1. Fluid balance and electrolyte distribution
in human body.
Mass Percent
• other way of describing the amount of solute in a solution
• Describes what percentage of a solution by mass is
comprised by solute.
mass of solute mass of solute
×100% = ×100%
total mass of solution mass of solute + mass of solvent
• Example
A student prepares a solution from 5.00 g of sodium fluoride dissolved
in 95.00 g of water.
What is the mass percent of sodium fluoride?

2. Using Moles to Describe the Amount of
Substance in a Solution
• A number of units may be used to describe the
concentration of a solute in a solution.
• The most common unit is molarity (M).
• The Molarity of a solution is equal to the moles of solute
divided by the total volume of the solution.
moles solute mass ( g ) solute
M= =
L solution molar mass solute x L solution
• If we know the mass of solute we dissolved in the
solution, we can convert the mass the solute to moles of
solute and calculate the molarity.
• The Molality of a solution is equal to the moles of solute
per kilogram of solvent
Total body water and
its distribution in the body
compartments.
The main functions of water in
the human organism.

3. Water
Largest single chemical component of the body:
45-75% of body mass
Fat (adipose tissue) is essentially water free, so
there is relatively more or less water
in the body depending on % fat composition
Water is the solvent for most biological
molecules within the body
Water also participates in a variety of
biochemical reactions, both anabolic and
catabolic
Body fat measuring
Skinfold Caliper
http://www.linear-software.com/online.html

4. Fluid Compartments
Body Fluids are separated by semi-permeable membranes into various
physiological (functional) compartments
• Two Compartment Model
- Intracellular = Cytoplasmic (inside cells)
- Extracellular (outside cells)
The Two Compartment Model is useful clinically for understanding the
distribution of many drugs in the body
• Three Compartment Model
– [1] Intracellular = Cytoplasmic (inside cells)
– Extracellular compartment is subdivided into:
• [2] Interstitial = Intercellular = Lymph (between the cells in the tissues)
• [3] Plasma (fluid portion of the blood)
The Three Compartment Model is more useful for understanding
physiological processes
Other models with more compartments can sometimes be useful, e.g., consider lymph in the
lymph vessels, CSF, ocular fluids, synovial and serous fluids as separate compartments
Fluid Compartments
• Total Body Water (TBW) - 42L,
60% of body weight
– Intracellular Fluid (ICF) -
28L, 67% of TBW
– Extracellular Fluid (ECF) -
14L, 33% of TBW
• Interstitial Fluid - 11L,
80% ECF
• Plasma - 3L, 20% of
ECF

5. Water balance
– Sources for 2500 ml
- average daily
intake
• Metabolic Water
• Preformed Water
– Ingested Foods
– Ingested Liquids
– Balance achieved if
daily output also =
2500 ml
• GI tract
• Lungs
• Skin
– evaporation
– perspiration
• Kidneys
Water Movement Between the ICF and ECF
Osmolality – the concentrations of solutes in water
H2O
– solutes will influence the movement of water across membranes
π = iRTc
Aquaporins- water channel proteins in membranes
Net filtration (Starling hypothesis) H2O
= forces favoring filtration – forces opposing filtration
As fluid flows through capillary it looses water and create greater osmotic
return of water as it flows toward veinule end of capillary
Forces favoring filtration
- Capillary hydrostatic pressure (blood pressure)
- Interstitial oncotic pressure (water-pulling)
Forces favoring reabsorption filtration
H2O
- Plasma oncotic pressure (water-pulling) reabsorption
- Interstitial hydrostatic pressure

6. •
Electrophoretic separation of plasma proteins
•
(directly proportional to size and charge)
20L/day
60%
Mr 67x103
Albumin
α1 globulin 1-antitrypsin, 1-acid glycoprotein
4%
α2 globulin haptoglobin, 2-macroglobulin,
2-antiplasmin, ceruloplasmin
7%
β globulin
in plasma the major part forms proteins 65-85 g/l
transferin, complement, LDL
is formed by colloid particles dissolved in solution
10%
5% fibrinogen
Mr340x103
γ globulin = Imunoglobulins
IgA, IgD, IgE, IgG and IgM
14%
Mr150x103
Water Movement Between the ICF and ECF
Oncotic pressure…Colloid osmotic pressure
18L/day

