Lab Values
These labs and their respective reference ranges are included in a Chem 7
* No units = no points
Na:135-147mEq/L, Cl: 95-110mEq/L, BUN: 8-20mg/dL
K:3.5-5mEq/L, CO2: 21-32mEq/L, Scr: <1.5mg/dL
Glucose: 65-115mg/dL
Serum Anion Gap
[Na+] - [Cl-] - [HCO3]
A 79 yo female is admitted to the hospital after a fall. She suffered a head injury and is in the ICU. An ABG is obtained and the results are: 7.64/29/97/25. You suggest the patient has this acid-base disorder.
respiratory alkalosis
•**If pH and PCO2 move in the OPPOSITE direction à RESPIRATORY**
This is an example of a fluid containing large solute molecules that do not readily pass from the plasma membrane to interstitial fluid but creates an osmotic pressure to hold water in the vascular compartment
25% albumin, 10% dextran-40, 6% hetactacrch, 5%a albumin- colloid fluids
This is the most common cause of drug-induced hypokalemia
loop diuretics and thiazides
These labs and their respective ranges may be ordered separately from a BMP
*No units = no points
Ca: 8.6-10.3mg/dL, P: 2.5-5mg/dL, Mg: 1.3-2.2mEq/L
Calcium Corrected
Sodium Corrected equation and electrolyte condition where this equation is required
Calcium corrected (mg/dL)= Ca + ((4-albumin)*0.8)
Na corrected= Na(measured) + 0.016 * (Serum Glu- 100)
* Only used in Hypertonic Hyponatremia
Caused of AG Acidosis
MUDPILES- Methanol, Uremia, DIABETIC KETOACIDOSIS, Propylene glycol/paracetamol, IRON or isoniazid, LACTATE, Ethylene glycol, SALICYLATE
Classifications of Hyponatremia and the most common causes
Isotonic- pseudohyponatremia
Hypertonic- hyperglycemia
Hypotonic: Hypovolemic- directics | Isovolemic- SIADH | Hypervolemic- CHF
This is the general rule of thumb for IV potassium dosing
For every 10mEq potassium (IV or PO), expect serum potassium to increase by 0.1mEq/L
The addition of these labs (and their respective ranges) upgrades a BMP to a CMP.
*No units = no points
Albumin: 3.6-5g/dL, ALP: 20-130IU/L, AST: 0-35IU/L, ALT: 0-35IU/L
+ GGT and Bilirubin
Ideal Body Weight M & F and Adjusted Body Weight Equations
When do you use each to calculate CrCl
IBWM: 50kg + (2.3kg)(# of in over 5ft)
IBWF: 45.5kg + (2.3kg)(# of in over 5ft)
AdjBW: IBW+0.4 (TBW-IBW)
IBW: Pt w/ normal BMI & AdjBW: Pt overweight
MG is a 67 year old woman (75 kg) presenting to the ED with 1 week of severe diarrhea. She presents with clinical evidence of dehydration (hypotension, tachycardia, decreased urine output) and weakness.
Lab values are as follows: Na 145 mEq/L, K 3.1 mEq/L, Cl 118 mEq/L, total CO2 18 mEq/L, BUN 29 mg/dL, SCr 0.9 mg/dL, glucose 122 mg/dL, calcium 9.1 mg/dL, phosphorus 3.7 mg/dL, magnesium 1.4 mg/L, albumin 3.9 g/dL, lactate 1.6 mmol/L.
ABG readings: pH 7.29, PCO2 34 mm Hg, PO2 93 mm Hg, HCO3 17 mEq/L, base excess -5 mEq/L.
You suggest MG’s has this acid-base disorder
Hyperchloremic, normal AG acidosis
22 year old male (170 kg) presents to the emergency department with altered mental status and lethargy. PMH includes sudden cardiac arrest in 2017, s/p AICD placement, and type 2 DM. ABG: 7.073/10.2/89/3. Labs are drawn with the following results:
Na: 121 | Cl: 100 | BUN: 20 | K: 5.1 | CO2: 3.9 | Scr: 1.7 | Gluc: 1222
What is the patient’s corrected serum sodium?
139mEq/L
Treatment options for Hyperkalemia
Calcium Gluconate, IV regular insulin, Sodium Bicarb, B agonist, Hemodialysis, Loop diuretics, Exchange resin
These labs and their respective ranges are used to determine cardiovascular health
* No units = no points
CK-MB: <6%, cTnI: 0.04ng/mL, BNP <100pg/mL
+ CRP, Myoglobin, Homocysteine, Lactate Dehydrogenase
Serum Osmolality Equation + reference range
Sosm= (2Na) + (Glu/18) + (BUN/2.8)
RR: 275-290mOsm/kg
These types of medication cause metabolic alkalosis
Diuretic agents: furosemide, torsemide, bumetanide, thiazides
Osmotic demyelination
Dose of IV potassium replacement therapy
10-20mEq K diluted to 100mL NaCl
These lab values and their respective ranges are included in a CBC.
*No units = no points
HgB- M:13.8-17.5g/dL | F: 12.1-15.3g/dL,
Hct- M: 40.7%-50.3% | F: 36%-44.6%
RBC- M: 4.3-5.9*10^6/mcL | F: 3.5-5.0*10^6/mcL
WBC: 3.8-9.8*10^3/mcL, PLTs: 150-450*10^3/mcL, Neutrophiles: 40% - 70%
Cockcroft-Gault CrCl
This age-dependent assumption is made for ease of calculation
CrCl (mL/min)= ((140-age) * Weight(kg)/(72*Scr)) (0.85 only if female)
If Pt > 65yo with Scr<1 we estimate Scr to be 1
Metabolic alkalosis treatment options
NaCl-resistant: Spironolactone, Amiloride & Triamterene
This occurs when hypernatremia is corrected too rapidly
Hypercalcemia treatment
Calcitonin, Bisphosphonates, Denosumab, Corticosteroids, and Cinacalcet (Sensipar)