Fluids and Electrolytes

ELECTROLYTES

Ions capable of carrying electric charges

AVP - Arginine vasopressin

Antidiuretic hormone is now called

serum; should be stored in red top

Specimen for electrolytes

Cations

positive charges; moves toward cathode

■ Anion

negative charges; move towards anode

Sodium (and Potassium

What is the most important electrolyte

- 135 to 145

Reference range: Sodium

3.5 to 5.1

Reference range: Potassium

extravascular; intravascular

Most of the potassium should be in the ____ space, not in the _____ space

Sodium, chloride, potassium

ELECTROLYTES: Volume and osmotic regulation

● Potassium, magnesium, calcium

ELECTROLYTES: Myocardial rhythm and contractility

Magnesium, calcium, zinc

ELECTROLYTES: Cofactors in enzyme activation

Magnesium

ELECTROLYTES: Regulation of the ATPase pump

Potassium, chlorine, bicarbonate, phosphate (but these two are not ions)

ELECTROLYTES: Acid-Base Balance

Magnesium. Calcium

ELECTROLYTES: Coagulation

Potassium, magnesium, calcium

ELECTROLYTES: Neuromuscular excitability

Magnesium

ELECTROLYTES: Production and use of ATP from glucose

slow heart

What happens if the potassium levels in the heart are low?

Active Transport

This requires energy (in the form of ATP) to move ions across cellular membrane ● Energy requiring since it is usually always against a concentration gradient

40-75%

Average water content of a human person is around --- of total body weight

TRUE

T/F: Women usually have lower water content than male

Transports nutrients to cells

Determines cell volume

Removes waste

Body's coolant

Functions of Water

Kidneys

What is the major organ to regulate your body volume?

OSMOLALITY

Physical property of solution that is based on concentration of solutes (mmol)/kg of solvent

Thirst

Secretion of AVP (ADH) by the hypothalamus

Physiological response that regulates osmolality

T

T or F: When ADH is increased, urination is decreased

ADH

What are the two major hormones that contributes to the regulation of your fluids and regulates

ADH/AVP

produced in they hypothalamus and stored in the posterior pituitary

275 to 295 mOsm/kg of plasma water

What is the normal plasma osmolarity?

4

For every 1-2% change in osmolarity, there is an increase release of AVP _ times (fourfold increase)

ANP (atrial natriuretic peptide)

○ Released from the myocardial atria

○ Promotes sodium excretion in the kidney

GFR (glomerular filtration rate)

increases the volume expansion and decrease with volume depletion

Lungs

Where can you find angiotensin I?

alam mo na yan

discuss RAAS process

Atrial Natriuretic Peptide (ANP)

Water volume that is high can be fixed by

Hypothalamus

What gland is responsible primarily for maintaining osmotic homeostasis?

Distal convoluted tubules and collecting ducts

What part of the nephrons are acted upon primarily by ADH?

Hypervolemia

What is the major stimulus to ANP production?

Freezing point depression

Vapor pressure

colligative properties

True

T or F: 🔑Any ⬆️increase in osmolality of your serum specimen can ⬇️ decrease freezing point depression and vapor pressure

Osmolality

is used to estimate the true osmolality or to determine osmolal gap

Osmolal gap

difference between the measured osmolality and the calculated osmolality

Osmolal gap

indirectly indicates the presence of osmotically active substances other than sodium, urea, or glucose

275-295 mOsm/kg

Reference Range for Osmolality: Serum

Sodium

Most abundant cation in the extracellular fluid

Sodium

Represents almost 90% of almost all extracellular cations

Its concentration in the ECF is much larger than inside the cell

Intake and excretion of water

RAAS

Regulation of Sodium

Hyponatremia

Low sodium 135 mmol/L (130 mmol/L)

Increased Sodium Loss

Increased water retention

Water imbalance

Causes of Hyponatremia

Hypernatremia

Less commonly seen in hospitalized patients

(related to sodium)

Lithium or NH4 heparin/oxalate

Anticoagulant Sodium Determination

(Suderman and Delory)

Colorimetric Method :sodium

Direct ISE

undiluted sample to interact with the ISE membrane

136-145 mmol/L

Sodium Reference Values Serum/Plasma

Potassium

Primary intracellular cation

Epinephrine

promotes cellular entry of potassium

Propranolol

impairs cellular entry of K

Exercise

Hyper osmolality

Cellular breakdown

Other factors that can cause the release of potassium

Hyperkalemia

The most common cause are decreased renal excretion but there can also be other causes

Hypokalemia or Hypopotassemia

When plasma potassium concentration is below the lower limit of your reference range

(Hoffman)

Colorimetric Method : k

3.4-5.0 mmol/L

Potassium Reference Values Serum/Plasma

Chloride

Extracellular anion - existing as NaCl (sodium chloride) or HCl (hydrogen chloride)

Chloride

Excreted with cations during massive diuresis or severe GI loss (vomiting, diarrhea)

98-107 mmol/L

Chloride Reference Values Serum/Plasma

Calcium

Most abundant mineral element in the body ● Important activator in the coagulation system

Bound - attached to albumin 40% Complex - 15%

Ionized - 45%

Three Forms of Calcium

Calcitonin

○ Inhibits the action of both PTH and Vit D

Osteoclasts

these are the cells of the body that breaks down the bone so that the calcium in those bones will be utilized

Osteoblasts

builds up of bones from the excess amount of calcium in the blood

Hyperparathyroidism

Hypervitaminosis D

Multiple myeloma

Sarcoidosis

Acromegaly

HYPERCALCEMIA

Hypoparathyroidism

Malabsorption

Rickets

Osteomalacia

Hyperphosphatemia

Tetany, muscle spasms, cramps, irritability

Acute pancreatitis

HYPOCALCEMIA

- 2.15-2.5 mmol/L

Normal Total Calcium

1.16-1.32 mmol/L

Normal Ionized Calcium

PTH

What is the hormone released initially because of hypocalcemia?

Magnesium

Fiske-Subbarow Method (Ammonium Molybdate Method) is the most common method used for the measurement of what serum electrolyte?

Lactate

by-product of an emergency mechanism produce a small amount of ATP when O2 delivery is severely diminished

Type A

Lactic Acidosis: associated with hypoxic conditions (shock, myocardial infarction, severe blood loss)

Type B

Lactic Acidosis: of metabolic origin (diabetes mellitus, severe infection, leukemia, liver or renal disease, and toxins [ethanol, methanol, or salicylate poisoning])

T

T/F for lactate : Heparinized blood may be used but must be delivered on ice and the plasma must be quickly separated

Iron

Stored in the liver, spleen, and bone marrow

Ferritin:

storage form of Iron

Hemosiderin

aggregates of ferritin

Transferrin

iron transport protein

65-170 ug/dL

Iron Reference Values Male

50-170 ug/dL

Iron Reference Values Female

Total iron binding capacity

Measures the transferrin level