Deck 38: Medical Gas Therapy

Question 1

Which of the following typically occurs first when monitoring the earliest physiologic response to breathing 100% O₂?

A)substernal chest pain
B)decreased diffusing capacity (DLCO)
C)decreased lung compliance (C_L)
D)decreased vital capacity (VC)

Answer 1

A

Question 2

Which of the following signs and symptoms are associated with the presence of hypoxemia?
I)tachypnea
II)tachycardia
III)cyanosis
IV)bradycardia

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

Answer 2

C

Question 3

To minimize the risk of retinopathy of prematurity (ROP), the American Academy of Pediatrics recommends keeping the PaO₂ below what level?

A)60 mm Hg
B)70 mm Hg
C)80 mm Hg
D)90 mm Hg

Answer 3

C

Question 4

A physician places a patient in respiratory failure on 100% O₂. To avoid the hazards of O₂ toxicity, you would recommend that every effort be made to reduce this FIO₂ to less than 50% within what time frame?

A)8 hours
B)24 hours
C)48 hours
D)5 days

Question 5

Benefits of properly applied O₂ therapy in patients with chronic hypoxemia include all of the following except:

A)reversal of pulmonary vasoconstriction
B)relief of pulmonary hypertension
C)decreased right ventricular workload
D)improved pulmonary diffusing capacity

Question 6

Retinopathy of prematurity may result in which of the following?

A)dyspnea
B)pneumonia
C)atelectasis
D)blindness

Question 7

What can properly applied O₂ therapy decrease?
I)ventilatory demand
II)work of breathing
III)cardiac output

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

Question 8

A patient with chronic hypercapnia placed on an FIO₂ of 0.6 starts hypoventilating. What is the probable cause of this phenomenon?

A)decreased cardiac output
B)O₂ toxicity
C)O₂-induced hypoventilation
D)absorption atelectasis

Question 9

What is the minimum criterion for how often an O₂ delivery system should be checked according to the clinical practice guidelines from the AARC?

A)every 4 hours
B)every 8 hours
C)every 24 hours
D)every 48 hours

Question 10

Retinopathy of prematurity (ROP) is a potentially serious management problem mainly in the care of whom?

A)premature or low-birth-weight infants
B)cystic fibrosis patients
C)children with asthma
D)patients with acute respiratory distress syndrome (ARDS)

Question 11

Which of the following would indicate a need for O₂ therapy for a newborn infant?
I)SaO₂ less than 88%
II)capillary PO₂ less than 40 mm Hg
III)PaO₂ less than 60 mm Hg

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

Question 12

When determining a need for O₂ therapy, the respiratory therapist should assess which of the following?
I)neurologic status
II)pulmonary status
III)cardiac status

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

Question 13

Which of the following is consistent with the radiographic appearance after prolonged exposure to O₂?

A)air bronchograms
B)pulmonary abscess
C)patchy infiltrates
D)pneumothorax

Question 14

You set up an Oxy-Hood with an FIO₂ of 0.5 for a newborn infant. What is the maximum time that should pass before assessing this patient's PaO₂ or SaO₂?

A)1 hour
B)2 hours
C)8 hours
D)12 hours

Question 15

Which of the following is false about absorption atelectasis?

A)It can occur only when breathing supplemental O₂.
B)Its risk is increased in patients breathing at low tidal volumes (V_T values).
C)Its risk is decreased through the natural "sigh" mechanism.
D)It results in an increase in the physiologic shunt fraction.

Question 16

Specific clinical objectives of oxygen (O₂) therapy include which of the following?
I)decrease the symptoms caused by chronic hypoxemia
II)decrease the workload hypoxemia imposes on the heart and lungs
III)correct documented arterial hypoxemia

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

Question 17

You start a chronic obstructive pulmonary disease (COPD) patient on a nasal O₂ cannula at 2 L/min. What is the maximum time that should pass before assessing this patient's PaO₂ or SaO₂?

