Fluids & Electrolyte

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  • Sequence An action potential arrives at the presynpatic terminal causing Ca2+ channels to open, increasing the Ca2+ permeability of the presynpatic terminal. Calcium ions enter the presynpatic terminal and initiate the release of a neruotransmitter, acetylcholine (Ach), from synaptic vesicle into the presynaptic cleft. Diffusion of Ach across the synaptic cleft and binding of Ach to its receptors on the postsynaptic muscle fiber membrane opens Na+ channels and increases the permeability of the postsynaptic membrane to Na+ The increase in Na+ permeability results in depolarization of the postsynaptic membrane; once threshold has been reached a postsynaptic action potential results.
  • Fluids & Electrolyte

    1. 1. Water, Electrolyte, and Acid-Base Balance 1
    2. 2. • Help maintain body temperature and cell shape• Help transport nutrients, gasses and wastes 2
    3. 3. Fluid• Is used to indicate that other substances are also found in these compartments and that they influence the water balance in and between compartments. 3
    4. 4. Fluids• 60% of an adult’s body weight * 70 Kg adult male: 60% X 70= 42 Liters• Infants = more water• Elderly = less water• More fat = ↓water• More muscle = ↑water• Infants and elderly - prone to fluid imbalance 4
    5. 5. FLUID BALANCETOTAL BODY WATER (AS PERCENTAGE OF BODY WEIGHT) IN RELATION TO AGE AND SEX AGE MALE FEMALE UNDER 18 65% 55% 18-40 60% 50% 40-60 50-60% 40-50% OVER 60 50% 40% 5
    6. 6. 60 %Intracellular Fluid 40% or 2/3 Extracellular Fluid 20% or 1/3Arterial Fluid 2% Intravascular Interstitial 5% or 1/4 15% or 3/4 Venous Fluid 3% Transcellular fluid 1-2% ie csf, pericardial, synovial, intraocular, sweat 6
    7. 7. Function of Water: Most of cellular activities are performed inwater solutions. 7
    8. 8. Intracellular Fluid Compartment• Includes all the water and electrolytes inside the cells of the body.• Contains high concentrations of: – potassium, – phosphate, – magnesium and – sulfate ions, – along with most of the proteins in the body. 8
    9. 9. 9
    10. 10. Extracellular Fluid Compartment• Includes all the fluid outside the cells: – interstitial fluid, plasma, lymph, secretions of glands, fluid within subcompartments separated by epithelial membranes.• Contains high concentrations of : – sodium, – chloride and – bicarbonate.• One-third of the ECF is in plasma. 10
    11. 11. Extracellular Fluid Osmolality• Osmolality – Adding or • Decreased removing water osmolality from a solution changes this – Inhibits thirst and ADH secretion• Increased osmolality – Triggers thirst and ADH secretion 11
    12. 12. Transcellular Exchange Mechanisms:• ACTIVE TRANSPORT• PASSIVE TRANSPORT – Diffusion – Osmosis – Filtration – Facilitated diffusion 12
    13. 13. Movement of Water Between Body Fluid Compartments:• HYDROSTATIC PRESSURE- pressure in the blood vessels resulting from the weight of the water and cardiac contraction• OSMOTIC PRESSURE- pressure exerted by proteins in plasma which pulls water into the circulatory system 13
    14. 14. 4% TBW 40% TBWBody Fluid- makes up~60% of totalbody weight(TBW) - distributed inthree fluidcompartments. 14 16% TBW
    15. 15. 4% TBW 40% TBWFluid is continuallyexchanged betweenthe threecompartments. 15 16% TBW
    16. 16. 4% TBW 40% TBWExchange betweenBlood & Tissue Fluid- determined byfour factors: capillary blood pressure plasma colloid osmotic pressure interstitium Hydrostatic Pressure Interstitium colloid osmotic pressure 16 16% TBW
