Which of the following are true about invasive versus noninvasive monitoring?

1. Invasive procedures require insertion of a device into the body.
2. Laboratory analysis of gas exchange is usually noninvasive in nature.
3. Physiologic monitoring can be either invasive or noninvasive.
4. Invasive procedures provide more accurate data but carry greater risks.
a. 2 and 4 only
b. 1, 3, and 4 only
c. 2 only
d. 1, 2, 3, and 4

ANS: B
Invasive procedures require the insertion of a sensor or collection device into the body, whereas noninvasive monitoring is a means of gathering data externally. Because laboratory analysis of gas exchange requires blood samples, it is usually considered invasive. On the other hand, moni-toring can be either invasive or noninvasive. In general, invasive procedures tend to provide more accurate data than do noninvasive methods but carry greater risk.