外科手术的水电解质平衡课件.ppt

1,FLUID AND ELECTROLYTE MANAGEMENT,2,For surgical patients:Diseases,injuries,operative trauma,lack of alimentation metabolism of salt,water,other electrolytes,3,Total Body Water 60%of body weigh 50%of body weight 75%to 80%lean individual obese person,6,Composition of Urine,WaterNitrogen-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。,7,Three functional compartments of the body water,intracellular water 40%,extracellular water 20%,body weight 60%,plasma 5%,interstitial fluid 15%,8,Total blood volume of human body,Generally 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,9,Plasma Intestitial fluid Intracellular fluid,Chemical composition of body fluid compartment:,10,Osmotic 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(139)non electrolyte(10)300mmol/L(280 310mmol/L),11,semipermeable membrane The cell wall maintained the differences in ionic composition between ICF and ECF.The cell membranes are completely permeable to water,12,colloid osmotic pressureThe dissolved proteins in the plasma are primarily responsible for effective osmotic pressure between the plasma and the interstitial fluid compartments.,13,The effective osmotic pressure,intracellular,extracellular dissolved proteins,plasma,interstitial fluid,14,The effective osmotic pressure The difference of pressure between the ECF and ICF compartments induced by any substance that does not traverse the cell membranes freely.,15,CLASSIFICATION OF BODY FLUID CHANGESThe disorders in fluid balance：volume deficit or Excessconcentration composition,16,Volume DeficitThe most common disorders leading to an ECF volume deficit include:losses of gastrointestinal fluids due to vomiting,nasogastric suction,diarrhea,fistula drainage.sequestration of fluid in soft tissue injuries and infections,intra-abdominal and peritonitis,intestinal obstruction,and burns.,17,Volume Excess Generally secondary to renal insufficiency.Both the plasma and the interstitial fluid volumes are increased.,18,CONCENTRATION CHANGESECF:Na+represent 90%of particles concentration.Hyponatremia and hypernatremia can be diagnosed by clinical manifestations,laboratory tests.,19,Mechanism of Hyponatremia,Water intake excess,Sodium intake deficient,Renal inadequacy,Vomite,suction,20,Hyponatremia Asymptomatic until the serum sodium level falls 120 mmol per liter.Acute symptomatic hyponatremia:CNS signs:Increased intracranial pressure;tissue signs of excessive intracellular water.,21,Hyponatremia:(Water intoxication)serum sodium level less than 120 mmol/LCNS:Moderate severe Muscle twitching Convulsions Hyperactive tendon reflexes Loss of reflexes increased intracranial pressureCardioVascular:Bp change Tissue:increased salivation Watery diarrhea Renal:Oliguria progressing to anuria Metabolic:None,22,Mechanism of Hypernatremia,Water intake deficient,Diseases of digestive tract,Excess loss water,excess perspiration,Vomite,diarrhea,suction,23,Hypernatremia:(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:Fever,24,MIXED 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 volume excess and hypernatremia:excessive quantities of sodium salts 4.ECF volume excess and hyponatremia(Water intoxication):oliguric renal failure,25,COMPOSITION CHANGESCompositional abnormalities include:concentration changes of potassium,calcium,magnesiumchanges in acid-base balance,26,PotassiumThe 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.Most of this is excreted in the urine.,27,Potassium AbnormaliliesHyperkalemiaExtracellular potassium 5.5 mmol/L.HypokalemiaExtracellular potassium 3.5 mmol/L.,28,Hyperkalemia Significant quantities of intracellular potassium are released into the extracellular space.Cause:severe injury or surgical stressAcidosis the catabolic state.oliguric or anuric renal failure,29,Hyperkalemia Signs:The 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 develop with increasing