Chapter III Major Intra- And Extracellular Electrolytes

Chapter III: Major Intra- and Extracellular Electrolytes The concentrations of electrolytes vary in the different fluid compartments: a. Intracellular fluid b. Interstitial fluid Extracellular c. plasma and vascular fluid -

separated from each other by membranes permeable to water and many organic and inorganic solutes. impermeable to macromolecules such as proteins selectively permeable to sodium, potassium and magnesium

SODIUM & CHLORIDE - found in plasma and interstitial fluids(extracellular) POTASSIUM, MAGNESIUM & PHOSPHATE - found in intracellular fluid Major Physiological Ions

Principal Metabolic Functions

CHLORIDE

Maintains normal hydration, osmotic pressure, gastric HCl, acid-base balance, electrolyte balance

SODIUM

Buffer constituent acid-base balance,

water balance, CO2 transport, osmotic pressure, cell membrane permeability, muscle irritability POTASSIUM

CALCIUM

MAGNESIUM PHOSPHOROUS (as HPO42-)

Buffer constituent acid-base balance,

water balance, CO2 transport, neuromuscular irritability Formation of apatite in bones and teeth Blood clotting Co-factor for PO4 transferring enzymes

constituent of bones and teeth Constituent of bones and teeth, of buffers ATP, NAD and FAD

Clinical Manifestation of Deficiency Hypochloremic Alkalosis (pernicious vomiting)

Dehydration acidosis tissue atrophy edema hypertension Acidosis Renal Damage Poor growth Osteoporosis Rickets muscular tremor chloreiform movement Renal rickets Cardiac Arrhythmia Osteomalacia

Electrolytes Used for Replacement Therapy SODIUM CHLORIDE - Table salt, Sea salt, Sal gemme - colorless, cubic crystals/white crystalline powder having saline taste - soluble in glycerin and slightly in alcohol - occurs in solid states called rock salt, halite, fossil salts, and sal gemme - prepared under the heat of the sun using “salt pans” (Mg+2 & Ca+2 present as impurities) o impurities readily precipitated by adding sodium carbonate to the brine (NaCl solution), crystals are collected by decantation or centrifugation - must be purified for medical purposes (100%)

Chapter III: Major Intra- and Extracellular Electrolytes | Suzette Pamela G. Santos | 1FPharmacy

USES:  Isotonic Solutions – for physiological fluids’ tonicity (0.9%w/v, NSS) - dressings for irritating body cavities/tissues - as injections when fluids and electrolytes are depleted **build up of extensive extracellular fluid due to administration of isotonic sodium chloride may lead to both pulmonary and peripheral edema 

Hypotonic solutions – for maintenance therapy when patients are unable to take fluids and nutrients orally - dextrose (glucose) is the caloric source



Hypertonic injections – used when there is loss of sodium in an excess of water



Sodium Chloride injection – fluid and electrolyte replenisher



Antidote to silver poisoning, condiment and preservative

POTASSIUM CHLORIDE (KCl) -

Kalium Chloratum, Kali Chloridum colorless, elongated prismatic/cubical crystals OR as white granular powder odorless, with saline taste neutral to litmus, solutions found in large deposits in the form of silvite and carnalite; sometimes in combination with NaCl drug of choice for ORAL REPLACEMENT OF K+ irritating to the gastrointestinal tract, must be enteric-coated

USES:  drug of choice for ORAL REPLACEMENT OF K+  component of Ringer’s injection and Solution & Lactated Ringer’s Injection o injection - fluid and electrolyte replenisher - patients with severe hypopotassemia* *defiency of K+, resulting to muscle weakness o solution – topical purposes  treatment of:  familial periodic paralysis  Meniere’s Syndrome - inbalance, noise in the inner ear 

antidote to Digitalis intoxification

CALCIUM CHLORIDE (CaCl2●2H2O) - Muriate of Lime - white, odorless, slightly translucent granules with slightly saline taste - colligative property – less than zero freezing point - very deliquescent, mixed with lactose to reduce deliquescence - irritating to the veins USES:  electrolyte replenisher  in internal hemorrhages  certain bone diseases  nervous disorders  deficiency of Calcium in the system  osteomalacia – softening of the bones

Chapter III: Major Intra- and Extracellular Electrolytes | Suzette Pamela G. Santos | 1FPharmacy

BUFFER SYSTEMS IN THE BODY 1. Bicarbonate/Carbonic Acid (HCO3-/H2CO3) - found in plasma and kidneys 2. Monohydrogen/Dihydrogen phosphate (HPO4-2/H2PO4-) - found in cells and kidneys 3. Hemoglobin and proteins - found in red blood cells - buffer for carbonic acid Acidosis – body’s acid levels increase, decrease alkali below normal Alkalosis – alkali levels increase, decreasing acid below normal 𝒂𝒄𝒊𝒅𝒐𝒔𝒊𝒔 ↓ 𝟕. 𝟑𝟖 − 𝟕. 𝟒𝟐 ↑ (𝒂𝒍𝒌𝒂𝒍𝒐𝒔𝒊𝒔) Compensatory Mechanisms of the Body Condition/Causes Buffer System Metabolic acidosis HCO3-/H2CO3 - HCO3- deficit

carbonic acid CO2 + H2O

: diabetic acidosis, renal failure, diarrhea

Metabolic alkalosis

-

HCO3 excess

HCO3-/H2CO3

Respiratory Function Hyperventilation increased excretion of H2CO3 as CO2

CO2 retention,

Renal Function Increased acid excretion by Na+ -- H+ exchange increased NH3 formation HCO3- reabsorption

