Fluid/Electrolyte Balance

Adult Male body water composition

60% water

Adult Female Water Body Composition

55% water

Normal Osmolality/Osmolarity

270-300

60-40-20 rule

60% of body weight is water, 40% is intracellular fluid (ICF), and 20% is extracellular fluid (ECF)

What works to regulate fluids in the body

heart and kidneys

What has more water in the body, muscle or fat?

muscle has more water than fat

Extra-Cellular Fluid

Fluid outside of cell

Comprises 1/3 or 14 L of total body H2O

Extracellular fluid consists of

INTRAVASCULAR FLUID (PLASMA) - is 92% water-

contains your salts, and enzymes, clotting factors, red and white blood cells.

TRANSCELLULAR FLUIDS- CSF, PLEURAL FLUID, joint fluid, and eye fluid

INTERSTITIAL FLUID- FLUID BETWEEN CELLS AND OUTSIDE BLOOD VESSELS

Intra-Cellular Fluid

FLUID INSIDE CELL

CONTAINS 2/3 OR 28L L OF TOTAL BODY H2O

More abundant electrolytes outside of the cell

Na+, Cl-, and HCO3-

More abundant electrolytes inside of the cell

Mg+, K+

Capillary membrane

it is a barrier of endothelial cells, that have pores- that transport blood, oxygen and nutrients between the blood and Interstitial fluid.

also where O2 and nutrients are exchanged for wastes and CO2

The cell membrane

a semi-permeable lipid layer-

separates the interior of the cell from the outside of the cell. It also regulates materials entering and exiting the cell

Active Transport

Movement of particles from a place of lower concentration to higher concentration through the use of energy (ATP)

Active transport Example

An example is a sodium-potassium pump moving potassium in the cell and sodium out of the cell

Diffusion

PASSIVE MOVEMENT OF SOLUTES OR PARTICLES ACROSS A PERMEABLE MEMBRANE, FROM AREAS OF HIGHER CONCENTRATION TO AREAS OF LOWER CONCENTRATION

Diffusion Example

EX- ALVEOLAR GAS EXCHANGE

O2 is diffused to the blood from alveoli and CO2 diffuses to the alveoli from the blood

OSMOSIS

THE MOVEMENT OF WATER THROUGH A SELECTIVELY OR SEMI-PERMEABLE MEMBRANE

Requires no energy

Colloids

Albumin and other proteins found in the blood that are suspended in the plasma and contribute to the osmotic pressure of the blood, which helps to maintain fluid balance and prevent fluid from leaking out of blood vessels.

COLLOID ONCOTIC PRESSURE OR ONCOTIC (OSMOTIC) PRESSURE

An inward pulling force exerted by the colloids in the blood

It draws fluid back into capillaries, counteracting hydrostatic pressure

Filtration

Fluid movement through a cell or blood vessel membrane because of hydrostatic pressure(blood pressure)

the net of forces—forces that move fluid out of the vascular system or cells, and forces that move fluid or water back into them ( osmotic or oncotic pressure)

Does not require energy

Filtration Example

Glomular filtration in the kidneys

under pressure from the arteries- blood enters the kidney, driving filtrates through the glomeruli’s- from this filtration- water, urea, glucose, acids and various salts come out as filtrate- which are the substances in urine

When will the fluid exit the capillaries

when the hydrostatic pressure is greater than the blood colloidal osmotic pressure

Net force of + mm Hg

When will the fluid inside the capillaries achieve no net movement

when the hydrostatic pressure equals the colloid osmotic pressure

net force of 0 mm Hg

When will fluid reenter the capillaries?

When the colloid osmotic pressure is greater than the hydrostatic pressure

net force of - mm Hg

Fluid Homeostasis Result of Three Processes

Fluid intake & absorption - Regulated by thirst which occurs in the hypothalamus

Fluid distribution - Movement of fluid among compartments, and occurs by osmosis in the ICF and ECF. Fluid distribution between the vascular & interstitial parts of the ECF—filtration.

Fluid Output - of fluid output. RAAS is triggered when the kidneys sense low blood pressure or blood volume- RAAS raises blood volume and pressure.

Fluid intake and regulation (Fluid Homeostasis)

Regulated by thirst which occurs in the hypothalamus

increases, or concentration of solutes in the body, or blood volume decreases.

ADH is also released- raises blood volume and decreases urine output. Older people, infants, & patients with neuro and cognitive issues are at risk to be impaired

Fluid distribution (Fluid Homeostasis)

Movement of fluid among compartments, and occurs by osmosis in the ICF and ECF. Fluid distribution between the vascular & interstitial parts of the ECF—filtration.

Fluid Output (Fluid Homeostasis)

kidneys are major regulator

RAAS is triggered when the kidneys sense low blood pressure or blood volume- RAAS raises blood volume and pressure.

