Chapter 9: Noninvasive Monitoring in Neonatal and Pediatric Care Test Bank
MULTIPLE CHOICE 1. What clinical parameter is critically important to monitor when mechanical ventilation is
administered? Blood pressure Heart rate Temperature Respiratory rate
a. b. c. d.
ANS: A
In mechanically ventilated children, increasing intrathoracic pressure (by increasing positive end expiratory pressure, for example) can reduce venous return, resulting in decreased BP. REF: p. 136 2. 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 SpO2 (oxygen saturation as determined by pulse oximetry). b. The percentage of infrared light that reaches the photodetector reflects the SpO2. c. The ratio of the red and infrared light that reaches the photodiode signifies the SpO2. d. The sum of the amount of red and infrared absorbed by the tissue determines the SpO2. ANS: C
A pulse oximeter sensor has two light-emitting diodes (LEDs) that function as light sources and a photodiode that measures the amount of light from the LEDs (see Figure 9-1 in the textbook). One LED emits red light, and the other diode emits infrared light. The sensor is placed over a translucent part of the body (finger, toe, earlobe, etc.). As the light from the diodes passes through the blood and tissue, some of the light from both the red and the infrared diodes is absorbed by oxyhemoglobin. The photodiode then measures the amount of light that passes through the body without being absorbed. Because oxyhemoglobin (hemoglobin bound with oxygen) and deoxyhemoglobin (hemoglobin not bound with oxygen) absorb significantly different amounts of light, the proportion of oxyhemoglobin (expressed as a percentage) is determined (see Figure 9-2 in the textbook). REF: p. 137 3. 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 SpO2 will read erroneously low. b. The SpO2 will read erroneously high. c. The monitor will display a message indicating inadequate pulse. d. The monitor will display fluctuating SpO2 values between being erroneously low and high.