Decreased ↑

increased H2CO3 concentration

: administration of excess alkali, vomiting

Respiratory Acidosis - H2CO3 excess : cardiac disease, lung damage, drowning

Respiratory Alkalosis

Hemoglobin and protein

Increased CO2 excretion

*Metabolic Acidosis

through the lungs

*Metabolic Alkalosis

*Metabolic Alkalosis

*Metabolic Alkalosis

- H2CO3 deficit : fever, hysteria, anoxia, salicylate poisoning

Steps in Kidney’s Acid Excretion 1. Glomerular filtration – sodium salts of mineral and organic acids are removed from the plasma 2. Sodium-hydrogen exchange – sodium is removed from the renal filtrate/tubular fluid and tubule cells Na+ + H2CO3 ----------------> Na+ + HCO3- + H+ 3. Sodium bicarbonate returns to the plasma and removed from the lungs as CO2 3 Mechanisms Maintaining the Normal Acid-Base Balance of the Plasma: 1. Buffers of the body fluids and red blood cells 2. Pulmonary excretion of excess CO2 3. Renal excretion of either acid or base, whichever is in excess Metabolic acidosis is treated with Sodium:  Bicarbonate  Lactate  Acetate  Citrate Metabolic alkalosis is treated with AMMONIUM SALTS, retards sodium-hydrogen exchange

SODIUM ACETATE (CH3COONa●3H2O) USES:    

Acetate of Soda colorless, transparent crystals/white granular powder/white flake faint acetous odor buffer in metabolic acidosis of acute cholera treatment for uremic acidosis (by infusion) Systemic alkalizer diuretic, diaphoretic, aperients

Chapter III: Major Intra- and Extracellular Electrolytes | Suzette Pamela G. Santos | 1FPharmacy

POTASSIUM ACETATE (CH3COOK) - Diuretic Salt - colorless monoclinic crystals/white crystalline powder - has a saline/alkaline taste - deliquesces on exposure to moist air, never prescribed in dry state USES:  Diaphoretic and Diuretic (1-4 grams)  Cathartic (16-30 grams)  Alkalizer

SODIUM BICARBONATE (NaHCO3) - Baking Soda - white crystalline powder - its alkanility in solutions increases as it stands - CO2 is liberated when treated with acids effervescence (bubbling) Ways of Sterilizing Sodium Bicarbonate 1. Bacteriological filtration - use of filterthingy with very small pores impermeable to bacteria 2. Autoclaving - ensures backward reaction, preserving the sodium bicarbonate 3. Heating the bicarbonate solution in an open vessel USES:  Combat gastric hyperacidity and systemic acidosis(orally&parenterally) o drug of choice for systemic acidosis  lessening of the acidity of the urine (orally)  inhibits the activity of other drugs when taken simultaneously with it  treatment of methyl alcohol poisoning  in the manufacture of effervescent salts, baking powder, fire extinguisher, carbonated drinks and cleaning mixtures

POTASSIUM BICARBONATE (KHCO3) -

Salaeratus transparent monoclinic prisms/white granular powder, odorless solutions: neutral or alkaline to litmus presence of carbonate indicated by deliquescence

USES:  electrolyte replenisher  component of Potassium Triplex (Acetate, Citrate, Bicarbonate)  oral effervescent potassium replacement solution  antacid

SODIUM CITRATE (C6H5Na3O7) - colorless crystals/white crystalline powder USES:  anticoagulant o chelates serum calcium, removing one of the components of blood clotting o fibrin - clot  chelation/sequestering of other cations  in chronic acidosis to restore bicarbonate reserve  diuretic effect due to increased body salt concentration

Chapter III: Major Intra- and Extracellular Electrolytes | Suzette Pamela G. Santos | 1FPharmacy

POTASSIUM CITRATE (C6H5K3O7●H2O) USES:      

white granular powder, odorless, cooling saline taste deliquescent systemic alkalizer diuretic diaphoretic expectorant laxative gastric antacid

Electrolyte Combination Therapy 1. Fluid Maintenance - intended to supply normal requirements for water and electrolytes for patients who cannot take them orally - should contain atleast 5% dextrose - minimizes build-up of metabolites associated with starvation (urea, phosphate and ketone bodies) - intravenously - composed generally of Na+, Cl-, HCO3-, Mg+2, HPO4-2 & Glucose 2. Electrolyte Replacement - loss is severe

Chapter III: Major Intra- and Extracellular Electrolytes | Suzette Pamela G. Santos | 1FPharmacy