Fluids & electrolytes imbalances

1. Fluids & Electrolytes
Imbalances

2. 2
Body Fluid Compartments
• 2/3 (65%) of TBW is intracellular fluid (ICF)
• 1/3 extracellular fluid (ECF)
– 25 % interstitial fluid (ISF)
– 5-8 % in plasma [(IVF) intravascular fluid]
– 1-2 % in trans-cellular fluids: CSF, intraocular
fluids, serous membranes, and in GI, respiratory
and urinary tracts (third space)

3. 3

4. 4
• Fluid compartments are separated by
membranes that are freely permeable to water.
• Movement of fluids due to:
– Diffusion
– Osmotic pressure
– Active transport
– Hydrostatic pressure
– Reabsorption
Movement of Fluids

5. DIFFUSION
•Solutes shift from an
area of greater
concentration to an
area of higher
concentration
•Passive process

6. OSMOSIS
•Movement of fluid across membrane from a
lower solute concentration to a higher solute
concentration
•Passive process

7. ACTIVE TRANSPORT
•Solutes move from
an area of lower
concentration to an
area of higher
concentration
•Process requires
energy

8. Hydrostatic Pressure
•Capillary filtration
•Movement of fluid
through capillaries
results from blood
pushing against walls
of the capillary. It forces
fluids and solutes
through the capillary
wall

9. REABSORPTION
•Prevents too much fluid from leaving
capillaries no matter how much hydrostatic
static pressure is inside them

10. 10
Homeostasis
Maintained by:
– Ion transport
– Water movement
– Kidney function

11. 11
TONICITY:
Isotonic – A solution that
has the same solute
concentration as another
solution to which it’s
being compared
• i.e. sodium in blood vs.
0.9% NSS

12. 12
• Hypertonic - A
solution that has a
higher solute
concentration than
another solution to
which it’s being
compared
• Dextrose 5% in
NSS
TONICITY:

13. 13
• Hypotonic - A
solution that has a
lower solute
concentration than
another solution to
which it’s being
compared
• 0.45%NSS
TONICITY:

14. 14
Balance
Fluid and electrolyte homeostasis is maintained in the body
• Neutral balance: input = output
• Positive balance: input > output
• Negative balance: input < output

15. Fluid Gain & Loss
Routes of Gain and Loss:
Kidneys (urine)
Skin (perspiration)
Lungs (respiration)
GI Tract (feces)

16. Fluid Gain & Loss
Average Intake of Body H2O
= 2600 ml/day
Liquid = 1500 ml
Solid Foods = 800 ml
Oxidation = 300 ml

17. Fluid Gain & Loss
Sensible Loss
• Fluid loss that can be measured
– Urination
– Defecation
– Bleeding
– Wound drainage
– Gastric drainage
– Vomiting

18. Fluid Gain & Loss
Insensible Loss
• Fluid loss that cannot be measured
– Perspiration
– Respiration
– Changes in humidity levels, respiratory rate
and depth, and fever affect insensible loss

19. Fluid Gain & Loss
Average Output of Body H2O
= 2600 ml/day
Urine = 1500 ml
Feces = 100 ml
Lungs = 400 ml
Skin = 600 ml

20. Balancing Systems
Renal System (kidneys)
–RF = difficulty maintaining fluid balance
–Na+ & K+ are either filtered or
reabsorbed via the renal system

21. Balancing Systems
Antidiuretic Hormone (ADH)
–Water-retaining hormone
–Hypothalamus senses low blood volume
& increased serum osmolality; triggers
its release from the pituitary gland
–Prompts kidneys to retain H2O
–Increases concentration of urine

22. Balancing Systems
Renin-Angiotensin-Aldoseterone
System (RAAS)
–Release of renin triggered by low
pressures
–Angiotensin II potent vasoconstrictor
and triggers the release of aldosterone
from the adrenal cortex
–Aldosterone = fluid retention and
secretion of K+; triggers the thirst center

