exam 4 Flashcards
what are electrolytes? and how to check levels ?
minerals in the body that conduct
electrical charges, essential for life, and are found in blood, urine, tissues, and body fluids, BMP and CMP
what is BMP and CMP? and what do they test for?
CMP Only
– Liver enzymes (alkaline phosphate ALP,
alanine transaminase ALT, aspartate
aminotransferase AST – liver function)
– Protein – total blood protein
– Albumin – liver function
BUN – kidney function
CO2 – blood bicarbonate level
Creatinine – kidney function
Glucose – blood sugar level
Cl – chloride level
K – potassium level
Na – sodium level
Ca – calcium level
BMP
- glucose levels
- electrolytes
- calcium
- BUN
- creatinine
functions of electrolytes?
Maintaining balance of water in body, balancing the blood pH (acid base level), moving nutrients into cells, moving wastes out of cells, maintaining proper function of body’s muscles, heart, nerves, and brain
how much is water a persons body weight?
average person’s weight consists of ½ to
2/3 water
for males – 60% of weight, for females –
54%, babies and children – 70%
balance in the body:
-the body works to maintain homeostasis by keeping water and electrolytes at a constant level in the blood
-this can be monitored by measuring the serum osmolality of the blood
-measures concentration of solutes to water
-most frequently used lab test to determine body fluid status, range is 285 – 295 mOsm/kg
how else can osmolality be measured?
be measured using urine and is used to
determine renal function as well as hydration status, expected range is 50-1200 mOsm/kg
what is the most obvious mechanism to maintaining balance?
body utilizes various homeostatic
mechanisms to increase or retain water, small increase in serum osmolality alerts
the brain to a decrease in fluid volume,
neurons in the brain then send out a signal to stimulate thirst, another mechanism to maintain the body’s
water balance is based on the brain and
kidneys interaction, as serum osmolality
rises, antidiuretic hormone is released
(vasopressin), nephrons in the kidney
increase the reabsorption of water,
decrease urine output, and increase fluid
volume in the body
filtration:
the kidneys help maintain balance by removing cellular waste and excess fluid through urine, kidneys filter the blood and eliminate wastes, also return the needed water and electrolytes back into
circulation, loss occurs from sweat and urine as well as liquid stool (hypovolemia), loss that occurs from the respiratory system, skin, and water in stool is called insensible fluid loss because it is hard to
measure
osmosis:
final mechanism used to maintain water balance, allows passive flow of water
between compartments of body to maintain equilibrium, water passes from areas of low solute concentration to
areas of high solute concentration, this helps maintain homeostasis within the body by equalizing the fluid inside and outside the cells
risk factors for imbalance?
dehydration, hypovolemia, over hydration, medications, heart, kidney, or liver disorders, incorrect IVF or feedings, profuse sweating, vomiting, diarrhea
expected values:
K 3.5-5 mEq/L (potassium)
Na 136-145 mEq/L (sodium)
Ca 9-10.5 mg/dL (calcium)
Mg 1.3-2.1 mEq/ (magnesium)
electrolyte movement:
-move across membranes through
diffusion and active transport
-diffusion – movement of solutes from
area of high concentration to area of low
concentration
-process continues until equal numbers of
solutes inside and outside cell
-passive process, does not require energy
what is active transport ?
