Lab values Flashcards
Cation vs Anion
Cation= loss of electron
Anion= gain of electron
Common Cations
•Sodium - Na+
•Calcium - Ca++
•Hydrogen - H+
•Magnesium - Mg++
•Potassium - K+
Common Anions
•Chloride — Cl-
•Bicarbonate — HCO3-
•Cyanide — CN-
Dominant Extracellular Cation
Na+ followed by Cl-
Dominant Intracellular Cation
K+
Sodium info
•Range — 135-145mEq/L (140 is perfect)
•Responsible for determining osmotic pressure
•Helps maintain acid-base balance because it’s a strong acid
BMP components
Basic Metabolic Panel
•Calcium
•Sodium
•Potassium
•Chloride
•CO2
•BUN
•Creatinine
•Glucose
Hyponatremia
•<135mEq/L
•causes are as follows: #1-burns, diuretics, vomit, #2-volume overload, CHF, kidney injury, #3-fluid loss, SIADH(holding onto fluid).
•Tx as follows: #1-Isotonic fluids, #2-Diuretics or fluid/Na+ restriction, #3-Fluid restriction, Lasix, hypertonic solution.
Calculate corrected Na+
Measured Na+, +[0.016x(serum glucose-100)]
- Hyponatremia can be seen in Hyperglycemic patient because high glucose can cause a shift in osmotic pressure.
Hypernatremia
•>145mEq/L
•Causes are as follows: #1- sweating, diarrhea, #2- Na retention, Cushing Syndrome, Aldosterone/Sodiun Bicarb admin, #3- water loss, diabetes insipidus.
•Tx- #1- NS admin, #2- diuretics or hypotonic solution, #3- DDAVP or fluid replacement(NS).
Chloride info
• 95-105mEq/L (102 is perfect)
• Strong acid like Na+
• Major anion of extracellular fluid
•A deficiency in Cl- will lead to a deficiency in K+ and vice versa
• stronger relationship with K+ than Na+ due to compensation from HCO3-
Potassium info
•(3.5-5.0mEq/L)
•K+ is the major intracellular cation
•Regulated by the kidneys
•Essential for cardiac, muscle, and CNS function
Hyperkalemia symptoms
•>5.0mEq/L
•Weakness/fatigue
•Metabolic acidosis
•Paresthesia/Paralysis
•Palpitations
•Bradycardia or extrasystoles
•New onset 2nd and 3rd degree blocks
•Diminished DTR or strength
•Edema
**Slow Vtach(150) w/ QRS > .200ms, almost always hyperkalemia. Don’t give lidocaine or amio! Give calcium gluconate or sodium Bicarb.
Hypokalemia symptoms
•Hypotension
•Ventricular arrhythmia
•Cardiac arrest
•Brady/Tachycardia
•PAC or PVC
•bradypnea/respiratory distress
•AMS/Lethargy
•weakness/fasciculations
•decreased dtr
BUN(Blood Urea Nitrogen)
•Renal health
•Urea is waste product of the liver
•6-23md/dL
•causes: high protein diet, renal failure, hypovolemia, or CHF
EKG changes in HypoK or HyperK
Low:
•Flat or inverted T waves
•prominent U waves(in V1)* test Q
•ST depression
•Atrial and Ventricular arrhythmias
High:
•slow Vtach
•peaked T waves in V2-V5
Bicarbonate—Total CO2
•23-30mEq/L
•total amount of CO2
•Serum bicarbonate comprises 95% of total CO2
Creatinine(Cr)
•0.6-1.4mg/dL
•renal health(used with BUN)
•indicates muscle breakdown
•shows kidney function by identifying GFR
Magnesium(Mg++)
•1.5-2.5mEq/L
•deficits usually seen with Ca++ & K+
•co-factor for ATP
•found in bone and intracellular fluid
•cleared by kidneys
•Hyper—(can be seen in renal failure) loss of DTR
Hypo—seen in 50% of ICU patients. Causes neuromuscular irritability and mood changes.
