Solubility and Electrolyte Imbalances

Solubility

• CO2 is 20 times more soluble in tissues than oxygen
• Solubility of CO2 and O2 in tissues is important for respiratory gas exchange
• Henry's Law: the number of gas molecules dissolved in a liquid is directly proportional to its partial pressure above the liquid
• Solubility coefficients: Bunsen and Ostwald
• Solubility of gases decreases with temperature, while solubility of liquids and solids increases with temperature

Partition Coefficient and Anesthetics

• Partition coefficient: the ratio of the concentration of anesthetic in one phase or solvent compared to another
• Comparison of blood-gas, brain-blood, liver-blood, kidney-blood, muscle-blood, and fat-blood partition coefficients
• The longer the case, the more anesthetic will go to fat
• Desflurane will go off faster in obese patients, and nitrous oxide doesn't get absorbed

MAC and Oil Solubility

• MAC (Minimum Alveolar Concentration) is the lowest concentration of an anesthetic that prevents movement in 50% of patients
• Isoflurane MAC is 1.17%
• Meyer-Overton Hypothesis: potency of an anesthetic agent is related to its lipid solubility
• High potency correlates with slow onset
• Oil-gas partition coefficient is proportional to fat-gas partition coefficient

Diffusion and Osmosis

• Fick's Law: rate of diffusion is proportional to the gradient of the concentration (liquid) or partial pressure (gas)
• Graham's Law: rate of diffusion of gases through a porous membrane is inversely proportional to the square root of the molar mass of the gas
• Bulk flow: ultrafiltration and reabsorption
• Ultrafiltration: fluid is pushed out through the pores in the capillary wall (on arterial side)
• Reabsorption: when the osmotic pressure of the blood plasma exceeds the outward pressure (on venous side)

Osmosis

• Osmosis: movement of water through a semi-permeable membrane
• Water flows to the more concentrated side
• In events of elevated ICP, use mannitol or hypertonic saline to increase concentration of plasma
• Hypertonic solutions shrink cells, while hypotonic solutions cause lysis and bursting

Osmolality and Osmotic Pressure

• Osmole: unit of measurement for osmotic activity
• 1 mole of particles dissolved in a solute that cannot diffuse through a semi-permeable membrane
• Osmotic pressure: pressure at which osmosis of a solvent into a semi-permeable membrane is prevented
• Non-ionizing solutions: carbon-based solutions with covalent bonds (won't dissociate)
• Ionizing solutions: salts with ionic bonds (will dissociate)
• Osmolarity of body fluids at body temperature: important for understanding osmosis and tonicity

Tonicity and Cellular Effects

• Tonicity: osmotic pressure of a solution relative to that of other body fluids
• Molar solution of any solute contains 1 mol/L
• Effects of mOsm on cells:
  • Hypotonic: cells swell and burst
  • Isotonic: cells remain normal
  • Hypertonic: cells shrink and crenate

Solubility

• CO2 is 20 times more soluble in tissues than oxygen
• Solubility of CO2 and O2 in tissues is important for respiratory gas exchange
• Henry's Law: the number of gas molecules dissolved in a liquid is directly proportional to its partial pressure above the liquid
• Solubility coefficients: Bunsen and Ostwald
• Solubility of gases decreases with temperature, while solubility of liquids and solids increases with temperature

Partition Coefficient and Anesthetics

• Partition coefficient: the ratio of the concentration of anesthetic in one phase or solvent compared to another
• Comparison of blood-gas, brain-blood, liver-blood, kidney-blood, muscle-blood, and fat-blood partition coefficients
• The longer the case, the more anesthetic will go to fat
• Desflurane will go off faster in obese patients, and nitrous oxide doesn't get absorbed

MAC and Oil Solubility

• MAC (Minimum Alveolar Concentration) is the lowest concentration of an anesthetic that prevents movement in 50% of patients
• Isoflurane MAC is 1.17%
• Meyer-Overton Hypothesis: potency of an anesthetic agent is related to its lipid solubility
• High potency correlates with slow onset
• Oil-gas partition coefficient is proportional to fat-gas partition coefficient

Diffusion and Osmosis

• Fick's Law: rate of diffusion is proportional to the gradient of the concentration (liquid) or partial pressure (gas)
• Graham's Law: rate of diffusion of gases through a porous membrane is inversely proportional to the square root of the molar mass of the gas
• Bulk flow: ultrafiltration and reabsorption
• Ultrafiltration: fluid is pushed out through the pores in the capillary wall (on arterial side)
• Reabsorption: when the osmotic pressure of the blood plasma exceeds the outward pressure (on venous side)

