1. Fluid & Electrolyte
Balance
NCM 103
Lecture
Prepared by: Marjo S. Malabanan

2. Body Fluids
 Water= most important nutrient for life.
 Water= primary body fluid.
Adult weight is 55-60% water.
 Loss of 10% body fluid = 8% weight loss SERIOUS
 Loss of 20% body fluid = 15% weight loss FATAL
 Fluid gained each day should = fluid lost each day
(2 -3L/day average)
 What is the minimum output per hour necessary to
maintain renal function? 30ml/hr

3. Functions of Body Fluid
 Medium for transport
 Needed for cellular metabolism
 Solvent for electrolytes and other
constituents
 Helps maintain body temperature
 Helps digestion and elimination
 Acts as a lubricant

4. Mechanisms of
Fluid Gain and Loss
Gain
 Fluid intake 1500ml
 Food intake 1000ml
 Oxidation of nutrients
300ml
(10ml of H20 per 100 Kcal)
Loss
 “Sensible”
Can be seen.
Urine 1500ml
Sweat 100ml
 “Insensible”
Not visible.
Skin (evaporation) 500ml
Lungs 400ml
Feces 200ml

5. Regulation of Fluids
 Hypothalmus –thirst receptors (osmoreceptors)
continuosly monitor serum osmolarity (concentration). If
it rises, thirst mechanism is triggered.
+Vasopressin (AKA ADH )– increasing H20 reabsorption
 Pituitary regulation- posterior pituitary releases
ADH (antidiuretic hormone) in response to increasing
serum osmolarity. Causes renal tubules to retain
H20.
 Thirst is a late sign of water deficit

6. Regulation of Fluids (continued )
 Renal regulation- Nephron receptors
sense decreased pressure (low
osmolarity) and kidney secretes RENIN.
Renin – Angiotensin I – Angiotensin II
 Angiotensin II causes Na and H20
retention by kidneys AND…..
 Stimulates Adrenal Cortex to secrete
Aldosterone which causes kidneys to
excrete K and retain Na and H20.

7. Consider This….
 The Geriatric Client
-normal physiological aging results in
decreased thirst mechanism
decreased # of sweat glands
decreased renal function
-there also may be decreased mobility
and/or cognitive function which impacts
their ability to get adequate fluid intake.

8. Variations in Body Fluids
 Elderly: Have lower % of total body fluid
than younger adults
 Women: Have lower % total body fluid
than men
 WHY DO YOU THINK THIS IS ?????
Muscle tissue has more H20 content THAN adipose tissue

9. Fluid Compartments
Intracellular
fluid (ICF)
 Fluid inside the
cell
 Most (2/3) of
the body’s H20
is in the ICF.
Extracellular Fluid
(ECF)
 Fluid outside the cell.
 1/3 of body’s H20
 More prone to loss
 3 types:
Interstitial- fluid
around/between cells
Intravascular- (plasma)
fluid in blood vessels
Transcellular –CSF,
Synovial fluid etc

10. Consider this….
 Age variations exist in regards to
H20 content of fluid compartments
 Infants =
60% of H20 is found in ECF
40% of H20 is found in ICF
 What might this mean in regards to fluid
loss for an infant? Reverse of adults!
Infant MORE PRONE to fluid
LOSS!

11. Fluid Balance
 Dynamic process
 Balance between body fluids and
electrolytes
 Attraction between ions
(electrolytes) and water (fluids)
causes fluids to move across
membranes and leave their
compartments.

12. Solvent (H20) Movement
 Cell membranes are semipermeable
allowing water to pass through
 Osmosis- major way fluids transported
Water shifts from low solute
concentration to high solute
concentration to reach homeostasis
(balance).

13. Osmolarity
 Concentration of particles in solution
 The greater the concentration (Osmolarity) of a
solution, the greater the pulling force (Osmotic
pressure)
 Normal serum (blood) osmolarity = 280-295 mOSM/kg
 A solution that has HIGH osmolarity is one that is >
serum osmolarity = HYPERTONIC solution
 A solution that has LOW osmolarity is one that is <
serum osmolarity = HYPOTONIC solution
 A solution that has equal osmolarity as serum =
ISOTONIC solution

14. Hypertonic Fluids
 Hypertonic fluids have a higher
concentration of particles (high
osmolality) than ICF
 This higher osmotic pressure
shifts fluid from the cells into the
ECF
 Therefore Cells placed in a
hypertonic solution will shrink

15. Hypertonic Fluids
 Used to temporarily treat hypovolemia
 Used to expand vascular volume
 Fosters normal BP and good urinary output
(often used post operatively)
 Monitor for hypervolemia !
Not used for renal or cardiac disease.

