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Fluid and Electrolytes

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Alfred Jarvis

on 9 June 2015

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Transcript of Fluid and Electrolytes

Muscle has more water, fat cells have less water
Body fluids are in constant motion transporting nutrients, electrolytes, and oxygen to cells while carrying away waste products
Fluid Intake and Loss
Intake Sources -

IVs Fluids
Fluid and Electrolytes
primary fluid in the body, more important than any other nutrient (we can only survive a few days without water)
More important to life than any other nutrient

Carries nutrients and waste products

Participates in metabolic reactions, food digestion, solvent for minerals, vitamins, glucose

Lubricant and cushion for the joints, eyes, spinal cord

Maintains blood volume

Aids in regulation of body temperature

Water is found in foods

Daily need is about 2000 mL -3000 mL (2 to 3 L) “intake” per day

Fluid output 2300-2600 mL/day

1 liter of water weighs 1kg

(Sudden changes in body weight are important to indicate fluid weight imbalances)
but not in alcohol - “acts as a diuretic = dehydrates you”
All important information to retain
(However, some will say I/O [Intake/Output] is the same)

70-80% - newborn (full-term)

Liquids (1500 mL/day)
Solid foods (800 mL/day)
Metabolism (300 mL/day)

Kidney (1200-1500 mL/day - 1500 for an adult)

Skin (500-600 mL/day) - insensible loss

Lungs 300 ml - insensible loss

GI tract (100-200 mL/day)

Drainage from fistulas/drains, GI suction, salivation (feces)

8% from sweat and 4% from feces
Fluid loss routes


Regulated by intake, output, acid-base balance, hormones, and cell integrity

Electrolytes are obtained from food and some drinks (Gatorade)

Kidneys control most electrolytes by excretion or absorption

cellular electrolyte

Controls and regulates water balance

cellular electrolyte

Helps maintain
cellular water balance

Transmit nerve impulses to muscle and contract skeletal and smooth muscles
Determines whether water is retained, excreted, or moved

Imbalances cause neurological problems

Sodium shares a reciprocal relationship with chloride

Sodium shares an inverse relationship with potassium:
if one is high than the other is low (vice versa)
Sodium (Na) 135-145 mEq/L –
Associate "Na" with neuro-problems

(Increased with poor kidney function)

(Decreased with excessive urination, diarrhea, vomiting)

K Imbalances cause cardiac problems

Potassium (K) 3.5-5.0 mEq/L -

Always associate "K" with cardiac functions

(Increased with poor kidney function, Na lowered)

(Decreased with excessive vomiting or diarrhea, Na increased)

Chloride shares a reciprocal relationship with sodium

(CI) 97-108
(also important with acid base balance)

Requires Vitamin D for absorption

Shares a reciprocal relationship with phosphate
(Ca) 8.6-10.2 mg/dL

Shares a reciprocal relationship with calcium

(PO4) 2.5-4.5 mg/dL
Osmolarity is particles per liter
Osmolality is particles per kilogram (most labs use this)
Pay attention to serum osmo or urine osmo
Osmo measures concentration of dissolved particles (mostly determined by sodium, glucose, and BUN)
Looking at solute to water ratio

Osmolarity and Osmolality
(terms often used interchangeably-slightly different calculations)

High is water deficit (concentrated blood)

Low is water excess (dilute)

Serum osmo is 280-300 mOsm/kg

Together are used to determine what is causing a sodium imbalance

Fluid problem or kidney problem determination

Urine osmo is 50-1200 mOsm/kg
(avg – 500-800 mOsm/kg)
Distribution of body fluids
“Fluid inside cells”

“Fluids outside of cells”
- Interstitial
Fluid between cells the ‘"Third Space''
(around blood lymph, bone, connective tissue)


“areas enclosed by membranes (CSF, cerebrospinal, pleural, peritoneal, joint fluids, synovial fluids)”

- Intravascular
(blood plasma)

Extracellular 33%,
Intracellular 66% 
Interstitial 25%
Plasma 8%

Body Water Percentage:
Change in electrolytes = acid base problems

Fluids and electrolytes are constantly shifting from compartment to compartment to allow all those fluid body processes.

Because we have cell membranes that separate these body fluid compartments water can pass through those because they are permeable.