A)2 hours
B)8 hours
C)12 hours
D)72 hours

Question 18

What is/are the primary organ system(s) affected by O₂ toxicity?
I)central nervous system (CNS)II.lungs
III)kidneys

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

Question 19

A patient breathing 100% O₂ for 24 hours or longer would most likely exhibit which of the following?
I)decreased DLCO
II)decreased C_L
III)increased PAO₂ - PaO₂
IV)decreased VC

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

Question 20

Which of the following would indicate a need for O₂ therapy for an adult or child?
I)SaO₂ less than 90%
II)PaCO₂ greater than 45 mm Hg
III)PaO₂ less than 60 mm Hg

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

Question 21

Which of the following is TRUE about reservoir cannulas?

A)They reduce O₂ use as much as 200%.
B)During exercise, they do not reduce O₂ use.
C)Humidification is absolutely necessary.
D)Nasal anatomy and breathing pattern can affect performance of the device.

Question 22

Disadvantages of standard O₂ masks include all of the following except:

A)being difficult to apply to patients
B)patient discomfort (straps and heat)
C)increasing the risk of aspiration
D)must be removed for eating

Question 23

Which of the following is considered an advantage of the transtracheal catheter?

A)It does not provide any economic benefit compared with the nasal cannula.
B)It decreases the anatomic reservoir.
C)It requires 40% to 60% less O₂ flow than the nasal cannula.
D)It requires higher flows than the nasal cannula.

Question 24

A well-fitted nonrebreathing mask, adjusted so that the patient's inhalation does not deflate the bag (flows between 6 and 10 L/min), should provide inspired O₂ concentrations in what range?

A)55% to 70%
B)45% to 60%
C)75% to 90%
D)70% to 85%

Question 25

A physician orders 2 L/min O₂ through a simple mask to a 33-year-old postoperative woman with moderate hypoxemia breathing room air (PaO₂ = 52 mm Hg). What would be the correct action at this time?

A)Carry out the physician's prescription exactly as written.
B)Recommend that the mask be changed to a cannula at 2 L/min.
C)Recommend a flow of at least 5 L/min to wash out carbon dioxide (CO₂).
D)Do not apply the O₂ until the medical director has been contacted.

Question 26

Low-flow O₂ delivery systems used in respiratory care include all of the following except:

A)nasal O₂ cannula
B)nasal O₂ catheter
C)air-entrainment mask
D)transtracheal catheter

Question 27

Which of the following statements is false about low-flow O₂ delivery systems?

A)The greater the patient's inspiratory flow, the greater is the FIO₂.
B)All low-flow devices provide variable O₂ concentrations.
C)The O₂ provided by a low-flow device is diluted with air.
D)The patient's flow usually exceeds that from a low-flow device.

Question 28

To ensure a stable FIO₂ under varying patient demands, what must an O₂ delivery system do?

A)have a reservoir system at least equal to the V_T
B)provide all the gas needed by the patient during inspiration
C)maintain flows that are at least equal to the patient's peak flows
D)be able to deliver any O₂ concentration from 21% to 100%

Question 29

A 27-year-old woman received from the emergency department is on a nasal cannula at 5 L/min. Approximately what FIO₂ is this patient receiving?

A)28%
B)32%
C)35%
D)40%

Question 30

A cooperative and alert postoperative patient taking food orally requires a small increment in FIO₂, to be provided continuously. Precise FIO₂ concentrations are not needed. Which of the following devices would best achieve this end?

A)simple O₂ mask
B)air-entrainment mask
C)nasal cannula
D)nonrebreathing mask

Question 31

Which of the following are advantages of the nasal cannula as a low-flow O₂ delivery system?
I)stability
II)low cost
III)easy application
IV)disposability

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

Question 32

Which of the following is FALSE about the simple O₂ mask?

A)It has no valving system or reservoir bag.
B)It can easily deliver high FIO₂ values (greater than 0.6 to 0.7)
C)It requires a minimal input flow of 5 L/min.
D)It functions as a variable-performance system.

Question 33

Which of the following factors should be used in properly selecting an O₂ delivery device?
I)knowledge of general performance of the device
II)physician's preference
III)individual capabilities of the equipment

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

Question 34

Delivery systems that provide only a portion of a patient's inspired gas are referred to as what?

