Author Question: Calculate the P(A-a)Do2 for a neonate who has the following ABGs while breathing an Fio2 of 0.8 HFV: ... (Read 66 times)

bcretired · **on:** Jul 16, 2018

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 · **Reply #1 on:** Jul 16, 2018

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