However, molecules and electrolytes pass through them more slowly and pass through the four mechanisms
(Filtration, Osmosis, Diffusion, and Active Transport)

Regulation of Fluid & Electrolyte Movement

Also to use some sort of system such as a pump
(sodium and potassium pump that requires ATP to move both substances in opposite directions – used to control cell volume and intracellular concentration)
Active Transport –

important in transporting gases, sometimes requires a transport system “facilitated diffusion”
(insulin and glucose, glucose cannot move through on its own and needs insulin) – movement of particles and fluids.
Diffusion -

refers to
hypertonic, isotonic, and hypotonic fluids that causes cells to shrink or swell

Differences in water volume, hydrostatic pressure, water pushing pressure, which moves fluids through the membranes, through the cell, and vessel walls (seen as edema).

– major regulatory of fluid balance

– stimulates thirst

Endocrine system
- helps control the fluid and electrolyte balance (when pituitary releases ADH or the adrenal cortex releases aldosterone)

– senses high volumes and low volumes through stretch receptors in the right atrium. Has the ability to stop ADH. Water tries to follow the sodium

Regulation of Water Balance

Capillary or interstitial pressure changes
-fluids shift
(albumin can move fluids, decreased protein can causes third spacing)
– pressure altered with shifts

Fluid Spacing

"Normal spacing" -
Normal distribution of fluids (IC and ECF)
First spacing -
"Edema" -
Abdnormal of accumulation of interstitial fluid

Second spacing -

Ascites is the build up of fluid in the space between the lining of the abdomen and abdominal organs (the peritoneal cavity).
Third spacing -
"Crystalloids is equal to body fluid"

and keeps fluid in the intravascular volume without causing any kind of fluid shift from a compartment
Isotonic -

Hypertonic -

¼ NS

Increase in ADH and ANP (More water is reabsorbed and sodium and water excreted [which normally these are lower blood volume and pressure])
Gerontologic Considerations (elderly people)

Loss of subcutaneous tissue
Elderly Continued

History – nutrition, I/O (ask about intake and output), insensible losses (breathing fast, sweating), use of diuretics/laxatives, weight changes, kidney (affects fluids and electrolytes) or endocrine disorders, LOC, mental status, depression, eating disorders, alcohol intake

Physical – hydration status, skin turgor (except in older people), mucous membranes (pink, wet), I/Os (Intake and output)

Dx tests – electrolyte levels, BUN, glucose, creatinine, pH, bicarb, osmolality, Hgb, Hct, urine dipstick, urine pH, and urine specific gravity.

Assessment Considerations

Primarily means Dehydration
(No Water, No Salt, or Both)

Profuse sweating (diaphoresis)





Renal failure

DI (diabetes insipidus)

Primarily losing water

No Water (hypertonic)

Water intoxication (too much water –most common cause)

Chronic illness, malnutrition, renal failure

Primarily losing electrolytes (least common cause of fluid volume deficit)

Cells swell causes neuro problems (OCD constantly drinking water)

No Salt (hypotonic)


Poor intake


Due to a lose of both water and electrolyte (typical dehydration)

Both (isotonic)

Low BP

High HR

Dry mouth


Rapid weight loss

Low urine output (because no fluids intake)


Lethargy (Lack of energy or enthusiasm)

SG>1.030, high Hct, high BUN, low Na, high osmo

Fluid Volume Deficit

Increase fluids (oral if patient is alert) intake with vigorous exercise

NS or LR (no potassium until urine output is increased)

Avoid drinking fluids that contain alcohol or caffeine. This increases fluid excretion.

Daily weight, strict I/Os (Intake/Output)

Older adults have an increased risk for dehydration due to a decrease in total body mass, which includes total body water content. The thirst mechanism is less sensitive is less sensitive in older adults.

May need antidiarrheals, antiemetics (against vomiting and nausea), abx, antipyretics (reduce fever)


Superfluous amount of sodium and water levels

Causes (Hypervolemia “isotonic,” Water intoxication “hypotonic,” excess Na intake “Hypertonic”…)

Fluid Volume Excess

Overabundant amount of IV fluid (extracellular fluid)

Kidney failure


Pump fails and overloads the patient

Hypervolemia (isotonic)

CHF (Congested Heart Failure)


IV fluids

Psychological problems (compelled to drink water)

Wound irrigation

Wrong type of IV fluids

Water intoxication (hypotonic)

Over-abundant amount of salt (sodium)

3% saline IV (to cause fluid exchange)

Superfluous amount of NaHCO3 (sodium bicarb)
– rare (consuming too much salt or intake of sodium "salt")

Rapid weight gain


High BP

Bounding pulses

May have increased urine output

JVD (jugular venous distension)

Crackles (fluids in the lungs)

Dyspnea (difficulty breathing)

Decreased LOC (Level of Consciousness)

Low Hct, low BUN, high Na, low osmo

Fluid Volume Excess

Diuretics (osmotic diuretics such as mannitol)

Fluid restriction (no IV fluids).