16. Hypotonic Fluids
 Hypotonic fluids have less
concentration of particles (low
osmolality) than ICF
 This low osmotic pressure shifts
fluid from ECF into cells
 Cells placed in a hypotonic solution
will swell

17. Hypotonic Fluids
 Used to “dilute” plasma particularly in
hypernatremia
 Treats cellular dehydration
 Do not use for pts with increased ICP
risk or third spacing risk

18. Isotonic Fluid
 Isotonic fluids have the same
concentration of particles (osmolality)
as ICF (275-295 mOsm/L)
 Osmotic pressure is therefore the
same inside & outside the cells
 Cells neither shrink nor swell in an
isotonic solution, they stay the same

19. Isotonic Fluid
 Expands both intracellular and
extracellular volume
 Used commonly for: excessive
vomiting,diarrhea
 0.9% Normal saline
 D5W
 Ringer’s Lactate

20. Other Osmotic Factors
 ALBUMIN ( a serum protein )
 Albumin in the serum has osmotic properties called
colloid pressure
 Albumin pulls H20 from the interstitial compartments
into the intravascular compartments (serum). Helps
to maintain BP.
 Persons with low serum albumin levels tend to retain
fluid in their interstitial layers.
What abnormal assessments might you find in the
client with low serum albumin levels?
Edema, hypotension

21. Hmmm…….
 What type of IV fluid
(hypotonic – isotonic – hypertonic)
might be of benefit to this client with low
albumin levels?

22. Consider this….
 When tissue injury occurs, proteins
pathologically leak from the
intravascular space into the intersititial
space.
Termed: Third spacing
 This explains __________ as a sign of
the inflammatory process.
EDEMA

23. Solute Movement -
Diffusion
 Movement of solutes from high
concentration to low concentration
 It is a PASSIVE movement DOWN the
concentration gradiant. (requires no energy)
 Many body processes use diffusion.
Example: O2 and CO2 exchange
 Rate is affected by: concentration gradiant,
permeability-surface area-thickness of
membranes, and size of particles.
(Fick’s Law)

24. Solute Movement –other
mechanisms
 Active transport- requires energy (ATP)
to move from low concentration to high
concentration (uphill)
Example: Na / K pump
 May be enhanced by carrier molecules with
binding sites on cell membrane
Example: Glucose
(Insulin promotes the insertion of binding
sites for Glucose on cell membranes).

25. Filtration
 Solvent AND solute movement
 Passage from an area of High Pressure to an area
of Low Pressure
Termed: Hydrostatic Pressure
 Example:
Arterioles have higher pressure than ICF
Fluid, oxygen and nutrients move into cells
Venules have lower pressure than ICF
Fluid, carbon dioxide and wastes move out of cells

26. Definitions
 An arteriole is a small diameter blood
vessel in the microcirculation that
extends and branches out from an
artery and leads to capillaries.
 A venule is a very small blood vessel
in the microcirculation that allows blood
to return from the capillary beds to the
larger blood vessels called veins.

27. Fluid volume deficit FVD
(Hypovolemia)
 Loss of both H20 and
electrolytes from ECF.
 Causes include:
Increased output, Hemorrhage,
vomiting, diarrhea, burns,
OR
 Fluid shift out of vascular space ( “third
spacing” ) into interstitial spaces

28. Dehydration
 Isotonic dehydration = H20 & electrolyte
loss in equal amounts; diarrhea and
vomiting
 Hypertonic dehydration = H20 loss
greater than electrolyte loss; excessive
perspiration, diabetes insipidus

29. Assessment
FVD - Hypovolemia
Cardiovascular:
 Diminished peripheral pulses; quality 1+(thready)
 Decreased BP & orthostatic hypotension
 Increased HR
 Flat neck & hand veins in dependent position
 Elevated Hematocrit (Hct)
Gastrointestinal:
 Thirst
 Decreased motility; diminished bowel sounds,
possible constipation

30. Assessment
FVD – Hypovolemia (continued)
Neuromuscular:
 Decreased CNS activity
(lethargy to coma)
 Possible fever
 Skeletal muscle weakness
 Hyperactive DTR
Renal:
 Decreased output
 Increased spec grav of urine
 Weight loss
 Hypernatremia
Integumentary:
 Dry mouth & skin
 Poor turgor (tenting)
 Pitting edema
 Sunken eyeballs
Respiratory:
 Increased rate and depth

31. Nursing Diagnosis - FVD
 Deficient Fluid Volume
R/T loss of GI Fluids via vomiting
AEB elevated Hct, dry mucous
membranes, decreased output, thirst

32. Planning - FVD
 Client will demonstrate fluid
balance aeb moist mucous
membranes, balanced I & O
measurements, Hct WNL, by ….