7. Osmotic Equilibrium
Plasma Osmolarity - Measures ECF Osmolarity
• Plasma is clinically accessible
• Dominated by [Na+] and the associated anions
• Under normal conditions, ECF osmolarity can be roughly estimated
as:
POSM = 2 [Na+]p ……..270-300 mOsm
{ POSM = 2[Na+] + 2[K+] + [Urea] + [Glucose] }

8. Edema
Accumulation of fluid within the
interstitial spaces
• Causes:
– Increase in hydrostatic pressure (blood pressure / hypertension)
– Losses or diminished production of plasma albumin (hypoproteinemia
…decrease in oncotic pressure /malnutrition (at insufficient supply of proteins
…abdominal edema/ insufficient production of proteins at cirrhosis/ large
losses of proteins by kidney at nephrotic syndrome/)
- Increases in capillary permeability (at anaphylaxis, allergic
reaction (release of histamin), inflammation)
- Lymph obstruction – elephantitus, flibitus
- Decreased resorption due to raised systemic venous
pressure – edema due to heart failure
Edema

9. Regulating Fluid Intake
Thirst Thirst Quenching
Wetting the oral mucosa
1. 2. (temporary)
Stretching of the stomach
Decreased blood/body
fluid osmolarity =
increased hydration
(dilution) of the blood is
the most important
Regulation of Fluid Output
• Hormonal control
– 1 Antidiuretic hormone (ADH) [neurohypophysis]
– 2 Aldosterone [adrenal cortex]
– 3 Atrial natriuretic peptide (ANP) [heart atrial walls]
• Causes of physiologic fluid imbalances
– Dehydration: ↓ blood pressure, ↓ GFR
– Overhydration: ↑ blood pressure, ↑ GFR
– Hyperventilation - water loss through lungs
– Vomiting & Diarrhea - excessive water loss
– Fever - heavy perspiration
– exudating Burns, contusion - fluid loss
– Hemorrhage – if blood loss is severe

11. Atrial natriuretic peptide (ANP) is a 28-amino acid peptide that is synthesized, stored, and
released by atrial myocytes in response to atrial distension
- elevated levels of ANP are found during hypervolemic states (elevated blood volume) and
congestive heart failure
A second natriuretic peptide (brain-type natriuretic peptide; BNP) is a 32-amino acid peptide that
is synthesized within the ventricles (as well as in the brain where it was first identified). Like
ANP, BNP is released by the same mechanisms that release ANP, and it has similar
physiological actions, BNP serves as sensitive, diagnostic markers for heart failure in
patients
Regulation of Fluid Output

12. Osm V PB
Factors affecting
ADH release
ADH
Urine osmolarity regulation by ADH
ADH

13. Human angiotensinogen
is 118 amino acids long
Pathway of RAAS
Principal cells & aldosterone

14. Atrial natriuretic peptide
28-amino acid peptide
Distribution of Solutes
Interstitial fluid is
essentially an ultrafiltrate
of plasma,
water and electrolytes move freely within
this compartment and between it and the
intravascular fluid.
Intravascular fluid has almost the same
composition as interstitial fluid except
for its higher protein level.

15. Electrolyte Balance
Electrolytes have 4 important physiological functions in the body
• essential minerals in certain biochemical reactions
• control osmosis = control the movement of water between
compartments
• maintain acid-base balance
• conduct electrical currents (depolarization events)
Regulators:
Aldosterone ↑ [Na+] [Cl-] [H2O] ↓ [K+]
Atrial Natriuretic Peptide (opposite effect)
↓
Antidiuretic Hormone ↑ [H2O] (↓ [solutes])
Parathyroid Hormone ↑ [Ca++] ↓ [HPO4-]
Calcitonin (opposite effect)
Female sex hormones ↑ [H2O]
Electrolytes
• Sodium (Na+) - 136-146 mmol/liter
– Most abundant cation
• major ECF cation (90% of cations present)
• determines osmolarity of ECF
– Regulation
• Aldosterone
• ADH
• ANP
– Homeostatic imbalances
• Hyponatremia
• Hypernatremia

