FLUIDANDELECTROLYTEMANAGEMENT水电解质平衡.ppt

1,FLUID AND ELECTROLYTE MANAGEMENT,中山二院心胸外科 熊利华,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,4,Water Exchange,Drink10001300 Food 700 900 Metabolic water300,Urine 8001500 Lung 350 Skin 500 Stool 250,2500,2500,5,Water Exchange A patient deprived of all external access to water must still excrete a minimum of 500 to 800 ml. of urine per day in order to excrete the products of catabolism, Insensible loss of water occurs through the skin (75%) and the lungs (25%) and is increased by hypermetabolism, hyperventilation, and fever.,6,Composition of Urine,Water Nitrogen-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 circulation Other 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 pressure The 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 CHANGES The disorders in fluid balance ： volume deficit or Excess concentration composition,16,Volume Deficit The 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 CHANGES ECF: 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/L CNS: Moderate severe Muscle twitching Convulsions Hyperactive tendon reflexes Loss of reflexes increased intracranial pressure CardioVascular: 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/L CNS: Moderate severe Restlessness Delirium Weakness Maniacal behavior CardioVascular: Tachycardia, Hypotension Tissue: Decreased saliva and tears Dry and sticky mucous membranes Renal: Oliguria Metabolic: Fever,24,MIXED VOLUME AND CONCENTRATION ABNORMALITIES Consequence 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 CHANGES Compositional abnormalities include: concentration changes of potassium, calcium, magnesium changes in acid-base balance,26,Potassium The 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 Abnormalilies Hyperkalemia Extracellular potassium 5.5 mmol/L. Hypokalemia Extracellular potassium 3.5 mmol/L.,28,Hyperkalemia Significant quantities of intracellular potassium are released into the extracellular space. Cause: severe injury or surgical stress Acidosis 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,Hyperkalemia Treatment: 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 potassium into cells definitive removal of excess potassium by cation-exchange resins, peritoneal dialysis, or hemodialysis.,31,Hypokalemia A more common problem in the surgical patient may occur as a result of: excessive renal excretion (1g/500ml) movement of potassium into cells prolonged 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 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 /day 1 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/L Salivary 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 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 2.75 mmol/L The 45% is the ionized portion that is responsible for neuromuscular stability.,37,Hypocalcemia The common causes: Acute pancreatitis Massive soft tissue infections Acute 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 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 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 Deficiency Cause: 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 symptoms The 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 Excess Cause: 1, Patients with impaired renal function 2, Early-stage burns 3, Massive trauma or surgical stress 4, Severe ECF volume deficit 5, 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 deficit Stop 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 bone Normal serum phosphonium level:0.961.62mmol/L Participate phosphorate of protein, cell membrain and acid-base balance,51,Hypophosphatemia,Cause: Hyperparathyroidism, severe burn or infection Syptom: manifestation in nervous-muscle. Treatment: administration of sodium glycerophosphate 10 ml,52,Hyperphosphatemia,Cause: acute renal failure, Hypoparathyroidism, acidosis Syptom: like hypocalcemia, ectopic calcification Treatment: treatment of hypocalcemia, dialysis,53,Acid-base Balance,Acid base: source and regulation,Source,Acid volatile （H2CO3） fixed acid,Resp. regul.,Renal regul,54,Alkali salt amonia,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: 7.357.45 2、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 plasma 5、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 solution Normal value：Artery blood 7.357.45 Meaning：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 equation pH = pK + log BHCO3/H2CO3 = 6.1+log HCO3 /0.03 PaCO2 = 