fluid, electrolytes, & IV solutions

fluid & electrolytes

• maintain homeostasis

distribution of body fluids

• humans are 50-60% water

  • intracellular

  • extracellular

intracellular fluids

• 2/3!

extracellular fluids

• interstitial

• intravascular

• transcellular

interstitial fluid

• not around/in cells

• the main one!

• high BP? fluids pushed here

  • 3rd space - swelling

3rd space fluids

• aka swelling

diseases that cause 3rd space swelling

• heart failure

• liver failure/cirrhosis → ascites

• renal failure

intravascular fluid

• plasma

• blood

• lymph

  • dictates BP

transcellular fluid

• everything else

  • joints

  • CSF

  • GI tract

  • pleural space

electrolytes

• molecules that dissociate to form ions

• carry charges!

  • cations

  • anions

• ICF & ECF anions & cations balanced!

cations

• + charge

• majority Na+ (ECF) & K+ (ICF)

anions

• - charge

• majority Cl - (ECF) and PO43- (ICF)

• bicarb! ECF & ICF

extracellular fluid electrolytes

• Na+ (cation)

  • and Ca2+

• Cl- (anion)

sodium

• Na+

• predominant cation in ECF

• 135-145

• brain brain brain!

sodium imbalance

• seizures

• confusion

• coma

  • brain symptoms

chloride

• 98-106

• Cl-

• ECF

• fluid balance

• nerve & muscular fxn

intracellular fluid electrolytes

• K+ (cation)

  • + Mg2+

• PO43- (anion)

potassium

• k+

• ICF

• 3.5-5

• heart, heart, heart!

• in food - bananas

potassium imbalances

• dysrhythmias → cardiac arrest

phosphorous

• PO43-

• ICF

• 2.5-4.4

calcium

• Ca2+

• ECF

• 9-10.5

• muscle contraction

  • can affect heart

magnesium

• Mg2+

• ICF

• 1.3-3.1

• muscles/nerves

• BP fxn

bicarb

• HCO3-

• helps reverse acidosis

  • low? pH low

• anion

• 21-28

fluid & electrolyte movement

• diffusion

• active transport

• osmosis

diffusion

• movement of molecules from high to low concentration

• no energy required

• stops @ equilibrium

facilitated diffusion

• no energy required

• protein carrier!

  • ie: increased sugar lvls & increased insulin

active transport

• needs energy

• molecules moving against concentration gradient

• ie: K+/Na+ pump

  • ICF/ECF

osmosis

• H2O movement

• from areas of low concentration to high concentration

  • affects osmolarity

osmolarity

• 280-295 mOsm/kg

• measure of concentration of plasma/urine/body fluids to molecules

• largely dependent on Na+

  • hypo, hyper

hypoosmolar

• less solutes, more water

  • high H20, low Na+

• seizures, confusion, coma

hyperosmolar

• more solutes, less water

  • low H2O, high Na+

• seizures, confusion, coma

serum osmolarity of 255 mOsm/kg?

• hypoosmolar!

• H2O excess

  • more water, less solutes, decreased Na+

serum osmolarity of 320 mOsm/kg?

• hyperosmolar!

• dehydration

  • H2O deficit

  • less water, more solutes, increased Na+

osmolality & tonicity

• hypotonic

• hypertonic

• isotonic

hypotonic solution

• more solutes in cell

• increased H2O in cell

  • cells swell & burst

hypertonic solution

• more solutes in ECF

• decreased H2O in cell

  • cell shrinkage

isotonic solution

• homeostasis

• equal

• good!

pressures

• hydrostatic pressure

• osmotic pressure

hydrostatic pressure

• push out!

  • too much fluid in

• big w/ HTN

osmotic pressure

• aka colloidal osmotic pressure

• albumin’s work

  • pulls in!

    • good for lowered BP, dialysis

albumin

• large protein

• give to raise BP! (+ dialysis pts esp)

  • increases oncotic pressure

  • increases interstitial pressure -→ pushed to intravascular

factors affecting water balance

• dehydration a big one

• hypothalamic-pituitary regulation

• renal regulation

• adrenal cortical regulation

• cardiac regulation

hypothalamic-pituitary fluid regulation

• regulates thirst mechanism

• antidiuretic hormone

antidiuretic hormone

• causes H2O retention

  • reduced diuresis

• good for low BPs

• excessive sweating may trigger it

renal fluid regulation

• good?

  • waste management all fine

adrenal cortical fluid regulation

• adrenal glands - on kidneys

  • glucocorticoids

  • mineralocorticoids

glucocorticoids

• anti-inflammatories

• cortisol!

  • for infection & swelling

• increase blood sugars bc they are sugars!

• steroids

mineralcorticoids

• Na+ & H2O retention!

  • aldosterone

cardiac fluid regulation

• afib, sinus tach, ventricle swelling → increased BNP

• b-type natriuretic peptide

  • BNP

  • works against RAS

    • renin-aldosterone system

  • promotes fluid loss

sodium correction

• adjust slowlyyy

  • too fast? → cerebral edema

    • give D5 to compensate

hyponatremia

• <135

• fluid excess

  • put on fluid restrictions

  • orrr give NS 0.9%!

hypernatremia

• >145

sodium imbalance nursing care

• monitor serial Na

• seizure precautions

hyperkalemia

• >5

• peaked T waves

• bc of

  • renal failure

  • beta blockers

  • ACE inhibitors

  • ARBs

hypokalemia

• <3.5

• diuretics, diarrhea, vomiting

• general weakness

• shallow/depressed T waves

potassium imbalance treatmetns

• sodium zirconum (lokelma)

• kayexalate - quicker!

  • oral, excreted thru bowel movements

• hemodialysis

• potassium IV infusion

potassium IV

• given peripherally

• burns

  • give it slowly!

  • 10-20meq given at a time

  • can be diluted

• give PO ix A&Ox4 & not critically low

critically high potassium cocktail

• insulin, D5 (sugar), calcium glycinate

• shifts K+ back into cell

• calcium helps w. heart contractions

  • can also be bicarb bc of acidosis

common laboratory values

• serum osmolality

• urine osmolality

• complete blood count

• arterial blood gas

• blood urea nitrogen

• serum creatinine

• electrolytes

urine osmolality

• if kidneys are cool, good!

• checks

  • diuresis

  • fluid & solute excretion

complete blood count

• CBC

• blood

  • WBC

  • hct

  • hgb

  • RBC

  • platelets

• super important! checked everyday

arterial blood gas

• ABG

• important for respiratory distress pts

  • ph (7.35-7.45)

  • pO2 (80-100)

  • HCO3 (7.2-8)

  • pCO2 (35-45)

blood urea nitrogen & serum creatinine

• BUN & creatinine

• indicates kidney fxn, renal failure

  • increases w/ failure - not urinating

electrolyte labs

• basic metabolic panel, complete (+phos) metabolic panel

  • Na+, K+, Cl-, HCO3

AST/ALT

• liver enzymes

• increased w/ cirrhosis

• 80% bc of alcoholism, 20% bc of hepatitis

ways to measure fluid balance

• daily weights

• I&Os

  • specifically urine output

daily weights

• important, esp in critical care & intubated + nonmoving

• same time, clothing, conditions each day

• concerned w/ 2-3lbs gain/loss in one night

fluid/electrolyte replacement

• parenteral

• enteral

fluid restriction

• needed w/ fluid overload

• big w/ propofol/pressors

medications

• PO

  • K+

  • Na+ (tolectin, samsca)

I&Os

• fluids in/out

  • in: meds, liquid

  • out: urine output

    • foley

    • urinals

    • urine hats

    • bed pan