fluid imbalances Flashcards
what is body fluid
- water within the body and particles dissolved in it
what is total body water (TBW) ?
- sum of fluids within all body compartments (all fluid in body)
what is extracellular fluid?
- fluid outside of the cell
- 1/3 TBW
what is interstitial compartment?
- between cells and outside of blood vessels
what is intravascular compartment?
- in the blood vessels
- ex: blood plasma or serum
what is intracellular fluid? and how much of it is TBW?
- inside the cell
- 2/3 TBW
what is the number 1 fluid excretion?
- pee or the urinary tract
what is urine volume dependent on?
- adequate blood pressure to kidneys for proper perfusion
- glomerular filtration rate (GFR)
what is the expected GFR?
- 1 mk per kg of body weight an hour for an adult
what affects fluid excretion?
- hormones
what hormones effect how much fluid is excreted?
- Antidiuretic hormone (ADH)
- Aldosterone
- Also makes you pee less
- Natriuretic peptides (ANP and BNP)
- All connected to the RAAS
what does antidiuretic hormone (ADH) ?
- makes you pee less, excrete less urine
what does aldosterone do?
- makes you pee less
- reabsorbed sodium and h20 and excrete potassium
what are natriuretic peptides (ANP and BNP)
- opposite of aldosterone, helps get rid of urine, but if it’s peptides vs aldosterone, aldosterone always wins, meaning that you don’t pee
what is does RAAS stand for?
- R = renin
- A = angiotensin
- A = aldosterone
- S = system
what does renin do?
- hormone secreted by kidney to help regulate blood and pressure by breaking angiotensin into Angiotensin 1
what does Angiotensin do?
- hormone that helps regulate BP by constricting (narrowing) of blood vessels and triggering water and salt intake
what does aldosterone do?
- holds onto h2o & na+ excretes potassium so you pee less but when you do pee its heavly concentrated with K+
what are the other 4 ways of fluid excretion?
- urination
- bowels
- skin = through sweat and insensible perspiration
- lungs = exhalation secretes fluid
how do nurses measure fluid imbalances?
- through I’s and O’s and BODY WEIGHTS to watch fluids
what are examples of abnormal fluid loss?
- emesis
- tubes in the GI track or other body cavities
- hemorrhage
- drainage from fistulas, wounds, open skin
- paracentesis
- ascites
what is a paracentesis?
- pulling fluid out of a drain
what is ascites?
= fluid build up in abdomen
what is fluid homeostasis?
- Regulation of fluids and electrolytes
what are the 4 general steps of fluid homeostasis?
- fluid intake
- fluid absorption
- fluid distribution
- fluid excretion
what is fluid intake triggered by? (intake = thirst)
- thirst is triggered by osmolality of ECF including blood volume, and dry mouth
what happens when your body needs/ does retain fluid?
- you get an IV, or drink more
- aldosterone or ADH gets triggered:
- meaning you hold onto fluid
- ADH only holds onto h20
what does high & low osmolarity mean in OJ example?
- more pulp
- low osmolarity means less pulp
- homeostats means normal pulp
when you have high osmolarity what does your body do?
- high osmolarity means high pulp and you need to drink more to water it down
when you have low osmolarity what does your body do?
- you have low pulp and your body pees more
where is fluid absorbed and what is it dependent on?
- GI track
- osmotically dependent
what primary stimulus for the sensation of thirst declines w/ aging?
- serum osmolarity
- as its the primary sensation for thirst
what is the number 1 protein in the blood?
- albumin
what does capillary osmotic pressure do?
- pulls h2o in (too much pulp, needs to water it down)
- water drawn IN from interstitial space into capillary
- opposing filtration
what does capillary hydrostatic pressure do?
- pushes h2o in
- too much pulp, needs to be watered down
- water moves OUT from capillaries into interstitial space
- favoring filtration
what does interstitial hydrostatic pressure do?
- pushes h20 out into the interstitial space
- water moves IN from interstitial space INTO capillary
- opposing filtration
what does interstitial osmotic pressure
- pull h20 in
- osmotically attracts water IN from the capillary into the interstitial space
- (favoring filtration)
what are two other ways that mean starling forces?
- net filtration
- fluid distribution
what does forces favoring filtration mean?
- going to something
what does forces opposing filtration mean?
- keep something in
what is the def of edema
- excessive accumulation of fluid within interstitial spaces
what are starling forces related causes of edema (systemic typically)
- increased capillary hydrostatic pressure
- maybe from heart / kidney failure - decreased capillary osmotic pressure
- due to low albumin
what are some non starling forces related causes of edema? (localized)
- increased capillary membrane permeability
- from wound healing or inflammation
- lymphatic cannel obstruction
- may be due to the removal of lymph nodes
what are adverse effects of edema?
- extra distances for nutrients / waste to travel (due to impaired blood flow)
- impaired blood flow
- delayed wound healing
- increased risk of infection and pressure sores
what are 2 big clinical variations of localized edema?
