Fluid Balance

Question 1

ICF vs ECF

Answer 1

• ICF: fluid inside cells
• ECF: Everything outside cells (3 subcompartments)
  
  • Intravascular fluid: fluid inside blood vessels or blood (made up of plasma and RBCs)
  • Interstitial fluid: fluid between cells (space where edema builds up)
  • Transcellular fluid: small and include specialized fluids like plural around lungs, peritoneal fluid in abd cavity, and lymph (pockets of fluid, small in volume, but matters a lot when there’s a problem like ascites, pleural effusion, or lymphedema)

Question 2

Osmotic pressure

Answer 2

• Mainly influenced by sodium in blood bc where sodium goes = water follows
• If there’s more sodium in the intravascular space compared to in the interstitial space ⇒ water moves into blood vessels ⇒ helps pull fluid in and keep blood volume up
• Pulls water into the blood vessel (intravascular space)

Question 3

Oncotic pressure

Answer 3

• what: pull of proteins, esp albumin, in blood
• Albumin acts like magnet for water ⇒ pulls water from interstitial space to intravascular space ⇒ helps maintain fluid volume in blood vessels
• Pulls water into the blood vessel (intravascular space)

Question 4

Hydrostatic pressure

Answer 4

• what: push of water or fluid outward against blood vessel walls
• More fluid inside the blood vessel = the higher the pressure pushing outward
• Pushes water outside of blood vessel (intravascular space) and into interstitial space

Question 5

Too much Na+

Answer 5

• Increased osmotic pressure: water shifts to blood ⇒ cells shrink
• S&S: Pt may have ↑ BP, dry mouth, thirst, confusion
• Seen in dehydration

Question 6

Too little Na+

Answer 6

• Decreased osmotic pressure: water shifts into cells ⇒ cells swell
• Risk for brain swelling, headache, confusion
• Seen in overhydration

Question 7

Too much albumin

Answer 7

• usually from dehydration

Question 8

too little albumin

Answer 8

• results in Decreased oncotic pressure: less pull on water ⇒ fluid leaks out of vessels
• Look for edema or ascites
• Seen in liver disease or malnutrition

Question 9

too much water

Answer 9

• results in Increased hydrostatic pressure: ↑ blood volume ⇒ ↑ BP, edema, ascites, pleural effusion
• Seen in HF, oliguric/anuric kidney disease

Question 10

too little water

Answer 10

• results in Decreased hydrostatic pressure: ↓ blood volume ⇒ ↓ BP, poor perfusion, dry mucous membranes
• Seen in vomiting, diarrhea, or bleeding

Question 11

Osmolality

Answer 11

• what: concentration of blood
• If blood is too concentrated and has ↑ osmolality ⇒ triggers release of antidiuretic hormone (ADH) ⇒ signals kidneys to hold onto water ⇒ keeps water in bloodstream to dilute concentrations

Question 12

Brain Natural Uric Peptides (BNP)

Answer 12

• what: released from heart ventricles when heart senses too much fluid ⇒ BNP tells kidneys to get rid of sodium and water
• BNP used in labs to check for fluid volume overload, specifically w/ HF pts

Question 13

Norm fluid intake + ice chips recording

Answer 13

• av: 2200 - 2700 mLs/day
• 240 mLs cups of ice chips = 120 mLs

Question 14

Goal norm fluid output urine

Answer 14

• minimum: 30 mLs/hr
• healthy adult av fluid output: 2200 - 2700 mLs/day

Question 15

To calculate fluid balance:

Answer 15

• Total intake – Total output = Fluid balance
• Make sure you’re calculating intake and output over same time frame for accuracy

Question 16

fluid volume deficit S&S

Answer 16

• Neuro: ↓ LOC, headaches, weakness, fatigue
• CV: postural hypotension, hypotension, tachycardia, 1+ pulses (thready), cap refill > 3 secs, flat neck veins when supine
• Skin/Mucous Membranes: dry oral membranes, cold/clammy skin, pallor, tenting skin turgor
• GI: thirst, constipation
• GU/Renal: dark colored urine, < 30 mLs urine/hr
• Other: weight loss (fluid loss: 2.2 lbs = 1000 mLs of fluid)
• Labs:
  
