FLUID, ELECTROLYTE AND ACID BASE IMBALANCES

Question 1

Occurs when the body loses more water than it
absorbs or absorbs less fluid than it excretes.
🠶 Common causes: Diarrhea, nausea, vomiting.
🠶 Result: Decrease in the volume of blood serum.
🠶 Symptoms: May include thirst, dry mouth,
decreased urine output, sunken Eyes, lethargy,
rapid heart rate, and cool, clammy skin

Answer 1

ISOTONIC DEHYDRATION

Question 2

Occurs when water loss is
greater than electrolyte loss.
🠶 Causes: Nausea, fever (increased perspiration),
profuse diarrhea, renal diseases with polyuria (e.g.,
nephrosis).
🠶 Result: Concentration of electrolytes (sodium,
chloride, bicarbonate) in the blood increases.
🠶 Blood characteristics: Elevated red blood cell count
and hematocrit due to blood becoming more
concentrated than usual.

Answer 2

HYPERTONIC DEHYDRATION

Question 3

Disproportionately high loss of electrolytes
compared to fluid loss.
🠶 Causes: Excessive loss of electrolytes from vomiting,
increased salt loss from diuresis, adrenocortical
insufficiency, diabetic acidosis.
🠶 Blood characteristics: Low plasma concentration of
sodium and chloride.
🠶 Kidney response: To restore electrolyte balance,
kidneys excrete more fluid, leading to secondary
extracellular dehydration.

Answer 3

HYPOTONIC DEHYDRATION

Question 4

Excessive body fluid intake, potentially as serious as dehydration.
🠶 Common occurrence: Children receiving IV fluids.
🠶 Risk: Can lead to cardiovascular and cardiac failure.
🠶 Causes: Ingestion of large quantities of salt-poor fluid (hypotonic
solutions) such as tap water, or administration by enema.
🠶 Mechanism: Body transfers water from extracellular space into
intracellular space to restore normal osmotic relationships.
🠶 Result: Intracellular edema, leading to symptoms such as
headache, nausea, vomiting, dimness and blurring of vision,
cramps, muscle twitching, and seizures.

Answer 4

OVERHYDRATION

Question 5

Results from diarrhea due to excessive loss of sodium (Na⁺) with stool.
🠶 Mechanism: Body conserves hydrogen ions (H⁺) to maintain balance
between positive and negative ions in serum.
🠶
Arterial blood gas analysis: Reveals decreased pH (under 7.35) and low
bicarbonate (HCO₃) value (near or below 22 mEq/L).
🠶 Relationship with Na⁺ loss: The lower the HCO₃ value, the more Na⁺ ions are
presumed to be lost or the more extensive the diarrhea.
🠶 Compensation: Child breathes rapidly (hyperpnea) to “blow off” CO₂ to
prevent it from combining with water and reforming HCO₃.
🠶 Urine characteristics: Becomes more acidic as ammonia formation in the
urine increases.

Answer 5

METABOLIC ACIDOSIS

Question 6

Result from loss of hydrochloric acid (HCl), primarily via loss of chloride ions (Cl⁻).
🠶
Mechanism: Body decreases the number of hydrogen ions (H⁺) to maintain balance
between positive and negative charges, causing the child to become alkalotic.
🠶
Lung response: Attempts to conserve carbon dioxide (CO₂) and water by slowing
respirations (hypopnea).
🠶
Resulting changes: Excessive retained CO₂ dissolves in the blood as carbonic acid,
leading to increased bicarbonate (HCO₃⁻) levels.
🠶
Arterial blood gas analysis: pH elevated (near or above 7.45), HCO₃ level elevated
(near or above 28 mEq/L).
🠶
Relationship with Cl⁻ loss: Higher HCO₃ value indicates more extensive Cl⁻ loss or
vomiting.
🠶
Secondary electrolyte problem: Kidneys conserve H⁺ ions by exchanging potassium
ions (K⁺) for H⁺ ions, leading to hypokalemia (low K⁺ levels) accompanying metabolic
alkalosis.

Answer 6

METABOLIC ALKALOSIS