- pulmonary edema
- cerebral edema
what is pulmonary edema?
- fluid in the lungs due to the heart not working (most the time)
- sounds like crackling sounds or bubbles when listening
- PT may also have pink bubbly sputum
what is cerebral edema?
- swelling in brain due to sodium imbalances in neurons causing CNS disturbances
- symptoms: headache, forgetfulness, vision loss, ect (gets worse)
what is generalized edema and two examples?
- general swelling of the whole body
- ex: dependent edema (in the legs)
- ex: pitting edema or non-pitting edema (lymphedema)
what is the why behind edema?
- kidney or heart disease
- decreased lymphatic flow
- increased capillary hydrostatic pressure (is ALWAYS the reason behind edema)
how is edema assessed?
- by pushing down the skin and evaluating the depth 1+ t0 4+
what does antidiuretic (ADH) hormone do?
- holds on to H2o only
- dilutes body fluid (the pulp)
what does angiotensin do?
- reabsorbs (holds on to) BOTH h20 and NA+ but secretes potassium
- expands extracellular fluid volume (doesn’t dilute it)
what is the function of atrial natriuretic peptides?
- excrete pee
What are the steps of the RAAS system from the kidney POV?
- drop in BP = drop in fluid volume
- renin released from the kidney
- liver releases angiotensinogen 1 & 2
- stimulating the reabsorption of h20 & NA+ acting directly on blood vessels narrowing to effect attempt to raise BP
what stimulates aldosterone release?
- angiotensin II
- actived by decrease of circulating blood volume
- increased concentration of K+ ions in plasma
- decreased fluid excretion (Causes renal tubules to reabsorb sodium & h20, & promotes excretion of K+)
what happens when there is decreased secretion of aldosterone released?
- larger urine volume
what factors increase release of ADH (antidiuretic hormone)
- increased osmolality (concentration) of extracellular fluid (plasma)
- decreased circulating fluid volume
- pain, nausea, physiological & psychological stressors (if bod`y is stressed = more fluid build up to help w/ immunity)
what does ADH do?
- reabsorbs only H20
- decrease urine volume and fluid excretion
- concentrates urine
what happens when ADH is decreased?
- large dilute urine volume
- may cause hypernatremia (increased NA+)
what is the difference between ADH and aldosterone?
- ADH =
- kidneys reabsorb h20 only
- dilutes body fluids - Aldosterone =
- kidneys reabsorb water and salt
- expands extracellular fluid volume
what is ANP and what does it mean or do?
- ANP is A type natriuretic peptides
- means that there is too much fluid and it needs to be excreted
where is ANP secreted from?
- a type naturetic peptides are secreted from the cells in the heart when the atria is stretched
what hormone do NP’s oppose?
- NP’s appose the action of aldosterone but they aren’t as strong, so aldosterone will always win
- causing natriuresis (sodium excretion in the urine)
when vascular volume is increased & decreased what does that do no NP’s
- when vascular volume is increased = NP causes kidneys to excrete less fluid (pee less) opposite effect when vascular volume is decreased (np causes kidneys to excrete less fluid)
what is osmolality?
- concentration of molecules per weight of water
what is tonicity?
- effective osmolarity of a solution
what is a isotonic solution?
- same osmolality (equal amount of fluids and water)
- if in doubt, give isotonic solution
- 0.9 sodium chloride
what is a hypotonic solution?
- lower concentration of solutes, more dilute than body fluids
- more water, less pulp, more watery
what is a hypertonic solution?
- higher concentration of solutes than body fluids
- more pulp / solutes / particles
- body needs more fluid to go back to homeostats if swelling
- 3% sodium chloride (makes cell shrink) or moves water out of the cell
what solution is best for general replenishment?
- isotonic fluid
- o.9% NS
what are the 3 other names for isotonic solution?
- 0.9% sodium chloride (NS)
- lactated ringers
- D5W
what solution is best for water replacement?
- hypotonic solution
- known as 0.45% NS solution
what solution is best for electrolyte REPLACEMENT?
- HYPERtonic
- D10W
- 3% NS
- 25% albumin
what is hypovolemia? and what solution should the nurse give?
- volume depletion (low fluid volume in body)
- give isotonic solution (bc everything is low, water and pulp)
what is dehydration? and what solution should the nurse give?
- negative water balance
- reduced total body water
- give HYPOTONIC solution (bc osmolarity is elevated, meaning there’s more pulp)
what fluid should nurses give to a PT with fluid volume excess? and what is it?
- elevated total body water
- give isotonic solution
- the nurse would want to give a slow isotonic drip to make sure the patient stays hydrated and the fluids are measured
what is hypotonic hydration? what solution should the nurse administer?
