Fluid & Electrolytes - Fluid focused

how much of the body is fluid

• what factors affect fluid (age? tissues? gender?)

• 60% of a typical adult

• the younger you are the more fluid you have (think plump baby)

• the older you are the less fluid you have (think dried & wrinkly)

• muscle retains more water than fat (lipid repels water)

• men typically hold more fluid than women (muscle mass)

Intracellular fluid

• how much of fluid

• inside cells

• 2/3rd of fluid

Extracellular fluid includes

• 3 kinds

• intravascular

• interstitial - the fluid immediately around cells

• transcellular - (CSF, synovial joint fluid, pericardial, intraocular fluid, GI fluid, etc.)

what is the largest component of ECF

• lymph fluid (interstitial)

• 11-12 liters

cations and examples

• positively charge

• sodium

• potassium

• calcium

• magnesium

• hydrogen

anions and examples

• negatively charged

• chloride

• bicarbonate

• phosphorus

hydrostatic pressure

• comes from?

• caused by?

• comes from inside the vessel

• pushing on the vessel wall

• from blood pressure/ heart contractions

albumin

• by product made by liver

• large protein that is trapped in vessels

osmotic pressure

• comes from?

• created by?

• comes from outside vessel

• water is pulled into vessel from albumin inside veins via osmosis

• water wants to move inside vessels bc it is attracted to the high concentration of albumin

how can liver issues affect osmotic pressure

• less albumin = less osmotic pressure

• less vascular fluid & more interstitial fluid

• pt will present with systemic swelling

osmosis

• Fluid moves from area of low solute concentration to an area of high concentration

• water wants to move to create an equal concentration of both sides

diffusion

• passive / no ATP required

• solutes move from area of high concentration to low concentration

filtration

• movement of fluid & solutes

• from an area of high hydrostatic pressure to an area of low hydrostatic pressure

active transport

• what is it?

• what does it require?

• what does it do?

• what does it maintain?

• Na+/K+ pump

• requires ATP

• moves solutes form an area of low concentration to an area of high concentration (against the concentration gradient)

• this maintains a higher concentration of extracellular sodium and intracellular potassium

how much fluid do we lose via kidneys

• daily vs hourly

• what is the number we watch for

• 1-2 Liters daily

• 1ml / kg every hour

• 30ml/hr MINIMUM, anything less we have a problem

skin losses is

• measurable ?

• what increases it

• sweating

• insensible

• fever / high temperature will increase sweating

losses via lungs

• measurable?

• how much?

• what increases it?

• insensible

• approximately 300ml/day

• tachypnea/ panic attacks/ dry climate increases

serum osmolality

• what is it

• what is the main electrolyte

• high vs Low serum osmolality (what does it look like & what are we thinking)

• the concentration of solute in blood

• mostly sodium

• high serum osmolality = thick & syrupy blood - think dehydration

• low serum osmolality = thin & watery blood - think water intoxication

urine osmolality

• the concentration of solute in urine

• high urine osmolality = dark & syrupy urine

• low urine osmolality = clear/ light urine

specific gravity

• weighed urine

• low specific gravity = light watery urine

• high specific gravity = thick heavy urine

ADH/ antidiuretic hormone

• functions ? 2

• produced by?

• stored in?

• tells kidneys to retain water

• constricts vessels

• produced by hypothalamus

• stored in posterior pituitary gland

Diabetes Insipidus

• what is the body lacking/ cant respond to

• how does it effect kidneys

• what is overloaded in the body

• body lacks ADH or kidneys don’t respond to ADH

• the kidneys cannot retain water → constant urination (dilute urine)

• sodium stays inside the body → hypernatremia + fluid volume deficit

what will labs look like in a patient with diabetes insipidus

• high serum osmolality (hypernaturemia)

• low urine osmolality (bc the urine is excessive and dilute)

Nursing considerations for pt with Diabetes Insipidous

• what is going on internally with the patient? how might that be confusing

• what are we trying to retain? what are we avoiding?

• what symptom are we especially keeping in mind?

• though pt has dilute urine, they are internally dehydrated

• we want to retain water as much as possible (avoid caffeine bc of diuretic effects, DO NOT restrict fluids)

• they have low blood volume, so keep in mind postural hypotension (dizzyness, fall risk )

SIADH - syndrome of inappropriate ADH

• what is it ?

• what are the side effects

• how does the heart try to help

• nuero changes ?

• too much ADH - kidneys are retaining too much water

• fluid overload, edema, crackles, rapid weight gain, high BP, tachycardia(heart tries to compensate for too much fluid)

• confusion, coma, death (swelling of the Brain cells, pressure building up in skull)

what will labs look like for SIADH pt?

• low amount of concentrated urine

• low serum osmolality (dilute, watery)

• high specific gravity and urine osmolality (concentrated, dark)

management of SIADH

• meds and fluid

• lasix - we want to lose that fluid

• hypertonic solution - we want to draw that fluid out of cells, relieving pressure on brain cells

nursing considerations for pt with SIADH

• restrict?