A)fixed-performance systems
B)variable-performance systems
C)high-flow O₂ systems
D)air-entrainment systems

Question 35

Which of the following factors will decrease the FIO₂ delivered by a low-flow O₂ system?
I)short inspiratory time
II)fast rate of breathing
III)lower O₂ input
IV)large minute ventilation

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

Question 36

A physician orders supplemental O₂ for a patient through a nasal cannula at a flow of 12 L/min. When you ask what the goal is, the physician states that the patient should receive about 60% O₂. Which of the following should you recommend?

A)The O₂ should be given through a reservoir mask at 10 L/min.
B)The cannula flow should be set to 15 instead of 12 L/min.
C)The O₂ should be given through a simple mask set at 5 to 12 L/min.
D)The O₂ should be given through a simple mask set at 12 to 15 L/min.

Question 37

A 52-year-old man is admitted to the hospital emergency department with a primary complaint of severe radiating chest pain and signs of central cyanosis. The attending asks for your advice on selecting a device that provides a moderate FIO₂ for this patient. Which of the following would you recommend?

A)simple O₂ mask at 8 L/min
B)air-entrainment mask at 40% O₂
C)nasal cannula at 5 L/min
D)nonrebreathing mask at 10 L/min

Question 38

What is the minimum flow setting for a simple mask applied to an adult?

A)3 L/min
B)5 L/min
C)8 L/min
D)10 L/min

Question 39

You enter the room of a patient who is receiving nasal O₂ through a bubble humidifier at 5 L/min. You immediately notice that the humidifier pressure relief is popping off. Which of the following actions would be most appropriate in this situation?

A)Check and tighten all connections.
B)Replace the humidifier with a new one.
C)Look for crimped or twisted delivery tubing.
D)Decrease the flow rate to 2 L/min.

Question 40

You can determine that a nasal O₂ catheter is properly positioned when its tip is where?

A)visualized just below the uvula
B)visualized in the oropharynx
C)advanced beyond the epiglottis
D)retracted just above the uvula

Question 41

A patient receiving 35% O₂ through an air-entrainment mask set at 6 L/min input flow becomes tachypneic. Simultaneously, you notice that the SpO₂ has fallen from 91% to 87%. Which of the following actions would be most appropriate in this situation?

A)Switch the patient to a 40% air-entrainment mask.
B)Increase the device's input flow to 10 L/min.
C)Switch the patient to a 28% air-entrainment mask.
D)Decrease the device's input flow to 4 L/min.

Question 42

To ensure the prescribed FIO₂ for a patient receiving 65% O₂, you apply a closed reservoir delivery system with a one-way expiratory valve. What other component must be included in this system to ensure a fail-safe operation?

A)water trap
B)high-pressure alarm
C)emergency inlet valve
D)low-pressure alarm

Question 43

A physician wants a stable FIO₂ of 0.5 for a newborn infant with severe hypoxemia. Which of the following systems would you select?

A)O₂ hood with blender and heated humidifier
B)pediatric ("croup") tent with O₂ input of 8 L/min
C)O₂ hood with blender and unheated humidifier
D)infant incubator with O₂ input of 10 L/min

Question 44

A true high-flow O₂ delivery system should provide at least what flow?

A)60 L/min
B)50 L/min
C)40 L/min
D)30 L/min

Question 45

Which of the following are components of a typical O₂ blender?
I)precision metering device or mixture control
II)audible dual low-pressure alarm system
III)pressure regulating and equalizing valves
IV)variable-size air-entrainment port

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

Question 46

To confirm proper operation of an O₂ blending system, what should you do?
I. Test low-pressure alarms and bypass systems.
II. Analyze FIO2 at 0.21, 1.00, and prescribed level.
III. Confirm air and O2 inlet pressures.

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

Question 47

A patient is receiving O₂ through a nonrebreathing mask set at 8 L/min. You notice that the mask's reservoir bag collapses completely before the end of each inspiration. Which of the following actions is appropriate in this case?

