIONpH other than 7.40?Acidosis if 7.45pH 7.55?Severe disorderPrompt correction requiredPaco2 other than 40 mm Hg?Ventilation compensates disorderChange ventilation Paco2 compensatesbase deficit oth

47、er than zero?Bicarbonate loss/gain compensates or contributes to disorder NaCO3 or HCl correct proton concentrationurine pH reflect acidosis/alkalosis?Acid/alkaline urine indicates renal function compensates or contributesRenal-active drugs or electrolyte replacement anion gap 12 mmol/L suggest lact

48、ic or ketoacidosisCorrect the primary metabolic problem64Simple typeMetab(Alk)Resp.(aci)Metab.alkalosisMetab.acidosisResp.acidosisResp.alkalosisThe four types of acid-base disturbances65The four types of acid-base disturbances Acute Chronic pH PCO2 HCO3 pH PCO2 HCO3 Resp acid N Resp alka N Meta acid

49、 N Meta alka N?66Acidosis and Alkalosis Defect Cause Resp acid Retention of CO2 Depression of respiratoryResp alka Excessive loss of CO2 HyperventilationMeta acid Retention of fixed acids Diabetes,diarrhea Loss of base bicarbonate Lactic acid accumulationMeta alka Loss of fixed acids Vomiting or gas

50、tric suction Gain of base bicarbonate Excessive intake of Potassium depletion bicarbonate 67Respiratory Acidosis:Hypoventilation PCO2 is elevated and plasma bicarbonate concentration is normal.In the chronic form,Pco2 remains elevated and bicarbonate concentration rises as renal compensation occurs.