• what are we watching closely?

• restrict fluid and sodium!!

• watch K+ if on lasix (it expels K+)

• pt will be confused - watch nuero changes closely

• daily weights, I and Os

step 1 of the RAAS system - watch videos on this! need more of an understanding!

• what does liver release?

• what does the kidney release ? in response to what

• liver releases angiotensinogen (precursor of angiotensin 1)

• kidneys will release renin in response to low blood pressure or low sodium

what does renin to do angiotensinogen

• renin turns angiotensinogen to angiotensin 1

when angiotensin 1 reaches lungs ?

• lungs will release ACE (angiotensin converting enzyme)

• ACE will convert angiotensin 1 to angiotensin 2

angiotensin 2 functions

• tells adrenal glands to create aldosterone

• casuses vasocontriction in arterioles (increases BP)

• increases sodium and water reabsorption

aldosterone functions

• retains? loses?

• tells kidneys to retain sodium and water (raises BP)

• tells kidneys to lose K+ via urine

Fluid volume deficit (FVD)/ hypovolemia

• how does it happen

• water and electrolyte balance?

• what are some causes

• happens when loss of ECF is greater than intake of fluid

• water and electrolytes are lost in the same proportion

• causes: vomiting, diarrhea, GI suction, hemorrhage, trauma, burns

dehydration

• what is being lost

• caused by?

• what increases

• loss of water alone , not along with sodium

• caused by sweating, fever

• serum osmolality is going to increase

peds/ elderly consideration for suspecting FVD

• elderly are more vulnerable to fluid loss bc of lack of reserve

• peds have more ECF, more vulnerable to fluid loss

• always ask how long have they been vomiting/ diarrhea (wtv the source of fluid loss is) and how many times a day

LOOK UP ADRENAL INSUFFICENCY/ HYPO AND HYPER ALDOSTERONEISM

how much weight is too much weight lost or gained

• what can it indicate

• when do we weigh pt

• 2.2 punds in a day

• 5 lbs in a week

• may indicate FVD

• always weigh pt first thing in the morning

what are some signs of FVD

• decreased skin turgor

• oliguria, concentrated urine

• postural hypotension (low BP from low volume )

• rapid and weak pulse (rapid bc heart is trying to compensate)

• low temp

• cool clammy skin

• thirst - decreased thirst sensation in older adults

• nausea

• cramps an muscle weakness

Lab values when a pt has FVD will look like

• urine ?

• blood?

• kidney function?

• high specific gravity & urine osmolality (dark and concentrated urine)

• hematocrit will be greater due to decreased plasma volume

• BUN/Creatinine is 20:1, when normally it is 10:1

medical management of FVD

• mild vs severe?

• what fluid? 1st vs 2nd defense

• increase fluid intake orally if mild , IV if severe or acute

• Isotonic fluid - 0.9% NS or lactated ringers (1st defense)

• once pt is normotensive, they may be on a hypotonic fluid (0.45% NS)

what do isotonic fluids do

• in comparison to blood ?

• who are we especially cautious about

• expands fluid volume

• equal osmolality to normal blood

• caution in pts with Heart failure, we need to monitor for fluid overload & pulmonary edema

nursing considerations for pt with FVD

• what are we checking, how often if severe?

• what vitals are especially important

• nuero?

• r/t hydration status ?

• I and O at least q8hrs , hourly if it is severe (needs foley to be accurate)

• daily weight

• vitals (orthostatic hypotension and pulse - is it weak or rapid?)

• asses mental status - Brain is very sensitive to fluid loss - we do not want coma, seizures death!

• skin turgor & specific gravity - checking hydration

Fluid Volume Excess

• due to?

• may signify?

• due to fluid overload

• abnormal retention of water and sodium - may be kidney failure

factors that contribute to FVE

• diseases

• excess of?

• heart failure, kidney failure or liver cirrhosis

• excess sodium in diet or IV fluids with sodium

what do pts with FVE look like

• 4 clinical signs

• what increases

• how does body try to compensate

• edema - starts in the ankles

• distended neck veins and JVD (high central venous pressure)

• crackles in lungs

• shortness of breath, worse when lying down

• increased weight

• increased BP

• increased urine output (kidneys try to compensate)

• tachycardia (heart tries to compensate)

medical management of FVE

• what meds? what are we watching closely?

• what are we restricting

• if severe?

• diuretics (lasix and demidex) - watch for hypokalemia

• K+ diuretic - spironolactone - watch for hyperkalemia

• restrict fluid and sodium

• If severe enough may need dialysis

nursing considerations for pts with FVE

• position?

• skin?

• assessing?

• promote?

• keep them in semi-fowlers or fowlers (expands lungs for better breathing)

• skin is very sensitive to breakdown, it is moist and weeping - q2hr turns

• asses all symptoms (edema, crackles, I+O, weights)

• assess electrolytes especially if on diuretics

• promote fluid and sodium restriction