A)change to a partial rebreather
B)decrease the liter flow
C)increase the liter flow
D)change to a simple mask

Question 48

A 45-year-old patient with congestive heart failure is receiving O₂ through a 35% air-entrainment mask. With an O₂ input of 6 L/min, what is the total output gas flow?

A)16 L/min
B)24 L/min
C)28 L/min
D)34 L/min

Question 49

You connect an intubated patient to an air-entrainment nebulizer system through a T-tube set at 60% with an input flow of 15 L/min. Toward the middle of inspiration, you observe that mist stops exiting from the open end of the T-tube. What does this indicate?

A)Flow is adequate to meet patient needs.
B)Patient has a low inspiratory flow rate.
C)Flowmeter must be calibrated.
D)Patient is not receiving 60% O₂.

Question 50

A physician requests you provide a patient with exactly 45% O₂ at a flow of 60 L/min. Lacking a blender, you must manually mix air and O₂ to achieve the desired mixture at the prescribed flow. Which of the following air and O₂ flows would you select?

Question 51

You must deliver the highest possible FIO₂ to a 67-year-old man with pulmonary edema breathing at a rate of 35/min. Which of the following O₂ delivery systems would be most appropriate?

A)nonrebreathing mask at 12 to 15 L/min
B)simple mask at 12 to 15 L/min
C)partial rebreathing mask at 12 to 15 L/min
D)aerosol mask with nebulizer set to 100%

Question 52

You design an air-entrainment system that mixes air with O₂ at a fixed ratio of 1:7 (1 L air to 7 L O₂). About what O₂ will this device provide?

A)33%
B)40%
C)80%
D)90%

Question 53

What is the maximum FIO₂ expected to be delivered by most air-entrainment masks?

A)30%
B)40%
C)50%
D)60%

Question 54

Which of the following factors determine the actual O₂ provided by an air-entrainment system?
I)O₂ input flow to the jet
II)air-to-O₂ ratio of the device
III)resistance downstream from the jet

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

Question 55

Which of the following alternatives may increase the FIO₂ capabilities of air-entrainment nebulizers?
I. Add open reservoir to expiratory side of T-tube.
II. Connect together two or more nebulizers.
III. Use a commercial dual-flow system.
IV. Add open reservoir to inspiratory side of T-tube.

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

Question 56

Which of the following is FALSE about air-entrainment systems?

A)Their FIO₂ values are directly proportional to their total flow.
B)They can provide variable FIO₂ values under some clinical conditions.
C)They always deliver O₂ concentrations less than 100%.
D)They yield a set FIO₂ only if their flow exceeds the patient's.

Question 57

What is the upper limit of O₂ concentrations available through tents?

A)60% to 70%
B)50% to 60%
C)40% to 50%
D)30% to 40%

Question 58

You note that the air intake ports surrounding the jet of a 35% air-entrainment mask are partially obstructed by the patient's bedding. Which of the following would you expect?
I)decrease in the device's total output flow
II)increase in the percent O₂ delivered by the device
III)change in the FIO₂ received by the patient

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

Question 59

A physician orders 40% O₂ through an air-entrainment nebulizer for a patient with a minute volume of 12 L/min. What is the minimum nebulizer input flow required to ensure the prescribed FIO₂?

A)8 L/min
B)10 L/min
C)12 L/min
D)14 L/min

Question 60

An O₂ delivery device takes separate pressurized air and O₂ sources as input, then mixes these gases through a precision valve. What does this describe?

A)O₂ blending system
B)reservoir system
C)air-entrainment system
D)low-flow system

Question 61

What temperature is required to maintain a neutral thermal environment (NTE) in an Oxy-Hood for infants weighing 2500 g or more?

A)25° C
B)30° C
C)35° C
D)40° C

Question 62

Directing a cool O₂ mixture to an infant in an Oxy-Hood can result in which of the following?
I)increased O₂ consumption
II)increased convective heat loss
III)apnea (cessation of breathing)

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

Question 63

Clogging of an isolette incubator air inlet filter will result in which of the following?

