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NUR242 / NUR 242 Exam 2 Study Guide
Medical-Surgical Nursing Concepts
100% Correct | Grade A Galen
Med Surge Exam #2 Study Guide
Fluid & Electrolytes & ABG’s
o Homeostasis:
● Water is the most common fluid, makes up 50-60% of total weight
▪ Needed to deliver dissolved nutrients, electrolytes, and all substances to
all organs, tissues, and cells
● Water is divided into 2 main compartments:
▪ Extracellular – fluid outside the cell
◆ Also includes interstitial fluid between the cells
▪ Intracellular – fluid inside the cell
o Filtration
● The movement of fluid (water) through a cell or blood vessel membrane
because of water pressure (hydrostatic pressure) differences on both sides of
the membrane
● The human body constantly seeks equilibrium
▪ Water movement occurs until hydrostatic pressure is equal on both
sides of membrane
▪ Blood pressure is an example of hydrostatic filtration. It moves whole
blood from the heart to capillaries where filtration can occur to
exchange water, nutrients, and waste products between the blood
and the tissues
, o Fluid Balance
● Fluid balance is closely linked and affected by electrolytes
● Fluid intake is regulated through the thirst drive
● Fluid loss occurs via the kidney, skin, lungs, and the intestinal tract
▪ Kidneys – the most important and sensitive water loss route d/t being
regulated and adjustable. Volume excreted varies based on intake and
body’s need to conserve fluids
o Minimum amount of urine per day to excrete toxic waste (400-600
ml)
o The kidney can make either diluted or concentrated urine to
maintain balance
● Insensible loss occurs via the skin, lungs, and stool as this is not regulated or
controlled
● **Normal urine output is 30cc/hr**
o Renin-Angiotensin
● Most critical fluid balance is to maintain blood volume to perfuse tissues/organs
▪ Requires specific hormone levels, kidney function, and blood vessel
responses to balance water and sodium
● If the kidneys sense BP is low, they secrete Renin that starts hormonal and blood
vessel responses to raise the BP to normal
, ● Renin activates angiotensin that causes vasoconstriction of small arteries and
veins which raise BP without the use of extra blood volume (Compensatory
Mechanism)
▪ This also decreases urine output increasing blood osmolality and prevents
further water loss
o Top 5 Fluids
● NS 0.9% (NaCl) - Isotonic
▪ Used to expand volume, dilute medications and to keep the vein open
● Lactated Ringers - Isotonic
▪ Used for fluid resuscitation
● D5W
▪ Isotonic until inside the body (metabolize glucose and become hypotonic)
● D5 ½ NS (D5NS)
▪ Used for Na and volume replacement. Go Slow, monitor BP, pulse, and
quality of lung sounds as well as serum Na and urine output
o Dehydration
● Fluid intake or retention is less than what is needed to meet the body’s needs
● Can be caused by either too little intake or too great a loss of fluid
● When circulating blood volume is decreased (hypovolemia) it causes poor tissue
perfusion
● Change in daily weight are best indication of fluid loss or gain
▪ 1L of H2O = 2.2lb
● What does it look like?