16. Hypertonic Alterations - Related to sodium gain or water loss
• Hypernatremia
– Serum sodium >146 mmol/L
– Water movement from the ICF to the ECF
• Intracellular dehydration
– Manifestations:
• Convulsions, pulmonary edema, tachycardia, etc.
• Water deficit
- Dehydration
- Renal free water clearance
- Manifestations:
– Tachycardia, weak pulses
– Elevated hematocrit and serum sodium level
Hypotonic Alterations - Related to Hyponatremia or free water excess
• Hyponatremia
- Serum sodium level <135 mmol/L
- decreases the ECF osmotic pressure, and water moves into the cell
- Manifestations:
- muscle weakness, coma
• Water Excess
- Compulsive water drinking
- Syndrome of inappropriate ADH (SIADH)
- Manifestations:
- cerebral edema, muscle twitching, headache, and weight gain

17. Electrolytes
• Chloride (Cl-) - 95-103 mmol/L
– Major ECF anion
• helps balance osmotic potential and electrostatic equilibrium
between fluid compartments
• plasma membranes tend to be leaky to Cl- anions
– Regulation: aldosterone
– Homeostatic imbalances
• Hypochloremia - results in muscle spasms, coma (usually
occurs with hyponatremia) often due to prolonged vomiting
(elevated sweat chloride diagnostic of Cystic Fibrosis)
Electrolytes
• Potassium (K+)
– Major ICF cation, concentration maintained by the Na+/K+ pump
• intracellular 120-125 mmol/L
• plasma 3.5-5.0 mmol/L
– Very important role in resting membrane potential (RMP) and in
action potentials = essential for transmission and conduction of nerve
impulses, normal cardiac rhythms, and skeletal and smooth muscle
contraction
• Changes in pH affect K+ balance
– Hydrogen ions accumulate in the ICF during states of acidosis. K+
shifts out to maintain a balance of cations across the membrane.
• Aldosterone, insulin, and catecholamines influence serum potassium
levels
• Homeostatic imbalances
• Hypokalemia
• Hyperkalemia

18. • Hypokalemia
- Potassium level <3.5 mmol/L
- Causes can be reduced intake of potassium, increased entry of potassium,
and increased loss of potassium
- Manifestations:
Membrane hyperpolarization causes a decrease in neuromuscular
excitability, skeletal muscle weakness, smooth muscle atony, and cardiac
dysrhythmias
• Hyperkalemia
- Potassium level >5.5 mmol/L
- Caused by increased intake, shift of K+ from ICF, decreased renal excretion,
insulin deficiency, or cell trauma
- Mild attacks
- Hypopolarized membrane, causing neuromuscular irritability, Tingling of lips
and fingers, restlessness, intestinal cramping, and diarrhea
- Severe attacks
- The cell is not able to repolarize, resulting in muscle weakness, loss or
muscle tone
Electrolytes
• Calcium (Ca2+)
– Most abundant ion in body
• plasma 2.3-2.6 mmol/L
• most stored in bone (98%) as hydroxyapatite
- Necessary for structure of bones and teeth, blood clotting, hormone
secretion, and cell receptor function
- Regulation:
• Parathyroid Hormone (PTH) - ↑ blood Ca2+
• Calcitonin (CT) - ↓ blood Ca2+
– Homeostatic imbalances:
• Hypocalcemia - muscle cramps, convulsions
• Hypercalcemia - vomiting, cardiovascular symptoms, coma;
prolonged abnormal calcium deposition, e.g., stone
formation

