How will the delivered tidal volume be affected during volume ...

[melina_rosy]

How will the delivered tidal volume be affected during volume control ventilation when the patient's pulmonary compliance decreases, or when the patient's airway resistance increases? The patient's tidal volume will ________________.
 
  A. increase
  B. decrease
  C. remain constant
  D. fluctuate

Question 2

The therapist enters the ICU, and hears the high-pressure alarm sounding on a mechanical ventilator. Which of the following considerations need to be taken into account as possible causes of this alarm situation? I. Auto-PEEP may have developed. II. The cuff on the patient's endotracheal tube has deflated. III. The patient may be experiencing increased lung secretions. IV. The flow waveform has converted from a square configuration to that of a descending ramp.
 
  A. I, III only
  B. II, III only
  C. I, II, IV only
  D. II, III, IV only

[bitingbit]

Answer to Question 1

ANS: C
A. Incorrect response: See the explanation associated with response C.
B. Incorrect response: See the explanation associated with response C.
C. Correct response: The description volume control, or volume targeted, ventilation means that volume is the variable that remains constant throughout the delivery of the breath. In addition to setting the tidal volume, the therapist is responsible for setting the inspiratory flow or inspiratory time, inspiratory flow pattern, and the mandatory rate. During a volume-controlled breath, the tidal volume, inspiratory flow, and flow pattern do not change despite alterations in lung characteristics (i.e., lung compliance and/or airway resistance).
D. Incorrect response: See the explanation associated with response C.

Answer to Question 2

ANS: AI. Correct response: Auto-PEEP is the inadvertent retention of air in the lungs at the end of exhalation. Dynamic hyperinflation (air trapping develops because of incomplete emptying of the lungs. Patients (COPD and status asthmaticus) whose lungs are characterized by long time constants are susceptible to this problem. Other causes include:
  High minute ventilation (<10 to 20 l>  Small ID endotracheal tube
  Bronchospasm
  Increased lung secretions
  Mucosal edema
  Short expiratory time
  Inverse ratio ventilation
II. Incorrect response: A deflated endotracheal tube cuff would not activate the low-pressure alarm. It would stimulate a low-pressure alarm, a low-volume alarm, low minute ventilation alarm, or an apnea alarm.
III. Correct response: Any condition that increases airway resistance and interferes with lung emptying can cause auto-PEEP.
IV. Incorrect response: Changing the flow waveform configuration from square (rectangular) to a descending ramp pattern does not influence lung emptying or cause auto-PEEP.

[melina_rosy]

Correct answers!

[bitingbit]

Great! Please up vote