Calculations/Values

Question 1

Winter’s Formula for PCO2 compensation

Answer 1

PaCO2 = 1.5 (bicarb) + 8 +/- 2

Question 2

Pseudohyponatremia from high glucose

high sugar pulls fluid from cells to dilute intravascular sodium

Answer 2

For every 100 mg/dL glucose > normal, 1.6 mEq/L decrease in sodium (add this amt to correct Na for high sugars)

Question 3

Naegle Rule for EDD

Answer 3

LMP -3mos + 7 days

Question 4

Serum Osmolality

Answer 4

2xNa + glucose/18 + BUN/2.8

Question 5

Attributable risk percent

Answer 5

(RR-1/RR)

i.e if the RR of getting a disease is 4.0, then 4-1/4 = 75%
ARP = 75%, meaning that 75% of tested outcome is attributable to tested risk

Question 6

Potassium replacement

Answer 6

Don’t give faster than 20mEq/hr

put on EKG for monitor rhythm

Question 7

Calcium correction for hypoalbuminemia

Answer 7

For every 1 g/dL decrease in alb

Question 8

NNT (number needed to treat)

Answer 8

1/ARR (absol. risk reduction)

*if ARR= 50%, NNT = 2

Question 9

Respiratory Quotient

Answer 9

0. 7-0.8 : primarily proteins for energy

1. 0-1.05: primarily carbs for energy (ventilated pts)