levels of potassium.,30,HyperkalemiaTreatment:intravenous administration of 1 gm.of 10%calcium gluconate under ECG monitoringadministration of bicarbonate and glucose with insulin(1/4gG)Rapid alkalinization of the ECF with either sodium lactate or bicarbonate promotes transfer of potassium into cells definitive removal of excess potassium by cation-exchange resins,peritoneal dialysis,or hemodialysis.,31,HypokalemiaA more common problem in the surgical patient may occur as a result of:excessive renal excretion(1g/500ml)movement of potassium into cellsprolonged administration of potassium-free parenteral fluids with continued obligatory renal loss of potassium parenteral nutrition with inadequate potassium replacement,loss of gastrointestinal secretions.,32,Hypokalemia The signs of potassium deficit:failure of normal contractility of skeletal,smooth,and cardiac muscle weakness to flaccid paralysis,diminished to absent tendon reflexes,and paralytic ileus.Sensitivity to digitalis with cardiac arrhythmias and ECG signs of low voltage,flattening of T waves,and depression of S-T segments,33,Normal Hypokalemia Hyperkalemia,34,Hypokalemia Treatment of hypokalemia involves:First prevention of these state.Intravenous administration of potassium No more than 40 mmol should be added to 1 liter of intravenous fluidThe rate of administration should not exceed 20 mmol/hour unless the ECG is being monitored.Administration of potassium is about 3-6 g/day1 gram of KCl=13.4mmol of potassium,35,Composition 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 35,36,Calcium AbnormalitiesMost 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 2.75 mmol/LThe 45%is the ionized portion that is responsible for neuromuscular stability.,37,Hypocalcemia The common causes:Acute pancreatitisMassive soft tissue infectionsAcute and chronic renal failure Pancreatic and small intestinal fistulas Hypoparathyroidism,38,Hypocalcemia The symptoms(serum 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),Chvosteks sign and Trousseausign positive,39,Hypocalcemia Treatment:correction of the underlying cause with concomitant repletion of the deficit.Intravenous administration of calcium gluconate or calcium chloride Calcium lactate may be given orally,With or without supplemental vitamin D,in a patient requiring prolonged replacement.,40,Hypercalcemia The two major causes:Hyperparathyroidism Cancer with bony metastasis.The latter is most frequently seen in a patient with metastatic breast cancer.,41,Hypercalcemia The manifestations of hypercalcemia include:Easy fatigue,lassitude,weakness of varying degree,Anorexia,nausea,vomiting,and weight loss.Lassitude,stupor,and finally coma.Severe headaches,pains in the back and extremities,thirst.,42,Hypercalcemia 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 intravenous inorganic phosphates Intravenous sodium sulfate also lowers serum calcium,43,Magnesium AbnormalitiesThe 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 ranges between 0.71.1mmol/L.The normal dietary intake of magnesium is approximately 20 mmol.(240 mg.)daily.The larger part is excreted in the feces and the remainder in the urine.The kidneys have a remarkable ability to conserve magnesium.,44,Magnesium DeficiencyCause:starvation,malabsorption syndromes,protracted losses of gastrointestinal fluid,prolonged parenteral fluid therapy with magnesium-free solutions.Acute pancreatitis,diabetic acidosis during treatment.primary aldosteronism,chronic alcoholism.,45,Magnesium Deficiency The signs and symptomsThe magnesium ion is essential for proper function of most enzyme systems,and depletion is characterized by neuromuscular and CNS hyperactivity,which are quite similar to those of calcium deficiency.,46,Magnesium Deficiency Treamient In asymptomatic patients:oral replacement.Severe symptomatic deficit:The intravenous route is preferable for the initial treatment.