Question 1

As the therapist applies a pulse oximeter finger probe to a neonate who is receiving supplemental oxygen, she notices that the SpO₂ reading is 100%. What should the therapist do in this situation? A) The therapist should continue monitoring the patient because the reading is accurate. B) The therapist should obtain an arterial blood sample to confirm SpO₂ level. C) The therapist should switch to using a capnometer. D) The therapist should reduce the fraction of inspired oxygen.

Accepted Answer

The sensitivity of pulse oximetry to detect the presence and degree of hyperoxia may be limited in the neonatal patient. If the oximeter is reading an SpO₂ of 100%, the arterial oxygen tension (PaO₂) could be between 90 and 250 mm Hg. However, many neonatal intensive care units will target an SpO₂ below a certain threshold in order to reduce the risk of retinopathy of prematurity in premature babies.

Question 2

While working in the NICU with a mechanically ventilated newborn who is being monitored for PetCO₂, the therapist observes the following capnogram. What interpretation should the therapist make of this capnogram?

A) This capnogram is normal.
B) The patient is receiving about 10 cm H₂O positive end-expiratory pressure.
C) The patient is rebreathing his own exhaled gas.
D) The neonate is being hyperventilated.

Accepted Answer

Rebreathing is characterized by an elevation in the A-B phase of the capnogram, with a corresponding increase in ETCO₂. It indicates the rebreathing of previously exhaled carbon dioxide. Rebreathing can be caused by allowing an insufficient expiratory time or by inadequate inspiratory flow (see Figure 9-7 in the textbook).

Question 3

What clinical parameter is critically important to monitor when mechanical ventilation is administered?&#10;A) Blood pressure&#10;B) Heart rate&#10;C) Temperature&#10;D) Respiratory rate

Accepted Answer

In mechanically ventilated children, increasing intrathoracic pressure (by increasing positive end expiratory pressure, for example) can reduce venous return, resulting in decreased blood pressure.

Question 4

While attending to a neonatal patient in the 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?&#10;A) The therapist should only continue monitoring the patient since the transcutaneous electrode is properly placed.&#10;B) The therapist should reposition the electrode on the neonate's abdomen.&#10;C) The therapist needs to move the transcutaneous electrode to the infant's right shoulder.&#10;D) The therapist should relocate the electrode on the sternum as close as possible to the heart.

Accepted Answer

The site should be a highly vascular area such as the earlobe, upper chest, abdomen, thighs, or the lower back if the patient is supine; bony areas and those with limited perfusion, such as over the spine, should be avoided.

Question 5

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 and II only
B) II and IV only
C) I, II, and III only
D) I, III, and IV only

Accepted Answer

Gases from an exhaled breath can reach the sample chamber in one of two ways. Mainstream capnographs are used in ventilated patients, with placement at the proximal end of an endotracheal tube (see Figure 9-5 in the textbook). This method employs infrared spectrometers. Sidestream capnograph analyzers continuously aspirate a sample of gas through a small tube to the analyzer.

Question 6

The therapist is assessing a mechanically ventilated infant and observes that the transcutaneous electrode temperature is set between 41 and 44°C. What action does the therapist need to take at this time?

A) The temperature range set is appropriate; therefore, no action is necessary.
B) The therapist should increase the temperature range to 46 to 48°C.
C) The temperature of the transcutaneous electrode needs to be reduced to 36 to 38°C.
D) The electrode needs to be repositioned and maintained at the same temperature.

Accepted Answer

Selecting a sensor temperature is important to proper operation. The temperature range is usually 41 to 44°C. Heating of the sensor requires that the site be changed on a routine basis to prevent thermal injuries. The frequency of site changes ranges from 4 to 12 hours (depending upon the device and sensor temperature) but can be reduced if necessary.

Question 7

Which of the following conditions will preclude the use of indirect calorimetry?
I) Cuffed endotracheal tubes
II) Circuit leaks
III) FiO₂ 0.40
IV) HFOV

A) I, II, and III only
B) II and III only
C) II and IV only
D) I, III, and IV only

Accepted Answer

Conditions that preclude the use of indirect calorimetry include uncuffed endotracheal tubes, cuff or ventilator circuit leaks >10% to 15%, FiO₂ >50%, need for high-frequency ventilation or extracorporeal membrane oxygenation, and active chest tube leakage.