Osmosis

• Osmosis: movement of water through a semi-permeable membrane
• Water flows to the more concentrated side
• In events of elevated ICP, use mannitol or hypertonic saline to increase concentration of plasma
• Hypertonic solutions shrink cells, while hypotonic solutions cause lysis and bursting

Osmolality and Osmotic Pressure

• Osmole: unit of measurement for osmotic activity
• 1 mole of particles dissolved in a solute that cannot diffuse through a semi-permeable membrane
• Osmotic pressure: pressure at which osmosis of a solvent into a semi-permeable membrane is prevented
• Non-ionizing solutions: carbon-based solutions with covalent bonds (won't dissociate)
• Ionizing solutions: salts with ionic bonds (will dissociate)
• Osmolarity of body fluids at body temperature: important for understanding osmosis and tonicity

Tonicity and Cellular Effects

• Tonicity: osmotic pressure of a solution relative to that of other body fluids
• Molar solution of any solute contains 1 mol/L
• Effects of mOsm on cells:
  • Hypotonic: cells swell and burst
  • Isotonic: cells remain normal
  • Hypertonic: cells shrink and crenate

Fluid Volume and Composition

• Fluid volume varies with age, and in adults, it's largely determined by muscle vs fat composition.
• Obese people have a decreased percentage of total body water (TBW) in relation to body weight, while lean people have an increased percentage.
• Fluid distribution is divided into:
  • Intra Cellular Fluid (ICF)
  • Extra Cellular Fluid (ECF) = interstitial, intravascular, CSF, sweat, urine, and organ fluids

Electrolytes and Non-Electrolytes

• Electrolytes are ions that have an electric charge:
  • ICF: K, Mg, Phosphate
  • ECF: Na, Bicarb, Cl
• Non-electrolytes do not have an electric charge:
  • Glucose, urea, protein, lipids, creatinine

Water Balance and Osmolality

• Osmolality is the measure of solute concentration.
• Osmotic forces include Na (ECF) and K (ICF).
• Aquaporins form pores in the cell membrane for water to pass through.
• Water moves freely through cell membranes.
• When osmolality of the plasma changes, water moves to reestablish equilibrium.

Water Movement between Plasma and Interstitial Fluid

• Starling hypothesis: net filtration is equal to the forces favoring filtration minus the forces opposing filtration.
• Forces favoring filtration:
  • Capillary hydrostatic pressure (BP)
  • Interstitial oncotic pressure (water pulling)
• Forces opposing filtration:
  • Capillary oncotic pressure (water pulling) is determined mostly by albumin
  • Interstitial hydrostatic pressure

Edema

• Edema is the accumulation of fluid in the interstitial spaces.
• Causes:
  • Increased capillary hydrostatic pressure (venous obstruction)
  • Decreased plasma oncotic pressure (losses or diminished production of albumin)
  • Increased capillary permeability (inflammation and immune response)
  • Lymphatic obstruction (lymphedema)
• Clinical manifestations:
  • Localized vs generalized
  • Dependent edema
  • Pitting edema
  • Third space
  • Weight gain
• Treatment:
  • Elevation of edematous limbs
  • Use compression
  • Avoid prolonged standing
  • Restrict salt intake
  • Take diuretics

Water Regulation

• Water losses: skin, lungs, urine, and feces
• Fluid intake and diet
• Levels of ADH (antidiuretic hormone)
• Tonicity and cells:
  • Hypertonic
  • Isotonic
  • Hypotonic

Sodium Regulation

• Aldosterone
• ANP (atrial natriuretic peptide)
• Baroreceptors
• Estrogen enhances Na reabsorption
• Progesterone decreases Na reabsorption
• Glucocorticoids enhance Na reabsorption
• Sodium is the primary ECF cation:
  • Regulates osmotic forces
  • Plays a role in neuromuscular irritability, acid-base balance, cellular reactions, and transport of substances
  • Is regulated by aldosterone and natriuretic peptides
• Water follows sodium

Chloride

• Primary ECF anion
• Provides electroneutrality
• Follows sodium

RAAS (Renin-Angiotensin-Aldosterone System)

• Aldosterone increases excretion of K by the distal tubule of the kidney
• Natriuretic peptides (ANP, BNP):
  • Decrease tubular reabsorption and promote urinary excretion of sodium
  • Urodilation

