This document provides an overview of fluid and electrolyte physiology, including disturbances. It discusses the functions of body fluids, composition and distribution of fluids between extracellular fluid (ECF) and intracellular fluid (ICF). Mechanisms regulating fluid balance like osmosis, diffusion and active transport are explained. Common electrolyte imbalances involving sodium, potassium, calcium and their causes, clinical features and treatment approaches are summarized.

1. By Abel
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2. Outline
 Overview of physiology of fluid and
electrolyte
 Disturbance of fluid volume
 Common electrolyte disturbance
 Acid -base disturbance
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3. Introduction
FUNCTIONS OF BODY FLUIDS
 Facilitate in the transport [nutrients, hormones,
proteins,& others]
 Aid in removal of cellular metabolic wastes
 Provide medium for cellular metabolism
 Regulate body temperature
 Provide lubrication of musculoskeletal jts. and all
body cavities [parietal, pleural fluids]
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4. Composition and distribution of
body fluids
 Water constitutes 50-70% of total body weight
 It depends on age, sex, fat distribution in the
body
 The body water is divided in to two functional
compartments, the ECF and ICF
 ECF is 1/3 of TBW, composed of plasma (5%),
and interstitial fluid(15%) .
 ICF is 2/3 of TBW, constitutes the fluid inside
the cell.
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5. 5
Female Male

6. Cont’d
Solutes – dissolved particles
 Electrolytes – charged particles
 Cations – positively charged ions
Na+, K+ , Ca++, H+
 Anions – negatively charged ions
Cl -, HCO3
- , PO4
3-
 Non-electrolytes - Uncharged
Proteins, urea, glucose, O2, CO2
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7. Regulation of Fluids in Compartments
Osmosis
 Movement of water through a selectively
permeable membrane from an area of low
solute concentration to a higher.
 Movement occurs until near equal
concentration found
 It is passive process
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8. Cont’d
Diffusion
 Movement of solutes from an area of higher
concentration to an area of lower
concentration in a solution and/or across a
permeable membrane (permeable for that
solute)
 Movement occurs until near equal state
 It is passive process
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9. Cont’d
Active Transport
 Allows molecules to move against
concentration and osmotic pressure to
areas of higher concentration
 Active process – energy is expended
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10. Cont’d
 Osmolality - amount of solute or particles
in KG of water.
 Osmolality = solute/solvent
 Plasma osmolality = 2 x (Na) +
(Glucose/18)+(Urea/2.8)
Normal value ( 275-290mOsm/L )
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11. Cont’d
 Body fluids characteristics
 Electrically neutral
 Osmotically maintained Specific no of
particles per volume of fluid
 ECF Osmolality = ICF Osmolality
 Homeostasis must preserve narrow
plasma osmolality Range for optimal
cellular functioning and viability
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12. Cont’d
 To maintain homeostasis water intake must
match with water excretion.
Water balance
• Daily Intake of Water
– it is ingested in the form of liquids or water in the food
– it is synthesized in the body as a result of oxidation of
carbohydrates, adding about
• Daily Loss of Body Water
• Insensible Water Loss
• evaporation from the respiratory tract and diffusion
through the skin
• Fluid Loss in Sweat
• Water Loss in Feces
• Kidneys
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13. Cont’d
Disturbances in body fluids can be classified into
three:
 Disturbance in fluid volume
 Disturbance in composition
 Disturbance in acid base balance
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14. Disturbance in fluid volume
Hypovolumia (dehydration)
 The lost fluid is not water alone, but water
and electrolytes in approximately the same
proportion as they exist in normal extra
cellular fluid.
 Causes include:-
 GIT losses,
 sequestration of fluids in third space,
 excess skin losses.
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15. Cont’d
 Diabetes - the body produces more urine
 Kidney disorders- kidneys unable to
concentrate urine as needed
 Problems with walking, because getting water
is difficult
 Dementia- sense of thirst is reduced and the
ability to get water impaired
 Diuretics- increase the of water and salt
excretion

16. Cont’d
Clinical features
 Dry skin
 Fast pulse
 low blood pressure
 Low urine out put- [ The kidneys try to
conserve -olig urea / an-urea]
 Sunken eyes
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17. Cont’d
Mild
 (loss: 5% of body weight): decresed skin turgor,
sunken eyes, dry mucous membranes
Moderate
 (loss: 10 % of body weight): + oliguria,
orthostatic hypotension, tachycardia
Severe
 (loss: 15% of body weight): + hypotension,
decreased level of consciusness, stupor

