Chapter 47 Discontinuing Ventilatory Support

Chapter 47  Discontinuing Ventilatory Support

Complete Chapter Questions And Answers
 

Sample Questions

MULTIPLE CHOICE

1. All of the following factors will increase ventilatory demand (workload) except:
a.
severe hypoxemia
b.
pulmonary infection
c.
increased compliance
d.
Bronchospasm

ANS: C
Factors that may increase ventilatory workload are summarized in Box 47-1.

DIF: Recall REF: p. 1224 OBJ: 1

2. Ventilatory capacity is determined by all of the following except:
a.
central nervous system (CNS) drive
b.
trigger level
c.
muscle strength
d.
muscle endurance

ANS: B
Ventilatory capacity is determined by (1) CNS drive, (2) ventilatory muscle strength, and (3) ventilatory muscle endurance.

DIF: Recall REF: p. 1221 OBJ: 1

3. All of the following factors can reduce a patient’s ventilatory drive except:
a.
respiratory alkalosis
b.
metabolic acidosis
c.
depressant drugs
d.
decreased metabolism

ANS: B
Box 47-2 summarizes factors that may reduce ventilatory drive.

DIF: Recall REF: p. 1202 OBJ: 2

4. When is ventilator dependence likely to occur?
1. when ventilatory capacity exceeds demand
2. when arterial hypoxemia is present
3. when the patient is malnourished
4. when the cardiovascular system is unstable
a.
2 and 4
b.
1, 2, and 3
c.
3 and 4
d.
2, 3, and 4

ANS: D
Other factors that may contribute to ventilator dependence include inadequate arterial oxygenation, poor tissue oxygen delivery, myocardial ischemia, arrhythmias, low cardiac output, and cardiovascular instability.

DIF: Recall REF: p. 1202 OBJ: 2

5. What is the most important prerequisite for weaning a patient from ventilatory support?
a.
improvement in the original problem requiring mechanical ventilation
b.
assurance that the patient’s ventilatory demand exceeds the patient’s capacity
c.
objective evidence indicating good respiratory muscle endurance
d.
ability to maintain adequate oxygenation with an FIO2 less than 0.4

ANS: A
The single most important criterion to consider when evaluating a patient for ventilator discontinuation or weaning is whether there has been significant alleviation or reversal of the disease state or condition that necessitated use of the ventilator in the first place.

DIF: Recall REF: p. 1203 OBJ: 3