23. Balancing Systems
Atrial Natriuretic Peptide (ANP)
– Released when atrial pressures increase
– Opposes the RAAS (shuts it off)
– Key Functions of ANP:
• Suppresses serum renin levels
• Decreases aldosterone release
• Increases glomerular filtration rate (excretion of
Na+ and H2O)
• Decreases ADH release
• Decreases vascular resistance by causing
vasodilation

24. Balancing Systems
Thirst Mechanism
– Simplest mechanism in maintaining fluid
balance
– Increases after even small fluid loss
– Increase in salty foods dries mucous
membranes, which stimulates the thirst center
in the hypothalamus

25. Hypovolemia
  blood volume caused by internal/external bleeding,
fluid losses, or inadequate fluid intake.
(AKA: Fluid Volume Deficit (FVD) or Extracellular Fluid Volume Deficit (ECFVD))

26. Hypovolemia
FVD occurs when loss of ECF exceeds intake of fluid.
Hypovolemia or FVD ≠ dehydration
Dehydration is loss of H2O only!!
FVD → Fluid Loss = Electrolyte Loss
Ratio Remains the Same (usually)

27. Hypovolemia
Signs & Symptoms
Weight Loss
 Skin Turgor
Oliguria
Concentrated Urine
Postural Hypotension
Weak, rapid pulse
Flattened Neck Veins
 Temp
Cool, clammy skin
Thirst
Anorexia
Nausea
Muscle Weakness
Muscle Cramps

28. Hypovolemia
Treatment:
 Infusion of Isotonic IV solutions: Hypotensive patients
 Infusion of Hypotonic IV solutions: Normotensive patients
 Hypovolemia d/t blood loss: Blood transfusion

29. Hypervolemia
ECF → H2O gain is balanced 𝒄 retention of sodium.
• Usually 2 retention of Na+
• Concentration of sodium to H2O is balanced.
• serum sodium levels WNL (usually)
(A.K.A. Extracellular Fluid Volume Excess (ECFVE))

30. Hypervolemia
Hormonal Imbalances - ADH
• Can occur 2 heart failure, renal failure, or cirrhosis.
• Fluid overload r/t administration of excessive IV fluids
• Dietary: Excessive sodium intake

31. Hypervolemia
Signs & Symptoms
JVD
Edema
Crackles
Tachycardia
 B/P
Weight Gain
 Urine Output
SOB/Wheezing

32. Hypervolemia
Treatment: Treat the underlying cause!!!
• Renal Failure: dialysis
• Heart Failure: diuretics, etc.
• Dietary: low-salt diet and/or fluid restriction
• Discontinuation of IV infusions

33. Sodium
Reference Range:
135 – 145 mEq/L

34. Sodium
• Accounts for 90% of ECF cations.
• Almost all Na+ is found in ECF; 10% in ICF.
• Na+ attracts fluid + helps preserve ECF volume/fluid
distribution.
• Na+ helps transmit impulses in nerve/muscle fibers, &
combines w/ Cl- & HCO3 to regulate acid-base balance

35. Sodium
• Excreted mainly via the kidneys (GU)
– Also via the GI tract and perspiration
• Increased Na+ levels trigger thirst & ADH
• Sodium-Potassium pump helps maintain normal Na+
levels
– Pump also creates an electrical charge for both cardiac &
neuromuscular function

36. Sodium
Hyponatremia is Na+ < 135
Hypernatremia is Na+ > 145

37. Hyponatremia
Causes an osmotic fluid shift from
plasma into brain cells

38. Hyponatremia
Signs & Symptoms:
Nausea/Vomiting
Headache
Malaise
Confusion
Diminished Reflexes
Confusion
Convulsions
Stupor or Coma

39. Hyponatremia
Causes:
• ↑ Vasopressin/ADH
• SIADH
• Adrenal Insufficiency
• Diuretics
• Hypervolemia
• Liver Failure
• Heart Failure

