The set tidal volume is 500 mL. During the first breath, the ...

[xclash]

The set tidal volume is 500 mL. During the first breath, the exhaled volume measures 390 mL, with a peak pressure of 18 cm H2O.
 
  The second breath returns 460 mL, with 20 cm H2O. The third breath has a peak pressure of 22 cm H2O, with an exhaled volume of 500 mL. This can be described as what type of system?
  a. Open-loop c. Single-circuit
  b. Closed-loop d. Double-circuit

Question 2

A patient is receiving a continuous positive airway pressure of 10 cm H2O via mask from a Downs continuous positive airway pressure generator. During each inspiration, the pressure ma-nometer decreases to 3 cm H2O.
 
  The patient is diaphoretic, tachypneic, and tachycardic. To correct this situation, the respiratory therapist should do which of the following?
  a. Increase the gas flow c. Tighten the fit of the mask
  b. Increase the pres-sure d. Replace the spring-loaded valve

[frejo]

Answer to Question 1

ANS: B
This is a closed-loop system because the ventilator is making changes to the pressure based on the exhaled tidal volume. The pressure is being increased incrementally, which increases the exhaled volume to the set tidal volume.

Answer to Question 2

ANS: A
The patient is pulling in more than the flow of the continuous positive airway pressure system is able to provide. This is evident by the swing in pressures between 10 cm H2O and 3 cm H2O. In-creasing the flow would decrease the patient's work of breathing. Increasing pressure would make the patient work harder because of the inadequate flow rate. If there was a leak through an improperly fitting mask, very little pressure could be maintained. Replacement of the spring-loaded valve would not solve this problem.

[xclash]

Thanks for the timely response, appreciate it

[tranoy]

Gracias!