Lab values

Question 1

Cation vs Anion

Answer 1

Cation= loss of electron
Anion= gain of electron

Question 2

Common Cations

Answer 2

•Sodium - Na+
•Calcium - Ca++
•Hydrogen - H+
•Magnesium - Mg++
•Potassium - K+

Question 3

Common Anions

Answer 3

•Chloride — Cl-
•Bicarbonate — HCO3-
•Cyanide — CN-

Question 4

Dominant Extracellular Cation

Answer 4

Na+ followed by Cl-

Question 5

Dominant Intracellular Cation

Answer 5

K+

Question 6

Sodium info

Answer 6

•Range — 135-145mEq/L (140 is perfect)
•Responsible for determining osmotic pressure
•Helps maintain acid-base balance because it’s a strong acid

Question 7

BMP components

Answer 7

Basic Metabolic Panel
•Calcium
•Sodium
•Potassium
•Chloride
•CO2
•BUN
•Creatinine
•Glucose

Question 8

Hyponatremia

Answer 8

•<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.

Question 9

Calculate corrected Na+

Answer 9

Measured Na+, +[0.016x(serum glucose-100)]

• Hyponatremia can be seen in Hyperglycemic patient because high glucose can cause a shift in osmotic pressure.

Question 10

Hypernatremia

Answer 10

•>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).

Question 11

Chloride info

Answer 11

• 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-

Question 12

Potassium info

Answer 12

•(3.5-5.0mEq/L)
•K+ is the major intracellular cation
•Regulated by the kidneys
•Essential for cardiac, muscle, and CNS function

Question 13

Hyperkalemia symptoms

Answer 13

•>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.

Question 14

Hypokalemia symptoms

Answer 14

•Hypotension
•Ventricular arrhythmia
•Cardiac arrest
•Brady/Tachycardia
•PAC or PVC
•bradypnea/respiratory distress
•AMS/Lethargy
•weakness/fasciculations
•decreased dtr

Question 15

BUN(Blood Urea Nitrogen)

Answer 15

•Renal health
•Urea is waste product of the liver
•6-23md/dL
•causes: high protein diet, renal failure, hypovolemia, or CHF

Question 16

EKG changes in HypoK or HyperK

Answer 16

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

Question 17

Bicarbonate—Total CO2

Answer 17

•23-30mEq/L
•total amount of CO2
•Serum bicarbonate comprises 95% of total CO2

Question 18

Creatinine(Cr)

Answer 18

•0.6-1.4mg/dL
•renal health(used with BUN)
•indicates muscle breakdown
•shows kidney function by identifying GFR

Question 19

Magnesium(Mg++)

Answer 19

•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

Question 20

Phosphorus (P+)

Answer 20

•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.

Question 21

Calcium(Calcium++)

Answer 21

•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

Question 22

HypoCalcemia manifestations

Answer 22

•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.

Question 23

CMP components

Answer 23

•Albumin (Liver)
•Alkaline phosphatase
•Alanine aminotransferase
•Aspartate aminotransferase
•BUN
•Calcium
•CO2
•Chloride
•Creatinine
•Glucose
•Potassium
•Sodium
•Total Bilirubin
•Total Protein

Question 24

Serum Osmolality

Answer 24

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.

Question 25

Urine specific gravity

Answer 25

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)

Question 26

Troponin 1

Answer 26

<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

Question 27

CK-MB

Answer 27

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

Question 28

proBNP

Answer 28

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

Question 29

BHB (Beta Hydroxybutyrate)

Answer 29

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.

Question 30

Quiz question:
What patient is high risk for developing hypernatremia?

Answer 30

Answer:
48-year-old female with bacterial pneumonia, fever, and diaphoresis.

Question 31

Quiz question:
Chovsteks sign is associated with which electrolyte abnormality?

Answer 31

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.

Question 32

Quiz question:
What would you expect to see on an ECG reading with hypokalemia?

Answer 32

Answer:
Hypokalemia results in inverted T waves, ST segment depression, and prominent U waves

Question 33

Quick question:
What is the most common cause of increased hematocrit?

Answer 33

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.