    17. 17. 4% TBW 40% TBWExchange betweenBlood & Tissue Fluid - not affected by electrolyte concentrations - Edema = water accumulation in tissue fluid 17 16% TBW
    18. 18. Exchange between 4% TBW 40% TBW Tissue Fluid & Intracellular Fluid- determined by two:1) intracellular osmoticpressure electrolytes2) interstitial osmoticpressure electrolytes 18 16% TBW
    19. 19. Water Gain Water is gained fromthree sources.1) food (~700 ml/day)2) drink – voluntarilycontrolled3) metabolic water (200ml/day) --- produced as abyproduct of aerobicrespiration 19
    20. 20. Routes of water loss1) Urine – obligatory (unavoidable) andphysiologically regulated, minimum 400ml/day2) Feces -- obligatory water loss, ~200 ml/day3) Breath – obligatory water loss, ~300ml/day4) Cutaneous evaporation -- obligatorywater loss, ~400 ml/day5) Sweat – for releasing heat, variessignificantly 20
    21. 21. Regulation of Water Intake - governed by thirst. ↓blood volume and ↑osmolarity ⇓ peripheral volume sensors central osmoreceptors ⇓ hypothalamus ⇓ thirst felt 21
    22. 22. Regulation of Urine Concentration and Volume• Volume and composition depends on the condition of the body.• blood concentration = kidney produce urine. – To eliminate solutes and conserve water – help to lower blood concentration• Blood concentration = kidney produce urine – Water is lost, solutes are conserved, blood concentration increases. 22
    23. 23. Regulation of Water Output - The only physiologicalcontrol is through variations inurine volume. - urine volume regulated byhormones 23
    24. 24. Water Content Regulation• Content regulated so • Sources of water total volume of water in – Ingestion body remains constant – Cellular metabolism• Kidneys primary • Routes of water loss regulator of water – Urine excretion – Evaporation • Perspiration• Regulation processes • Respiratory passages – Osmosis – Feces – Osmolality – Baroreceptors 24 – Learned behavior
    25. 25. HORMONAL MECHANISMS Helps to regulate blood composition and blood volume. 25
    26. 26. 1. ANTIDIURETIC HORMONE (ADH)• Secreted by posterior pituitary gland into circulation to the kidney• Function: – to regulate the amount of water reabsorbed BLOOD – RETAINS WATER VOL BLOOD PRESSURE CONC. URINE 26
    27. 27. 1. ANTIDIURETIC HORMONE (ADH)• ADH – permeability to water of the kidney = more water is reabsorbed = CONCENTRATED URINE• ADH – Kidney is less permeable to water = DILUTED URINE 27
    28. 28. 1) ADH dehydration ⇓ ↓blood volume and/or ↑osmolality ⇓ hypothalamic receptors / peripheral volume sensors ⇓ posterior pituitary to release ADH ⇓ ↑ H2O reabsorption ⇓ Water retention 28
    29. 29. 2. ATRIAL NATRIURETIC FACTOR• Secreted by the cells in the RIGHT ATRIUM when the BP in the RA is• Function: – Reduces the ability of the kidney to concentrate urine PRODUCTION OF LARGE VOLUME OF URINE BLOOD VOLUME CAUSES BP 29
    30. 30. 2) Atrial Natriuretic Factor ↑ blood volume =↑ BP ⇓ atrial volume sensors ⇓ atria to release ANF ⇓ inhibits Na+ and H2O reabsorption ⇓ ↑ water output = ↓ BP 30
    31. 31. 3. ALDOSTERONE• Secreted by ADRENAL GLAND• Function: – regulates the rate of active transport in the kidney – REABSORPTION OF NaCl 31
    32. 32. 3. ALDOSTERONE• ABSENCE of aldosterone = Na+ and Cl- remain in nephron = part of the urine 32
    33. 33. 4. RENIN AND ANGIOTENSIN• FUNCTION: regulate aldosterone secretion• RENIN secreted by the cells in the juxtaglomerular apparatus in the kidney. – An enzyme that acts on proteins produce by liver 33
