Lab Values Flashcards
Electroneutrality
in aqueous solution, in any compartment, the sum of all the + ions must equal the sum of all negatively charged ions.
Basic metabolic panel (wishbone)
wishbone
cations anions kidney
Na+ | Cl- | BUN /
135-145 |95-105| 4.5-11 / GLU
————————————- 60-110
K+ | HCO3- | CR \
3.5-5 | 23-30 | 0.6-1.2 \
K+
3.5-5
dominant inntracellular cation.
Na+
135-145 mEq/L
dominat extracellular cation
Constitutes 90% of cations in extracellular fluid
Responsible for determining osmotic pressure
Helps maintain acid-base balance
Cl-
95-105
strong acid
HCO3-
normal serum bicarb 23-30
referenced as CO2
base
BUN
4.5-11
CR
0.6-1.2
Glucose
60-110
cations
Na+
Ca++
H+
Mg+
K+
anions
Cl-
HCO3-
CN- (cyanide)
Fluid vs concentration
labs measure a ratio of volume % to solute.
labs measure extracellular concentration.
Hypovolemic Hyponatremia
Na+ < 135 mEq/L
low volume and low sodium
diuretics, burns, vomiting, diarrhea
Treatment: isotonic fluids
Hypervolemic Hyponatremia
Na+ < 135 mEq/L
Volume overload
Kidneys cannot excrete water efficiently
CHF, kidney injury, SIADH
Treatment: sodium-fluid restriction, diuretic therapy.
Euvolemic Hyponatremia
Na+ < 135 mEq/L
Normal water content w/low Na+
SIADH (antidiuresis hormone). Pts hold on to water.
Normal BUN and Cr.
Urine specific gravity will be high.
Treatment: fluid restriction, lasix, hypertonic raise Na+ 0.5 mEq/L per hour
hypovolemic hypernatremia
Na+ > 145 mEq/L
Sweating (free water loss), fever
Treatment: isotonic fluids
hypervolemic hypernatremia
Na+ > 145 mEq/L
Sodium retention
Resuscitation w/NS
Cushing syndrome
Aldosterone
Urine Na+ >20
NaHCO3- administration
Treatment: diuresis, hypotonic solution (free water)
K+
3.5-5 mEq/L
Major intracellular cation
regulated by kidneys
essential for cardiac, muscle, and CNS function
hyperkalemia
> 5 mEq/L
adrenal insufficiency
kidney function
tissue damage (ie burn)
Excessive K+ intake
metabolic acidosis
Hemolysis
Sx: fatigue, paresthesia, paralysis, palp, Brady, new 2nd or 3rd degree blocks, wide complex tachycardia
hypokalemia
<3.5 mEq/L
sx:
hypotension
ventricular arrhythmia
DKA
cardiac arrest
Brady or tachycardia
respiratory arrest
lethargy, decreased strength
t-wave flattening, inverted t-waves, prominent U-waves, ventricular arrhythmias, atrial arrhythmias
Cl-
95-105 mEq/L
Major anion of extracellular fluid
passively moves with Na and water
necessary for K+ retention and CO2 transport
most common cause of high Cl = NS resuscitation (hyperchloremic metabolic acidosis)
Serum bicarb (CO2)
23-30 mEq/L
CO2 = serum bicarb
BUN
4.5-11 mg/dL
indication of real health
urea is a waste product of the liver
Cr
0.6-1.4 mg/dL
indication of muscle breakdown
indicates kidney function by identifying glomerular filtration rate
indication of hypovolemia (elevated Cr)
GLU
60-110 mg/dL
primary source of energy
glucose regulated by insulin from pancreas
beta-hydroxybutyrate (BHB)
0.4-0.5 mmol/L
predominant ketone body at onset of DKA
allows earlier identification of DKA
Mg++
1.5-2.5 mEq/L
found 50% inn bone and/or 45% intracellular
low Mg is usually seen with deficits in Ca and/or K
hypermagnesemia
> 2.5 mEq/L
usually cleared by kidneys; seen in renal failure.
Loss of deep tendon reflexes
hypomagnesemia
<1.5 mEq/L
associated with hypokalemia or hypocalcemia
causes neuromuscular irritability and mood changes.
Mg loss in ICU patients…
…Urine loss, GI loss, Meds (abx), nutrition, stress response
phosphorus (P+)
3-4.5 mEq/L
provides mineral strength to bones
strong relationships between P and Ca
High P+ likely means low Ca level, vice versa
Causes tetany, sz, hypotension