Normal Amount of Urine excreted per hour

30 ml/hr

Insensible water loss

water lost during salivation, sweating, breathing, waste excretion

Water or output cannot be measured

What Pts should be on IOs

Most likely all pts

Tonicity

the ability of a solution to cause a cell to gain or lose water

The driving force of a solution

Isotonic

IV SOLUTIONS THAT HAVE THE SAME OSMOLARITY (270-300MOSM/L) AS BODY FLUIDS

Do not result in any movement across the membrane through osmosis or diffusion

HYPERTONIC

IV SOLUTIONS with >300 MOSM/L HAVE A GREATER OSMOTIC PRESSURE

PULL FLUID FROM THE CELLS INTO THE VASCULAR SPACE.

HYPOTONIC

IV SOLUTIONS< 270MOSM/L

MOVE FLUIDS INTO CELLS

ICF volume expands

Isotonic IV solution Examples

Normal Saline

0.9% Sodium Chloride

Lactated Ringers solution

Isotonic IV solutions Indications

Should be used in pts in hypotensive and hypovolemic states because these pts require volume expansion

Older adults risk with isotonic IV solutions

Fluid overload

Fluid stays in the ECF-

and if the older adult has a decreased cardiac and/or renal function- the fluid can accumulate in the tissues and lungs- assess for crackles in lungs, and edema in extremities.

Hypertonic IV Solutions Indications

Used in pts with elevated cranial pressure or hyponatremia

Only infuse on an IV pump

Hypertonic IV Solutions Examples

3% Sodium Chloride

5% Dextrose in normal saline (D5NS)

5% dextrose in lactated ringers (D5LRS)

Hypertonic Solutions Risk

Have the potential to be deadly if they are infused too fast

Must be infused on a pump

Hypotonic IV Solutions Indications

Used in pts with dehydration or hypernatremia

Hypotonic IV solutions Examples

0.45% NS (Also referred to as one half normal saline)

0.45% sodium chloride

D5 0.45%NS

Dehydration

Fluid intake is needed

Weak or thready pulses

Look at labs, UA

Dehydration at risk population

Older adults, anyone cognitively impaired

Hypovolemia

Circulating blood volume is decreased

Dehydration Assessment

Skin turgor, decreased urine output, urine dark yellow or amber and concentrated,, mucous membranes, blood pressure- low, pulse rate elevated- thready, cap refill- greater than 3 seconds, increased respirations, altered mentation

Dehydration Lab Values

BUN increased, Creatinine will be increased if the severe and prolonged- as this affects the kidneys.

Hemoglobin and Hematocrit is increased due to the decreased circulating water volume-

Urine specific gravity is greater than 1.030- less fluid volume- more particles

Dehydration Treatment

Treat the cause

Isotonic IV fluids- encourage fluid

Fluid Overload Assessment

Listen to their lungs, do you hear crackles, wheezing, decreased or absent breath sounds. Are the respirations elevated, and/or the oxygen sats low?

Listen to the heart. Are heart sounds muffled? Do you see Jugular Venous Distention?

Do you see edema in the extremities? Did you check the patient’s sacrum, abdomen, pelvic area?

Fluid Overload Lab Values

BUN is decreased as the plasma level is increased and diluted from the fluid; Hematocrit is increased from the dilution of the volume of fluid

Fluid Overload Medication Treatment

Diuretics

Fluid Overload

AN EXCESS OF BODY FLUID INTAKE/INADEQUATE EXCRETION OF FLUIDS

FLUID INTAKE OR RETENTION IS > THAN THE BODY’S NEEDS

NET FLUID POSITIVE BALANCE

Bounding Pulses

Fluid Overload Effects this

CARDIAC/PULMONARY/RENAL SYSTEM ESP. IN OLDER ADULTS

Hypervolemia

Circulating blood volume is increased

ELECTROLYTES (IONS

DISSOLVED SUBSTANCES (SOLUTES) THAT HAVE AN ELECTRICAL CHARGE

Cation

POSITIVELY CHARGE IONS

Cation Examples

NA+, K+, CA+, MG+

Anions

NEGATIVELY CHARGED IONS

Anions Examples

CL-. HCO3-

MOST CRITICAL ELECTROLYTES FOR MAINTAINING HOMEOSTASIS

CA+, K+, MG+, & NA+

Hyperkalemia

K+ > 5.0 mE1-q/liter

Hyperkalemia Symptoms

Dysrhythmias- tall t waves

N&v, abd. Cramps,

hyperactive bowel sounds,

Diarrhea

Paresthesia - numbness in extremities

You notice everything is hyper

Hyperkalemia Causes

Caused by renal failure, acidosis, burns, starvation, meds

Hyperkalemia Treatment

meds- Kayexalate, lokelma, Furosemide

all used to get rid of extra potassium

Hyperkalemia - Nursing Considerations

Patient needs to be on heart monitor- watch for dysrhythmias

Low Potassium diet

Assess lab values

Give meds as ordered

Hypokalemia

K+ <3.5 meq/liter

Hypokalemia Symptoms

Dysrhythmias,

Decreased bowel sounds

Muscle cramps & weakness

Shallow breathing

Hypokalemia Causes

Caused by diuretics, alkalosis, diarrhea, severe vomiting, and gastric suctioning