    34. 34. RENIN AND ANGIOTENSIN– Liver: In the protein, certain amino acids are removed leaving ANGIOTENSIN I.– ANGIOTENSIN I is rapidly converted into smaller peptide called ANGIOTENSIN II.– ANGIOTENSIN II acts on the adrenal gland causing it to secrete ALDOSTERONE!!! 34
    35. 35. – BP– Na+ RENIN production– K+– BP = RENIN IS RELEASED Na+ reabsorbed by nephron H2O is reabsorbedCONSERVE WATER = PREVENT IN BP 35
    36. 36. Dehydration- decrease in body fluid- Causes 2) the lack of drinking water 2) excessive loss of body fluid due to: overheat diabetes overuse of diuretics diarrhea 36
    37. 37. Edema- the accumulation of fluid in the interstitial spacescaused by: 1) increased capillary filtration, or 2) reduced capillary reabsorption, or 3) obstructed lymphatic drainage 37
    38. 38. ELECTROLYTE BALANCEHORMONE REGULATION:Insulin and Epinephrine = cause K+ and phosphate to move fromextracellular fluid into cellsParathyroid hormone = cause Ca++ and phosphate to move from bone toextracellular fluidCalcitonin = moves calcium to bones 38
    39. 39. Electrolytes = small ions that carry charges 39
    40. 40. 40
    41. 41. Distribution of Electrolytes Na+ Ca ++ K+ Cell PO4--- Cl-Extracellularspace 41
    42. 42. Ions• Factors which influence the concentration of water and solutes inside the cells: – Transport mechanisms – Permeability of the cell membrane – Concentration of water and solutes in the extracellular fluid 42
    43. 43. Ions NORMAL VALUES AND MASS CONVERSION FACTORS Normal Plasma Values Mass ConversionSodium (Na+) 135 – 145 meq/L 23 mg = 1 meqPotassium (K+) 3.5 – 5.0 meq/L 39 mg = 1 meqChloride (Cl-) 98 – 107 meq/L 35 mg = 1 meqBicarbonate (HCO3-) 22 – 26 meq/L 61 mg = 1 meqCalcium (Ca2+) 8.5 – 10.5 mg/dL 40 mg = 1 mmolPhosphorus 2.5 – 4.5 mg/dL 31 mg = 1 mmolMagnesium (Mg2+) 1.8 – 3.0 mg/dL 24 mg = 1 mmolOsmolality 285 – 295 mosm/kg - 43
    44. 44. Sodium• Dominant extracellular ion.• About 90 to 95% of the osmotic pressure of the extracellular fluid results from sodium ions and the negative ions associated with them.• Recommended dietary intake is less than 2.5 grams per day.• Kidneys provide the major route by which the excess sodium ions are excreted. 44
    45. 45. SODIUM (Na)• MOST ABUNDANT cation in the ECF• 135-145 mEq/L• Aldosterone increases sodium reabsorption• ANP increases sodium excretion• Cl accompanies NaFUNCTIONS:1. assists in nerve transmission and muscle contraction2. Major determinant of ECF osmolality3. Primary regulator of ECF volume 45
    46. 46. Sodium• Primary mechanisms that regulate the sodium ion concentration in the extracellular fluid: – Changes in the blood pressure – Changes in the osmolality of the extracellular fluid 46
    47. 47. Regulation of plasma Na+4) Aldosterone ↓plasma Na+ Na+ ⇓ ↑ aldosterone ⇓↓renal Na + excretion plasma ⇓ ↑ plasma Na + 47
    48. 48. 1) Renin-angiotensin-II renin ⇓ angiotensin-II ⇓ Na+ ↑ aldosterone ⇓ ↓ renal Na+ excretion ⇓ plasma ↑ plasma Na+ 48
    49. 49. 3) ADH increases water reabsorption in kidneys ⇓ H2O water retention ⇓ dilute plasma Na+ Na+ plasma 49
    50. 50. 1) Atrial Natriuretic Factorinhibits renal reabsorption of Na+ and H2O and the excretion of renin Na+ and ADH ⇓ eliminate more sodium and water plasma ⇓ Na+ ↓ plasma Na + 50
    51. 51. Sodium imbalance hypernatremia plasma sodium > 145 mEq/L, hyponatremia plasma sodium < 130 mEq/L 51
    52. 52. 52
