Overview of

Fluids,Fluids, ElectrolytesElectrolytes BalanceBalance

MOHAMMED ALHABSI INDANAN,RNClinical Instructor

King Abdul Aziz Specialist Hospital-Taif

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Concept of Fluid & Electrolyte Balance:Concept of Fluid & Electrolyte Balance: Properties & components of Electrolytes Description & Measurement of Electrolytes Body Fluid Compartments Third Spacing Edema Description & Constituent of Body Fluids Body Fluid Transport Movement of Body Fluid Body Fluid Excretion

Surah Surah AL- MURSALATAL- MURSALAT (Those Sent Forth) (Those Sent Forth)

20

““ Have We not created You from Have We not created You from a f luid (Held) despicable?” a f luid (Held) despicable?” Holy Qur’anHoly Qur’an

Body Fluids

Intercellular

Intravascular

Interstitial

Body Water = 60% of a patient’s body weight

16%

4%40%

Figure 1-1

Fluid CompartmentsFluid Compartments

Intracellular spaceExtracellular space

InterstitialIntravascular

Solutethe substance that dissolved

Solventsubstance in which solute is dissolved

Osmolalityconcentration of solute per kg of water

Osmolarityconcentration of solute per L of solution

Solution- substance that dissolve in other substances

Composition of the Body FluidsComposition of the Body Fluids

The fluids circulating throughout the body in ECF & ICF spaces contain:

1. Electrolytes

2. Minerals

3. Cells

Movement of BODY FLUIDSMovement of BODY FLUIDS

DiffusionOsmosisActive TransportFiltration

Definition:Definition:Diffusion is the natural tendency of a substance to

move from an area of higher concentration to one of lower concentration.

OsmosisOsmosis fluid shift to the membrane from the region of low concentration to the region of high concentration.

Active TransportActive Transport this is movement of molecules against a concentration as they move from an area of lower concentration to an area of higher concentration and requires an energy.

FiltrationFiltration movement of water & solutes occurs from an area of high hydrostatic pressure to an area of low.

OsmosisOsmosisFigure 2.

FluidFluid

High Solution High Solution Concentration, Concentration,

Low Fluid Low Fluid ConcentrationConcentration

Low Solute Low Solute Concentration, Concentration,

High Fluid High Fluid ConcentrationConcentration

DiffusionDiffusion

High Solute ConcentrationHigh Solute Concentration Low Solute ConcentrationLow Solute Concentration

FluidFluid

SolutesSolutes

Figure 3.

Active transportActive transport

K K ++

K K ++

K K ++

K K ++ K K ++

K K ++K K ++

K K ++

K K ++ K K ++

K K ++

K K ++

K K ++

K K ++

K K ++

K K ++

K K ++ATPATP

ATPATP

ATPATP

ATPATP Na Na ++

Na Na ++

Na Na ++

Na Na ++ Na Na ++

Na Na ++

Na Na ++

Na Na ++

Na Na ++

Na Na ++

Na Na ++

Na Na ++

Na Na ++

Na Na ++

Na Na ++

Na Na ++

Na Na ++

Na Na ++

Na Na ++

Na Na ++

Figure 4.INTRACELLULAR FLUIDINTRACELLULAR FLUID

EXTRACELLULAR FLUIDEXTRACELLULAR FLUID

BLOOD BLOOD VESSELVESSEL

NORMAL NORMAL CELLCELL

ISOTONIC ISOTONIC

BLOOD BLOOD VESSELVESSEL

SHRUNKEN SHRUNKEN CELLCELL

HYPERTONICHYPERTONIC

HYPOTONICHYPOTONIC

BLOOD BLOOD VESSELVESSEL SWOLLEN SWOLLEN

CELLCELL

Electrolytes

Chemically, electrolytes are substances that become ions in solution & acquire the capacity to conduct electricity.

Essential for normal function of the cells & our organs.

Sodium, Potassium, chloride, & Bicarbonate

Sodium (Na)Sodium (Na)

135 to 145 mEq/L (135-145 mmol/L)Major positive ion in fluid outside the cells.Regulates the total amount of water in the

body & the transmission of into & out of cells.

Potassium (K+)Potassium (K+)

3.5 to 5.0 mEq/L (3.5 to 5.0 mmol/L)Major positive ion found inside the cells.Regulation of the heartbeat & function of

the muscles.

