Given the following information, calculate the ventilation time ...

[Brittanyd9008]

Given the following information, calculate the ventilation time constant. PIP 40 cm H2O; Pplateau 30 cm H2O; Raw 1.3 cm H2O/L/sec; CL 0.2 ml/cm H2O
 
  A. 0.8 second
  B. 0.26 second
  C. 1.3 seconds
  D. 3.9 seconds

Question 2

Normal respiratory muscles generally do not fatigue with work less than _________.
 
  A. 4 to 6 joules/minute
  B. 10 to 12 joules/minute
  C. 15 to 20 joules/minute
  D. 20 to 25 joules/minute

[aadams68]

Answer to Question 1

ANS: B
A. Incorrect response: See explanation B.
B. Correct response: The ventilation time constant is calculated by multiplying the airway resistance by the lung compliance. That is,
(Raw)  (CL) = ventilation time constant
(1.3 cm H2O/L/sec)(0.2 ml/cm H2O) = 0.26 second
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 normal range for work done by the respiratory muscles is 4 to 6 joules/minute. Normal respiratory muscles generally do not fatigue with work less than 20 to 25 joules/minute.