Which of the following intermittent positive-pressure breathing machines is unable to provide ...

(Answer to Q. 1)  ANS: C
The Puritan Bennett AP-4 is only patient-triggered, so it can be used for intermittent posi-tive-pressure breathing therapy but not for providing short-term ventilatory support of patients with apnea. The other ventilators mentioned are able to support patients for short-term mechani-cal ventilation.

(Answer to Q. 2)  ANS: D
The patient's ability to ventilate and cough effectively is compromised because she is not alert. Because of this, incentive spirometry, deep-breathing exercises, and positive expiratory pressure are not appropriate therapies. Intermittent positive-pressure breathing is appropriate because she is not alert.

(Answer to Q. 3)  ANS: B
When assessing for outcome from incentive spirometry, the respiratory therapist is looking for the absence of or an improvement in signs of atelectasis. These signs are decreased respiratory rate, resolution of fever, normal pulse rate, improved breath sounds, a normal chest radiograph, im-proved arterial oxygenation, increased vital capacity and peak expiratory flows, return of func-tional residual capacity or vital capacity to preoperative values, and improved inspiratory muscle performance.

(Answer to Q. 4)  ANS: D
Flow = Tidal volume  Inspiratory time.
Tidal volume = Flow  Inspiratory time.
Tidal volume = 900 mL/s  2 s = 1800 mL, or 1.80 L.

Makes tons more sense now!