Ch 13: Fluid & Electrolyte Balance

who is at the highest risk for imbalances

• older adults

  • bc of age related organ changes

  • they are more likely to be taking drugs that affect fluid & electrolyte balance

3 hormones that regulate fluid balance

• aldosterone

• ADH (vasopressin)

• natriuretic peptide

Key concepts of aldosterone

• when sodium is LOW, aldosterone is secreted

• need it to hold onto water and sodium, also gets rid of potassium

• aka: water and sodium sparing hormone

ADH key concepts

• when sodium is HIGH, ADH is released and the body reabsorbs more water

• dilutes sodium

key concepts of natriuretic peptide

• when blood vol and bp are elevated, np is secreted to work on the kidneys causes decreases in blood osmolarity and cause less sodium and water in the circulation

• comes from the atria and ventricles

what 2 hormones work opposite of each other

aldosterone and NP

best indicator of fluid loss or gain is what

weight

1 L of water = ?lbs

2.2 lbs

500mL = ?lbs

1lb

causes of dehydration

• hemorrhage

• vomiting

• profuse salivation

• iloestomy

• burns

• diuretics

• hyperventilation

• fever

s/s of dehydration

• dizzy

• dry skin

• paple

• decreased urine output

• FLAT NECK VEINS WHILE SUPINE

• decreased bp

• orthostatic hypotension

• weak pulse

• increased RR & HR

• tongue fissures

• pasty tongue

• decreased LOC

• can cause fever or fever can cause dehdration

why does fever occur with dehydration

because you have less body water and less ability to regulate temp

why does rr & hr increase with dehydration

body is trying to perfuse more o2 and water

what is the best way to treat dehydration

• give fluid (preferably PO)

  • monitor response every 2 hrs esp pulse, urine output, and weight (every 8 hrs)

are females or males at greater risk for dehydration

• females

  • less total body water bc males tend to have more muscle mass than females (more muscle = more water)

what is hypervolemia

extra fluid in the ECF

causes of fluid overload

• bad kidneys

• heart failure

• polydipsia

• steroids (make you retain NA)

• long-term corticosteroid therapy

• SIADH

• excessive fluid replacement

s/s of fluid vol overload

• increased hr

• bounding pulse

• narrowed pulse pressure

• weight gain

• engorged neck veins

• increased rr

• pitting edema

• pale skin, cool to touch

• visual disturbances

• altered LOC

• enlarged liver

• skeletal muscle weakness

what is the calculation for pulse pressure

systolic - diastolic

nursing priority for pt with fluid overload

assess them every 2 hrs to recognize pulmonary edema (can occur quickly and lead to death

where should you assess skin turgor on an older adult

over the sternum rather than back of hand

Normal value mg

1.3-2.1

Normal value potassium

3.5-5

Normal value calcium

9-10.5

Normal value sodium

135-145

mg function

muscle relaxation

potassium function

intracellular excitation

calcium function

bones-muscle excitation

sodium function

extracellular excitability

high osmolarity

indicates a more concentrated solution, causing water to move towards it to achieve equilibrium

low osmolarity

indicates more dilute solution, causing water to move away from it

Normal value osmolarity

270-300

osmolarity function

regulate fluid balance

hypomagnesemia s/s

• MUSCLES EXCITED

• increased DTRs

• seizures

• CV changes (increase HR & BP)

• may see: chvosteks and trousseuas

hypermagnesmia s/s

• muscles RELAXED

• decreased DTRs

• drowsy and lethargy

• resp arrest

hypomagnesemia often occurs with what other imbalance

• hypocalcemia… leads to positive chvostek and trousseau sign

when serum mg levels are low

intracellular potassium is low

hypophosphatemia

• muscles relaxed

• weakness

• resp failure

hyperphosphatemia

• muscles excited

• tetany

who is most vulnerable to potassium imbalances

aging adults

hypokalemia s/s

• muscles relax

• paresthesias

• flattened t wave

• prominent u waves

never administer potassium what route

IV push, IM, or subq

hypokalemia treatment

• Cardiac monitor !

• replinish k

• k sparing diuretics

hypokalemia action alert

assess resp status every 2 hrs bc resp insufficiency and dysrhythmias are major causes of death

hyperkalemia

• tight and contracted heart and GI muscles

• increased DTRs

• tall peaked t waves

• resp arrest

• paresthesias, twitching

hyperkalemia treatment

• loop diuretic

• cardiac monitor! (can become bradycardia & hypotensive)

recommended rate of infusion for potassium

5-10 mEq/hr

what should you do if infiltration occurs with solution containing potassium

• stop IV immediately

• remove venous access

• notify PCP

• document and photograph IV site

what cardiac changes to recognize with hyperkalemia

• if hr falls below 60 or if t waves become spiked notify rapid response team

hypocalcemia s/s

• muscles excited

• increased DTRs

• seizures

• tachycardia

• chvosteks and trousseua

hypercalcemia s/s

• muscles relaxed

• decreased DTRs

• CV changes

• blood clots

hypercalcemia tx

• admin normal saline (na excretes excess ca)

in aging women, encourage them to (ca)

• continue walking and other weight bearing activities to prevent osteoporosis at a rapid rate

what to watch for hypercalcemia

weakness, decreased LOC, dysrhythmias, cardiac status, blood clots

s/s hypochloremia

• dehydration

• dizzy

• muscle weakness

s/s hyperchloremia

• no specific s/s

• can get HTN

s/s hyponatremia

• muscle cramps

• confusion

• weakness (monitor resp muscle)

• cerebral changes

hyponatermia w hypovolemia

• monitor for rapid, weak, thready pulse, drop in bp and severe orthostatic hypotension

hyponatermia w hypervolemia

• monitor for cardiac changes, check for full, bounding pulse with normal to high BP

hypernatermia s/s

• increased thirst

• dry, flushed skin

• assess nervous system changes (attention span and cognitive function, stuporous)**

hypernatremia treatment

• fluid replacement and na restriction

• monitor bpo and rate/quality of apical and peripheral pulses

difference between actual and relative hyponatermia

• actual: true decrease in sodium in the blood

• relative: low sodium due to excess water

ex of relative hyponatremia

drinking large amounts of water resulting in dilution

ex of actual hyponatremia

severe vomitinig or diarrhea can lead to significant sodium loss

high hematocrit can indicate

dehydration