Water Regulation and ADH

• Thirst perception:
  • Osmolality receptors are located in the hypothalamus
  • Signal posterior pituitary to release ADH
  • Increase water intake
• Baroreceptors:
  • Stimulated from depleted plasma volume
  • Cause release of ADH
• ADH = arginine vasopressin:
  • Is released when there is an increase in plasma osmolality or decrease in circulating blood volume
  • Increases water reabsorption

Abnormalities in Water and Electrolyte Balance

• Pure water deficit = hypertonic volume depletion
• Isotonic alterations in Na, Cl, and water:
  • TBW change with proportional electrolyte change
  • Isotonic fluid loss (dehydration and hypovolemia)
  • Isotonic fluid excess (hypervolemia)
• Hypernatremia:
  • Na > 145
  • Related to sodium gain or water loss
  • Water movement from the ICF to ECF leads to intracellular dehydration
  • Manifestations: cerebral hemorrhage, seizures, muscle twitching, hyperreflexia
  • Treatment: isotonic salt-free fluids
• Water deficit:
  • Dehydration – sodium and water loss
  • Manifestations: hypotension, weak pulse, postural hypotension, elevated Hct and Na, headache, dry skin, mucous membranes
  • Treatment: oral fluids, hypotonic saline (D5 in water)
• Hyperchloremia:
  • Occurs with hypernatremia or a bicarb deficit
  • Usually secondary to a pathophysiologic process
  • Is managed by treating the underlying disorders
• Hypotonic alterations in Na, Cl, and water:
  • Decreased osmolality
  • Hyponatremia or free water excess
  • Hyponatremia decreases the ECF osmotic pressure and water moves into cell
  • Water excess:
    • Compulsive water drinking causing water intoxication
    • Cellular edema
    • Manifestations: cerebral edema, pulmonary edema
    • Treatment: fluid restriction, hypertonic saline
• Hyponatremia:
  • Na < 135
  • Manifestations: cerebral edema, pulmonary edema
  • Treatment: fluid restriction, hypertonic saline

Fluid Volume and Composition

• Fluid volume varies with age, and in adults, it's largely determined by muscle vs fat composition.
• Obese people have a decreased percentage of total body water (TBW) in relation to body weight, while lean people have an increased percentage.
• Fluid distribution is divided into:
  • Intra Cellular Fluid (ICF)
  • Extra Cellular Fluid (ECF) = interstitial, intravascular, CSF, sweat, urine, and organ fluids

Electrolytes and Non-Electrolytes

• Electrolytes are ions that have an electric charge:
  • ICF: K, Mg, Phosphate
  • ECF: Na, Bicarb, Cl
• Non-electrolytes do not have an electric charge:
  • Glucose, urea, protein, lipids, creatinine

Water Balance and Osmolality

• Osmolality is the measure of solute concentration.
• Osmotic forces include Na (ECF) and K (ICF).
• Aquaporins form pores in the cell membrane for water to pass through.
• Water moves freely through cell membranes.
• When osmolality of the plasma changes, water moves to reestablish equilibrium.

Water Movement between Plasma and Interstitial Fluid

• Starling hypothesis: net filtration is equal to the forces favoring filtration minus the forces opposing filtration.
• Forces favoring filtration:
  • Capillary hydrostatic pressure (BP)
  • Interstitial oncotic pressure (water pulling)
• Forces opposing filtration:
  • Capillary oncotic pressure (water pulling) is determined mostly by albumin
  • Interstitial hydrostatic pressure

Edema

• Edema is the accumulation of fluid in the interstitial spaces.
• Causes:
  • Increased capillary hydrostatic pressure (venous obstruction)
  • Decreased plasma oncotic pressure (losses or diminished production of albumin)
  • Increased capillary permeability (inflammation and immune response)
  • Lymphatic obstruction (lymphedema)
• Clinical manifestations:
  • Localized vs generalized
  • Dependent edema
  • Pitting edema
  • Third space
  • Weight gain
• Treatment:
  • Elevation of edematous limbs
  • Use compression
  • Avoid prolonged standing
  • Restrict salt intake
  • Take diuretics

Water Regulation

• Water losses: skin, lungs, urine, and feces
• Fluid intake and diet
• Levels of ADH (antidiuretic hormone)
• Tonicity and cells:
  • Hypertonic
  • Isotonic
  • Hypotonic