40. Hyponatremia
Treatment:
• Administration of oral or IV Na+ (3%) Supplements
• Encourage foods high in Na+
• Fluid restriction
• Monitor Neuro Status
• Monitor for Arrhythmias
• Normovolemic hyponatremia
– Vaprisol (conivaptan) – IV infusion
– Samsca (tolvaptan) - PO

41. Hypernatremia
Causes:
• Dehydration/Hypovolemia
• Diabetes Insipidus
• Ingestion of Hypertonic Solutions
• IV Infusion of Hypertonic Solutions
• Cushing’s Syndrome
• Hyperaldosteronism
• Loss of pure water (excessive sweating or respiratory infections)

42. Hypernatremia
Signs & symptoms
• Thirst
• Lethargy
• Neurologic Dysfunction (d/t dehydration of brain cells)
– Irritability
– Weakness
– Seizures
– Coma
• Edema
• Decreased vascular volume

43. Hypernatremia
Treatment:
• Administration of IV Fluids
– (Isotonic Salt-Free)
• Encourage foods low in Na+
• Push P.O. Fluids
• Monitor Neuro Status
• Monitor for Arrhythmias

44. Potassium
Reference Range:
3.5 – 5.0 mEq/L

45. Potassium
Potassium is gained by intake and lost by excretion.
If either is altered, hyperkalemia or hypokalemia may result!
Regulated by aldosterone and insulin

46. Potassium
Potassium levels directly affect cell, nerve, & muscle
function:
– Maintains electrical neutrality and osmolality of cells
– Aids in neuromuscular transmission of nerve impulses
– Assists skeletal & cardiac muscle contraction and electrical
conductivity
– Affects acid-base balance in relationship to H+ (another cation)

47. Potassium
Hypokalemia is K+ < 3.5
Hyperkalemia is K+ > 5.o

48. Hypokalemia
Levels < 3.5
Mildly Low Levels usually asymptomatic
If level < 3.2, usually accompanied by
symptoms

49. Hypokalemia
Causes of Hypokalemia:
Increased Urine Output
Malnutrition
Vomiting and/or Diarrhea
Hypomagnesemia
DKA

50. Hypokalemia
May be a result of acid-base imbalances = alkalosis
• In alkalosis, K+ moves into cell to maintain balance,
-may lead to hypokalemia

52. Treatment
• Oral or IV Potassium Chloride
Replacement
• D/C or adjust medications that may
cause hypokalemia
• Reverse alkalosis, if cause
• Monitor closely for arrhythmias
• Monitor Respiratory Status
• Monitor LOC
• Monitor GI symptoms

53. Hyperkalemia
Levels > 5.0
Mildly elevated levels usually asymptomatic
Levels > 8.0
Disturbances in cardiac conduction occur

54. Hyperkalemia
Causes:
• Renal Failure
• Meds (ACEIs, ARBs, K+ sparing diuretics, NSAIDs)
• Addison’s Disease
• Aldosterone Insufficiencies
• Dig Overdose
• Beta-Blocker Therapy

55. Hyperkalemia
May be a result of acid-base imbalances = acidosis
In acidosis, excess [H+] move into cells & push K+ into ECF,
- may lead to hyperkalemia as K+ moves out of cell to maintain
balance.

57. Hyperkalemia
Treatment:
Medications:
– Cation-exchange resins (bind with K+ and excreted via feces)
– IVP insulin & glucose (K+ binds to insulin)
– IV Ca++ (protect the heart from the effects of hyperkalemia)
– Sodium bicarbonate (to reverse acidosis)
– Diuretics (non-K+ sparing)
– Beta2 Adrenergic agonists (epinephrine, albuterol)
D/C meds that may cause hyperkalemia
Restrict foods with K+
Dialysis for renal failure
Monitor closely for arrhythmias
Monitor Blood Pressure
Monitor GI symptoms

