Calculate the P(A-a)Do2 for a neonate who has the following ABGs ...

[bcretired]

Calculate the P(A-a)Do2 for a neonate who has the following ABGs while breathing an Fio2 of 0.8 HFV: pH 7.32; PaCO2 55 mm Hg; PaO2 50 mm Hg; 22 mEq/L The inspired gas is 100 humidified at body temperature, and the patient has a normal respiratory quotient.
 
  A. 425
  B. 450
  C. 490
  D. 525

Question 2

Calculate the oxygenation index for a neonate who has a Pao2 of 40 mm Hg while receiving an Fio2 of 0.70 on HFV with a mean airway pressure of 20 cm H2O.
 
  A. 75
  B. 55
  C. 45
  D. 35

[ansleighelindsey]

Answer to Question 1

ANS: B
A. Incorrect response: See explanation B.
B. Correct response: The alveolar-arterial O2 tension difference is calculated as follows:
STEP 1: Determine the corrected barometric pressure (Pcorrected).
Pcorrected = PB  PH2O
= 760 mm Hg  47 mm Hg
= 713 mm Hg
STEP 2: Determine the Pio2.
Pio2 = Pcorrected  Fio2
= 713 mm Hg  0.8
= 570 mm Hg
STEP 3: calculate the P(A-a)Do2.
Comp: small cap o, io, co, and o in Do2, Pio2, Paco2, Pao2, respsectively

= 450 mm Hg
C. Incorrect response: See explanation B.
D. Incorrect response: See explanation B.

Answer to Question 2

ANS: D
A. Incorrect response: See explanation D.
B. Incorrect response: See explanation D.
C. Incorrect response: See explanation D.
D. Correct response: The oxygenation index can be calculated as follows:
OI = (Fio2) (Paw)  100
Pao2

= 35

[bcretired]

Excellent

[apple]

Gracias!