NRS136-006

8/13/2019 NRS136-006

1/55

Fundamentals of

Fluid and Electrolyte BalanceParenteral Solutions

ADN136

Fall 09

8/13/2019 NRS136-006

2/55

Fluid Balance

Body fluid is body water in whichelectrolytes are dissolved

Bodywater makes up 60% of Total Body weight in young

men

50-55% in women

70-80% in infants

8/13/2019 NRS136-006

3/55

8/13/2019 NRS136-006

4/55

Fluid Balance (cont)

Homeostasis- Dependent on fluid andelectrolyte intake physiologic factors,disease state factors, external

environmental factors and pharmacologicintervention. Intracellular fluid(ICF) water in the cells =

40%

Extractracellular fluid (ECF) fluid out side

the cells = 20% 15% in tissue space (interstitial) outside the

blood vessel, between cells

5% in plasma (intravascular space)

8/13/2019 NRS136-006

5/55

Percentage of Body Fluid

8/13/2019 NRS136-006

6/55

Fluid Balance

Normal intake 1-3 L/day

200-300 ml produced by oxidation

Normal intake and output willbalance approximately every 72hours

8/13/2019 NRS136-006

7/55

Fluid Balance

Elimination of fluids is considered

Sensible (measurable) loss

Skin, Kidneys, Bowels, lungs lose fluid

300-500ml lost through lungs every 24hrs.

500ml lost with perspiration

Insensible (not measurable) loss

Considered to be 500-1000ml/day

Lost through GI tract only 100-200 ml/day

8/13/2019 NRS136-006

8/55

Fluid Balance (cont)

Loss from Diarrhea or intestinalfistula

Significant sweat loss when bodytemp >101F-38.3C or room temp >90F

When respirations > 20/min

Formula to calculate insensible loss

300-400ml/m2/day

8/13/2019 NRS136-006

9/55

Fluid Function

The fluid in the body has the following function:

1. Maintains blood volume

2. Regulates body temperature

3. Transports material to and from cells

4. Serves as an aqueous medium for cellularmetabloism

5. Assists digestion of food through hydrolysis

6. Acts as a solvent in which solutes are available

for cell function7. Serves as a medium for the excretion of waste

8/13/2019 NRS136-006

10/55

Fluid Transport

4 transport mechanisms

Passive transport

Passive diffusion-

Osmosis

Filtration

Active transport

8/13/2019 NRS136-006

11/55

Fluid Transport

Passive transport-non carrier mediatedtransport- Fluid moves throughmembranes with out the expenditure of

energy Passive diffusion- movement of water and

other elements in all directions from highconcentration to low concentration

Osmosis passage of water from low particleconcentration toward one of higher particleconcentration

Normal osmolarity280-295 mOsm/L Osmolarity of ICF and ECF is always equal

8/13/2019 NRS136-006

12/55

Fluid Transport (cont)

Filtration the transfer of waterand a dissolved substance from aregion of high pressure to a region

of low pressure. Force behind it ishydrostatic pressure (the pressureof water at rest) Pumping heat provides hydrostatic

pressure in the movement of water andelectrolytes from the arterial capillarybed to the interstitial fluid.

8/13/2019 NRS136-006

13/55


Plasma protein creates and osmoticpressure at the capillary membrane,preventing fluid from plasmaleaking into interstitial spaces

Osmotic pressure (created withinthe plasma) keeps water in the

vascular system

8/13/2019 NRS136-006

14/55


Starlings law of capillaries

Under normal circumstances fluidfiltered out of the arterial end of a

capillary bed and reabsorbed at thevenous end is exactly the same,creating a state of near equilibrium

8/13/2019 NRS136-006

15/55


Active Transportacts as aconcentration gradient ATPreleased from the cell to enable

substances to acquire the energyneeded to pass through the cellmembrane

Active Transport is vital for maintaining

the unique composition of both theintracellular and intracellularcompartments

8/13/2019 NRS136-006

16/55

Tonicity of Solution

Isotonic - .9% saline, 5%dextrose

same as body fluids

Osmolarity of 250-375mOsm/L

Remains within the ECF space

Used to expand ECF compartment

8/13/2019 NRS136-006

17/55

Isotonic Solution

8/13/2019 NRS136-006

18/55


Hypotonic contains less saltthan the intracellular space

2.5% DW Osmolarity below 250mOsm/L

Hydrates cells

Depletes the circulatory system

8/13/2019 NRS136-006

19/55

Hypotonic Solution

8/13/2019 NRS136-006

20/55


Hypertonic causes water fromwithin a cell to move to the ECFcompartment

Osmolarity of 375mOsm/l or greater

Used to replace electrolytes Used to shift EDF from interstitial tissue

to plasma

D5W, .9 Normal Saline

8/13/2019 NRS136-006

21/55

Hypertonic Solution

8/13/2019 NRS136-006

22/55

Homeostatic Mechanism

Regulation of body water ismaintained

Exogenous sources - Intake of food &Fluids (nurses responsibility)