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.,47,Magnesium ExcessCause:1,Patients with impaired renal function 2,Early-stage burns3,Massive trauma or surgical stress4,Severe ECF volume deficit5,Severe acidosis.,48,Magnesium 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)resemble those seen with hyperkalemia.Somnolence leading to coma and muscular paralysis occurs in the later stages,and death is usually caused by respiratory or cardiac arrest.,49,Magnesium Excess Treatment Correcting any acidosis,Replenishing any preexisting ECF volume deficitStop exogenously administered magnesium.Acute symptoms may be controlled by slow intravenous administration of 2.5 to 5 mmol.of calcium gluconate.(about 10%calcium gluconate 1020ml)If elevated levels or symptoms persist,peritoneal dialysis or hemodialysis is indicated.,50,Phosphonium Abnormalities,About 85%of phosphonium exite in boneNormal serum phosphonium level:0.961.62mmol/LParticipate phosphorate of protein,cell membrain and acid-base balance,51,Hypophosphatemia,Cause:Hyperparathyroidism,severe burn or infectionSyptom:manifestation in nervous-muscle.Treatment:administration of sodium glycerophosphate 10 ml,52,Hyperphosphatemia,Cause:acute renal failure,Hypoparathyroidism,acidosisSyptom:like hypocalcemia,ectopic calcificationTreatment:treatment of hypocalcemia,dialysis,53,Acid-base Balance,Acid base:source and regulation,Source,Acidvolatile（H2CO3）fixed acid,Resp.regul.,Renal regul,54,Alkalisaltamonia,Acid-base Balance,Source,55,Asid and Alkali in body,volatile acid:carbonic acid（H2CO3）fixed acid：H2SO4、H2PO4、ketobodies,Acid:,Alkali：HCO3-、Hb-、Na2HPO4、NH3,56,Acid-base Balance,Intracellular PH:proteins and phosphates,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.,57,Acid base:source and regulation,Blood buffer:,pH,React quick,58,Regulation by lung and kidney,59,Excrete H+and reuptake NaHCO3,Proximal nephron,60,Acid-base Balance,1、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=40mmHg,HbO2=100%，T=37.0 Normal AB=S B=2227mmol/L,average 24mmol/L,61,pH,Conception：Negative logarithm of H+concentration in solutionNormal value：Artery blood 7.357.45Meaning：To distinguish acidosis or alkalosis,7.35 7.45,Acidosis,6.8,Alkalosis,7.8,death,death,pH,16 nmol/L,40,160,【H+】,62,Hendeison-Hasselbalch equationpH=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 respiration,63,Six-Step to the Interpretation of Arterial Blood Gas With Serum Sodium,Potassium,and Chloride Concentrations,64,Simple type,Metab.alkalosis,Metab.acidosis,Resp.acidosis,Resp.alkalosis,The four types of acid-base disturbances,65,The four types of acid-base disturbances Acute Chronic pH PCO2 HCO3 pH PCO2 HCO3 Resp acid N Resp alka N Meta acid N Meta alka N?,66,Acidosis 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 gastric suction Gain of base bicarbonate Excessive intake of Potassium depletion bicarbonate,67,Respiratory 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.Cause:Airway obstruction:Foreign body,pneumonia,emphysema.CNS:Depression,injury,tumor.Thoracic injury:Pneumothorax,flail chest,tracheal.Mechanical ventilation:Inadequate rate and/or tidal volume.,68,Mecanism of ventilation dysfunction,Inhibit Resp.centerResp.m.paralysisThorac lung disea.Airway obstructionMal-ventilation,69,co2,o2,co2,co2,O2+Hb HbO2,o2,o2,o2,co2,co2,Hb,+,HbcO,External respiration,Internal respiration,Airway,Pulm。alveolus,blood vessel,Cell,Respiration course,70,Respiratory Acidosis Signs：chest stuffy，dyspnea，restless，cyanosis and headache caused by hypoxia，Delirium even comaExamination laboratory revealed a decreased pH,increased PaCO2,HCO3 may remain normal.,71,Respiratory AcidosisTreatment:Treatment primary disorder.Ameliorate the patients ventilationVentilator may be used,72,Respiratory Alkalosiscauses:Hyperventilationapprehension,pain,hypoxia,CNS injury,assisted ventilationTreatment is directed primarily towa