33. Interventions for
FVD - Hypovolemia
 Prevent further fluid loss
 Oral rehydration therapy
 IV therapy
 Medications; antiemetics, antidiarrheals
 Monitor CV, Resp, Renal, GI status
 Monitor electrolytes – possible supplement rx
 MONITOR WEIGHT and I & O

34. Fluid Volume Excess
FVE - Hypervolemia
 Fluid overload is an excess of body
fluid - overhydration
 Excess fluid volume in the
intravascular area-hypervolemia
 Excess fluid volume in interstitial
spaces edema

35. Fluid Volume Excess
 Causes:
 Increased Na/H2O retention
 Excessive intake of Na (PO or IV)
 Excessive intake of H2O ( PO or IV)
(Water intoxication)
 Syndrome of inappropriate antidiuretic
hormone (SIADH)
 Renal failure, congestive heart failure

36. Assessment
FVE - Hypervolemia
CV:
Elevated pulse; bounding,
elevated BP, distended neck
& hand veins, ventricular
gallop (S3)
Hyponatremia
Resp:
Dyspnea, Moist
Crackles,Tachypnea
Integumentary:
Periorbital edema
Pitting or Non-pitting edema
GI:
Increased motility
Stomach cramps
Nausea & Vomiting
Renal:
Weight gain
Decreased spec grav of
urine
Neuromuscular:
Altered LOC, headache,
skeletal muscle twitching

37. Nursing Diagnosis - FVE
Fluid volume excess
R/T excessive H20 intake
confusion, headache, muscle twitching,
abdominal cramps, elevated BP and
HR, hyponatremia.

38. Planning - FVE
 Client will demonstrate fluid balance by
balanced I & O measurements, Serum
Na WNL, etc. by ….

39. Interventions
FVE - Hypervolemia
 Restore normal fluid balance, prevent
further overload
 Drug therapy; diuretics
 Diet therapy; decrease Na & fluids
 Monitor intake and output (I & O)
 Monitor weights
 Monitor electrolytes
 Monitor CV, Resp, Renal systems

40. Electrolytes
 Work with fluids to keep the body healthy and in
balance
 They are solutes that are found in various
concentrations and measured in terms of
milliequivalent (mEq) units
 Can be negatively charged (anions) or
positively charged (cations)
 For homeostasis body needs:
Total body ANIONS = Total body CATIONS

41. Electrolytes
Cations
Positively charged
 Sodium Na+
 Potassium K+
 Calcium Ca++
 Magnesium Mg++
Anions
Negatively charged
 Chloride Cl-
 Phosphate PO4-
 Bicarbonate
HCO3-

42. Electrolyte Functions
 Regulate water distribution
 Muscle contraction
 Nerve impulse transmission
 Blood clotting
 Regulate enzyme reactions (ATP)
 Regulate acid-base balance

43. Sodium Na+
 135-145mEq/L
 Major Cation
 Chief electrolyte of the ECF
 Regulates volume of body fluids
 Needed for nerve impulse & muscle
fiber transmission (Na/K pump)
 Regulated by kidneys/ hormones

44. Hmmm…
Hyper and Hypo Natremia are the most
common electrolyte disturbances. Why do
you think that is?
It is most abundant in the
EXTRACELLULAR FLUID and therefore
more prone to fluctuation.

45. Hyponatremia
 Serum Na+ <135mEq/L
 Results from excess of water or loss
of Na+
 Water shifts from ECF into cells
 S/S: abd cramps, confusion, N/V,
H/A, pitting edema over sternum
 Tx: Diet/IV therapy/fluid restrictions

46. Lets think about …
Hyponatremia
 What are some medical conditions that may cause a dilutional
hyponatremia?
CHF
Renal Failure
SIADH ( Cancer, pituitary trauma )
Addisons Disease ( hypoaldosteronism & Na loss )
 What are some conditions that might cause actual loss of
sodium from the body?
GI losses – nasogastric suctioning, vomiting, diarrhea
Certain diuretic therapies
 Permanent neurological damage can occur when serum Na
levels fall below 110 mEq/L. Why?
Hypotonic environment swells cells, increasing ICP – brain
damage

