When synchronized intermittent mandatory ventilation is used, ...

[Jkov05]

When synchronized intermittent mandatory ventilation is used, which of the following variables can be the cycle variables? I. time II. flow III. volume IV. pressure
 
  A. IV only
  B. II, III only
  C. I, II, III only
  D. I, III, IV only

Question 2

The therapist is about to establish mechanical ventilator settings for a COPD patient who has a large ventilation time constant. Which of the following considerations should the therapist have in mind at this time?
 
  A. a large T
  B. a long TE
  C. a long TI
  D. a low I

[Perkypinki]

Answer to Question 1

ANS: D
A. Incorrect response: See explanation D.
B. Incorrect response: See explanation D.
C. Incorrect response: See explanation D.
D. Correct response: During PC-SIMV the cycle variable can be either pressure or time. During VC-SIMV, the cycle variable can be either volume or time.

Answer to Question 2

ANS: B
A. Incorrect response: A large T contributes to a longer inspiratory time and increases the risk of auto-PEEP developing.
B. Correct response: Because the COPD patient has a large ventilation time constant (CL  Raw), this patient is likely to develop auto-PEEP if the expiratory phase is too short and inspiratory time is too long. This type patient requires a rapid inspiratory time and a prolonged expiratory time.
C. Incorrect response: A long inspiratory time will increase the likelihood of the patient developing auto-PEEP because less time would be devoted to expiration.
D. Incorrect response: A low inspiratory flow may cause patient-ventilator dyssynchrony.

[Jkov05]

Thanks for the timely response, appreciate it

[kthug]

TYSM