58. Calcium
Reference Range:
8.5 – 10.5 mg/dl

59. Calcium
• 99% Ca++ in bones; 1% in serum/soft tissue (measured in
blood serum levels)
• Found in both ECF & ICF
• Can be measured in 2 ways:
– Total serum calcium (total Ca++in blood)
– Ionized calcium level (various forms of Ca++ in ECF)
• 41% ECF Ca++ is bound to protein; 9% bound to citrate or
other organic ions

60. Calcium
• Ca++ functions in the following ways:
– Responsible for formation of teeth & bones
– Helps maintain cell structure & function
– Plays a role in cell membrane permeability & impulse
transmission
– Affects contraction of cardiac, smooth, and skeletal muscle
– Participates in blood-clotting process

61. Calcium
Ca++ helps K+ & Na+ move into and out
of cells in the sodium-potassium
pump mechanism

62. Hypocalcemia
Causes:
• Vitamin D Deficiency
– Vitamin D promotes Ca++ absorption in intestines, resorption from bones,
and kidney resorption all of which raise Ca++ levels
• Deficiency of parathyroid hormone
– Calcitonin, secreted by PTH, helps regulate Ca++
– s absorption of Ca++/enhances excretion by kidneys
• Inefficient parathyroid hormone

63. Hypocalcemia
Manifestations
• Tetany
• Laryngospasm
• Cardiac Arrhythmias
• EKG Δ’s → prolonged QT interval

64. Hypocalcemia
Management…
• PO or IV calcium replacement
(depends on severity of symptoms or deficiency)
• Vitamin D supplement
• Encourage foods high in calcium

65. Hypercalcemia
Causes:
• Excessive calcium release
• Increased intestinal calcium absorption
** Decreased renal calcium excretion **

66. Hypercalcemia
Manifestations:
• Cardiac Arrhythmias
• EKG Δ’s → shortened QT interval

67. Hypercalcemia
Severe Hypercalcemia (> 15mg/dl) is a…
Medical Emergency
May result in
Coma or Cardiac Arrest

68. Hypercalcemia
Signs & Symptoms
Fatigue
Depression
Confusion
Anorexia
N/V
Constipation
Pancreatitis
Increased Urination

69. Hypercalcemia
Treatment…
• Hydration
• Increased Salt Intake
• Diuretics
• Dialysis (renal failure)
• Glucocorticoids

70. Magnesium
Reference Range:
1.3 – 2.3 mEq/L

71. Magnesium
• 2nd most abundant ICF cation (K+ #1)
• 60% Mg+ found in bones, < 1% ECF
• Mg+ performs the following functions:
– Promotes enzyme reactions in carbohydrate metabolism
– Helps produce ADP (adenosine triphosphate)
– Helps with protein synthesis
– Influences vasodilation (normal CV function)
– Helps Na+ and K+ ions cross cell membranes

72. Magnesium
• Mg+ performs the following functions:
– Regulates muscle contractions
– Affects irritability and contractility of
cardiac and skeletal muscle
– Influences Ca++ levels
• maintain Ca++ levels in ECF

73. Magnesium
Hypomagnesemia is Mg+ < 1.8
Hypermagnesemia is Mg+ > 2.4

74. Hypomagnesemia
Results in cardiac dysrhythmias and
irritates the nervous system (tetany)

75. Hypomagnesemia
Causes:
• ETOH Abuse (#1)
• Malnutrition
• Chronic Diarrhea
• Malabsorption
• Diuretics
• AMI
• Pancreatitis

76. Hypomagnesemia
• Does not produce specific EKG changes
• May contribute to arrhythmias caused by digoxin toxicity,
ischemia, or K+ imbalances
• Monitor:
– EKG for Arrhythmias
– Muscle cramps

77. Hypomagnesemia
Replacement of Mg: PO or IV
• PO = Mg Oxide 400mg tabs
• MgSo4 IV administration is usually given at a rate of 1 gram/hr
(1 gram/100 ml)
• Encourage foods high in magnesium

78. Hypermagnesemia
Severe hypermagnesemia is associated with:
– AV blocks
– Intraventricular conduction disturbances