Sodium restriction

Daily weights, monitor I/Os (Implement/Monitor Intake and Output)

Interventions -

Major cation of ECF (extracellular fluid - regulates body fluid and determines whether water is retained, excreted, or moved from one space to another, primary cause of osmolality, change in sodium affects plasma volume, blood pressure, ICF “intracellular” and ECF “extracellular”. Also combines with chloride or bicarb to prevent acid base balance)

Sodium level reflects the ratio of sodium to water

Stored by kidneys and regulated by ADH & aldosterone (conserves sodium)

GI tract absorbs sodium from food (output from urine and sweat)

Imbalances are typically associated with fluid volume problems

Foods high in sodium: processed meats, condiments, and dairy

Sodium has an inverse relationship with potassium, so if one is high the other is low.

Sodium problems = brain problems

Sodium (135-145 mEq/L)

Low lab values because it is the primary ion of the ICF

Major cation of ICF (intracellular fluid)

Sodium-potassium pump is a major controller (naturally we have no hormonal control over potassium) – moves potassium into the cell and pumps the sodium out

Moves into cells during formation of new tissues and leaves the cell during tissue breakdown

Primary source of reabsorption of potassium is the kidneys

Aldosterone does increase sodium and will decrease potassium by having the kidneys secrete it (kind of hormonal control)

Primary reason for high potassium levels is because the kidneys are impaired

Source of potassium – diet

Primary route of loss – kidneys

Increases when the pH is low, so if the body is in acidosis, then hydrogen ions will shift in and out of the cells as potassium will shift in the opposite direction causes to increase

Foods – avocado, fish, banana, orange juice, raisins, dried fruits, meat, milk, fruits, veggies, salt

Potassium associated symptoms = heart problems (disrupts electrical condition “high or low”)

Potassium 3.5-5.0 mEq/L

Max concentration in IV fluids is 40 mEq/L (per liter - IV bag could have up to 40 mEq)
Potassium Administration Rules:

Free or Ionized calcium versus bound calcium (attached to protein) we usually measure free or ionized calcium

Affects transmission of nerve impulses, heart, muscles, and blood clotting

To absorb we must have vitamin D

Primary Calcium from Dietary intake and absorption from the intestines

Primary source is bones

Regulated by parathyroid hormone (causes calcium to increase, tells the body to release it from bones, and increases Vitamin D activation and decreases the kidneys from excreting calcium).

Calcitonin (secreted by the thyroid) decreases calcium levels by inhibiting bone reabsorption (opposite of parathyroid), and vitamin D

Calcium and phosphorus have an inverse relationship if one is high the other will drop

Affects transmission of nerve impulses, heart and muscle contractions, blood clotting, and forming of teeth and bone

8.6-10.2 mg/dL

Low = excitability and tetany of the muscle (spasms of the hands and feet, cramps, spasm of the voice box (larynx), and overactive neurological reflexes)

High = harder arrhythmias and interrupts the muscles cells


Normal Phosphate 2.5-4.5 mg/dL – if phosphate high then calcium is low (reciprocal relationship)

Most phosphorus is in the bones and ICF (intracellular fluids) – helps us with nutrient metabolism and acid base buffering and balancing calcium

Kidneys major route of excretion

Found most in fish or dairy cheese milk yogurt or meats

Regulated by the parathyroid hormone

Phosphate Imbalances

Most stored in the bones found in the intracellular fluids

Affects blood coagulation and skeletal muscle contractions

Food source: avocado, spinach, meats, dairy, and veggies

Regulated by GI absorption and renal excretion

Can affect the heart and muscular skeletal function

Magnesium Imbalances

Loop diuretics
: Lasix – tremendous loss of potassium

Thiazide diuretics
: ACTZ, such as hydrochlorides

Potassium sparing diuretics
: spironolactone

: potassium most common one to give (remember rules)

: binds with potassium to remove it from the body (comes in liquid or powder)