uses energy to move solutes from low concentration to higher concentration
dehydration:
-Loss of water or lack of intake without
loss of Na
-Hypernatremia and increased osmolality
occur
-Body water shifts from inside of cell to
extracellular space causing cell shrinkage
-Can occur from diarrhea, vomiting,
sweating, urinating too much, illness, fever, decreased intake
-Meds – SSRIs decrease thirst sensation
-Symptoms – altered cognitive and neuromuscular function, thirst lethargy, dry mucosa, oliguria
-Severe – vital signs include
tachycardia, hypotension
-Lab tests – BMP or CMP, serum
osmolality will be elevated, urine
concentrated, increased urine specific
gravity
-Treatment – oral rehydration, IVF (D5W)
Why? It disperses to all fluid spaces
-Slow IVF administration to prevent
cerebral edema
hypovolemia:
-Loss of both fluid and electrolytes
-Can lead to a decrease in circulating blood volume and perfusion to tissues
-Also known as fluid volume deficit
-Can occur from blood loss, GI losses, severe burns, third spacing, excessive sweating, fever, medications, trauma
-Bleeding – can be internal or external
-GI losses – diarrhea and vomiting
-Severe burns – massive electrolyte shifts with fluid loss
-Third spacing – fluids become sequestered in other body cavities
-Meds – diuretics
-Serious symptoms – confusion, tachypnea, chest pain with palpitations, oliguria, hypotension
-Treatment – oral rehydration, 0.9% NS, LR, blood products
hypervolemia:
-Too much water and sodium in the extracellular space
-Can result from heart failure, kidney failure, nephrotic syndrome, cirrhosis or end stage liver disease
*-Heart failure – heart cannot effectively circulate blood
-Cirrhosis – inflammation of liver, fluid retention and edema in abdomen
-Pregnancy – hormone imbalance resulting in hypervolemia
-Meds – CCBs, vasodilators, glitazones (T2DM)
-No specific tests – weight, edema, BMP, CMP, urine Na
-Treatment – diuretics, limit fluid and Na, daily weights
-Nursing interventions – monitor for JVD, HTN, bounding pulses, dyspnea, adventitious lung sounds, I&O, daily weight
any age related:
-Older adults are vulnerable to
imbalances, unable to manage
alterations, changes to renal system,
decrease in thirst sensation, medications
-Infants and young children – dehydration and hypovolemia risk, higher rate of metabolism, higher body water content, higher ratio of surface area to volume, lose more through sweating, most common cause of fluid loss is vomiting and diarrhea
rehydration:
-Restoring water that has been lost back into tissues and fluids
-Orally or by IVF
-Oral – ingesting fluids by mouth if renal function is adequate, use water or sports drinks, record intake and output hourly
-Monitor urine specific gravity, less than expected range indicates excessively diluted urine from over hydration
-Drink 25 ml/kg over 2 hours, if able to drink this for 12 hours they are considered rehydrated
iv therapy includes:
initiation, care, and management of
vascular access devices along with administration of fluids and meds, RN must monitor the IV site, tubing, solution, rate, and effects, lab results, skin integrity, I&O, solutions include crystalloid solutions
(electrolytes or dextrose), classified according to osmolality (hypotonic, isotonic, or hypertonic), further categorized by tonicity or ability for water to move into or out of cells
iv flow rate :
flow rate is the rate at which IV fluids
are infused, based on patient need, nurses need to verify flow rate by
calculating infusion time and volume, can be administered using volume
control pump or drip rate by gravity
blood product transfusion :
-If fluid loss is due to hemorrhage from trauma
-Healthy bodies contain 5 liters of blood
(composed of RBCs, WBCs, plasma, and
platelets)
-Whole blood is divided into cells (red cells, white cells, platelets) approximately 40% of blood volume and plasma is remaining 60%
-Prior to giving a blood transfusion, the patient must be typed and crossmatched to ensure compatibility
-Universal donor blood type is O-
-Universal recipient blood type is AB+
acid base homeostasis
-To understand acid base balance, you must understand pH
-pH is the degree of acidity or alkalinity of a substance determined by the hydrogen ion
-the pH scale ranges from 0-14 (strongly
acidic to strongly alkaline), 7 is neutral
-< 7 is acidic, > 7 is alkaline
-The expected range for the pH of human
blood is narrow (from 7.35-7.45)
-This range should be maintained by the
body through buffers and respiratory and
renal regulation
ABGs
-Arterial blood gases are used to interpret acid base balance in the body
-Minimal variations in pH can have significant effects in the body
-The blood sample is drawn from an artery (radial is typical) and analyzed for pH (acidic or alkaline), partial pressure of CO2 (PaCO2), and bicarbonate (HCO3),
oxygen content in arterial blood (PaO2)
-These results tell us if there is an acid base imbalance in the body
-Expected Results: pH 7.35-7.45
* PaCO2 35-45 mmHg
* HCO3 22-26 mEq/L
* PaO2 80-100 Hg
* O2 sat 95-100%
how to interpret: ROME
-respiratory opposite metabolic equal
-When blood is acidic the pH decreases
-When blood is alkaline the pH increases