47. Hypernatremia
 Serum Na+> 145mEq/L
 Results from Na+ gained in excess of H2O
OR Water is lost in excess of Na+
 Water shifts from cells to ECF
 S/S: thirst, dry mucous membranes & lips,
oliguria, increased temp & pulse,flushed
skin,confusion
 Tx: IV therapy/diet

48. Let’s think about….
Hypernatremia
 What are some medical conditions that may cause elevated
serum Na?
Renal failure
Diabetes Insipidus
Diabetes Mellitus ( hyperglycemic dehydration)
Cushings syndrome (hyperaldosteronism)
 What are some other patient populations at risk for
hypernatremia?
Elderly ( decreased thirst mechanism )
Patient’s receiving:
-tube feedings
-corticosteroid drugs
-certain diuretic therapies
 Seizures, coma, death my result if hypernatremia is left
untreated. Why?

49. Potassium K+
 3.5-5.0 mEq/L
 Chief electrolyte of ICF
 Major mineral in all cellular fluids
 Aids in muscle contraction, nerve &
electrical impulse conduction, regulates
enzyme activity, regulates IC H20 content,
assists in acid-base balance
 Regulated by kidneys/ hormones
 Inversely proportional to Na

50. Hypokalemia
 Serum level < 3.5mEq/L
 Results from decreased intake, loss via
GI/Renal & potassium depleting diuretics
 Life threatening-all body systems affected
 S/S muscle weakness & leg cramps,
decreased GI motility, cardiac arrhythmias
 Tx: diet/supplements/IV therapy

51. Lets think about …
Hypokalemia
 What are some medical conditions that may cause a
hypokalemia?
Renal Disease / CHF (dilutional)
Metabolic Alkalosis
Cushings Disease ( Na retention leads to K loss )
 What are some conditions that might cause actual loss of
potassium from the body?
GI losses – nasogastric suctioning, vomiting, diarrhea
Certain diuretic therapies
Inadequate intake – ( body cannot conserve K, need PO intake)
 Cardiac arrest may occur when serum K levels fall below 2.5
mEq/L. Why?
Increased cardiac muscle irritability leads to PACs and PVCs,
then AF

52. Hyperkalemia
 Serum level >5 mEq/L
 Results from excessive intake,
trauma, crush injuries, burns, renal
failure
 S/S muscle weakness, cardiac
changes, N/V, parathesias of
face/fingers/tongue
 Tx:diet/meds/IV therapy/ possible
dialysis

53. Lets think about …
Hyperkalemia
 What are some medical conditions that may cause
hyperkalemia?
Renal Disease=most common cause
Burns and other major tissue trauma
Metabolic Acidosis
Addison’s Disease ( Na loss leads to K retention )
 What are some conditions that might cause potassium levels to
rise in the body?
Certain diuretic therapies
Excessive intake – ( inappropriate supplements)
 Cardiac arrest may occur when serum K levels rise above
mEq/L. Why?
Decreased electrical impulse conduction leads to bradycardia
and eventual asystole.

54. Calcium Ca++
 4.5-5.5mEq/L
 Most abundant in body but:
99% in teeth and bones
 Needed for nerve transmission, vitamin
B12 absorption, muscle contraction & blood
clotting
 Inverse relationship with Phosphorus
 Vitamin D needed for Ca absorption

55. Hypocalcemia
 Serum Ca < 4.3mEq/L
 Results from low intake, loop diuretics,
parathyroid disorders, renal failure
 S/S osteomalacia, EKG changes,
numbness/tingling in fingers, muscle
cramps / tetany, seizures, Chovstek
Sign & Trousseau Sign
 Tx: diet/IV therapy

56. Chovstek Trousseau

57. Lets think about …
Hypocalcemia
 What are some medical conditions that may cause
hypocalcemia?
Hypoparathyroidism (low PTH levels = decreased release of Ca
from bones)
S/P thryoid surgery ( low Calcitonin = decreased release of Ca
from bones) Acute pancreatitis
Crohns Disease
Hyperphosphatemia ( ESRF)
 What are some other conditions that might cause low Ca?
GI losses – nasogastric suctioning, vomiting, diarrhea
Long term immobilization
Lactose intolerance
 If hypocalcemia is prolonged, the body will utilize stored Ca
from bones.
What complication might arise?