6.1 + log 24 /0.03 40 = 6.1+log20/1 = 7.4 PK represents the dissociation constant of carbonic acid in the presence of base bicarbonate HCO3 represent the factor of metabolism PaCO2 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 respiratory Resp alka Excessive loss of CO2 Hyperventilation Meta acid Retention of fixed acids Diabetes, diarrhea Loss of base bicarbonate Lactic acid accumulation Meta 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.center Resp. m.paralysis Thorac lung disea. Airway obstruction Mal-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 coma Examination laboratory revealed a decreased pH, increased PaCO2, HCO3 may remain normal.,71,Respiratory Acidosis Treatment: Treatment primary disorder. Ameliorate the patients ventilation Ventilator may be used,72,Respiratory Alkalosis causes : Hyperventilation apprehension, pain, hypoxia, CNS injury, assisted ventilation Treatment is directed primarily toward the cause of the disorder.,73,Metabolic acidosis Cause: acute circulatory failure with accumulation of lactic acid, renal failure retention or production of acids (diabetic ketoacidosis, lactic acidosis) loss of bicarbonate (diarrhea, pancreatic or small bowel fistula).,74,Metabolic acidosis The causes of metabolic acidosis can be divided into two groups by determining the anion gap: Normal anion gap and elevated anion gap. The normal value is 10 to 15 mmol/L. The unmeasured anions that account for the gap are sulfate and phosphate plus lactate and other organic anions.,75,153 mmol/L 153 mmol/L cations anions Na+ 142 Cl- 104 HCO3- 27 PO4 3 SO4 Organic acid 5 K+ 4 Ca+ 5 Protein 14 Mg+ 2 The anion gap,76,AG (anion gap),Na+,HCO3 ,AG,Normal value,12 mmol/L,Meaning,AGFix acid Metab.Acid.,AG=UAUC,AG=Na+ (HCO3-+Cl-),77,. (metabolic acidosis),Simple,Feature:,AG Normal,AG,AG,Normal,78,Metabolic acidosis Signs： In mild patient: maybe asymptomatic In severe patient: lassitude, weakness, restlessness, deep and quick rate of respiration Increased heart rate, decreased blood preasure, cardiac arrhythmias Loss of reflexes, coma Decreased pH, HCO3,79,Influence :,Simple,Cardiovascular system:,Arrhythmia,Cardiac contract.,pH7.2,80,compensation,Simple,Blood,Lung,Cell,Kidney,81,Metabolic acidosis Treatment: Treatment primary disorder. Replenishing any preexisting ECF volume deficit Infusion with 5% NaHCO3 100250ml Intravenous administration of calcium gluconate or calcium chloride,82,Metabolic Alkalosis Causes are loss of fixed acids or gain of bicarbonate and is aggravated by any existing potassium deficit. Both the pH and the plasma bicarbonate concentration are elevated. Compensation occurs primarily through renal mechanisms.,83,Influence of Met. Alkolosis,1 CNS：Excitation Mechanism：（1）GABA （2）brain tissue hypoxia 2.Nerve-Muscle: Excitability Ca+ 3. K + : Hypokalemia 4. Tissue hypoxia,84,Stomach,duodenum,Blood vessel,H2CO3,HCO3-,H+,HCO3-,H+,H+,H2CO3,H+,HCO3-,Cl -,Na+,Na+,Cl -,Cl -,gastric fluid loss and metab.Alk.,Pancreas,HCO3-,Na+,esophagus,85,(1) H+Loss,Stomach,Vomit,H+,H+,H+,H+,H +,H+,Simple,86,(1) H+ ,Stomach,Vomit,H+,H+,H+,H+,H+,H+,Simple,Enteric cavity H+,Pancreatic secretion HCO3,Metablic alkolosis,87,Metabolic Alkalosis Treatment: Treatment primary disorder. Replenishing any preexisting ECF volume deficit Intravenous administration of KCl Intravenous administration of 0.1mmol/L (1 mol/L chloride acid 150 ml+saline 1000ml，2550ml/h）,88,Salt Gain and Losses In a normal individual the daily salt intake varies between 50 and 90 mmol. (3 to 5 gm.) as sodium chloride. Balance is maintained primarily by the kidneys, which excrete the excess salt.,89,Salt Gain and Losses Sodium ExchangeAverage Sodium Gain Diet 50-90 mmol/day Sodium loss Skin (sweat) 10-60 mmol/day Urine 10-80 mmol/day Intestine 0-20 mmol/day,90,FLUID AND ELECTROLYTE THERAPY lactated Ringers solution: A good available isotonic salt solution for replacing gastrointestinal losses and ECF volume deficits. This solution is physiologic and contains 130 mmol. of sodium balanced by 109 mmol. of chloride and 28 mmol. of lactate. Lactate is used instead of bicarbonate, The lactate is readily converted to bicarbonate by the liver after infusion.,91,PREOPERATIVE FLUID THERAPY Preoperative evaluation and correction of existing fluid disorders Correction of Volume Changes :Volume deficit Correction of Concentration Changes : severe symptomatic hyponatremia or hypernatremia Composition and Miscellaneous Considerations :Cor