    53. 53. HYPERNATREMIA• Na > 145 mEq/L• Assoc w/ water loss or sodium gain• Etiology: – inadequate water intake, – excessive salt ingestion /hypertonic feedings w/o water supplements, – near drowning in sea water, – diuretics 53
    54. 54. HYPERNATREMIAS/SX:• Polyuria Dx:• Anorexia • inc serum sodium and Cl• Nausea/vomiting, level,• Thirst• Dry and swollen tongue • inc serum osmolality,• Fever • inc urine sp.gravity,• Dry and flushed skin • inc urine osmolality• Altered LOC• Seizure• Muscle weakness• Crackles• Dyspnea• Cardiac manifestations dependent on type of hypernatremia 54
    55. 55. • Mgt: – sodium restriction, – water restriction, – diuretics, – isotonic non saline soln. (D5W) or hypotonic soln, – Desmopressin Acetate for Diabetes InsipidusNsg considerations• History – diet, medication• Monitor VS, LOC, I and O, weight, lung sounds• Monitor Na levels• Oral care• Initiate gastric feedings slowly• Seizure precaution 55
    56. 56. HYPONATREMIA• Na < 135 mEq/L• Etiology: – diuretics, – excessive sweating, – vomiting, – diarrhea, – SIADH, – aldosterone deficiency, – cardiac, renal, liver disease 56
    57. 57. HYPONATREMIAs/sx: • Dx:• headache,• apprehension, – dec serum and urine• restlessness, sodium and osmolality,• altered LOC, – dec Cl• seizures(<115meq/l),• coma,• poor skin turgor,• dry mucosa,• orthostatic• hypotension,• crackles,• nausea/vomiting,• abdominal cramping 57
    58. 58. • Mgt: – sodium replacement, – water restriction, – isotonic soln for moderate hyponatremia, – hypertonic saline soln for neurologic manifestations, – diuretic for SIADHNsg. Consideration Monitor I and O, LOC, VS, serum Na Seizure precaution diet 58
    59. 59. HyponatremiaHypernatremia 59
    60. 60. Potassium (K)• MOST ABUNDANT cation in the ICF• 3.5-5.5 mEq/L• Major electrolyte maintaining ICF balance• maintains ICF Osmolality• Aldosterone promotes renal excretion of K+• Mg accompanies KFUNCTIONS:1. nerve conduction and muscle contraction2. metabolism of carbohydrates, fats and proteins3. Fosters acid-base balance 60
    61. 61. 61
    62. 62. Potassium• Electrically excitable tissue such as muscle and nerves are highly sensitive to slight changes in extracellular potassium concentration.• concentration of potassium must be maintained within a narrow range for tissues to function normally. 62
    63. 63. PotassiumCONDITIONS THAT MAKE K+ BECOME MORE CONC – Circulatory system shock resulting from plasma loss – dehydration – tissue damage• In response, aldosterone secretion increases and causes potassium secretion to increase. 63
    64. 64. Regulation of Potassium- by aldosterone Aldosterone K+ ⇓ stimulates K+ secretion by the kidneys ⇓ ↓ Plasma K+ plasma K+ 64
    65. 65. Potassium Imbalance hyperkalemia (> 5.5 mEq/L) hypokalemia (< 3.5 mEq/L) 65
    66. 66. Abnormal Concentration of Potassium Ions 66
    67. 67. HYPERKALEMIA 67
    68. 68. a. HYPERKALEMIA• K+ > 5.0 mEq/L • Dx:• Etiology: – inc serum K level – IVF with K+, – acidosis, – ECG: peaked T waves and – hyper-alimentation wide QRS – excess K+ replacement, – ABGs – metabolic acidosis – decreased renal excretion, – Diuretics• s/sx: – nerve and muscle irritability – Tachycardia – Diarrhea – ECG changes – ventricular dysrythmia and – cardiac arrest – skeletal muscle weakness, 68 paralysis
    69. 69. Mgmt: K restriction (coffee, cocoa, tea, dried fruits, beans, whole grain breads, milk, eggs) diuretics Polystyrene Sulfonate (Kayexalate) IV insulin Beta 2 agonist IV Calcium gluconate IV NaHCo3 – alkalinize plasma DialysisNsg consideration: Monitor VS, urine output, lung sounds, Crea, BUN monitor K levels and ECG observe for muscle weakness and dysrythmia, paresthesia and GI symptoms 69