Hypokalemia - Treatment

Administer k+ replacement- iv or po

Hypokalemia Nursing Considerations

Utilize heart monitor

Monitor potassium

Monitor for respiratory depression

Hypernatremia

Na level >145 meq/liter

a water deficit and is a hypertonic condition- body fluids are too concentrated

Hypernatremia Causes

Either a gain of more salt than water- or a loss of more water than salt

Hypernatremia Symptoms

The patient will have excessive thirst- body is trying to dilute the high sodium level

Elevated temp, dry, sticky membranes

The patient will also be restless, irritable, twitchy, have nausea/vomiting.

Increased pulse, increased BP

Hypernatremia Labs

increased serum sodium. Increased urine specific gravity

Hypernatremia Late signs

seizures can occur

Hypernatremia Treatment

patients are given a hypotonic solution)- this helps decrease the plasma sodium

D51/2NS, or ½ NS

Hyponatremia

Na levels <136 meq/liter

Hyponatremia Symptoms

•The patient will have weakness, fatigue,

•Headaches, confusion, lethargy, muscle twitching

•The patient may be also confused

NA < 115 can lead to this

coma and death

Hyponatremia Treatment

the patient may be placed on a fluid restriction (order from provider)- to help prevent further dilution of Na+.

The patient is also given Na+ replacement fluids such as NS.

In patients with severe cases- 3% NS is administered.

Hyponatremia Nursing Considerations

Monitor LOC, labs, neuro status, Strict Intake and Output.

You may also have an order that states “Free water limited to 1000cc’s/day- this is to avoid further dilution of the patient who has hypovolemia.

Hypercalcemia

Ca+ >10.5 mg/dl

Hypercalcemia Symptoms

•Fatigue, muscle weakness, kidney stones

•Headache, confusion, lethargy

•N&V, constipation, thirst

Cardiac dysrhythmias

can also increase digoxin levels as well

Hypercalcemia Causes

Caused by Bone cancer and other cancers increases calcium in bloodstream and

increased thiazides, increased serum lithium values , excessive calcium supp.

Hypercalcemia Treatment

•Treated by dc of calcium supp., low calcium diet, Normal Saline (dilutes the serum calcium level)-

Hypocalcemia

Ca+ < 9 mg/dl

Hypocalcemia Causes

alkalosis, chronic diarrhea, Vit. D deficiency

Hypocalcemia Symptoms

Bradycardia, hypotension,

Paresthesia in fingers, hyperactive reflexes, muscle cramps, tetany, twitchiness of muscles

Confusion, possible seizures

Decreased Blood pressure

Bone fractures can occur

A patient may have a normal serum level, but a total body deficit (as in osteoporosis)

Chvoteks’s Sign

Seen in hypocalcemia

involves twitching of facial muscles when the facial nerve is tapped, specifically in the area in front of the ear and below the cheekbone

Trousseau’s Sign

Seen in hypocalcemia

characterized by carpopedal spasm, or a hand and wrist spasm, that can be induced by inflating a blood pressure cuff on the arm

Hypermagnesemia

Mg+ > 2.1

Hypermagnesemia Symptoms

Flaccid muscle tone- diminishes the excitability of the muscle cells

Decreased deep tendon reflexes-Deep Tendon Reflex or DTRs- is a reflex arc by percussion or tapping on a tendon- the “knee jerk “ by tapping the knee- reflex is an example.

Hypotension

Peaked t-waves

Hypermagnesemia Causes

renal disease, acidosis, and over ingestion of magnesium containing products

hypermagnesemia Treatment

Treated with Ca gluconate, dialysis

Assess K+ levels as well- they like to hang out together

Hypomagnesemia

mg+ <1.3

Hypomagnesemia Causes

Caused by DKA, malabsorption in the gut, or poor diet, DKA, chronic laxative use, poor diet

Hypomagnesemia Symptoms

Muscle cramps, tremors- a deficit increases neuromuscular irritability and contractility, mood changes

Flat or inverted t waves, increased BP

Positive Chvostek may be seen

Hypomagnesemia Treatments

Treated with mg replacements- iv or po

check Potassium levels