Quiz Ch 11

How is the percentage of functional hemoglobin that is saturated with oxygen determined via pulse oximetry?
A. The percentage of red light that lands on the photodiode represents the Sp02 (oxygen saturation as determined by pulse oximetry.
B. The ratio of the red and infrared light that reaches the photodiode signifies the Sp02
C. The percentage of infrared light that reaches the photodetector reflects the Sp02
D. The sum of the amount of red and infrared absorbed by the tissue determines the Sp02

The therapist has applied a bandage-type pulse oximetry probe too tightly to an infant’s finger. What problem can be expected to occur in this situation?
A. The Sp02 will read erroneously low.
B. The Sp02 will read erroneously high.
C. The monitor displays a message indicating inadequate pulse.
D The monitor displays fluctuating Sp02 values between being erroneously low and high.

As the therapist applies a pulse oximeter finger probe to a neonate who is receiving supplemental oxygen, she notices that the Sp0 reading is 100%. What should the therapist do in this situation?
A. The therapist should reduce the fraction of inspired oxygen.
B. The therapist should obtain an arterial blood sample from this patient.
C. The therapist should switch to using a capnometer.
D. The therapist should do nothing, because the reading is accurate.

Why do transcutaneous oxygen tension (P0 and carbon dioxide tension (PCO values differ from Pa0 and PaCO measurements?
A. Because the skin is much more permeable to oxygen than carbon dioxide
B. Because metabolism in the tissue consumes oxygen and produces carbon dioxide at the site of the electrode
C. Because oxygen is consumed and carbon dioxide is produced in transit from the left ventricle to the electrode site
D. Because of the lag time between the cardiac output and the time the blood reaches the transcutaneous electrode site

While attending to a neonatal patient in the neonatal intensive care unit (NICU), the therapist notices that a transcutaneous electrode is affixed to the upper chest of the neonate. What should the therapist do at this time?
A. The therapist should do nothing because the transcutaneous electrode is properly placed.
B. The therapist needs to move the transcutaneous electrode to the infant’s right shoulder.
C. The therapist should relocate the electrode on the sternum as close as possible to the heart.
D. The therapist should reposition the electrode on the neonate’s abdomen.

The therapist is assessing a mechanically ventilated infant and observes that the transcutaneous electrode temperature is set between 430 C and 44° C. What action does the therapist need to take at this time?
A. The therapist should increase the temperature range to 470 C to 48° C.
B. The temperature of the transcutaneous electrode needs to be reduced to 36° C to
C. The temperature range set is appropriate; therefore, no action is necessary.
38° C.
D. The electrode needs to be repositioned and maintained at the same temperature.

Which of the following factors is the main physiologic factor responsible for deriving accurate transcutaneous data?
A. Heart rate
B. Minute ventilation
C. Ventilation—perfusion ratios
D. Peripheral perfusion

Which of the following features or characteristics apply to mainstream capnography?
I. The mainstream capnograph contains narrow tubing that can become occluded with mucus.
II. Mainstream capnography generally employs infrared spectrometers.
III. The mainstream capnograph does not add much weight to the breathing circuit.
IV. The mainstream capnograph is placed at the proximal end of the endotracheal tube.
A. I, II, and III only
B. II and IV only
C. I, III, and IV only
D. I and II only