    70. 70. Abnormal Concentration of Potassium Ions 70
    71. 71. HYPOKALEMIA 71
    72. 72. b. HYPOKALEMIA • s/sx:• K+ < 3.5 mEq/L – anorexia, – Nausea/vomiting,• Etiology: – decreased bowel motility, – use of diuretic, – fatigue, – corticosteroids and penicillin, – muscle weakness, – vomiting and diarrhea, – leg cramps, – ileostomy, – paresthesias, – villous adenoma, – shallow respiration, – alkalosis, – SOB – hyperinsulinism, – dysrhythmias and increased sensitivity – to digitalis, hyperaldosteronism – hypotension, – weak pulse, – dilute urine, – glucose intolerance 72
    73. 73. • Dx: – dec serum K level – ECG - flattened , depressed T waves, presence of “U” waves – ABGs - metabolic alkalosis• Medical Mgmt: – diet ( fruits, fruit juices, vegetables, fish, whole grains, nuts, milk, meats) – oral or IV replacement• Nsg mgmt: – monitor cardiac function, pulses, renal function – monitor serum potassium concentration – IV K diluted in saline – monitor IV sites for phlebitis 73
    74. 74. Normal ECG Hypokalemia Hyperkalemia 74
    75. 75. CALCIUM (Ca) Majority of calcium - bones and teeth Normal serum range 8.5-10.5 mg/dL Ca++ has an inverse relationship with PO4FUNCTIONS1. formation and mineralization of bones/teeth2. muscular contraction and relaxation3. cardiac function4. blood coagulation5. Promotes absorption and utilization of Vit B12 75
    76. 76. Functions of Ca++ - lends strength to the skeleton - activates muscle contraction ++ Excitation [ Ca ]i Contraction(Action Potentials) (shortening) 76
    77. 77. Functions of Ca++ - lends strength to the skeleton - activates muscle contraction - serves as a second messenger for some hormones and neurotransmitters 77
    78. 78. Functions of Ca++ - lends strength to the skeleton - activates muscle contraction - serves as a second messenger for some hormones and neurotransmitters - activates exocytosis of neurotransmitters and other cellular secretions 78
    79. 79. Muscle Contraction 79
    80. 80. Functions of Ca++ - lends strength to the skeleton - activates muscle contraction - serves as a second messenger for some Ca++ hormones and neurotransmitters - activates exocytosis of neurotransmitters and other cellular secretions - essential factor in blood clotting. 80
    81. 81. Functions of Ca++ - lends strength to the skeleton - activates muscle contraction - serves as a second messenger for some hormones and neurotransmitters - activates exocytosis of neurotransmitters and other cellular secretions - essential factor in blood clotting. - activates many cellular enzymes 81
    82. 82. Dynamics of Calcium Ca++ Ca++Ca++ plasma Ca++ 82
    83. 83. Regulation of calcium 1) parathyroid hormone (PTH): -dissolving Ca++ in bones -Respond ↓blood Ca++ →↑ PTH production = ↑ blood Ca++ -- reducing renal excretion of Ca++PTH increases Vit.D synthesis in thekidney which Ca++increases Ca2+absorption in thesmall intestine.PTH decreasesurinary Ca2+excretion andincreases urinary Ca++phosphateexcretion. plasma 83
    84. 84. 2) calcitonin (secreted by C cells in thyroidgland): 84
    85. 85. 2) calcitonin (secreted by C cells in thyroid gland):depositing Ca++ in bonesRespond when high Ca++ in the blood Ca++ Ca++ plasma 85
    86. 86. 3) calcitrol (derivative of vitamin D):- enhancing intestinal absorption of Ca++ from food Ca++ Ca++ plasma Ca++ 86