  • ↑ Hct: due to loss of plasma fluid volume
  • Hct is percentage of RBCs in comparison to plasma → if there’s ↓ in plasma = ↑ Hct
  • ↑ BUN: becomes more concentrated so value increases
  • ↑ Na+: becomes more concentrated so value increases

Question 17

Crystalloids (categories of IV fluids)

Answer 17

• Ie. 0.9% NaCl (Normal Saline)
• Contains smaller particles like Na+, Cl-, Ca+, K+, or glucose dissolved in water
• Goal: exert osmotic pressure
• More common on medsurg units as “maintenance” fluids
• Used for:
  
  • Hydration
  • Electrolyte replacement
• Note: make sure to monitor what electrolytes the pt has less or more of to make sure you’re giving more or less of those electrolytes
• Composed of: isotonic, hypertonic, hypotonic fluids

Question 18

Isotonic Fluids

Answer 18

• Ie. 0.9% NaCl (Normal Saline), Lactated Ringer’s
• Has same solute concentration as healthy adult’s blood plasma ⇒ water doesn’t shift into or out of intravascular space
• Action: offers little to no fluid shift between compartments
• Used for:
  
  • When needing to restore volume to intravascular space
  • Restoring volume to ↑ BP
• Note: watch out for fluid volume overload in at-risk pts who have HF, oliguric/anuric w/ kidney disease

Question 19

Hypertonic Fluids

Answer 19

• Ie. 3% NaCl (Saline)
• Has higher solute concentration of sodium than healthy adult’s blood serum ⇒ pulls water from interstitial and intracellular space to intravascular space
• Action: pulls fluid into intravascular space
• Used for:
  
  • Sodium replacement bc pt’s Na+ is ↓↓↓
  • Reducing cerebral edema in stroke/neuro pts
  • Critical care settings
• Note: raising Na+ too fast ⇒ can lead to seizures

Question 20

Hypotonic Fluids

Answer 20

• Ie. 0.45% NaCl (Half-Normal Saline), 0.225% NaCl (Quarter Normal)
• Has less sodium than in healthy adult’s blood plasma ⇒ water diluting blood plasma will move out of intravascular space and into interstitial and intracellular spaces
• Action: provides hydration w/o sodium
• Used for: When pt’s Na+ is ↑↑↑
• Note: too much of this can cause cerebral cell swelling ⇒ be careful when using w/ neuro pts

Question 21

Colloids

Answer 21

• ie. albumin
• contains larger molecules that stay in bloodstream/intravascular space
• goal: exert oncotic pressure to pull water into intravascular space
• Used for:
  
  • edema
  • ascites
  • low albumin

Question 22

IV Infiltration

Answer 22

• What: IV fluids infused into tissue surrounding IV site
• Assess IV site for coolness at site, swelling, and pain

Question 23

IV Phlebitis

Answer 23

• What: inflammation of vein
• Assess S&S of: warmth at site, pain/tenderness, redness, swelling, palpable venous cord that feels like rope under skin and trails up vein

Question 24

IV Extravasation

Answer 24

• What: when there’s infiltration of vesicant IV medication or solution capable of causes tissue damage and necrosis

Question 25

Fluid Volume Overload/Excess S&S

Answer 25

- Resp: crackles/pulm edema, SOB, ↓ pulse ox % - CV: HTN, dependent pitting edema (ankles/scrotal), full neck veins when in semi-fowlers/upright, 3+ (bounding) pulses - Skin: stretched,, shiny, weeping fluid - GI: ascites - GU/Renal: light yellow urine - Other: sudden weight gain of > 2 lbs within 24hrs - Labs: basically opposite of fluid volume deficit - ↓ Hct - ↓ BUN - ↓ Na+ - ↑ BNP (B-type Natriuretic Peptide)