Sodium Regulation

• Aldosterone
• ANP (atrial natriuretic peptide)
• Baroreceptors
• Estrogen enhances Na reabsorption
• Progesterone decreases Na reabsorption
• Glucocorticoids enhance Na reabsorption
• Sodium is the primary ECF cation:
  • Regulates osmotic forces
  • Plays a role in neuromuscular irritability, acid-base balance, cellular reactions, and transport of substances
  • Is regulated by aldosterone and natriuretic peptides
• Water follows sodium

Chloride

• Primary ECF anion
• Provides electroneutrality
• Follows sodium

RAAS (Renin-Angiotensin-Aldosterone System)

• Aldosterone increases excretion of K by the distal tubule of the kidney
• Natriuretic peptides (ANP, BNP):
  • Decrease tubular reabsorption and promote urinary excretion of sodium
  • Urodilation

Water Regulation and ADH

• Thirst perception:
  • Osmolality receptors are located in the hypothalamus
  • Signal posterior pituitary to release ADH
  • Increase water intake
• Baroreceptors:
  • Stimulated from depleted plasma volume
  • Cause release of ADH
• ADH = arginine vasopressin:
  • Is released when there is an increase in plasma osmolality or decrease in circulating blood volume
  • Increases water reabsorption

Abnormalities in Water and Electrolyte Balance

• Pure water deficit = hypertonic volume depletion
• Isotonic alterations in Na, Cl, and water:
  • TBW change with proportional electrolyte change
  • Isotonic fluid loss (dehydration and hypovolemia)
  • Isotonic fluid excess (hypervolemia)
• Hypernatremia:
  • Na > 145
  • Related to sodium gain or water loss
  • Water movement from the ICF to ECF leads to intracellular dehydration
  • Manifestations: cerebral hemorrhage, seizures, muscle twitching, hyperreflexia
  • Treatment: isotonic salt-free fluids
• Water deficit:
  • Dehydration – sodium and water loss
  • Manifestations: hypotension, weak pulse, postural hypotension, elevated Hct and Na, headache, dry skin, mucous membranes
  • Treatment: oral fluids, hypotonic saline (D5 in water)
• Hyperchloremia:
  • Occurs with hypernatremia or a bicarb deficit
  • Usually secondary to a pathophysiologic process
  • Is managed by treating the underlying disorders
• Hypotonic alterations in Na, Cl, and water:
  • Decreased osmolality
  • Hyponatremia or free water excess
  • Hyponatremia decreases the ECF osmotic pressure and water moves into cell
  • Water excess:
    • Compulsive water drinking causing water intoxication
    • Cellular edema
    • Manifestations: cerebral edema, pulmonary edema
    • Treatment: fluid restriction, hypertonic saline
• Hyponatremia:
  • Na < 135
  • Manifestations: cerebral edema, pulmonary edema
  • Treatment: fluid restriction, hypertonic saline

Fluid Volume and Composition

• Fluid volume varies with age, and in adults, it's largely determined by muscle vs fat composition.
• Obese people have a decreased percentage of total body water (TBW) in relation to body weight, while lean people have an increased percentage.
• Fluid distribution is divided into:
  • Intra Cellular Fluid (ICF)
  • Extra Cellular Fluid (ECF) = interstitial, intravascular, CSF, sweat, urine, and organ fluids

Electrolytes and Non-Electrolytes

• Electrolytes are ions that have an electric charge:
  • ICF: K, Mg, Phosphate
  • ECF: Na, Bicarb, Cl
• Non-electrolytes do not have an electric charge:
  • Glucose, urea, protein, lipids, creatinine

Water Balance and Osmolality

• Osmolality is the measure of solute concentration.
• Osmotic forces include Na (ECF) and K (ICF).
• Aquaporins form pores in the cell membrane for water to pass through.
• Water moves freely through cell membranes.
• When osmolality of the plasma changes, water moves to reestablish equilibrium.