    87. 87. Calcium imbalances hypocalcemia (< 4.5 mEq/L) hypercalcemia (> 5.8 mEq/L). 87
    88. 88. Regulation:• GIT absorbs Ca+ in the intestine with the help of Vitamin D• Kidney Ca+ is filtered in the glomerulus and reabsorbed in the tubules• PTH increases Ca+ by bone resorption, increase intestinal and renal Ca+ reabsorption and activation of Vitamin D• Calcitonin reduces bone resorption, increase Ca and Phosphorus deposition in bones and secretion in urine 88
    89. 89. a. HYPERCALCEMIA• Serum calcium > 10.5 • s/sx: – anorexia, mg/dL – Nausea/vomiting, – polyuria,• Etiology: – muscle weakness, – Overuse of calcium – fatigue, – lethargy supplements and antacids, – excessive Vitamin A and D, • Dx: – malignancy, – inc serum Ca – hyperparathyroidism, – ECG: – prolonged immobilization, • Shortened QT interval, ST segments – thiazide diuretic – inc PTH levels – xrays - osteoporosis 89
    90. 90. • Mgmt: 0.9% NaCl IV Phosphate Diuretics – Furosemide IM Calcitonin corticosteroids dietary restriction (cheese, ice cream, milk, yogurt, oatmeal, tofu)Nsg Mgmt: Assess VS, apical pulses and ECG, bowel sounds, renal function, hydration status safety precautions in unconscious patients inc mobility inc fluid intake 90 monitor cardiac rate and rhythm
    91. 91. b. HYPOCALCEMIA• Calcium < 8.5 mg/dL • s/sx:• Etiology: – Tetany, – removal of parathyroid gland – (+) Chovstek’s during thyroid surgery, – (+) Trousseaus’s, – Vit. D and Mg deficiency, – Furosemide, – seizures, – infusion of citrated blood, – depression, – inflammation of pancreas, – impaired memory, – renal failure, – confusion, – thyroid CA, – low albumin, – delirium, – alkalosis, – hallucinations, – alcohol abuse, – hypotension, – osteoporosis (total body Ca – dysrythmia deficit) 91
    92. 92. (+) Chovstek’s Trousseaus Sign 92
    93. 93. • Dx: dec Ca level ECG: prolonged QT interval• Mgmt: Calcium salts Vit D diet (milk, cheese, yogurt, green leafy vegetables)• Nsg mgmt monitor cardiac status, bleeding monitor IV sites for phlebitis seizure precautions reduce smoking 93
    94. 94. Magnesium Mg• Second to K+ in the ICF• Normal range is 1.3-2.1 mEq/LFUNCTIONS1. intracellular production and utilization of ATP2. protein and DNA synthesis3. neuromuscular irritability4, produce vasodilation of peripheral arteries 94
    95. 95. a. HYPERMAGNESEMIA• M > 2.1 mEq/L• Etiology: use of Mg antacids, K sparing diuretics, Renal failure, Mg medications, DKA, adrenocortical insufficiency• s/sx: hypotension, nausea, vomiting, flushing, lethargy, difficulty speaking, drowsiness, dec LOC, coma, muscle weakness, paralysis, depressed tendon reflexes, oliguria, ↓RR 95
    96. 96. • Mgmt: discontinue Mg supplements Loop diuretics IV Ca gluconate HemodialysisNsg mgmt: monitor VS observe DTR’s and changes in LOC seizure precautions 96
    97. 97. b. HYPOMAGNESEMIA• Mg < 1.5 mEq/l• Etiology: alcohol w/drawal, tube feedings, diarrhea, fistula, GIT suctioning, drugs ie antacid, aminoglycosides, insulin therapy, sepsis, burns, hypothermia• s/sx: hyperexcitability w/ muscle weakness, tremors, tetany, seizures, stridor, Chvostek and Trousseau’s signs, ECG changes, mood changes 97
    98. 98. • Dx: serum Mg level ECG – prolonged PR and QT interval, ST depression, Widened QRS, flat T waves low albumin level• Mgmt: diet (green leafy vegetables, nuts, legumes, whole grains, seafood, peanut butter, chocolate) IV Mg Sulfate via infusion pump• Nsg Mgmt: seizure precautions Test ability to swallow, DTR’s Monitor I and O, VS during Mg administration 98