A)excessive heat buildup
B)increased convection cooling
C)increased O₂ concentrations
D)automatic sounding of an alarm

Question 64

Physiologic effects of hyperbaric oxygen (HBO) therapy include all of the following except:

A)neovascularization
B)bubble reduction
C)enhanced immune function
D)systemic vasodilation

Question 65

All of the following conditions can be treated with hyperbaric oxygen (HBO) therapy except:

A)carbon monoxide poisoning
B)septic shock
C)air embolism
D)clostridial gangrene

Question 66

In giving O₂ to an infant through a hood, which of the following is/are correct?
I. A neutral thermal environment should be maintained.
II. Gases should be directed away from the infant’s face.
III. High input flow (greater than 10 to 15 L/min) should be avoided.
IV. A minimum flow of 7 L/min must be maintained.

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

Question 67

What does 1 atmospheric pressure absolute (ATA) equal?
I)101 kPa
II)50 psi
III)760 mm Hg

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

Question 68

Criteria for initiating hyperbaric oxygen (HBO) therapy on an adult patient suspected of suffering from acute carbon monoxide poisoning include all of the following except:

A)history of unconsciousness
B)carboxyhemoglobin saturation less than 20%
C)presence of neurologic abnormality
D)presence of cardiac instability

Question 69

During hyperbaric oxygen therapy at 3 ATA, plasma contains about how much dissolved O₂?

A)1 ml/dl
B)3 ml/dl
C)5 ml/dl
D)7 ml/dl

Question 70

A patient receiving 3 L/min O₂ through a nasal cannula has a measured SpO₂ of 93% and no clinical signs of hypoxemia. At this point, what should you recommend?

A)decreasing the flow to 2 L/min and rechecking the SpO₂
B)maintaining the therapy as is and rechecking the SpO₂ on the next shift
C)increasing the flow to 4 L/min and rechecking the SpO₂
D)discontinuing the O₂ therapy

Question 71

What is the level of SpO₂ typically associated with discontinuation of O₂ therapy?

A)88%
B)90%
C)92%
D)94%

Question 72

An infant requires both a precise high FIO₂ and maintenance of a neutral thermal environment. Which of the following systems can best achieve these goals?
I)Oxy-Hood or warmed O₂ blending system without incubator
II)heated incubator with automatic O₂ controlling system
III)heated incubator with Oxy-Hood or O₂ blending system

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

Question 73

In which of the following clinical situations would you recommend hyperbaric oxygen (HBO) therapy, if available?
I)carbon monoxide poisoning
II)respiratory or cardiac arrest
III)severe trauma
IV)cyanide poisoning

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

Question 74

What are some key patient considerations in selecting O₂ therapy equipment?
I)type of airway (natural or artificial)II.severity and cause of the hypoxemia
III)age group (infant, child, adult)IV.stability of the minute ventilation

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

Question 75

At an FIO₂ of 1, what is the approximate half-life of blood carboxyhemoglobin?

A)20 minutes
B)80 minutes
C)3 hours
D)5 hours

Question 76

In which of the following procedures is air embolism a potential complication?
I)central line placement
II)lung biopsy
III)hemodialysis

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

Question 77

Which of the following is false about multiplace hyperbaric oxygenation chambers?

A)The chamber normally is filled with 100% O₂.
B)Air locks allow entry and egress of caregivers.
C)Pressures of 6 ATA or more can be applied.
D)Care is provided directly within the chamber.

Question 78

During hyperbaric oxygen (HBO) therapy at 3 ATA, what is the approximate half-life of blood carboxyhemoglobin?

A)20 minutes
B)80 minutes
C)5 hours
D)24 hours

Question 79

What is the problem with input flows greater than 10 to 15 L/min in an infant Oxy-Hood?

A)production of harmful noise levels
B)difficulty in maintaining adequate humidification
C)difficulty in maintaining stable high FIO₂ values
D)increased likelihood of cold stress

Question 80

Which of the following would indicate adequate oxygenation for adult patients with chronic lung disease and an accompanying acute-on-chronic hypoxemia?
I)SaO₂ of 90% or higher
II)PaO₂ of 50 mm Hg to 60 mm Hg
III)SaO₂ of 85% to 90%

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