Water Movement between Plasma and Interstitial Fluid

• Starling hypothesis: net filtration is equal to the forces favoring filtration minus the forces opposing filtration.
• Forces favoring filtration:
  • Capillary hydrostatic pressure (BP)
  • Interstitial oncotic pressure (water pulling)
• Forces opposing filtration:
  • Capillary oncotic pressure (water pulling) is determined mostly by albumin
  • Interstitial hydrostatic pressure

Edema

• Edema is the accumulation of fluid in the interstitial spaces.
• Causes:
  • Increased capillary hydrostatic pressure (venous obstruction)
  • Decreased plasma oncotic pressure (losses or diminished production of albumin)
  • Increased capillary permeability (inflammation and immune response)
  • Lymphatic obstruction (lymphedema)
• Clinical manifestations:
  • Localized vs generalized
  • Dependent edema
  • Pitting edema
  • Third space
  • Weight gain
• Treatment:
  • Elevation of edematous limbs
  • Use compression
  • Avoid prolonged standing
  • Restrict salt intake
  • Take diuretics

Water Regulation

• Water losses: skin, lungs, urine, and feces
• Fluid intake and diet
• Levels of ADH (antidiuretic hormone)
• Tonicity and cells:
  • Hypertonic
  • Isotonic
  • Hypotonic

Sodium Regulation

• Aldosterone
• ANP (atrial natriuretic peptide)
• Baroreceptors
• Estrogen enhances Na reabsorption
• Progesterone decreases Na reabsorption
• Glucocorticoids enhance Na reabsorption
• Sodium is the primary ECF cation:
  • Regulates osmotic forces
  • Plays a role in neuromuscular irritability, acid-base balance, cellular reactions, and transport of substances
  • Is regulated by aldosterone and natriuretic peptides
• Water follows sodium

Chloride

• Primary ECF anion
• Provides electroneutrality
• Follows sodium

RAAS (Renin-Angiotensin-Aldosterone System)

• Aldosterone increases excretion of K by the distal tubule of the kidney
• Natriuretic peptides (ANP, BNP):
  • Decrease tubular reabsorption and promote urinary excretion of sodium
  • Urodilation

Water Regulation and ADH

• Thirst perception:
  • Osmolality receptors are located in the hypothalamus
  • Signal posterior pituitary to release ADH
  • Increase water intake
• Baroreceptors:
  • Stimulated from depleted plasma volume
  • Cause release of ADH
• ADH = arginine vasopressin:
  • Is released when there is an increase in plasma osmolality or decrease in circulating blood volume
  • Increases water reabsorption

Abnormalities in Water and Electrolyte Balance

• Pure water deficit = hypertonic volume depletion
• Isotonic alterations in Na, Cl, and water:
  • TBW change with proportional electrolyte change
  • Isotonic fluid loss (dehydration and hypovolemia)
  • Isotonic fluid excess (hypervolemia)
• Hypernatremia:
  • Na > 145
  • Related to sodium gain or water loss
  • Water movement from the ICF to ECF leads to intracellular dehydration
  • Manifestations: cerebral hemorrhage, seizures, muscle twitching, hyperreflexia
  • Treatment: isotonic salt-free fluids
• Water deficit:
  • Dehydration – sodium and water loss
  • Manifestations: hypotension, weak pulse, postural hypotension, elevated Hct and Na, headache, dry skin, mucous membranes
  • Treatment: oral fluids, hypotonic saline (D5 in water)
• Hyperchloremia:
  • Occurs with hypernatremia or a bicarb deficit
  • Usually secondary to a pathophysiologic process
  • Is managed by treating the underlying disorders
• Hypotonic alterations in Na, Cl, and water:
  • Decreased osmolality
  • Hyponatremia or free water excess
  • Hyponatremia decreases the ECF osmotic pressure and water moves into cell
  • Water excess:
    • Compulsive water drinking causing water intoxication
    • Cellular edema
    • Manifestations: cerebral edema, pulmonary edema
    • Treatment: fluid restriction, hypertonic saline
• Hyponatremia:
  • Na < 135
  • Manifestations: cerebral edema, pulmonary edema
  • Treatment: fluid restriction, hypertonic saline

Fluid Volume and Composition

• Fluid volume varies with age, and in adults, it's largely determined by muscle vs fat composition.
• Obese people have a decreased percentage of total body water (TBW) in relation to body weight, while lean people have an increased percentage.
• Fluid distribution is divided into:
  • Intra Cellular Fluid (ICF)
  • Extra Cellular Fluid (ECF) = interstitial, intravascular, CSF, sweat, urine, and organ fluids

Electrolytes and Non-Electrolytes

• Electrolytes are ions that have an electric charge:
  • ICF: K, Mg, Phosphate
  • ECF: Na, Bicarb, Cl
• Non-electrolytes do not have an electric charge:
  • Glucose, urea, protein, lipids, creatinine

Water Balance and Osmolality

• Osmolality is the measure of solute concentration.
• Osmotic forces include Na (ECF) and K (ICF).
• Aquaporins form pores in the cell membrane for water to pass through.
• Water moves freely through cell membranes.
• When osmolality of the plasma changes, water moves to reestablish equilibrium.