General Rules:

Do not give at night (patients will be up all night urinating and can causes problems)

Commonly given with anti-hypertensive medication

All but potassium-sparing will decrease potassium levels


Many diseases and treatments affect this balance

Insensible water loss -
trauma, burns, extreme stress, fever, breathing quickly (tachypnea), ventilator, all of these increase fluid loss.
(mostly from the kidneys, minimum amount loss of urine per day 400-600 mL/day)

Must have urine output -
(must have at least 600 milis a day before giving any potassium supplement, have to be sure that the body can expel before giving the medication or could give them hyperkalemia)

Never give IV push (bolus is in an IVPB [Intravenous piggy-back, which is appropriate to administer)

Patient must be on cardiac monitor

Often Assess IV site for irritation (prefer CVC “central venous catheter” but does not have to be this site)

Always dilute potassium and give no more than 20 mEq (for bolus), no faster than 1 hr (always in a bolus IVPB)

Percent of body weight of water is decreased (40% instead of 60% - decreased muscle mass)

Structural changes in the kidney and decreased renal blood flow

Decreased GFR

Decreased creatine clearance

Loss of ability to concentrate urine and thus conserve water

Decrease in renin and aldosterone (so the body cannot retain sodium or secrete potassium)
Fluid Volume Deficit

Over-abundant amount of sodium intake (hypertonic)
Test question: All the symptoms of fluid volume excess and something about giving IV fluids = Stop all IV fluids, unless trying to exchange fluids
regulated through thirst strive
“triggered by rising blood osmolality or decreasing blood volume, but does not work for everyone, someone in a coma-thirst strive not stimulated”
distribution affects fluid balance (commonly measured in mili-equivalents,

includes salt, acids, bases, and some proteins
“osmotic power.”

Chemicals dissolved in the body fluid
includes glucose, lipids, keratin urea
- do not have electrical charge & do not effect water, but do affect water balance)
– tells concentration ability of the kidney and if there is a problem of ADH compares to serum osmo

85% -newborns (premature)

64% Child (1-12 y)

Puberty-39y (Male: 60%, Female: 52%

40-60 y (Male: 55%, Female: 47%

Older than 60 y (Male: 52%, Female: 46%)
Side note: Infants, very young children, and very old adults are at a greater risk for Fluid & Electrolyte Imbalances
FVD includes hypovolemia-isotonic (loss of water and electrolytes from the ECF) and dehydration-osmolar (loss of water with no loss of electrolytes)
Hypovolemia can lead to hypovolemic shock
(Patient-Centered Care)
Nursing Care
Subjective (Opinions) & Objective (Facts) Data
Signs & Symptoms
Vital Signs -



Thready pulse
(a scarcely perceptible and commonly rapid pulse that feels like a fine mobile thread under a palpating finger)


Orthostatic hypotension

Decreased central venous pressure

(increased respirations

FVEs includes hypervolemia-isotonic (water and sodium are retained in abnormally high porportions)
& overhydration-osmolar (more water is gained than electrolytes)
Subjective Data & Objective Data
S/S (Signs/Symptoms) Continued
Vital Signs -
Bounding pulse
Increased central venous pressure

Neuromusculoskeletal -
Muscle weakness
Weight gain
Diminished breath sounds
Other signs -
Distended neck veins
Pale and cool skin

Chronic stimulus to the kidney to conserve sodium and water (heart failure, cirrhosis, increased glucocorticosteroids)

Abnormal renal function with reduced excretion of sodium & water (renal failure)

Interstitial to plasma fluid shifts (hypertonic fluids, burns)

Age-related changes in cardiovascular and renal failure

Excessive sodium intake
Abnormal gastrointestinal (GI) losses -
Nasogastric suction
Abnormal skin losses -
Diaphoresis (profuse sweating)
Abnormal renal losses -
Diuretic therapy
Diabetes insipidus
Renal disease
Adrenal insufficiency
Osmotic diuresis
Third spacing -
Intestinal obstruction
Altered intake, such as nothing by mouth NPO
Complications -
Hypovolemic Shock
Hypovolemia can lead to hypovolemic shock
Hypovolemia Causes -

Body fluids are distributed between intraceullar (ICF), which is two thirds of body water, and extracellular (ECF), which is one third of body water, fluid compartments.

