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
Calcium (Ca++)
8.8-10.2 mg/dL
essential for blood coagulation, endocrine and neurological functions
parathyroid, thyroid, and vit D influence Ca values
kidney disease will cause reduction in Ca++
reciprocal relationship with P+ (high Ca = low P, vice versa.
Pts w/kidney disease always have lower Ca
hypercalcemia
> 10.2 mg/dL
paresthesia, weakness
pancreatitis
arrhythmias, shortened QT
hypotension
confusion
hypocalcemia
<8.8mg/dL
numbness in perioral area
hypotension
coarse, brittle hair
seizures
numbness in fingers and toes
muscle cramps
dysphagia
Low Ca++ = elevated P+ and vice versa
Chvostek’s sign
Indication of low Ca++
touching side of cheek draws cheek/lip up.
Trousseau’s sign
indication of low Ca++
sign of muscular excitability
inflated BP cuff causes flexion of hand towards forearm
Complete blood count (CBC)
WBC
Hgb
Hct
Plt
RBCs
RBC
M: 4.7-6.1 million/mcL
F: 4.2-5.4 million/mcL
Decreases can be due to iron deficiency, blood loss, bone marrow suppression
Increases can be due to high altitude, compensation for hypoxia (ie sleep apnea), dehydration, medications
Hemoglobin (Hgb)
M: 14-18 g/dL
F: 12-16 g/dL
Oxygen carrying capacity of RBCs
Carries CO2 back to the lungs as carboxyhemoglobin
Transfusion <7g/dL
1 unit increases hgb by 1g/dL
Hematocrit (Hct)
M: 42-52%
F: 37-47%
Percent of volume made up of RBCs
Normal range is 3x greater than Hgb
1 unit increases hct by about 3%
low Hct
M: <42%
F: <37%
Low in anemia, SIADH (not diuresing), overhydration (higher volume w/same RBCs)
high Hct
M: >52%
F: >47%
Higher concentration of RBCs due to less volume.
Dehydration, polycythemia (more RTBC production…ie COPD)
indices
measure characteristics of erythrocyte (RBC). Used to dx anemia
1. mean corpuscular volume (MCV)
2. Mean corpuscular hemoglobin (MCH)
3. Red cell distribution width (RDW)
mean corpuscular volume (MCV)
80-95 fL
measurement of average size/volume of RBC
high MCV = larger than normal RBC (b12 or folate deficiency
low MCV = iron deficiency
Mean corpuscular hemoglobin (MCH)
23-31 pg
amount of Hgb per RBC
average weight of Hgb in RBCs
high MCH: liver disease, hypothyroid, etoh abuse
low MCH: iron deficiency, lead poisoning, CKD
Red cell distribution width (RDW)
11-15%
Measurement of variation in size of RBCs
Most issues are caused by greater RBC width
Platelets
150-400 mcL
formed in bone marrow
essential for clotting
Thrombocythemia
> 400/mcL (High platelet count)
anemia
polycythemia (high RBC in relation to volume)
Inflammatory disorders
Thrombocytopenia
<150/mcL (low platelet count)
DIC (clotting disorder - too much clotting)
Heparin induced thrombocytopenia
sepsis
bone marrow failure, cancers
certain viruses (hantavirus)
White blood cells (WBC)
4,500-11,000 cells/mcL
Responds to an inflammatory process.
Elevated in infections, inflammation, stress
Decreased in cancer, bone marrow damage, HIV, hepatitis, malnutrition, dehydration.
When abnormal, the differential count is utilized to measure which types of WBC is affected.
Never Let Monkeys Eat Bananas
Never - Neutrophils
Let - Lymphocytes
Monkeys - monocytes
Eat - eosinophils
Bananas - basophils
Neutrophils
45-75% (segs)
specific to bacterial and fungal infections
Lymphocytes
18-45%
specific to viral illnesses
regulate T and B cells
Monocytes
1-10%
clean-up (phagocytosis)
Eosinophils
0-7%
allergic reaction, parasites
Basophils
0-2%
inflammatory response marker
Coagulation studies
PT
PTT
INR
Ammonia
INR
0.8-1.2
(international normalized ratio)
Measurement of how long it takes blood to clot compared to a standard rate.