Water Movement between Plasma and Interstitial Fluid

• Starling hypothesis: net filtration is equal to the forces favoring filtration minus the forces opposing filtration.
• Forces favoring filtration:
  • Capillary hydrostatic pressure (BP)
  • Interstitial oncotic pressure (water pulling)
• Forces opposing filtration:
  • Capillary oncotic pressure (water pulling) is determined mostly by albumin
  • Interstitial hydrostatic pressure

Edema

• Edema is the accumulation of fluid in the interstitial spaces.
• Causes:
  • Increased capillary hydrostatic pressure (venous obstruction)
  • Decreased plasma oncotic pressure (losses or diminished production of albumin)
  • Increased capillary permeability (inflammation and immune response)
  • Lymphatic obstruction (lymphedema)
• Clinical manifestations:
  • Localized vs generalized
  • Dependent edema
  • Pitting edema
  • Third space
  • Weight gain
• Treatment:
  • Elevation of edematous limbs
  • Use compression
  • Avoid prolonged standing
  • Restrict salt intake
  • Take diuretics

Water Regulation

• Water losses: skin, lungs, urine, and feces
• Fluid intake and diet
• Levels of ADH (antidiuretic hormone)
• Tonicity and cells:
  • Hypertonic
  • Isotonic
  • Hypotonic

Sodium Regulation

• Aldosterone
• ANP (atrial natriuretic peptide)
• Baroreceptors
• Estrogen enhances Na reabsorption
• Progesterone decreases Na reabsorption
• Glucocorticoids enhance Na reabsorption
• Sodium is the primary ECF cation:
  • Regulates osmotic forces
  • Plays a role in neuromuscular irritability, acid-base balance, cellular reactions, and transport of substances
  • Is regulated by aldosterone and natriuretic peptides
• Water follows sodium

Chloride

• Primary ECF anion
• Provides electroneutrality
• Follows sodium

RAAS (Renin-Angiotensin-Aldosterone System)

• Aldosterone increases excretion of K by the distal tubule of the kidney
• Natriuretic peptides (ANP, BNP):
  • Decrease tubular reabsorption and promote urinary excretion of sodium
  • Urodilation

Water Regulation and ADH

• Thirst perception:
  • Osmolality receptors are located in the hypothalamus
  • Signal posterior pituitary to release ADH
  • Increase water intake
• Baroreceptors:
  • Stimulated from depleted plasma volume
  • Cause release of ADH
• ADH = arginine vasopressin:
  • Is released when there is an increase in plasma osmolality or decrease in circulating blood volume
  • Increases water reabsorption

Abnormalities in Water and Electrolyte Balance

• Pure water deficit = hypertonic volume depletion
• Isotonic alterations in Na, Cl, and water:
  • TBW change with proportional electrolyte change
  • Isotonic fluid loss (dehydration and hypovolemia)
  • Isotonic fluid excess (hypervolemia)
• Hypernatremia:
  • Na > 145
  • Related to sodium gain or water loss
  • Water movement from the ICF to ECF leads to intracellular dehydration
  • Manifestations: cerebral hemorrhage, seizures, muscle twitching, hyperreflexia
  • Treatment: isotonic salt-free fluids
• Water deficit:
  • Dehydration – sodium and water loss
  • Manifestations: hypotension, weak pulse, postural hypotension, elevated Hct and Na, headache, dry skin, mucous membranes
  • Treatment: oral fluids, hypotonic saline (D5 in water)
• Hyperchloremia:
  • Occurs with hypernatremia or a bicarb deficit
  • Usually secondary to a pathophysiologic process
  • Is managed by treating the underlying disorders
• Hypotonic alterations in Na, Cl, and water:
  • Decreased osmolality
  • Hyponatremia or free water excess
  • Hyponatremia decreases the ECF osmotic pressure and water moves into cell
  • Water excess:
    • Compulsive water drinking causing water intoxication
    • Cellular edema
    • Manifestations: cerebral edema, pulmonary edema
    • Treatment: fluid restriction, hypertonic saline
• Hyponatremia:
  • Na < 135
  • Manifestations: cerebral edema, pulmonary edema
  • Treatment: fluid restriction, hypertonic saline