Fluid can between compartments (through selectively permeable membranes) by a variety of methods (diffusion, active transport, osmosis) to maintain homeostasis

Balance is maintained through input and ouput

Intake is regulated by thirst

Output regulated by the kidneys, skin, lungs, and GI tract

Fluid imbalances that nurses should be familiar with are
-Fluid volume deficits
- Fluid volume excess
(occurs in an attempt to maintain a normal blood pressure)
Neuromusculoskeletal -





(temporary loss of consciousness caused by a fall in blood pressure)
Gastrointestinal -


Dry furrowed tongue



Acute weight loss
Renal -

(decreased production & concentration of urine)
Other signs -

Diminished capillary refill

Cool clammy skin


Sunken eyeballs

Flattened neck veins

Poor skin turgor


Vital organ hypoxia/anoxia -
Decreased hemoglobin oxygen saturation &
pulse pressure (systolic-disastoloic blood pressure)
Nursing Actions (Interventions)

Administer oxygen

Provide fluid replacement with the following:
-Colloids (whole blood, packed RBCs, plasma, synthetic plasma expanders)
-Crystalloids (Ringer's lactate, normal saline)
• Administer vasoconstrictors, such as dopamine (Intropin) & norepinephrine (Levophed); coronary vasodilators, such as sodium nitroprusside (Nipride); and/or positive inotropic
• Perform hemodynamic monitoring
(expert collection and analysis of qualitative and quantitative data of cardiopulmonary function)
Body Water Percentages:
Simple way to memorize

Makes up 83% of blood

Removes waste

Accounts for 22% of bones

Cushions Joints

Makes up 75% of muscles

Helps body absorb nutrients

Protects and cushions vital organs

Helps convert food into energy

Moistens Oxygen for breathing

Helps carry nutrients and oxygen to cells

Regulates body temperature

Composes 75% of the brain
Total Body Water (TBW)
(70Kg man)
42 Liters
TBW = 0.6 x Body weight
Extracellular Fluid Volume (ECF)
1/3 of Total Body weight = 14 Liters
Intracellular Fluid Volume (ICF)
2/3 of Total Body Weight =
28 Liters
Interstitial Fluid
3/4 of ECF =
10.5 Liters
1/4 of ECF =
3 Liters
Transcellular Fluid
0.5 Litre

Needs to maintain a balance of 1/3
- Na+(sodium)
- CI- (chloride)

Needs to maintain a balance of 2/3
- K+(potassium)
- PO4 (phosphate)
Extracellular contains:

molecules have to move against the concentration gradient which requires some energy
similar to melting a lump of sugar into a cup of water
movement of water only between two compartments,
(example, thirst or sweating that causes cells to shrink and makes us thirsty)
normal distribution of fluid in the intracellular fluid and extracellular fluid compartments.
fluid accumulation in areas that normally have no fluid or a minimum amount of fluid

Ascites (trapped)

Burn edema (trapped)

Fluid trapped (and not available for use) in part of the body and cannot be easily exchanged with extracellular fluid

LR (lactative ringers)
(withhold fluid intake – become dehydrated trying to prevent the incontinence )
(unable to hold a glass, less likely to get the hydration they need)

Mental status changes (confused or disoriented unable to get fluids needed)

(increased loss of moisture through the skin and skin turgor is not accurate for elderly people – so use intake, output, and daily weights)

Musculoskeletal changes
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Replacement or maintenance fluids

NS (normal saline)

D5W– given fast will become hypotonic

ISOTONIC Fluid: expands ECF volume, used in hypovolemia, resuscitation, shock, diabetic ketoacidosis, metabolic alkalosis,hypercalemia, mild NA deficit. May be administered with blood. Examples: NS, LR, D5W

"Thicker than body fluid"

Will shift into the blood plasma by moving from the tissue cells by pulling it out

Causes cells to shrink

Used to replace electrolytes or hyponatremia – can cause fluid overload

3% NS (normal saline)

D5 ½ NS (lactative ringers and a half of normal saline)

HYPOTONIC Fluid: provides NA,CL, and free water. Used to treat hypertonic dehydration, NA & CL depletion, and gastric fluid loss, not for 3rd spacing or Increased ICP. Administer cautiously bec it can cause fluid shifts from vascular system into cells, resulting in CV collapse & Inc ICP. (0.45% NACL)

HYPERTONIC Fluid: used to increase ECF volume, decrease cellular swelling. Must be given slowly, can cause intravascular volume overload & pulm edema (3% NACL, 5% NACl)

