Fluid/Electrolytes

Sensible loss

• measured loss

• urine, suction cannister, wounds/drains, stool, gastric contents (via suction)

Insensible loss

• cannot be seen or counted

• sweat, breathing, etc.

Osmolality

concentration of particles (solute) in 1 L of body fluid (water-solvent)

Hyperosmolar

• increased concentration

• volume deficit

Hypo-osmolar

• decreased concentration

• volume excess

Hypertonic

• water in but needs out

• high volume of solute/very concentrated/lots of salt

• cell shrivels up

• fluid is pulled out of cell and off of body, moved to blood stream

• *used more rarely — severe cerebral edema (get fluid out)

Isotonic

• water out = water in

• equal concentration to amount in body

• no fluid shift

• used for fluid replacement in hypovolemic dehydrated patient

• dehydrated at all levels & require fluid replacement everywhere

Hypotonic

• water out but needs in

• diluted, more water than particles

• cell swells & bursts

• used to prevent dehydration preemptively (ex. NPO, pre-op)

• dehydrated at cellular level

• 5% dextrose in LR

• 5% dextrose in 0.9% NaCl

Hypertonic IV fluids

• 0.9% NaCl

• LR

Isotonic IV fluids

• 0.33% NaCl

• 0.45% NaCl

Hypotonic IV fluids

Dehydration

• loss/deprivation of water from cells

• DECREASED blood volume

• INCREASED blood concentration

• CM: dec. LOC, inc. RR and HR, weak pulse, dec. BP

Hypovolemia

• low volume in blood

• inc HR, weak and thready

• dec. BP and urine output (less vol = less pressure)

• **inc. serum sodium

• dehydration

Hypervolemia

• high volume in blood

• inc HR, bounding

• inc. BP and urine output

• fluid overload

3rd spacing

• leaking of extra-cellular fluid into a serous cavity

• fluid is trapped, not lost

• ex. ascites, burns

135-145 mEq/L

Normal sodium level

3.5-5 mEq/L

Normal potassium level

1.3-2.3 mEq/L

Normal magnesium level

8.6-10.2 mg/dL

Normal serum calcium level

97-107 mEq/L

Normal chloride level

25-29 mEq/L

Normal bicarbonate level

2.5-4.5 mg/dL

Normal phosphate level

Sodium

• maintains water and acid-based balance

• conduction of muscle and nerve tissue

• attracts fluid

• NEURO!

Hypernatremia

• very concentrated in little amount of fluid

• causes: fluid loss (diarrhea, insensible loss), fluid deprivation

• manifestations: seizures, disorientation, hallucinations, agitation

Hyponatremia

• loss of electrolytes; too much fluid, this electrolyte is diluted

• causes: fluid loss (vomiting, diarrhea, sweating, diuretics), water gain

• manifestations: lethargy, confusion, edema, hypotension

• increased intracranial pressure

Potassium

• cardiac muscle contraction

• electrical conductivity

• neuromuscular transmission of nerve impulses

• CARDIAC!

• NEVER give IV push

• IV: 10-20 mEq/hr

Hyperkalemia

• causes: renal failure (not being filtered out), meds, diet

• manifestations: muscle weakness, cardiac irregularities, paresthesia

• SLOW HR — can lead to asystole

Hypokalemia

• causes: fluid loss (vomiting, GI suction, diarrhea, diuretics)

• manifestations: muscle weakness, cramps, dysrhythmias

• FAST HR

Calcium

• cell permeability

• bone and teeth formation

• blood coagulation

• nerve impulse transmission

• normal muscle contractions

• regulated by parathyroid hormone

Hypercalcemia

• causes: cancer, hyperparathyroidism

• manifestations: lethargy, bone pain, n/v, confusion

Hypocalcemia

• causes: inadequate intake/absorption, excess loss

• manifestations: numbness/tingling, cramps

Trousseau’s sign

• result of hypocalcemia

• hand/finger spasm in palmar flexion

Chvostek’s sign

• result of hypocalcemia

• facial twitching

Magnesium

• enhances neuromuscular communication

Hypermagnesemia

• causes: renal failure, use of antacids/laxatives

• manifestations: lethargy, diminished DTRs, respiratory depression, n/v, weakness

Hypomagnesemia

• causes: fluid loss, enteral/parenteral feedings, alcohol use, sepsis

• manifestations: increased DTRs, weakness, tremors, seizures, resp. paralysis

Chloride

• acts w/ sodium to maintain osmotic pressure

• excreted and conserved w/ sodium by kidneys

• regulated by aldosterone

Hyperchloremia

• causes: metabolic acidosis, hyperparathyroidism, hypernatremia

• manifestations: tachypnea, weakness, decreased cognition, lethargy

Hypochloremia

• causes: fluid loss, metabolic alkalosis

• manifestations: muscle excitability, tetany, cramps, inc. DTRs

Phosphate

• promotes energy storage

• carb, protein, fat metabolism

• bone & teeth formation

• activated by vitamin D

• regulates calcium (inverse relationship)

Hyperphosphatemia

• causes: renal impairment

• manifestations: weakness, dysrhythmias, anorexia

Hypophosphatemia

• causes: alcohol withdrawal, DKA, diuretics, absorption issues

• manifestations: weakness, slurring, dysphagia, paresthesia, dec. resp. effort, confusion