18. Treatment for dehydration
involves replacing lost fluids.
Mild dehydration - 2 to 3 liters of water to drink
over a period of a few hours.
Moderate dehydration - Add some salt (sodium)
and other electrolytes. Rehydration formulas
(available without a prescription)
Severe Dehydration –
INTRAVENOUS REPLACEMENT.
I/V also for those who cannot swallow, and
those who are in a coma. If electrolytes must
also be replaced, they are given intravenously
with the fluids.
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19. Cont’d
Hypervolemia
 Extra cellular fluid volume excess is
generally
 secondary to renal insufficiency
 cirrhosis,
 congestive heart failure.
 TURP Syndrome
 Excessive IV infusion
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20. Cont’d
 Sign and symptom of hypervolemia
 Distended neck vein
 Pedal edema
 Body Wight gain
 HTN, tacycardic, pulmonary edema
 Confusion, restlessness, comma
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21. Cont’d
 Management of hypervolemia
 Treat the cause
 Restriction of water and salt
 Diuretics
 Dialysis if necessary
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22. Disturbance in composition
Sodium (Na+)
 It is the most abundant cation of the extra
cellular fluid. 90 % of total ECF cations
 Normal value is 135- 145mom/l
 Daily requirement of sodium is 1.2-2moml/kg
 Most important ion in regulating water balance
 Important in nerve and muscle function.
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23. Cont’d
Hyponatremia
 Defined as Sodium level < 135mmol/L
 Abnormalities of sodium concentration
commonly result from alteration in
water balance
 Most hyponatremias are as a result of
too much water not too little salt
 Results from excess Na loss or water
gain
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24. Causes of hyponatremia
1. Volume depletion, sodium and water depletion.
Most frequent cause of sodium and water
depletion in surgery is SBO, Duodenal, Biliary,
pancreatic and high intestinal fistula are also
causes of hyponatremia.
2. Water intoxication with excess volume and
edema, over-prescribing of IV 5% and colorectal
washouts with plain water and TURP syndrome
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25. Clinical feature
 Symptoms are primarily neurologic due to
brain cell swelling & brain edema.
 Symptoms include:
 headache.
 Lethargy
 confusion& obtundation, Stupor,seizure
coma[Na<120mmol/L]
 Neuro - Generalized skeletal muscle weakness.
 Resp.- Shallow respirations
 CV - Cardiac changes depend on fluid volume
 GI – Nausea, Diarrhea (explosive)
 GU - Increased urine output
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26. Management
 A low sodium level - restored to a normal by
gradually and steadily giving sodium and
water Orally/intravenously
 Over rapid correction may result in Dangers of
central pontine myelinosis
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28. Hypernatremia
 Na+ more than 145 mmol
Causes
 Excessive water loss in burns or sweating, insensible losses
through the lungs.
 Excess amount of 0.9% saline solution is given IV during the
early operative period
 where there is some degree of retention of sodium.
Clinical feature
 Depending on the cause it can be of fluid excess or fluid
deficit 28