"Thinner than body fluids"

Shift fluids from the intravascular to the tissue cells

Used to hydrate cells “get them bigger”

Can deplete the circulatory system so use 1/2 NS)

½ NS (fluid of half normal saline)

1/3 NS
COLLOID Solution:
used as volume/plasma expander for intravascular part of ECF

Example: Dextran 40, Dextran 70

Used to treat hypovolemia in early shock to increase pulse pressure, cardiac output, and arterial blood pressure

Not a substitute for blood or blood products
- 60% of healthy adult’s weight is water
- 45-55% in older adult
- 70-80% in infants

Vital to cell function

Contains solutes: O2, glucose, electrolytes

subdivided into compartments (adults): -Intravascular- plasma- 20% of ECF
-Interstitial- surrounds cells, transports wastes, nutrients-75% of ECF

Transcellular-CSF, pericardial, pancreatic, pleural,
intraocular, biliary, perotineal, synovial

ECF is transport system, carries nutritents to & waste products from cells

Interstitial fluid transports wastes via lymph system, capillaries

Maintaining balance of fluid volumes, elect compositions ESSENTIAL to health.

Fluids within cells
● 42% of total body weight
● Two thirds of total body water or 25 liters
● 28 liters in males
● 20 liters in females

Fluid outside of cells
● One third of total body water or 12 liters
● Interstitial (8 L), intravascular(3 L), and transcellular (1 L)
● Makes up 17% of total body weight

Solvent – component of solution that can dissolve a solute
In human body, solvent = water

Solutes = crystalloids, colloids

Osmolality – concentration of solutes
- Extracellular Fluid → sodium, glucose, urea
- Intracellular Fluid → potassium, glucose, urea

Movement of fluid and solutes together across a membrane from one compartment to another
- From area of higher pressure to lower pressure
- Hydrostatic pressure – force within a fluid compartment that pushes water out of vascular system at capillary level, pressure a fluid exerts on walls
Substances move across membranes using metabolic energy
- From less concentrated solution to more
concentrated solution

Hydrostatic Pressure
- Force within a fluid compartment
- Major force that pushes water out of vascular system
at capillary level

Oncotic Pressure
- Protein is a major colloid; albumin is a large protein molecule
that acts like a magnet to attract water
- Plasma colloid osmotic pressure in capillaries is approximately
25 mmHg

Fluid Shifts
• Edema: Plasma-to-interstitial fluid shift

-Elevation of hydrostatic pressure
-Decrease in plasma osmotic pressure
-Elevation of interstitial osmotic pressure
• Interstitial fluid to plasma

-Fluid drawn into plasma space with increase in plasma osmotic pressure
-Compression stockings decrease peripheral edema by increasing the hydrostatic pressure.

Water deficit (Increased ECF osmolality) pulls water from cells to equalize both compartments.

Water excess (Decreased ECF osmolality) develops from gain or retention of excess water.

Brain cells are especially sensitive.

Fluid Movement Between ECF and ICF

Total Average

2600 ml
causes of fluid loss:

Maintaining Homeostasis
- Kidneys primary regulator
Regulating Body Fluids
Antidiuretic hormone
: regulates water excretion from kidney
Renin-angiotensin-aldersterone system
: renin converts antio to angio I; Angio I converts to Angio II; aldosterone promotes NA retention.
How is Aldosterone stimulated to increase sodium retention and potassium excretion?
Natriuretic Peptides
Natriuretic peptides are produced by cardiomyocytes in the heart.

Atrial natriuretic peptide (ANP): peptide hormone
-Released in heart, promotes
-NA wasting

B-type natriuretic peptide (BNP) in the left ventricle
Regulating Electrolytes

Maintain fluid balance

Contribute to acid-base regulation

Facilitate enzyme reactions

Transmit neuromuscular reactions


Sodium (Na+)

Potassium (K+)


Magnesium (Mg++)

Chloride (Cl-)

Bicarbonate (HCO3-)

Phosphate (HPO4-)
• Intracellular Fluid (ICF)-
Prevalent cation is K+
Prevalent anion is HPO4

• Extracellular Fluid (ECF)
Prevalent cation is Na+
Prevalent anion is Cl-
Regulating ElectrolytesComposition of Electrolytes:

Contributes to serum osmolality
- Regulated ADH, Aldosterone function
- Control and regulate body fluids
- Maintains blood volume