    99. 99. The Anions• CHLORIDE• PHOSPHATES• BICARBONATES 99
    100. 100. Chloride (Cl)• The MAJOR Anion in the ECF• Normal range is 95-108 mEq/L• Inc Na reabsorption causes increased Cl reabsorptionFUNCTIONS1. major component of gastric juice aside from H+2. together with Na+, regulates plasma osmolality3. participates in the chloride shift – inverse relationship with Bicarbonate4. acts as chemical buffer 100
    101. 101. Regulation of Cl–- No direct regulation- indirectly regulated as an effect of Na+homeostasis. As sodium is retained orexcreted, Cl– passively follows. Chloride Imbalance hyperchloremia (> 105 mEq/L) hypochloremia (< 95 mEq/L). 101
    102. 102. a. HYPERCHLOREMIA• Serum Cl > 108 mEq/L• Etiology: sodium excess, loss of bicarbonate ions• s/sx: tachypnea, weakness, lethargy, deep rapid respirations, diminished cognitive ability and hypertension, dysrhytmia, coma 102
    103. 103. • Dx: inc serum Cl dec serum bicarbonateMgmt: Lactated Ringers soln IV Na Bicarbonate DiureticsNsg mgmt: monitor VS, ABGs, I and O, neurologic, cardiac and respiratory changes 103
    104. 104. b. HYPOCHLOREMIA• Cl < 96 mEq/l• Etiology: Cl deficient formula, salt restricted diets, severe vomiting and diarrhea• s/sx: hyperexcitability of muscles, tetany, hyperactive DTR’s, weakness, twitching, muscle cramps, dysrhytmias, seizures, coma 104
    105. 105. • Dx: dec serum Cl level ABG’s – metabolic alkalosisMgmt: Normal saline/half strength saline diet ( tomato juice, salty broth, canned vegetables, processed meats and fruits avoid free/bottled water)Nsg mgmt: monitor I and O, ABG’s, VS, LOC, muscle strength and movement 105
    106. 106. Phosphates (PO4)• The MAJOR Anion in the ICF• Normal range is 2.5-4.5 mg/L• Reciprocal relationship w/ Ca• PTH inc bone resorption, inc PO4 absorption from GIT, inhibit PO4 excretion from kidney• Calcitonin increases renal excretion of PO4FUNCTIONS1. component of bones2. needed to generate ATP3. components of DNA and RNA 106
    107. 107. Phosphates- needed for the synthesis of: ATP, GTP DNA, RNA phospholipids 107
    108. 108. Regulation ofPhosphate- by parathyroid hormone PTH ⇓ PO4---increases renal excretion of phosphate ⇓ decrease plasma phosphate plasma PO4--- - no real phosphate imbalances 108
    109. 109. a. HYPERPHOSPHATEMIA• Serum PO4 > 4.5 mg/dL• Etiology: excess vit D, renal failure, tissue trauma, chemotherapy, PO4 containing medications, hypoparathyroidism• s/sx: tetany, tachycardia, palpitations, anorexia, vomiting, muscle weakness, hyperreflexia, tachycardia, soft tissue calcification 109
    110. 110. • Dx: inc serum phosphorus level dec Ca level xray – skeletal changesMgmt: diet – limit milk, ice cream, cheese, meat, fish, carbonated beverages, nuts, dried food, sardines DialysisNsg mgmt: dietary restrictions monitor signs of impending hypocalcemia and changes in urine output 110
    111. 111. b. HYPOPHOSPHATEMIA• Serum PO4 < 2.5 mg/dl• Etiology: administration of calories in severe CHON- Calorie malnutrition (iatrogenic), chronic alcoholism, prolonged hyperventilation, poor dietary intake, DKA, thermal burns, respiratory alkalosis, antacids w/c bind with PO4, Vit D deficiency• s/sx: irritability, fatigue, apprehension, weakness, hyperglycemia, numbness, paresthesias, confusion, seizure, coma 111
    112. 112. • Dx: dec serum PO4 levelMgmt: oral or IV Phosphorus correction diet (milk, organ meat, nuts, fish, poultry, whole grains)Nsg mgmt: introduce TPN solution gradually prevent infection 112