19. Electrolytes
• Phosphate (H2PO4-, HPO42-, PO43-)
– Important ICF anions; plasma 1.7-2.6 mmol/L
• most (85%) is stored in bone as calcium salts
• also combined with lipids, proteins, carbohydrates, nucleic acids (DNA
and RNA), and high energy phosphate transport compound
• important acid-base buffer in body fluids
– Regulation - regulated in an inverse relationship with Ca2+ by PTH and
calcitonin and Vitamin D (If the concentration of one increases, that of the other
decreases)
– Parathyroid hormone (PTH) - Increases plasma calcium levels
– Vitamin D = Fat-soluble steroid - Increases calcium absorption from the GI tract
– Calcitonin - Decreases plasma calcium levels
– Homeostatic imbalances
• Phosphate concentrations shift oppositely from calcium concentrations
and symptoms are usually due to the related calcium excess or deficit
Hypophosphatemia and Hyperphosphatemia
• Hypophosphatemia
– Osteomalacia (soft bones)
– Muscle weakness
– Bleeding disorders (platelet impairment)
– Anemia
– Leukocyte alterations
• Hyperphosphatemia
– High phosphate levels are related to the low calcium levels
- Increased neuromuscular excitability (partial depolarization)
- Muscle cramps

20. Electrolytes
• Magnesium (Mg2+)
– 2nd most abundant intracellular electrolyte, 0.8-1.3 mmol/L in plasma
• more than half is stored in bone, most of the rest in ICF
(cytoplasm)
• important enzyme cofactor; involved in neuromuscular activity,
nerve transmission in CNS, and myocardial functioning
– Homeostatic imbalance
• Hypomagnesemia - Associated with hypocalcemia and
hypokalemia, Neuromuscular irritability,Tetany, Convulsions,
Hyperactive reflexes vomiting, cardiac arrhythmias
• Hypermagnesemia - Muscle weakness, Hypotension,
Respiratory depression, Lethargy, drowsiness, Bradycardia
Acid-Base Balance
• Normal metabolism produces H+ (acidity)
• Three Homeostatic mechanisms:
– Buffer systems - instantaneous; temporary
– Exhalation of CO2 - operates within minutes; cannot
completely correct serious imbalances
– Kidney excretion - can completely correct any imbalance
(eventually)
• Buffer Systems
– Consists of a weak acid and the salt of that acid which
functions as a weak base

21. Acid-Base Balance
• Carbonic Acid - Bicarbonate Buffer
– A weak base (carbonic anhydrase)
H+ + HCO3- ⇔ H2CO3 ⇔ H2O + CO2
• Phosphate Buffer
NaOH + NaH2PO4 ⇔ H2O + Na2HPO4
HCl + Na2HPO4 ⇔ NaCl + NaH2PO4
• Protein Buffer (resp. hemoglobin & albumin)
Most abundant buffer in body cells and plasma
Amino acids have amine group (proton
acceptor = weak base) and a carboxyl group
(proton donor = weak acid)
Acid-Base Balance
• CNS and peripheral
chemoreceptors control
changes in blood pH
• Increased [H+] causes
immediate hyperventilation
and later increased renal
secretion of [H+] and [NH4+]
• Decreased [H+] causes
immediate hypoventilation
and later decreased renal
secretion of [H+] and [NH4+]

22. Acid-Base Imbalances
• Acidosis
– High blood [H+]
– Low blood pH, <7.35
Alkalosis
– Low blood [H+]
– High blood pH, >7.45
• Acid-Base imbalances may be due to problems with ventilation or due to a
variety of metabolic problems
– Respiratory Acidosis (pCO2 > 45 mm Hg)
– Respiratory Alkalosis (pCO2 < 35 mm Hg)
– Metabolic Acidosis (HCO3- < 23 mmol/l)
– Metabolic Alkalosis (HCO3- > 26 mmol/l)
• Compensation: the physiological response to an acid-base imbalance
begins with adjustments by the system less involved
Causes of Acid-Base Imbalances
• Respiratory Acidosis
– Chronic Obstructive Pulmonary Diseases e.g., emphysema,
pulmonary fibrosis
– Pneumonia
• Respiratory Alkalosis
– Hysteria
– Fever
– Asthma

23. Causes of Acid-Base Imbalances
• Metabolic Acidosis
– Diabetic ketoacidosis, Lactic acidosis
– Salicylate poisoning (children)
– Methanol, ethylene glycol poisoning
– Renal failure
– Diarrhea
• Metabolic Alkalosis
– Prolonged vomiting
– Diuretic therapy
– Hyperadrenocortical disease
– Exogenous base (antacids, bicarbonate IV, citrate toxicity after
massive blood transfusions)
Metabolic Acidosis

