【正文】 , intermittent intestinal colic, and diarrhea. The cardiovascular signs are apparent on the ECG initially, with high peaked T waves, widened QRS plex, and depressed ST segments. Disappearance of T waves, heart block, and diastolic cardiac arrest may develop with increasing levels of potassium. 30 Hyperkalemia Treatment: 1. intravenous administration of 1 gm. of 10% calcium gluconate under ECG monitoring 2. administration of bicarbonate and glucose with insulin (1181。 increase23％～ 25％ in pregnancy women。 Little protein and sugar， positive in urine pathology。1 FLUID AND ELECTROLYTE MANAGEMENT 中山二院心胸外科 熊利華 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 Drink1000～ 1300 Food 700 ～ 900 Metabolic water300 Urine 800～ 1500 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 Nitrogencontaining material： urea、uric acid、 creatine、 creatinine、 amino acid and amonia。 Organic pound： hippuric acid、glucuronate、 lactic acid、 ethanedioic. Electrolyte： Cl、 Na 、 K and phosphate。 7 Three functional partments 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 8％ of body weight， About 5000 ml for an adult。 About 80％ of total volume in circulation Other 20% stored in liver and spleen 9 154mEq/l 154mEq/l 153mEq/l 153mEq/l 200 mEq/l 200 mEq/l Cation Anions Na+ 142 Cl 103 HCO3 27 SO4= PO4≡ 3 K+ 4 Ca++ 5 Mg++ 3 Protein 16 Organic acid 5 Cation Anions Na+ 144 Cl 114 HCO3 30 SO4= PO4≡ 3 K+ 4 Ca++ 3 Mg++ 2 Protein 1 Organic acid 5 Cation Anions K+ 150 HPO4= SO4= 150 HCO3 10 Na+ 10 Mg++ 40 Protein 40 Plasma Intestitial fluid Intracellular fluid Chemical position of body fluid partment: 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 position between ICF and ECF. ?The cell membranes are pletely 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 partments. 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 partments 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 ?position 16 Volume Deficit The most mon disorders leading to an ECF volume deficit include: 1. losses of gastrointestinal fluids due to vomiting, nasogastric suction, diarrhea, fistula drainage. 2. sequestration of fluid in soft tissue injuries and infections, intraabdominal 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。/ 4gG) 3. Rapid alkalinization of the ECF with either sodium lactate or bicarbonate promotes transfer of potassium into cells 4. definitive removal of excess potassium by cationexchange resins, peritoneal dialysis, or hemodialysis. 31 Hypokalemia A more mon problem in the surgical patient may occur as a result of: 1. excessive renal excretion (1g/500ml) 2. movement of potassium into cells 3. prolonged administration of potassiumfree