    113. 113. ACID-BASE BALANCE 113
    114. 114. Acid An acid is any chemical thatreleases H+ in solution.Base A base is any chemical that accepts H+. 114
    115. 115. pH is the negative logarithm of H+concentration, and an indicator of acidity. pH = - log [H+ ] Example: [H+ ] = 0.1 µM = 10 –7 M 115
    116. 116. Normal functions of proteins (especiallyenzymes) heavily depend on an optimal pH. pH7.35-pH7.45 116
    117. 117. Regulation of acid-base balance 1) Chemical Buffers 2) Respiratory Control of pH 3) Renal Control of pH 117
    118. 118. Buffer•is any mechanism that resists changes in pH.•substance that can accept or donate hydrogen•prevent excessive changes in pH 118
    119. 119. Dynamics of Acid Base Balance• Acids and bases are constantly produced in the body• They must be constantly regulated• CO2 and HCO3 are crucial in the balance• Respiratory and renal system are active in regulation 119
    120. 120. Kidney- Regulate bicarbonate level in ECF1. RESPIRATORY/METABOLIC ACIDOSIS - kidney excrete H and reabsorbs/generates Bicarbonate2. RESPIRATORY/METABOLIC ALKALOSIS - kidney retains H ion and excrete Bicarbonate 120
    121. 121. Lung- Control CO2 and Carbonic acid content of ECF1. METABOLIC ACIDOSIS - increased RR to eliminate CO22. METABOLIC ALKALOSIS - decreased RR to retain CO2 121
    122. 122. Chemical BuffersThere are three major buffers in body fluid. 1) The Bicarbonate (HCO3-) Buffer 2) The Phosphate Buffer 3) The Protein Buffer 122
    123. 123. Properties of Chemical Buffers - respond to pH changes within a fraction of a second. - Bind to H+ but can not remove H+ out of the body - Limited ability to correct pH changes 123
    124. 124. ↓ pH ⇓ stimulate peripheral/central chemoreceptors ⇓ ↑ pulmonary ventilation ⇓ removal of CO2 and ↑ pHH+ + HCO3- H2CO3 H2O + CO2 124
    125. 125. Limit to respiratory control of pH The respiratory regulatory mechanism cannot remove H+ out of the body. Its efficiency depends on the availability of HCO3- .H+ + HCO3- H2CO3 H2O + CO2 125
    126. 126. Renal Control of pH3. The kidneys can neutralize more acid or base than both the respiratory system and chemical buffers. a. Renal tubules secrete hydrogen ions into the tubular fluid, where most of it combines with bicarbonate, ammonia, and phosphate buffers. b. Bound and free H+ are then excreted in urine. 126
    127. 127. • The kidneys are the only organs that actually expel H+ from the body. Other buffering systems only reduce its concentration by binding it to another chemical.3. Tubular secretion of H+ continues as long as a sufficient concentration gradient exists between the tubule cells and the tubular fluid. 127
    128. 128. Disorders of Acid-Base BalanceAcidosis: < pH 7.35 , Alkalosis: > pH 7.45 - Mild acidosis depresses CNS, causing confusion, disorientation, and coma. - Mild alkalosis CNS becomes hyperexcitable. Nerves fire spontaneously and overstimulate skeletal muscles. - Severe acidosis or alkalosis is lethal. 128
    129. 129. Respiratory vs Metabolic CauseRespiratory acidosis / alkalosis - caused by hypoventilation or hyperventilation Initial changeH+ + HCO- H2CO3 H2O + CO2 Emphysema 129
    130. 130. Respiratory acidosis / alkalosis - caused by hypoventilation or hyperventilationMetabolic acidosis or alkalosis - result from any causes but respiratory problems Diabetes Chronic vomiting ⇓ ⇓ ↑ production of loss of stomach acid organic acids ⇓ ⇓ metabolic alkalosis metabolic acidosis 130

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