▪ **When I’m Dry, my Labs are HIGH**
▪ Dy mucous membranes
▪ (Weak pulse) HR, BP, RR
▪ Postural Hypotension (due to low volume)
▪ Confusion
▪ Assess skin for color and moisture
▪ Assess Skin Turgor
◆ **Pinch skin over the sternum or the forehead**
● Interventions
▪ Strict I’s and O’s (q8hr) **Urine output should be 240cc/8hr**
▪ Monitor Electrolytes (Urine specific gravity & CBC)
● (**USG would be elevated**)
▪ Provide oral fluids that meet dietary requirement (sugar free, low Na &
thickened)
▪ Offer fluids at least q2hr
▪ Ensure education to assistive personnel to not withhold fluids
▪ Monitor pt. response to fluid therapy q2hr
● Pulse quality and pressure
● Urine output
● Weight (q8hr)
▪ Monitor for fluid overload
NUR242 / NUR 242 Exam 2 Study Guide
Medical-Surgical Nursing Concepts
100% Correct | Grade A Galen
Med Surge Exam #2 Study Guide
Fluid & Electrolytes & ABG’s
o Homeostasis:
● Water is the most common fluid, makes up 50-60% of total weight
▪ Needed to deliver dissolved nutrients, electrolytes, and all substances to
all organs, tissues, and cells
● Water is divided into 2 main compartments:
▪ Extracellular – fluid outside the cell
◆ Also includes interstitial fluid between the cells
▪ Intracellular – fluid inside the cell
o Filtration
● The movement of fluid (water) through a cell or blood vessel membrane
because of water pressure (hydrostatic pressure) differences on both sides of
the membrane
● The human body constantly seeks equilibrium
▪ Water movement occurs until hydrostatic pressure is equal on both
sides of membrane
▪ Blood pressure is an example of hydrostatic filtration. It moves whole
blood from the heart to capillaries where filtration can occur to
exchange water, nutrients, and waste products between the blood
and the tissues
, o Fluid Balance
● Fluid balance is closely linked and affected by electrolytes
● Fluid intake is regulated through the thirst drive
● Fluid loss occurs via the kidney, skin, lungs, and the intestinal tract
▪ Kidneys – the most important and sensitive water loss route d/t being
regulated and adjustable. Volume excreted varies based on intake and
body’s need to conserve fluids
o Minimum amount of urine per day to excrete toxic waste (400-600
ml)
o The kidney can make either diluted or concentrated urine to
maintain balance
● Insensible loss occurs via the skin, lungs, and stool as this is not regulated or
controlled
● **Normal urine output is 30cc/hr**
o Renin-Angiotensin
● Most critical fluid balance is to maintain blood volume to perfuse tissues/organs
▪ Requires specific hormone levels, kidney function, and blood vessel
responses to balance water and sodium
● If the kidneys sense BP is low, they secrete Renin that starts hormonal and blood
vessel responses to raise the BP to normal
, ● Renin activates angiotensin that causes vasoconstriction of small arteries and
veins which raise BP without the use of extra blood volume (Compensatory
Mechanism)
▪ This also decreases urine output increasing blood osmolality and prevents
further water loss
o Top 5 Fluids
● NS 0.9% (NaCl) - Isotonic
▪ Used to expand volume, dilute medications and to keep the vein open
● Lactated Ringers - Isotonic
▪ Used for fluid resuscitation
● D5W
▪ Isotonic until inside the body (metabolize glucose and become hypotonic)
● D5 ½ NS (D5NS)
▪ Used for Na and volume replacement. Go Slow, monitor BP, pulse, and
quality of lung sounds as well as serum Na and urine output
o Dehydration
● Fluid intake or retention is less than what is needed to meet the body’s needs
● Can be caused by either too little intake or too great a loss of fluid
● When circulating blood volume is decreased (hypovolemia) it causes poor tissue
perfusion
● Change in daily weight are best indication of fluid loss or gain
▪ 1L of H2O = 2.2lb
● What does it look like?
▪ **When I’m Dry, my Labs are HIGH**
▪ Dy mucous membranes
▪ (Weak pulse) HR, BP, RR
▪ Postural Hypotension (due to low volume)
▪ Confusion
▪ Assess skin for color and moisture
▪ Assess Skin Turgor
◆ **Pinch skin over the sternum or the forehead**
● Interventions
▪ Strict I’s and O’s (q8hr) **Urine output should be 240cc/8hr**
▪ Monitor Electrolytes (Urine specific gravity & CBC)
● (**USG would be elevated**)
▪ Provide oral fluids that meet dietary requirement (sugar free, low Na &
thickened)
▪ Offer fluids at least q2hr
▪ Ensure education to assistive personnel to not withhold fluids
▪ Monitor pt. response to fluid therapy q2hr
● Pulse quality and pressure
● Urine output
● Weight (q8hr)
▪ Monitor for fluid overload