Chloride (Cl-)Chloride (Cl-)

98 to 108 mmol/LMajor anion (negatively charged ion)

found outside the cells & in the blood.Helping the body maintain a normal

balance of fluids

Bicarbonate (HCO3)Bicarbonate (HCO3)

22 to 30 mmol/LActs a buffer to maintain the normal level

of pH in the blood & other fluids in the body.

Measured to monitor the acidity of the blood & body fluids.

Third Spacing

Occurs when the fluid is “trapped” in the interstitial spaces.

Fluids shifts from the vascular space into an area where it is not readily accessible as extracellular fluid.

This fluid is remains in the body but is essentially unavailable for use, causing an isotonic fluid volume deficit.

Pt. may not manifest fluid loss or weight loss.

Decreased Oncotic Pressure

Loss of albumin or protein leads to decreased oncotic pressure, causing fluid to “leak” from the intravascular space to the interstitial space

Due to the loss in circulating fluid volume, cardiac output decreases

Causes of Fluid Shifts Albumin losses can occur in liver failure, liver

dysfunction, and malnutrition

Albumin losses can lead to fluid shifting into the peritoneum, causing ascites

Destruction of endothelial cells, such as in bowel surgery, can cause fluid to move and be trapped in the interstitial spaces

Fluid trapped in the lungs can lead to pulmonary edema

Inside the CellsInside the CellsInterstitial fluid trapping can cause

compression of the microvasculature, resulting in hypoperfusion and ischemia

Inflammatory “mediators” are released into the bloodstream, which can lead to systemic inflammatory response syndrome (SIRS)

Multiple organ dysfunction syndrome (MODS) occurs, leading to organ failure and death

What Happens When Fluids Shift? With decreased circulating volume,

baroreceptors in the aorta are activated Sympathetic nervous system releases

epinephrine and norepinephrine, causing vasoconstriction and an increased heart rate

Kidneys launch the renin-angiotensin-aldosterone system in response to a lower glomerular filtration rate

All this happens with the goal of increasing circulating volume, blood pressure, and cardiac output

Fluid Shift in the BowelFluid Shift in the Bowel

Causes abdominal distentionMeasure bladder pressure and

abdominal girth at least every 4 to 8 hours while signs are abnormal.

Monitoring the PatientMonitoring the PatientFluid shift will either resolve over the next

several hours (up to 48 hours) or the patient will continue to develop bowel edema and, eventually, ischemia

Closely monitor vital signs, urine output, peripheral perfusion, mental status, ventilation/perfusion status, hematocrit/hemoglobin, serum electrolytes (elevated lactate may indicate bowel ischemia)

Fluid ResuscitationFluid ResuscitationAdminister maintenance I.V. isotonic fluid

plus intermittent colloids (i.e., albumin); pulls fluid from the interstitial spaces into the intravascular space

Small dose of a loop diuretic, such as furosemide (Lasix) may be ordered if kidneys can’t get rid of the excess fluid

If hemoglobin is low, infuse blood products, such as packed red blood cells, as ordered to help increase oxygen and pull fluid from the interstitial space

EDEMAEDEMAIn fluid volume excess, both intravascular

& interstitial spaces have an increased water & Na content.

Excess interstitial fluidMost apparent areas where the tissue

pressure is low like around the eye.Dependent tissues known as dependent

edema , where hydrostatic capillary pressure is high.

3 MAIN MACHANISM OF EDEMA3 MAIN MACHANISM OF EDEMA

1. Increase capillary hydrostatic pressure

2. Decrease plasma oncotic pressure

3. Increase capillary permeability

1. Due to FVE that increase capillary hydrostatic pressure, pushing fluids into the interstitial tissues. This type of edema seen in dependent tissue such as feet, ankles, & sacrum.

2. Low level of plasma proteins from malnutrition or liver or kidney disease can reduce the plasma oncotic pressure.

3. With tissue trauma & some disorders like allergic reactions, capillaries becomes more permeable, allowing fluid to escape into interstitial tissues.

Pitting EdemaPitting Edema

That leaves a small depression or pit after finger pressure is applied to the swollen area.

The pit is caused by movement of fluid to adjacent tissue, away from the point of pressure.

Within 10 to 30 seconds the pit normally disappears.

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