Ch. 40—Fluid, Electrolyte, and Acid-Base Balance
 Body fluid compartments
o Body fluid is located in two fluid compartments
 Intracellular fluid (ICF) is the fluid within cells, constituting about 70% of
the total body water or 40% of the adult’s body weight.
 Extracellular fluid (ECF) is all the fluid outside the cells, accounting for
about 30% of the total body water or 20% of the adult’s body weight. ECF
includes two major areas and a minor:
 intravascular
o fluid, or plasma, is the liquid component of the blood (i.e.,
fluid found within the vascular system).
 interstitial
o fluid that surrounds tissue cells and includes lymph
 transcellular - minor
o fluids include cerebrospinal, pericardial, synovial,
intraocular, and pleural fluids, as well as sweat and
digestive secretions.

Electrolyte imbalances, signs and symptoms of each, nursing interventions and
precautions for each imbalance
o Hyponatremia – serum sodium <135 mEq/L
o caused through:
 Vomiting
 Diarrhea
 Sweating
 diuretics
 S&S
 Swelling cells
 Confusion
 Hypotension
 Edema
 Muscle cramps
 Weakness
 Dry skin
o Severe hyponatremia - serum sodium <115 mEq/L
 Increasing intracranial pressure
 lethargy
 muscle twitching
 focal weakness
 hemiparesis
 seizures
 death
o Hypernatremia - serum sodium > 145 mEq/L
o Caused through:
 Water loss
 Excessive sodium
 Fluid deprivation
 Lack of fluid consumption
 Diarrhea
 Excessive insensible waterloss
 S&S
 Increased extracellular osmotic pressure
 Cells shrink
 Neurological impairment
 Restlessness
 Weakness
 Disorientation
 Delusion
 Hallucinations
 Permanent brain damage – esp. in children
o Hypokalemia - serum potassium < 3.5 mEq/L
 Caused by:
 Vomiting
 Gastric suction
 Alkalosis
 Diarrhea
 Diuretics
 S&S
o Muscle weakness
o Cramps
o Fatigue
o Paresthesias
o Dysrhythmias
o Hyperkalemia – serum potassium > 5mEq/L
 Caused by:
 Renal failure
 Hypoaldosteronism
o Aldosterone causes sodium reabsorption and potassium
excretion
o Hypoaldosteronism causes you to hold on to K+
 Potassium chloride
 Heparin
 Angiotensin-converting enzyme inhibitors
 NSAIDs
 Potassium sparing diuretics
 S&S
 Nerve conduction and muscle contractility affected
 Skeletal muscle weakness and paralysis
 Variety of cardiac irregularities
o Cardiac arrest
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Hypocalcemia – serum calcium < 8.9 mg/dL
o Caused by:
 Inadequate calcium intake
 Impaired calcium absorption
 Excessive calcium loss
o S&S
 Numbness
 Tingling of:
 Fingers
 Mouth
 Feet
 Muscle cramps
 Tetany
 Seizures
Hypercalcemia – serum calcium > 10.1 mg/dL
o Caused by:
 Cancer
 Hypothyroidism
o S&S
 N/V
 Constipation
 Bonepain
 Excessive urination
 Thirst
 Confusion
 Lethargy
 Slurred speech
 Severe hypercalcemia >17 mg/dL
 Cardiac arrest


Hypomagnesemia – serum magnesium < 1.5 mEq/L
o Caused by:
 NG suction
 Diarrhea
 Alcohol withdraws
 Administration of tube feedings or parenteral nutrition
 Sepsis
 Burns
o S&S
 Muscle weakness
 tremors
 Tetany
 Seizures
 Heart block
 Change in mental status
 Hyperactive deep tendon reflexes (DTRs)
 Respiratory paralysis
Hypermagnesemia – serum magnesium < 2.5mEq/L
o Caused by:
 Renal failure
 Kidneys fail to excrete magnesium from excessive magnesium
intake
 Excessive magnesium-containing antacids or laxatives
o S&S
 N/V
 Weakness
 Flushing
 Lethargy
 Loss of DTRs
 Respiratory depression
 Coma
 Cardiac arrest
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Hypophosphatemia – serum phosphate <2.5 mg/dL or 1.8 mEq/dL
o Caused by:
 Administration of calories to malnourished patients
 Alcohol withdrawal
 DKA
 Hyperventilation
 Insulin release
 Absorption problems
 Diuretic use
o S&S
 Irritability
 Fatigue
 Weakness
 Paresthesias
 Confusion
 Seizures
 Coma
Hyperphosphatemia – serum phosphate > 4.5 mg/dL or 2.6 mEq/L
o Caused by:
 Impaired kidney excretion
 Hypoparathyroidism
o S&S
 Tetany
 Anorexia
 Nausea
 Muscle weakness
 Tachycardia
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Hypochloremia – serum chloride < 96 mEq/L
o Caused by:
 Severe vomiting and diarrhea
 Drainage of gastric fluid (GI tube)
 Metabolic alkalosis
 Diuretic therapy
 Burns
o S&S
 Hyperexcitability of muscle
 Tetany
 Hyperactive DTRs
 Weakness
 Muscle cramps
Hyperchloremia – serum chloride > 106 mEq/L
o Caused by:
 Metabolic acidosis
 Head trauma
 Increased perspiration
 Excess adrenocortical hormone production
 Decreased glomular filtration
o S&S
 Tachypnea
 Weakness
 Lethargy
 Diminished cognitive ability
 Hypertension
 Decreased cardiac output
 Dysthymias
 coma
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Arterial blood gas (ABG) interpretation
o Normal ranges
 pH – (acidotic) 7.35 – 7.45 (alkalotic)
 PaCO2 – respiratory (alkalotic) 35 – 45 (acidotic)
 HCO3 - metabolic (acidotic) 22 – 26 ( alkalotic)
Intake and output
o
What patient population is most at risk for fluid & electrolyte imbalances
o Older population
IV fluids appropriate for different electrolyte imbalances
Nursing responsibilities for IV therapy
o Initiating, monitoring/maintaining, discontinuing IV therapy
o Per order or per facility protocol
o Initiating—putting the IV in (not prescribing what fluid to give, which requires an
order from the provider)
o Monitoring/maintaining
o Discontinuing—removing the IV (not determining when to stop an ordered
therapy, which requires an order from the provider)
o Critically evaluating all pt orders prior to administration
o Assessing
o At varying intervals per faculty policy—do first assessment when getting bedside
shift report so you have a baseline to compare
o Assess during hourly rounds
 Site
 Redness
 Swelling (edema)
 Streaking
 Drainage
 Pain
 Firmness of veins
 Blanching
 Temperature (warm may indicate infection, cool may indicate
infiltration)
 Tightness to skin
 Fluid leakage (from skin or hub of catheter)
 Solution
 Tubing
 Flow rate
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IV therapy complications and nursing interventions for complications
Infection
o Redness
o Edema
o Warmth
o Purulent drainage
Treatment
o Discontinue IV
o May send IV tip or drainage for culture
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•
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Infiltration
• Edema
• Pallor
• Coolness
• Pain
Treatment
• Discontinue IV
• Warm compress
Phlebitis
• Pain
• Warmth
• Redness along vein
Treatment
• Discontinue IV
• Moist, warm compress over area
•
•
Extravasation
• Vesicant medication infuses into tissues,
can cause minor to major tissue damage
• Stinging/burning
• Edema
• Redness
Treatment
• Discontinue IV
• Cool compress
• Antidote if necessary
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•
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Fluid overload – edema
• Dyspnea
• Elevated BP
• Dependent edema
• Coarse or “congested” lung sounds
Treatment
• Notify MD
• Stop fluids
• Diuretics
0.9% NaCl (normal saline) and Lactated Ringer's solution are isotonic solutions that
have a total osmolality close to that of the ECF and help replace the ECF in the
treatment of hypovolemia.
5% dextrose in 0.9% NaCl is a hypertonic solution that can temporarily be used to treat
hypovolemia if plasma expander is not available.
10% dextrose in water (D10W) is a hypertonic solution that is used in peripheral
parenteral nutrition.
0.45% NaCl (½-strength normal saline) is a hypotonic solution that provides Na+, Cl-',
and free water and is used as a basic fluid for maintenance needs.
5% dextrose in water (D5W) is used in fluid loss, dehydration and hypernatremia, and
should not be used in excessive volumes because it does not contain any sodium.