Endogenous sources produce with inthe body through chemical exidationprocess (various body systemsresponsible)

8/13/2019 NRS136-006

23/55

Homeostatic Mechanisms

Renal System Kidneys filter 170L l of

plasma/day and excrete 1.5L of urine

Regulation of fluid volume and osmolarity byselective retention and secretion of body fluid

Regulation of electrolyte levels by selective

retention of needed substances and excretionof unneeded substances

Regulation of pH of ECF by excretion orretention of hydrogen ions

Excretion of metabolic wastes (primarily acids)

and toxic substances

8/13/2019 NRS136-006

24/55


Cardiovascular System

Pumping action of the heartprovidescirculation of blood through the kidneysunder pressure

Allow urine to form Renal perfusion makes renal function

possible

8/13/2019 NRS136-006

25/55


Lymphatic system

Serves as an adjunct to the cardio

vascular system by removing excessinterstitial fluid (lymph) and returningit to the circulatory system

Prevents fluid overload

8/13/2019 NRS136-006

26/55


Respiratory System

Lungs are vital for maintaininghomeostasis and constitute one of themain regulatory orgnas of fluid andacid base balance

Functions of the lungs

Regulation of metabolic alkalosis bycompensatory hypoventilation

Regulation of metabolic acidosis by

causing compensatory hyperventilation

Removal of 300-500 ml of water dailythrough exhalation

8/13/2019 NRS136-006

27/55

8/13/2019 NRS136-006

28/55

Physical Assessment

Vital signs, infusion rate of IV fluids,intake and output.

Neurological - Changes inorientation, irritability, lethargy,

confusion, seizures or coma Cardiovascular

Quality and rate of pulse

Peripheral vein filling

Orthostatic hypertension

Distended or Flat neck veins

8/13/2019 NRS136-006

29/55

Physical Assessment

8/13/2019 NRS136-006

30/55

Physical Assessment

Respiratory

Changes in respiratory rate

Tachypnea > 20/min or dysphnea indicateexcess Fluid Volume (FVE)

Moist crackles (FVE)

Shallow Slow breathing- MetabolicAcidosis

Deep rapid Breathing MetabolicAlkalosis

8/13/2019 NRS136-006

31/55

Physical Assessment

Skin Appearance & Temperature

Access skin turgor

Appearance of the tongue

8/13/2019 NRS136-006

32/55

Physical Assessment

Body Weight

Weigh Daily better indicator than I&Orecords

Loss or gain of 1 kg indicates a loss orgain of 1 L of body fluid

15% flucation is considered sever

8/13/2019 NRS136-006

33/55

Fluid Volume Imbalance

Fluid Volume Deficit

Common Causes of Isotonic Dehydration

Hemorrhage resulting in loss of fluid,

electrolytes, proteins and blood cells resultingin inadequate vascular volume

Gastrointestinal losses

Fever, environmental heat, profuse sweating

Burns Diuretics

Third spaced fluids

8/13/2019 NRS136-006

34/55


Causes of Hypertonic FluidDehydration

Inadequate fluid intake

Decreased water intake results in ECFsolute concentration and leads tocellular dehydration

8/13/2019 NRS136-006

35/55

8/13/2019 NRS136-006

36/55


Common causes of Hypotonic Overhydration (Water intoxication)

More fluid is gained than solute

Serum osmolality falls causing cells to swell

Repeated water enemas

Overuse of hypotonic IV fluids

Ingestion of inappropriately prepared formula

SIADH causes kidneys to retain large amounts

of water without sodium

Treatment- sodium and fluid restriction,diuretics, treat underlying cause.

8/13/2019 NRS136-006

37/55

Electrolyte Balance

Major electrolytes in body fluid aresodium, potassium, calcium, magnesium,chloride, phosphorus and bicarb

Expressed in meq/liter. Measureschemical activity or combining powerrather than weight

Each water compartment of the body

contains electrolytes Concentration and composition vary from

compartment to compartment

8/13/2019 NRS136-006

38/55

Electrolyte Balance (cont)

Physiological role of electrolytes Maintaining electroneutrality in fluid

compartments

Mediating enzyme reactions

Altering cell membrane permeability Regulating muscle contraction and

relaxation

Regulating nerve impulse transmission

Influencing blood clotting time

8/13/2019 NRS136-006

39/55

8/13/2019 NRS136-006

40/55

8/13/2019 NRS136-006

41/55


Signs and Symptoms - Marked thirst,elevated body temperature, swollentongue. Chronic Hyponatremia: impaired sensation of

taste, anorexia, muscle cramps, feeling ofexhaustion, apprehension, feeling of impendingdoom and focal weakness.