Question 8

Which of the following is the main physiologic factor responsible for deriving accurate transcutaneous data?&#10;A) Heart rate&#10;B) Minute ventilation&#10;C) Peripheral perfusion&#10;D) Ventilation-perfusion ratios

Accepted Answer

Changes in perfusion can adversely affect the accuracy of transcutaneous measurements. The skin reacts to cold, shock, and certain drugs by contracting the superficial blood vessels, opening larger, deeper arterioles to achieve a shunting effect. Capillary blood flow is reduced on exposure to cold temperatures in order to reduce the loss of body heat. Shock and certain medications can also divert blood from capillaries to the central circulation. In all cases of reduced capillary perfusion, the capillary blood that is measured using a transcutaneous monitor may reflect measurements associated with venous blood, with a considerably lower PO₂ and higher PCO₂ (compared to values obtained with good capillary perfusion). If a patient has poor skin integrity, transcutaneous monitoring may also be contraindicated.

Question 9

The therapist has been asked to measure preductal oxygen saturation. Where could the therapist place the pulse oximeter probe?&#10;A) Right thumb&#10;B) Left leg&#10;C) Right leg&#10;D) Left earlobe

Accepted Answer

Sensor placement on right arm or head will reflect preductal values while the left arm and the lower parts of the body will reflect postductal oxygen saturation values.

Question 10

What is the purpose of indirect calorimetry? A) To measure heat produced and lost from the body B) To calculate energy expenditure by measuring VO₂ and VCO₂ C) To calculate resting energy expenditure D) To measure gas exchange

Accepted Answer

Direct calorimetry extrapolates energy expenditure by measuring heat produced and lost from the body while indirect calorimetry combines measurements of VO₂ and VCO₂ into an equation to calculate energy expenditure. Most energy expenditure reports will contain results for VO₂, VCO₂, REE, and respiratory quotient (which is VCO₂/VO₂ and can be used to determine substrate utilization).

Question 11

A therapist is monitoring a child on the mechanical ventilator who is hemodynamically stable. The PetCO₂ is 48 mm Hg. If accurate, what should be the PaCO₂? A) 43 to 48 mm Hg B) 45 to 48 mm Hg C) 50 to 53 mm Hg D) Exactly the same as PetCO₂

Accepted Answer

The answer of A therapist is monitoring a child on...

Question 12

Why do transcutaneous oxygen tension (PO₂) and carbon dioxide tension (PCO₂) values differ from PaO₂ and PaCO₂ measurements? A) Because of the lag time between the cardiac output and the time the blood reaches the transcutaneous electrode site B) Because the skin is much more permeable to oxygen than carbon dioxide C) Because oxygen is consumed and carbon dioxide is produced in transit from the left ventricle to the electrode site D) Because metabolism in the tissue consumes oxygen and produces carbon dioxide at the site of the electrode

Accepted Answer

The answer of Why do transcutaneous oxygen tension (PO₂) and...

Question 13

The following capnogram was obtained from a newborn infant receiving mechanical ventilation.   How should the therapist evaluate this capnogram?&#10;A) Airway obstruction&#10;B) Hypoventilation&#10;C) Hyperventilation&#10;D) Increased dead space ventilation

Accepted Answer

The answer of The following capnogram was obtained from a...

Question 14

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.

Accepted Answer

The answer of How is the percentage of functional hemoglobin...

Question 15

Which of the following is volumetric capnography able to determine?
I) Airway dead space
II) Alveolar tidal volume
III) Shunt fraction
IV) Alveolar minute volume

A) III and IV only
B) II, III, and IV only
C) I, II, and IV only
D) I, II, and III only

Accepted Answer

The answer of Which of the following is volumetric capnography...

Question 16

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.

Accepted Answer

The answer of The therapist has applied a bandage-type pulse...

Deck 9: Noninvasive Monitoring in Neonatal and Pediatric Care