- hypotonic hydration is a positive water balance or water intoxication, too much pulp
- total water body is elevated, too much water in the body, not enough fluids
- nurse should give a hypotonic (reduced h20, more particles) solution (to replace lost other fluids)
what is hypovolemia?
- fluid volume deficit & fluid loss
How does the body go into hypovolemia?
- removal of fluid from the exocellular compartment
- GI excretion
- renal excretion
- other losses, ex = hemorrhage
- In some instances, fluid is sequestered in a third space in the body, outside the extracellular compartment (ex: fluid is going somewhere lost thats inside the body)
what are the clinical manifestations of hypovolemia?
- sudden weight loss
- postural BP decrease w/ increased heart rate (in pt with healthy heart)
- flat neck veins w/ pt in supine
- lightheadedness
- dizziness
- syncope
- oliguria = small volume of concentrated urine (if kidneys are responding normally) (aka = little pee)
- decreased skin turgor
- dryness of mucus membranes (Lips)
- hard stools
- soft sunken eyeballs
- in infants = frontal sunken in (!!!)
what are some nursing managements for hypovolemia (fluid volume deficits)
- monitoring I’s and O’s!!
- lab values for electrolyte
- cardiovascular = hypotension & weak pulses, but fast pulse due to an increase of HR
- raspatory = tissue perfusion and oxygen saturations (trying to breath more)
- neuro = assess orientation, vision, hearing, reflexes, and muscle strength
- daily weights
- oral and skin care = prevent breakdown (fluid gives tissue extra support)
- IV solutions = isotonic (ten monitor)
what is hypervolemia?
- fluid volume excess
- amount of extracellular fluid is abnormally increased
- vascular and interstitial areas have too much fluid
what is the “why” behind hypervolemia?
- by an addition or retention (retainment) of isotonic saline (salt) sometimes termed saline excess
- excessive secretion of aldosterone (keeps NA & H2O in, takes K out)
- causes the kidneys to retain salt, may lead to heart failure
- excessive intravenous infusion of sodium - containing isotonic solutions
- renal retention of sodium & H20
what are the clinical manifestations of hypervolemia
- manifestation of circulatory overload
- bounding pulse = increase of BP (strong)
- neck vein distention in upright position
- crackles in lungs = pulmonary edema due to fluid buildup in the lungs
- dyspnea = shortness of breath
- orthopnea = shortness of breath when lying on back bc pulm edema or heart problems
- sudden weight gain = bc body hands on to more fluid
- edema (any kind)
- if advanced= frothy sputum
- in infant = building frontanel
what is hyponatremia?
- serum sodium concentration below the normal limit
- body has low NA and too much water
- extracellular fluid (EFC) is more diluted than normal
why does hyponatremia happen?
- factors that produce a relative access of water proportion to salt in extracellular fluid
- 2 causes: causing cell swelling
- a gain of relatively more water than salt:
- prolonged or excess release of ADH
- water intake that exceeds normal limit
- ex: marathon runners (get neuro issues due to low na)
- loss of relatively more salt than water
- a gain of relatively more water than salt:
what are the clinical manifestations of hyponatremia?
- mild CNS dysfunction: needs more hypertonic solution
- malaise = lack of energy
- nausea & vomiting
- headache
- Severe CNS dysfunction =
- confusion
- lethargy
- seizures
coma - fatal cerebral herniation (pocket of brain swelling)
what is the treatment for hyponatremia?
- hypertonic saline solution (3% NS)
- water intake restriction: dilution hyponatremia (PT not thirsty)
what is hypernatremia?
- too much sodium in EFC, not enough water
- ECF is too concentrated
- cells shrivel
what is the etiology of hypernatremia?
- gain more salt than water
- excess release of aldosterone
- ex: poorly regulated feeding tubes
- loss of more water than salt
what are the clinical manifestations of hypernatremia?
- mild: thirst, oliguria (sever urine reduction), confusion, lethargy
- severe = seizures, coma, death
what is the treatment for hypernatremia?
- give PO fluids or isotonic fluids slowly
- potential S/E = cerebral edema secondar to rapid corrective of hypernatremia
what is syndrome of inappropriate ADH (SIADH)
- extracellular volume excess
- too large a volume of fluid in the extracellular compartment
etiology of SIADH:
- malignant tumors (in the lungs mostly can make ADH be excreted a lot)
- pulmonary TB
- drug induced
what are the clinical manifestations of SIADH?
- headache = cerebral edema
- muscle twitching
- weight gain
what is diabetes insipidus?
- too much pee, not enough fluid for the body
- extracellular volume deficit
- too much NA
- voiding up too 15 L of pee per day
etiology of diabetes insipidus?
- Idiopathic = diseases comes at random for unknown reasons
- surgical/nonsurgical brain trauma !
- Brain tumors !
- Hypophysectomy - pituitary gland removal
what are the clinical manifestations of Diabetes insipidus
- excessive urination & drinking
- presents the same as clinical dehydration