24. Metabolic Alkalosis
Respiratory Acidosis

25. Respiratory Alkalosis
Electrolyte Balance
Electrolytes have 4 important physiological functions in the body
• essential minerals in certain biochemical reactions
• control osmosis = control the movement of water between
compartments
• maintain acid-base balance
• conduct electrical currents (depolarization events)
Regulators:
Aldosterone ↑ [Na+] [Cl-] [H2O] ↓ [K+]
Atrial Natriuretic Peptide (opposite effect)
↓
Antidiuretic Hormone ↑ [H2O] (↓ [solutes])
Parathyroid Hormone ↑ [Ca++] ↓ [HPO4-]
Calcitonin (opposite effect)
Female sex hormones ↑ [H2O]

26. Electrolytes
• Sodium (Na+) - 136-146 mmol/liter
– Most abundant cation
• major ECF cation (90% of cations present)
• determines osmolarity of ECF
PlasmaOSM = 2[Na+] + 2[K+] + [Urea] + [Glucose]
– Regulation
• Aldosterone
• ADH
• ANP
– Homeostatic imbalances
• Hyponatremia
• Hypernatremia
Hypertonic Alterations - Related to sodium gain or water loss
• Hypernatremia
– Serum sodium >146 mmol/L
– Intake of hypertonic salt solution
– Water movement from the ICF to the ECF
• Intracellular dehydration
– Manifestations: in consequence of cell dehydration
• Excitability, convulsions, or on the other hand drowsiness
accompanying with pulmonary edema, tachycardia, etc.
• Water deficit
- Dehydration (osmotic diuresis at glycosuria (diabetes),
gastrointestinal losses-osmotic diarrhea, infectious enteritis, high
fever, burn injury, elevated perspiration)
- Renal free water clearance
- Manifestations:
– Tachycardia, weak pulses
– Elevated hematocrit and serum sodium level

27. Hypernatremia
Serum sodium >160 mmol/L in 60 % lethal
Therapy: at water deficit – isotonic solutions (physiological saline
solution) or slightly hypotonic (2/3 F)
at normovolemia or hypervolemia – thiazide diuretics
(hydrochlorothiazide, decreasing of electrolytes reabsorption in
renal tubules) and 5% glucose
frequent monitoring of electrolyte plasma level during the
treatment, avoid to fast reestablishment of the electrolyte level
(max 1-2 mmol/L/h and 12 mmol/L/day
Hypotonic Alterations - Related to Hyponatremia or free water excess
• Hyponatremia
- Serum sodium level <135 mmol/L
- decreases the ECF osmotic pressure, and water moves into the
cell
--- losses of Na+ by GIT (emesis, diarrhea), kidney
(hypoaldosteronism, thiazide diuretics), perspiration, burn injury
---edema at heart failure, cirrhosis, nephrotic syndrome
- Manifestations: in consequence of brain edema and increase of
intracranial pressure
- disorientation, lethargy, apathy, headache, nausea, muscle
weakness, coma
• Water Excess
- Compulsive water drinking
- Syndrome of inappropriate ADH secretion (SIADH)
- Manifestations:
- cerebral edema, muscle twitching, headache, and weight gain

28. Hyponatremia
- water moves into cells based on osmolarity difference, brain cells (neurons)
decrease water uptake by compensatory mechanisms decreasing the intracellular
! osmolarity by elevation of K+ efflux (during 24h), and organic substances metabolism
(during 48h, e.g. elimination of polyalcohols, aminoacids, cholin derivates)
Therapy:
the major risk is to fast reestablish the normal level of Na+ ions. The lower
! osmolarity of neurons due to compensatory mechanisms causes water efflux from
the neurons, the neurons will shrink and released from myelin sheath!!!
1. if the disnatremia was developed during the last 48hrs, than fast correction
could be made (1-2mmol/L/h)
2. if plasma [Na+] is 105-120 mmol/L and neurological symptoms are present make
the correction by 1-2mmol/L/h
without neurological symptoms the speed of correction could be only
0.5mmol/L/h
3. if plasma [Na+] is less than 105 mmol/L, first 20 mmol/L at 1-2mmol/L/h, and then
slowly
Hyponatremia
Calculation of total need of Na+
mmol Na+ = mass (kg) x f x (targeted Na+ - determined Na+)
f = 0.6 for man
f = 0.55 for woman
Example: 70 kg weighted man has plasma [Na+] 115 mmol/L, we would like to
increase the [Na+] to 127 mmol/L/day (i.e. by 12 mmol/L)
mmol Na+ = 70 x 0.6 x (12) = 504
concentrations of available salt solutions:
0.9% NaCl (physiological saline solution)…1ml = 0.15 mmol Na+ and Cl-
10% NaCl ….1ml = 1.7 mmol Na+ and Cl-
5.8% NaCl …1ml = 1 mmol Na+ and Cl-
4.2% NaHCO3 ….1ml = 0.5 mmol Na+ and HCO3-