Treatment: Gradually lower seum sodiumlevel by infusion of hypotonic electrolytesolution .45 Normal Saline or D5W. Levellowered no more than 15 mEq/L in 8 hr.

8/13/2019 NRS136-006

42/55


Potassium: Physiological role

Regulation of fluid volume within the cell

Promotion of nerve impulse transmission

Contraction of skeletal smooth and cardiacmuscle

Control of hydrogen ion concentration, acid-base balance

Role of enzyme action for cellular energy

production.

8/13/2019 NRS136-006

43/55


Potassium is an intracellularelectrolyte with 98% in ICF and 2%in the ECF

Acquired thru diet and must beingested daily

Daily requirement is 40 mEq

Involved in muscle activity andtransmission of nerve impulses.

8/13/2019 NRS136-006

44/55


Hypokalemia (cont)Can causealkalosis

S&S fatigue, muscle weakness,

anorexia, nausea and vomiting,irregularity

Treatment at level less than3.5mEq/L replacement must be slow to

prevent hyperkalemia

8/13/2019 NRS136-006

45/55


Hyperkalemia- Serum plasma levelgreater than 5.5mEq/L Increased intake of potassium Decreased urinary excretion

Movement out of cells into extra cellular space. Signs & Symptoms

Changes shown on ECG Vague muscle weakness Flaccid paralysis Anxiety Nausea and vomiting Cramping and diaherrea

8/13/2019 NRS136-006

46/55


Calcium: Physiological role

Maintaining skeletal elements; calciumis needed for strong bones and teeth

Regulating neuromuscular activity

Influencing enzyme activity

Converting prothrombin to thrombin, a

necessary part of clotting. 99% resides in bones and teeth

8/13/2019 NRS136-006

47/55


Hypocalcemia: reduction in total bodycalcium levels Because of increase calcium loss, reduced

intake secondary to altered intestinalabsorption, altered regulation

hypoparathyroidism S & S:

Numbness of fingers, muscle cramps,hyperactive deep tendon reflexes, positiveTrousseauss sign and Chevosteks sign

Treatment with Calcium Gluconate oral orIV

8/13/2019 NRS136-006

48/55


Hyperclacemia: Excessive release ofcalcium from bone

S & S Neuromuscular symptoms,lethargy, bone pain, flank pain,pathological fractures, constipation,anorexia, N & V, Stone formation.

8/13/2019 NRS136-006

49/55


Magnesium: Physiological role

Enzyme action

Regulation of neuromuscular activity

Regulation of electrolyte balance,including facilitating transport ofsodium and potassium across cellmembranes, influencing the utilization

of calcium, potassium, and protein.

A major intracellular electrolyte

8/13/2019 NRS136-006

50/55


Hypomagnesemia: often overlooked incritically ill patients

Results from:

Chronic alcoholism Malabsorption syndrome

Prolonged malnutrition or starvation

Prolonged diarrhea

Acute pancreatitis

Administration of magnesium-free solutions formore than one week

Prolonged NG tube suctioning

8/13/2019 NRS136-006

51/55


S & S Neuromuscular symptoms

Hyperactive reflexes,

Coarse tremors

Muscle cramps

Positive Chvosteks and Trousseaus signs

Seizures

Paresthesia of the feet and legs

Painfully cold hands and feet

Disorientation dysrhythmias tachycardiaand indreased potential for digitalistoxicity

8/13/2019 NRS136-006

52/55


Hypermagnesemia: renal failure,addisons disease, and inadequateexcretion of magnesium by kidneys

S & S: Neuromuscular symptoms Flushing and sense of skin warmth

Lethargy

Sedation

Hypoactive deep tendon reflexes, Depressed respiration

Weak or absent new born cry

8/13/2019 NRS136-006

53/55

8/13/2019 NRS136-006

54/55


Approximately 80% is contained in thebones and teeth 20% is abundant in the ICF Plays and important role in delivery of

oxygen to tissues by regulating the level

of 2,3-DPG Hyphphosphatemia: results from

Overzealous refeeding, TPN administered without adequate

phosphorus

Malabsorption Alcohol withdrawal Vomiting, chronic diarrhea, and malabsorption

syndromes

8/13/2019 NRS136-006

55/55


Other Electrolyte imbalance:

Hyperphosphatemia

Hypochloremia

Hyperchloremia

NRS136-006

Documents