- Salt
- Processed Foods

- Maintains ICF osmolality
- Transmits nerve and other electrical impulses
- Skeletal, cardiac, and smooth muscle function
- Regulates acid-base balance

Dairy products, Fresh oysters, Sardines, canned salmon, Molasses, Macaroni, Nuts: almonds, filberts, and Greens: collard, mustard, spinach, turnip
- Normal range is 1.3-2.3 mg/dL

Regulated by parathyroid hormone

Approximately one third is bound to protein

- Intracellular metabolism, Protein synthesis
- Operates sodium-potassium pump
- Regulates cardiac and neuromuscular function
- Relaxes muscle contractions

Unprocessed cereal grains, nuts, legumes, green leafy vegetables, seafood, peanut butter, and cocoa

Controlled by the parathyroid hormone and calcitonin

- Bone formation (skeletal maintenance)
- Transmission nerve impulses, neuromuscular function
- regulates Muscle contraction (cardiac)
- Blood coagulation
- Activation of certain enzymes

Transmission of nerve impulses, heart and muscle contractions, blood clotting, formation of teeth and bone

Lean meats, whole grains, green leafy vegetables, potatoes, beans, fruit (bananas, melons, and oranges), sodas

Produced in the stomach, where it combines with hydrogen to form hydrochloric acid

- Regulates serum osmolality & blood volume
- Regulates ECF balance
- Major component of stomach fluids, Regulates acid-base balance
- Buffer in oxygen-carbon dioxide exchange

Works with sodium to maintain osmotic pressure (always relates to sodium)

Chloride is primarily obtained from the diet as table salt

(change in phosphate equal change in calcium)

Balance is intertwined with calcium (change in phosphate equal change in calcium)

Most phosphorus is in the bones and ICF (intracellular fluid) - helps us with nutrients, metabolism, acid base buffering and balancing calcium

- Bone and tooth formation
- Metabolism of protein, fat, carbohydrates
- Cellular metabolism, chemical actions of cells
- Essential for Muscle, nerve, and RBC function
- Regulates acid-base balance
- Regulates calcium levels

Almonds, dried beans, barley, bran, pumpkin, squash, and cheese, milk, organ meats, nuts, fish, poultry

- Major body buffer
- Regulates acid-base balance
- Produced through metabolic processes

Regulating Electrolytes

infants and young children are more vulnerable to imbalances; BSA proportionately greater, % body water greater, Resp & metabolic rates higher
Very young: - Pediatric differences:

hirst response blunted;

Nephrons less able to conserve H2O;

Chronic diseases affect F&E balance;

Hormonal changes lead to dec in renin & aldosterone;

ss of sq tissue leads to inc loss of moisture
Very old:- Older adults:
- Individuals with serious injuries
- Individuals with significant health conditions: certain chronic conditions predispose to f&e like hx of renal failure, heart failure, resp dysfx, dm, liver disease, Addison’s disease, Cushing dis., thyroid disease

Reduced thirst mechanism results in decreased fluid intake.
There are normal physiological changes of aging that may alter the responses of the elderly to F&E imbalances:

Structural changes in kidneys decrease ability to conserve water.

Hormonal changes lead to decrease in renin and aldosterone; increase in ADH and ANP

Hormonal changes lead to decrease in renin and aldosterone; increase in ADH and ANP

Fluid and electrolyte replacement in the infant and child should be implemented cautiously to prevent overcorrection.

Infants have the highest proportion of water, accounting for 70-80% of their body weight.

Have a larger extracellular fluid volume.

The very young are at risk for fluid and electrolyte imbalances.
Pediatric Maintenance Fluid Requirements

Daily Fluid Requirements by Body Weight

Minimum Urine Output by Age Group
Intervention - Treatment

Note lab orders to repeat NA+ levels as ordered, tell pt that this will occur, keep pt apprised of results, assist with ADL’s

Oral or IV replacement of NA, Cl, & H2O in same concentration found in body fluid

Oral rehydration fluids, salty liquids such as broth & tomato juice, or Normal Saline.