29. • Chloride (Cl-) - 95-108 mmol/L
– Major ECF anion
• helps balance osmotic potential and electrostatic equilibrium
between fluid compartments
• plasma membranes tend to be leaky to Cl- anions
– Regulation: aldosterone
– Homeostatic imbalances
• Hypochloremia - results in muscle spasms, coma (usually
occurs with hyponatremia) often due to prolonged vomiting
(elevated sweat chloride diagnostic of Cystic Fibrosis)
Hypochloremia with normonatremia results in metabolic
hypochloremic alkalosis
Heperchloremia with normonatremia results in metabolic
hyperchloremic acidosis
Combined disbalances are treated based on the plasma [Na+]
Hypochloremia with normonatremia or hypernatremia (e.g. due to
administration of drugs with Na+ , such as NaHCO3, Na-lactate, Na-acetate,
..), vomiting at hyperaldosteronism (e.g. at activation of JG cells due to
stenosis of renal artery)
1. treatment of the cause, e.g. antiemetics at vomiting
2. solution NaCl, KCl at hypokalemia, 4.2% Argininhydrochloride at significant
alkalosis
Calculation of total need of Cl-
mmol Cl- = mass (kg) x 0.3 x BE
where BE is base excess…. is in the normal range from -2.5 to +2.5 mmol/L, is equal to
amount of strong acid (or base) which is needed to titrate 1L of plasma to pH 7.4 at normal
pCO2 (5.3 kPa and temp. 37 ° C)
in the case, where respiratory compensatory mechanism is involved in regulation of pH (at
the alkalosis is pCO2 due to hypoventilation), then use Nejedly’s formula:
pHdetermined-pHtargeted
mmol Cl- = mass (kg) x 0.3 x BE x
pHdetermined-pHX
pCO2 2 2.5 3 3.5 4 4.5 5 5.5 6 6.5 7 7.5 8 8.5 9 9.5
pHX 7.67 7.61 7.567 7.517 7.487 7.457 7.427 7.397 7.377 7.35 7.332 7.314 7.298 7.28 7.263 7.248

30. Hyperchloremia with normonatreia
1. treatment of the cause, obstruction of urinary tract (accompanied with
hypernatremia and hyperkalemia), hypoaldosteronism, drug
administration e.g. HCl, NH4Cl, lysine-HCl, arginine-HCl), acute
diarrhea (accompanied with hypokalemia)
2. treatment of acidosis by NaHCO3
if pH of artery blood is <6.9 apply 100 mmol NaHCO3/2h
if pH is from 6.9 to 7.0 apply 50 mmol NaHCO3/1.5h
always check after 1h [K+]
• Potassium (K+)
– Major ICF cation, concentration maintained by the Na+/K+ pump
• intracellular 120-125 mmol/L
• plasma 3.5-5.5 mmol/L
– Very important role in resting membrane potential (RMP) and in
action potentials = essential for transmission and conduction of nerve
impulses, normal cardiac rhythms, and skeletal and smooth muscle
contraction
• Changes in pH affect K+ balance
– Hydrogen ions accumulate in the ICF during states of acidosis. K+
! shifts out to maintain a balance of cations across the membrane.
• Aldosterone, insulin, and catecholamines influence serum potassium
levels
• Homeostatic imbalances
• Hypokalemia
• Hyperkalemia