29. Clinical feature
 Neuro - Spontaneous muscle spasms , Skeletal muscle
weakness , diminished deep tendon reflexes
 Resp. – Pulmonary edema
 CV – Diminished CO, HR and BP depend on vascular
volume
 GU – Decreased urine output.
 Skin – Dry skin. Edema .
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30. Management of hypernatremia
 usually consists of treatment of the associated water
deficit
 In hypovolemic patients, volume should be restored
with normal saline
 Water deficit(L)= serum Na+ -140 X TBW
140
 decrease in serum sodium of no more than 1 mEq/h
 Rapid correction of chronic hypernatremiabrain
edema
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31. Disorders Of Potassium Balance
Hypokalemia
causes
 Diarrhea or vomiting for a long time.
 Enterocutaneos fistula
 Diuretic.
Symptoms
Mild decrease no symptoms.
The body tends to produce less insulin. As a result, the
level of sugar in the blood may increase.
Moderate fatigue, confusion, and muscle weakness
cramps .
Severe paralysis and abnormal heart rhythms
(arrhythmias).
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32. Hypokalemia-Treatment
 Potassium supplements by mouth as a
tablet or liquid or eating foods rich in
potassium.
 Potassium-sparing diuretic –In People on
diuretics - reduces the amount of
potassium excreted .
 IV-supplement in surgical cases
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33. Hyperkalemia
 A high potassium level (hyperkalemia) is
much more dangerous than a low potassium
level.
 Most common causes
 Renal failure
 Drugs that reduce the amount of potassium
excreted by the kidneys.
 diuretic spironolactone and angiotensin-converting
 enzyme (ACE) inhibitors (used to lower blood
pressure). When a person who takes one of these
drugs also eats potassium-rich foods or takes a
potassium supplement, the kidneys cannot always
excrete the potassium.
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34. Cont’d
 The first symptom of a high potassium
level may be an abnormal heart rhythm.
 Electrocardiography (ECG) may help with
the diagnosis. This procedure can detect
changes in the heart's rhythm that occur
when the potassium level is high.
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35. Hyperkalemia Treatment
 Stop eating potassium-rich foods and stop taking
potassium supplements.
 Drugs that cause the body to excrete excess
potassium, such as diuretics.
 If the potassium level is very high or is increasing,
treatment must be started immediately.
Then diuretics – Frusemide prevents potassium from
being re-absorbed are given to reduce the amount of
potassium in the body. These drugs may be given
intravenously, taken by mouth, or given as enemas.
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36. Disorder of Calcium balance
Hypocalcaemia: result when a disorder such as;.
 Hypoparathyroidism- if the parathyroid glands
are removed or damaged during neck surgery.
 Deficiency of vitamin D. [Vitamin D helps the
body absorb calcium ]
 Certain drugs, such as the anticonvulsants
phenytoin and phenobarbital, can interfere
with the processing of vitamin D, resulting in a
deficiency of vitamin D.
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37. Cont’d
Hypocalcaemia -Clinical Features
weak ness , numbness in the hands or feet.
confusion or seizures
Muscle twitching
Treatment
 Involves taking calcium supplements by
mouth. Or I/V
 Treat the Cause.
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38. Cont’d
Hypercalcemia:
A. Excessive intake – milk alkali syndrome
B. Exessive brake down of bone and release of
calcium into the bloodstream.
 Calcium may be released when cancer spreads
to the bone
 Paget's disease .
 Hyperparathyroidism.
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39. Cont’d
Hypercalcaemia: Symptoms;
 A slight increase in the calcium level may
not cause any symptoms.
 A very high level can result in dehydration
because it causes the kidneys to excrete
more water.
 A very high level can also cause loss of
appetite, nausea, vomiting, and confusion.
A person may even go into a coma and die.
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40. Hypercalcemia: Treatment
 High calcium level rapid treatment is needed.
 fluids intravenously
calcitonin and bisphosphonates - given
intravenously for short periods of time. [
decrease the amount of bone being broken
down /decrease calcium released into the
bloodstream.
 Treat the cause of the high calcium level.
Paget's disease, bisphosphonates are often
taken by mouth
 Tumor of parathyroid gland,-surgery
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41. Acid-Base disturbance
 Many of the body metabolic & physiology
functions are PH dependent & PH sensitive
 Slight deviation of its value may cause
dismal result
 The normal arterial PH =7.35-7.45
 Lower limit of pH at which a person can live
more than a few hours is about 6.8, and the
upper limit is about 8.0
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42. Cont’d
 The control of this tight balance is
accomplished by:
Three mechanisms:
1) Chemical Buffers
2) Respiratory Regulation
3) Renal Regulation.
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43. Cont’d
Alkalosis (accumulation of Base or loss of acid)
Metabolic Alkalosis
 Loss of fixed acids , Gain of base bicarbonate or
Potassium depletion
 Vomiting, Gastric suction, Excessive
bicarbonate intake
Respiratory alkalosis
 Excessive loss of CO2 (increased alveolar
ventilation)
 Emotional, Severe pain, Assisted ventilation
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44. Cont’d
Acidosis (accumulation of acid or loss of base)
Metabolic Acidosis
 Retention of fixed acids or Loss of base
bicarbonate.
 Diabetes, Lactic acid accumulation, Starvation.
Diarrhea, Small-bowel fistula
Respiratory Acidosis
 Retention of CO2 (Decreased alveolar
ventilation)
 Respiratory center depression: morphine,CNS
injury, Pulmonary disease:
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