Often used to monitor effects of blood thinners like Coumadin.
Elevated INR = blood clots more slowly
PT
10-13 seconds
Prothrombin time
Measures the time it takes for plasma (liquid part of blood) to clot.
Used in combination with INR, which standardizes the PT results, allowing for consistent interpretation.
PTT
25-35 seconds
Partial prothrombin time
Often specific to pts on heparin
Tool in dx and monitoring clotting, bleeding disorders, or heparin therapy
Normally drawn with abnormal bleeding, chest pain, liver disease, suspected PE
Serum Osmolality
275-295 mOsm/kg
Amt of solute in serum part of blood
Body regulates osmolality by withholding or secreting ADH
More cellularly hydrated, the lower the #
High: concentrated state (diabetes insipidus…lack of ADH…lots of urination)
Low: diluted stater (SIADH - lots of ADH…holding onto volume/urine)
urine specific gravity
1.005-1.030
measurement of concentration of urine.
ratio of urine density and water density
low number = more diluted urine
high umber = more concentrated urine
high Urine specific gravity
> 1.030
concentrated urine state
SIADH. ADH overstimulated, holding onto fluid (urine). Lots of fluid vs solute.
Dehydration…causes include vom/diarrhea
SIADH: low serum os but high specific grav
low urine specific gravity
<1.005
Decreased USG is dilute - closer to water.
diabetes insipidus
Less release of ADH = lots of peeing.
Urine is diluted but cells are dry so serum os is high. Specific gravity is low.
troponin
<0.04 ng/mL
Protein that is essential for muscle contraction.
Binding site for calcium
Troponin levels start rising 3-4 hrs after myocardial injury. Peak around 12 hrs.
CK-MB
0-0.3ng/mL
Creatine kinase - muscle brain
Found in cardiac muscle and some skeletal muscle (can be elevated in both cardiac and skeletal muscle damage)
Compare to total CK.
high CK-MB
> 0.3 ng/mL
if CK-MB to CK ratio is >2.5-3, likely indicates cardiac damage.
proBNP
<100pg/mL
NT-proB-type natriuretic peptide
Secreted by cardiomyocytes based on ventricular stretch.
Used as a marker in CHF patients.
<125 for 0-74 yrs old
<450 for 75-99 yrs old
Beta-hydroxybutyrate (BHB)
0.4-0.5 mmol/L
predominant ketone body at ONSET of DKA
allows earlier identification of DKA
Magnesium (Mg++)
1.5-2.5 mEq/L
Essential to bone health.
Found 50% in bone and/or 45% intracellular
Low Mg++ usually seen w/deficits in Ca and/or K.
Hypermagnesemia
> 2.5 mEq/L
Usually cleared in kidneys. High Mg usually seen in renal failure.
Sx: Loss of Deep tendon reflexes.
Hypomagnesemia
<1.5 mEq/L
Seen in 50% of ICU patientns
Associated with low Ca and low K
Causes neuromuscular irritability and mood changes.
Mg loss in ICU patients…
1. urine loss
2. GI loss
3. Medications (abx)
4. Nutritionn
5. Stress response
Phosphorus
3-4.5 mEq/L
Provides mineral strength to the bone
Strong relationship between P+ and Ca++
Hyperphosphatemia
> 4.5 mEq/L
Acidotic states. High P+ = Low Ca, vice versa
Sx: tetany, seizures, and/or hypotension
ADH
Antidiuretic hormone
Secreted by posterior pituitary
Release of ADH = reabsorption of water in kidneys.
Diabetes Insipidus
Less release of ADH…
…Kidneys don’t reabsorb water
Lots of urination (peeing out dilute urine)
S/S of dehydration.
Decreased:
…urine specific gravity
…urine osmolality
…urine sodium levels
Increased:
…BLOOD (serum) osmolality
…BLOOD sodium levels
SIADH
…excess release of ADH…
kidneys increase reabsorption of water
S/S:
small amts of concentrated urine
fluid volume excess: crackles, JVD, weight gain, HTN, tachycardia
Dilutional hyponatremia - confusion, sz.
Increased: (concentrated urine)
…urine specific gravity
…urine osmolality
…urine sodium levels
Decreased: (diluted blood)
blood (serum) osmolality
blood sodium levels