31. • Hypokalemia
- Potassium level <3.5 mmol/L
- Causes: intake reduction of potassium, and increased loss of potassium (by GIT-
vomiting, diarrhea, urinary tract-osmotic diuresis (diabetes), hyperaldosteronism)
- Manifestations:
Membrane hyperpolarization causes a decrease in neuromuscular excitability,
skeletal muscle weakness, smooth muscle atony, and cardiac dysrhythmias
Estimation of total K+ deficit from
plasma [K+] and pH
Therapy: severe hypokalemia (<2 mmol/l
requires fast i.v. administration of K+ in form of
KCl solution (0.75 mmol/kg/1h, more safety is 20
mmol/h repeatedly, one that dose increases
plasma [K+] app. by 0.25mmol/l
you can use a formula to calculate a total need of
K+: ECT(L)
mmol K+ = 0.3 x mass (kg) x (4.4 - plasma [K+]) +
substitution of losses
losses: mainly by urine = volume x urine [K+]
available solutions: 7.5% KCl (1ml = 1mmolK+), 13.8% KH2PO4 (1ml = 1mmolK+)
! these solutions have to be added into glucose solution with max. [K+] 40mmol/l, at
max appl. speed 20 mmol/h and max day dose 150 mmol
• Hyperkalemia
- Potassium level >5.5 mmol/L
- Caused by increased intake, shift of K+ from ICF (at acidosis),
decreased renal excretion, insulin deficiency, or cell trauma (release of K+
ions)
- Mild attacks
- Hypopolarized membrane, causing neuromuscular irritability, Tingling
of lips and fingers, restlessness, intestinal cramping, and diarrhea
- Severe attacks
- The cell is not able to repolarize, resulting in muscle weakness, loss
or muscle tone
Therapy:
1. based on antagonistic effect of Ca+ ions on cell membrane (20ml of
10% Ca-gluconicum)
2. appl. of insulin (10-20 IU/h) {stimulates K+ influx into muscle cells}
always with glucose infusion!!! (50g/h)
3. diuretics (furosemid)
4. cation exchanger (resonium)
5. haemodialysis

32. Calcium (Ca2+)
– Most abundant ion in body
• plasma 2.3-2.6 mmol/L
• most stored in bone (98%) as hydroxyapatite
- Necessary for structure of bones and teeth, blood clotting, hormone
secretion, and cell receptor function
- Regulation:
• Parathyroid Hormone (PTH) - ↑ blood Ca2+
• Calcitonin (CT) - ↓ blood Ca2+
- Homeostatic imbalances:
Hypocalcemia (necrotic pancreatitis, malabsorption, hypoparathyreosis,
vitamin D deficit (osteomalacia)) - muscle cramps, convulsions
Therapy: 1. cause, 2. 10% Ca-gluconicum (10ml ampules, 1ml =
0.25mmol)
Hypercalcemia (hyperparathyreosis, hypervitaminosis D, osteolytic tumor
metastasis)- vomiting, cardiovascular symptoms, coma (critical [Ca+] is
above 3.75 mmol/l); prolonged abnormal calcium deposition, e.g.,
stone formation
Therapy: 1.cause, 2. increase of diuresis by furosemide (at 3L/day),
glucocorticoids decreasing Ca+ absorption by intestine, calcitonin
Phosphate (H2PO4-, HPO42-, PO43-)
– Important ICF anions; plasma 0.7-1.5 mmol/L
• most (85%) is stored in bone as calcium salts
• also combined with lipids, proteins, carbohydrates, nucleic acids
(DNA and RNA), and high energy phosphate transport compound
• important acid-base buffer in body fluids
– Regulation - regulated in an inverse relationship with Ca2+ by PTH and
calcitonin and Vitamin D (If the concentration of one increases, that of
the other decreases)
– Parathyroid hormone (PTH) - Increases plasma calcium levels
– Vitamin D (fat-soluble steroid) - Increases calcium absorption from the
GI tract
– Calcitonin - Decreases plasma calcium levels
– Homeostatic imbalances
• Phosphate concentrations shift oppositely from calcium
concentrations and symptoms are usually due to the related
calcium excess or deficit