Protect from injury that could result from dizziness & weakness secondary to postural hypotension

Restrict NA & saline intake (low sodium diet)


Identify underlying pathology & treat

Note lab orders to repeat NA+ levels as ordered, tell pt that this will occur, keep pt apprised of results, assist with ADL’s
Intervention - Treatment:
Professional Nursing Competencies- Skills

Assessment of intake and output

Assessment of hydration/dehydration status (mucous membrane, tears, skin turgor, edema)

Nursing History
− Risk factors
− Current and past medical history
− Medications – including over the counter
− Functional, developmental, socioeconomic factors
− Age
− Lifestyle

Assessment, continued
Current Fluid and Electrolyte Status

Intake and output:
dr can order, nurse can monitor f&e
< normal; abnormal losses occurring, i.e., surgical drain, vomiting; getting IV tx; medical prob affecting f&e; pt NOT physically stable, i.e., post op or trauma

ALL oral/parenteral fluids, oral = liquids ingested or that turn into liquids at room temp, i.e., jello, sherbet, frozen treats, ice cream; tube feedings thru abdomen. Parenteral: IV fluid, IV med, blood products

Operative site (chest tube, hemovac), NG tube. Diaphoresis/drainage on dressing: hard to measure, but needs noted in documentation

Do Each shift, then 24 hour totals.

Teach pt/family about it, WHY it is done, do in Milliliter
-(ounce = 30 ml)
-(milk = 240 ml), etc. Ice chips = half volume
Assessment, continued

OUTPUT: no toilet paper in container.
Transfer urine from bedpan to measuring device

Incontinent: say how many times, like X2.
- Using commode: place “hat” on seat
- Empty foley/drainage bags at end of shift
- Urine output <30 ml/hr = impending renal failure or marked ECF deficit. Maintain ACCURATE data.

WEIGHT: gives data re. fluid balance.
Rapid changes in wt = body fluid changes
-Each KG weight change = 1 liter of fluid change.
-The greater the wt change, the greater severity of problem.
-Nursing: do DAILY weights. WEIGH at SAME time every day (before bkft is recommended). Use bed scales if needed.
Assessment, continued

Get dietician help
Increasing Oral Fluids:

Keep water pitcher full, fluids close to pt.
Set goals for pt.

Get family involved, bring favorite fluids, assist pt (put straw in mouth, keep diet restriction, like low K+ diet = no orange juice)

Offer custard, soup, ice cream.

See DR order for SPECIFIC fluid intake: divide per shift, largest amount in daytime & evening.

With tube feedings, do this also.

Usually, there is a MEAL allocation, & amount for nurse to use with meds.
Assessment, continued

Heart failure, renal failure (See DR order).

Can have FREE WATER restriction, pt can have other liquids. Divide per shift amounts.
Assessment, continued

To help decrease thirst, avoid salty/sweet fluids. Gum, hard candy may help (draws fluid into oral cavity bec sugar inc tonicity). Can have rebound effect. So, may use sugar-free candy/gum.

Avoid dry foods: crackers, bread

Allow to rinse mouth with sip of water & spit out

Frequent oral care

Moisten lips with water-soluble gel to prevent drying/cracking
Assessment, continued

Liquid oral K+ supplements: taste unpleasant, mix w. juice.

IV K= irritating to veins, potentially lethal, administer & monitor carefully (K by scale, no >10-20meq/hr)

Nurses INITIATE, MONITOR, AND DISCONTINUE iv’s. DR orders type & amount (given in homes also).
Assessment, continued

Skin turgor: changes can indicate fluid balance.
flushed, dry skin may = fluid volume deficit

Edema: excess accumulation of interstitial fluid; check around eyes, sacrum, & extremities

Pitting edema = 10% increase in body wt. Range: 0-4+
1+ = 2mm, just perceptible
2+ = 4 mm, moderate edema
3+ = 6mm, deeper
4+ = 8mm or >

Precise measurement = measuring circumference of body parts (leg, abd)

Mucous membranes
− Sunken eyes
− Cardiovascular system
− Respiratory system
− Edema
− General appearance

Press finger into tissue over bony prominence (lower tibia): best place

Clinical Measurements
− Daily weights
− Vital signs
− Fluid intake and output
 Oral fluids
 Tube feedings
 Parenteral fluids and medications
 Irrigants
 Output

Assessment, continued

Diagnostic Tests
− Osmolality
 Serum: 280-300 mOsm/L; dec in water excess, inc in water deficit
 Urine: 50-1200 mOsm/L; concentrated = inc
− Urine specific gravity: 1.010-1.020; concent = inc
− Urine sodium and chloride excretion

Assessment, continued

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