58. Hypercalcemia
 Serum Ca > 5.3mEq/L
 Results from hyperparathyroidism,
some cancers, prolonged
immobilization
 S/S muscle weakness, renal calculi,
fatigue, altered LOC, decreased GI
motility, cardiac changes
 Tx: medication/ IV therapy

59. Lets think about …
Hypercalcemia
 What are some medical conditions that may cause
hypercalcemia?
Hyperparathyroidism (high PTH levels = increased release of
Ca from bones)
Paget’s Disease
Some Cancers – Multiple Myleoma
Chronic Alcoholism ( with low serum phosphorus )
 What are some other conditions that might cause low Ca?
Excessive intake of Ca OR Vitamin D
Excessive intake of OTC antacids
If hypercalcemia is uncorrected, AV block and cardiac arrest
may occur.

60. Magnesium Mg2+
 1.5-2.5mEq/L
 Most located within ICF
 Needed for activating enzymes,
electrical activity, metabolism of
carbs/proteins, DNA synthesis
 Regulated by intestinal absorption
and kidney

61. Hypomagnesemia
 Serum < 1.5mEq/L
 Results from decreased intake, prolonged NPO
status, chronic alcoholism & nasogastric
suctioning
 S/S: muscle weakness, cardiac changes,
mental changes, hyperactive reflexes & other
hypocalcemia S/S.
 Tx: replacement IV therapy
restore normal Ca levels ( Mg mimics Ca)
seizure precautions

62. Hypomagnesemia
 Common in critically ill patients
 Associated with high mortality rates
 Increases cardiac irritability and ventricular
dysrhythmias - especially in patients with
recent MI
 Maintenance of adequate serum Mg has
been shown to reduce mortality rates post MI

63. Hypermagnesemia
 Serum>2.5mEq/L
 Results from renal failure, increased
intake
 S/S: flushing, lethargy, cardiac changes
(decreased HR),decreased resp, loss of
deep tendon reflexes
 Tx: restrict intake
diuretic rx

64. Chloride Cl-
 95-105mEq/L
 Most abundant anion in ECF
 Combines with Na to form salts
 Maintains water balance, acid-base balance,
aids in digestion (hydrochoric acid) & osmotic
pressure (with Na and H20)
 Regulated by kidneys
 Follows Sodium (Na)

65. Hypochloremia
 Serum level 96mEq/L
 Results from prolonged vomiting &
suctioning
 S/S metabolic alkalosis, nerve
excitability, muscle cramps, twitching,
hypoventilation, decreased BP if severe
 Tx: diet/IV therapy

66. Hyperchloremia
 Serum level > 106mEq/L
 Results from excessive intake or
retention by kidneys – metabolic
acidosis
 S/S Arrhythmias, decreased cardiac
output, muscle weakness, LOC
changes, Kussmauls’s respirations
 Tx: restore fluid & electrolyte balance

67. Phosphate PO4-
 2.5-4.5mg/dl
 Needed for acid-base balance,neurological
& muscle function, energy transfer ATP &
affects metabolism of carbs/proteins/lipids,
B vitamin synthesis
 Found in the bones
 Regulated by intake and kidneys
 Inversely proportional to Calcium
Therefore some regulation by PTH as well

68. Hypophosphatemia
 Serum level < 1.8mEq/L
 Results from decreased intestinal
absorption and increased excretion
 S/S bone & muscle pain, mental
changes, chest pain, resp. failure
 Tx: Diet/ IV therapy

69. Hyperphosphatemia
 Serum level> 2.6mEq/L
 Results from renal failure, low intake of
calcium
 S/S: neuromuscular changes (tetany), EKG
changes, parathesia-fingertips/mouth
 Tx: Diet; hypocalcemic interventions
Medications: phosphate binding
 The body can tolerate hyperphosphatemia
fairly well BUT the accompanying
hypocalcemia is a larger problem!

70. Electrolyte homeostasis
 This means to maintain balance…
to control by balancing the dietary
intake of electrolytes with the renal
excretion and reabsorption of
electrolytes

71. Interventions for F/E balance
 Assess patient carefully- note changes
 Monitor I & O (Intake & Output)
 Monitor weight changes
 Monitor urine
 Monitor vs
 Monitor lab results and dx test
 Maintain proper IV therapy

72. Summary
 Fluid compartments in the body must
balance
 Body systems regulate F&E balance
 Assessment of body fluid is important
to determine causes of imbalance
 Interventions for imbalances are based
on the cause