**Calcium and Magnesium always mimic each other
Phosphorus (P+)
•3.0-4.0mEq/L
•strong relationship between P+ & Ca++ so if one is abnormal, check the other.
•Provides mineral strength to bone
•Hyper—acidotic states; problems with hypoCa++(tetany, seizures, hypotension)
•Hypo—Alkalotic states, diuretics; < 1.5 may cause weakness, hemolysis of RBC, and bone deformities.
Calcium(Calcium++)
•8.8-10.4mg/dL
•patients with Kidney disease always have a decrease in Ca++
•HypoCa++: muscle spasms/cramps, numbness, seizures, dysphagia.
•HyperCa++: AMS, paresis, hypotension, short QT interval, signs of pancreatitis, hypotonia/hyporeflexia
HypoCalcemia manifestations
•Chvosteks sign- tapping on the cheek(face) will causes twitching.
•Trousseau sign- muscle excitability( if you pump up the BP cuff on the arm, the muscles will contract up and in.
CMP components
•Albumin (Liver)
•Alkaline phosphatase
•Alanine aminotransferase
•Aspartate aminotransferase
•BUN
•Calcium
•CO2
•Chloride
•Creatinine
•Glucose
•Potassium
•Sodium
•Total Bilirubin
•Total Protein
Serum Osmolality
275-295 mOsm/kg
•amount of solute in serum part of blood
•high osmolality means concentrated state like Diabetes Insipidus (sheds water)
• low osmolality means dilute state like SIADH (holds onto water)
•the body regulates osmolality by withholding or secreting ADH
* when you have a head bleed, they give hypertonic solution (causing hyper osmolality) to try and reduce swelling by “drying out” the cells.
Urine specific gravity
1.005-1.030
•measures concentration of urine
•ratio of urine and water density
•low specific gravity = dilutional state (diabetes insipidus)
•high specific gravity = hemoconcentrated state (SIADH)
Troponin 1
<0.04ng/mL
•Troponin is a protein that is essential for muscle contraction
•Calcium binding site
•Troponin 1 levels detected at 2-3 hr after injury. Peak at 24hr and lasts up to 2 weeks.
•Can be elevated for non-cardiac related reasons
CK-MB
Creatine Kinase-Muscle Brain
0-3ng/mL
•Found in cardiac muscle and some skeletal muscle
•normally undetectable in blood
•Abnormal lab
•Compare to total CK
*If CK-MB to CK ratio(relative index) is > 2.5-3.0 = cardiac damage, if high CK with relative index < 2.5-3.0 = skeletal muscle damage
*should be requested for cardiac symptoms/NSTEMI
proBNP
NT-proB-type Natriuetic Peptide
<100pg/mL
• used as marker in CHF patients
•Secreted my cardiomyocytes based on Ventricular stretch
• most BNP markers are significant
-< 125pg/mL for 0-74 yo
-< 450pg/mL for 75-99 yo
BHB (Beta Hydroxybutyrate)
0.4-0.5 mmol/L
•Measures the % of volume that is made up of RBCs
• Predominant ketone body at the onset of DKA
• allows earlier identification of ketosis
*should have DKA symptoms as well.
Quiz question:
What patient is high risk for developing hypernatremia?
Answer:
48-year-old female with bacterial pneumonia, fever, and diaphoresis.
Quiz question:
Chovsteks sign is associated with which electrolyte abnormality?
Answer:
Hypocalcemia. Excitability seen in the facial nerve. When you tap the cheek, it will cause the corner of the mouth to draw up toward the direction of the tapping.
Quiz question:
What would you expect to see on an ECG reading with hypokalemia?
Answer:
Hypokalemia results in inverted T waves, ST segment depression, and prominent U waves
Quick question:
What is the most common cause of increased hematocrit?
Answer:
Dehydration. As volume of fluid in the blood drops, the RBC per volume of fluid rise, the NA+ levels also rise due to loss of fluid or volume during a state of dehydration. Remember, it’s a concentration based on the fluid.