33. Hypophosphatemia and Hyperphosphatemia
• Hypophosphatemia
(abrosia, malnutrition, renal losses, hyperparathyreosis)
– Osteomalacia (soft bones)
– Muscle weakness
– Bleeding disorders (platelet impairment)
– Anemia
– Leukocyte alterations
Therapy: significant decrease <0.3 mmol/l - for first 3 days 30 mmol,
maintenance dose 10 mmol/d
available solutions: 13.6% KH2PO4 (1ml = 1 mmol K+ and 1 mmol
H2PO4-, 10% Na2HPO4 (1ml = 0.6 mmol Na+, 0.3 mmol HPO4-2)
• Hyperphosphatemia (renal failure, hyperthyreosis)
– High phosphate levels are related to the low calcium levels
- Increased neuromuscular excitability (partial depolarization)
- Muscle cramps
Therapy: decrease of intestine absorption by antacids,
haemodialysis
Magnesium (Mg2+)
– 2nd most abundant intracellular electrolyte, 0.8-1.3 mmol/L in plasma
• more than half is stored in bone, most of the rest in ICF (cytoplasm)
• important enzyme cofactor; involved in neuromuscular activity, nerve
transmission in CNS, and myocardial functioning
– Homeostatic imbalance
• Hypomagnesemia - Associated with hypocalcemia and hypokalemia
(abrosia, alcoholism, malabsorption, diarrhea, renal losses)
Neuromuscular irritability, Tetany, Convulsions, Hyperactive reflexes
vomiting, cardiac arrhythmias,
Therapy: at acute stages (cardiac arrhythmias) 20-30 mmol in 200ml 5%
glucose per 20 min, mild severe stages per 3h, asymptomatic stages per
24h, repeatedly with frequent level monitoring
available solution: 10% MgSO4 (1ml = 0.4 mmol Mg+), 10% MgCl2 (1ml =
0.5 mmol Mg+ and 1mmol Cl-)
• Hypermagnesemia – (acute or chronic renal failure, cells trauma),
Muscle weakness, Hypotension, Respiratory depression, Lethargy,
drowsiness, Bradycardia
Therapy: Ca salts as an antagonist, haemodialysis

34. Acid-Base Balance
• Normal metabolism produces H+ (acidity)
• Three Homeostatic mechanisms:
– Buffer systems - instantaneous; temporary
– Exhalation of CO2 - operates within minutes; cannot
completely correct serious imbalances
– Kidney excretion - can completely correct any imbalance
(eventually)
• Buffer Systems
– Consists of a weak acid and the salt of that acid which
functions as a weak base
Acid-Base Balance
• Carbonic Acid - Bicarbonate Buffer
– A weak base (carbonic anhydrase)
H+ + HCO3- ⇔ H2CO3 ⇔ H2O + CO2
• Phosphate Buffer
NaOH + NaH2PO4 ⇔ H2O + Na2HPO4
HCl + Na2HPO4 ⇔ NaCl + NaH2PO4
- mainly intracellularly, during acidemia proton is bound, during alkalemia proton is
released via cell membrane K+/H+ antiporter
• Protein Buffer (resp. albumin & hemoglobin )
Amino acids have amine group (proton
acceptor = weak base) and a carboxyl group
(proton donor = weak acid)
hemoglobin- oxyhemoglobin systém, where
oxyhemoglobin is stronger acid than
hemoglobin (proton is more simply released)

35. Acid-Base balance systems in blood
1. Carbonic Acid - Bicarbonate Buffer 53 %
2. Hemoglobin-oxyhemoglobin 35 %
3. Plasma proteins 7 %
4. Phosphate buffers 5 %
plasma pH 7.37-7.43
Examples:
Prescribe infusion therapy for mineral blood alteration:
a) 70 kg man with polyuria 3.5 L/d, plasma [K+] = 2.8 mmol/L, urine
[K+] = 13 mmol/L and with normal levels of other minerals and
normal blood pH
b) 60 kg woman with plasma [Cl-] = 78 mmol/L with normal levels of
other minerals and blood pH 7.52, pCO2 6.5 kPa, BE +4.2 and
normal renal function