Egan’s Chapter 38 Practice Questions:

1. Three types of oxygen delivery: 1. Low-flow, 2. High-flow, and 3. Reservoir

2. Three ways to determine need for O2 therapy: documented labs, specific clinical problem or condition, and hypoxemia causes other problems

3. AARC indications: documented hypoxemia, acute care situation in which hypoxemia is suspected, severe trauma, acute myocardial infarction, short term therapy, and surgical intervention ie post-anesthesia recovery

4. AARC monitoring: 2X in 12 hour shift, 1X in 8 hour shift, neonates and COPD are very sensitive

5. AARC precautions/possible complications: PaO2 great than 60mmHg, ventilator depression may occur in pt with elevated PaCO2, creating hypoxic drive, FiO2 greater than .50, babies, fire hazard

6. AEMs total output flow can be boosted with: simple increase in input flow

7. Air entrainment mask (venturi mask): high flow, ranges from .24-.40 FiO2

8. Air entrainment nebulizer: pneumatically powered added ability to humidification and temp control. Patient needs by visual inspection-seeing mist from t-tube then meeting pt needs-compare with pt peak inspiratory flow

9. Air entrainment system: direct a high pressure O2 though small nozzle or jet surrounded by ports. Depends on air to O2 ratio and amount of flow resistance downstream for the mixing site

10. atmospheric pressure absolute (ATA): measure of pressure used in HBO

11. avoiding oxygen toxicity: limit pt exposure to 100%O2 to less than 24 hours whenever possible. High FiO2 is okay when concentration can be 5 decreased to 70% within 2 day and 50% or less in 5 days

12. Bag-mask devices: emergency life support, critical care, Provide up too 100% FiO2

13. Benefits of HBO: bubble reduction in air embolism and decompression sickness, hyperoxia, wound healing, immune system, vasoconstriction, crush injuries, burns, cerebral edema, neovascularization, carbon monoxide poisoning

14. bronchopneumonia: acute inflammation of the lungs and bronchioles; chills, fever, high pulse rate, high RR, bronchial breathing, cough, purulent bloody sputum, chest pain

15. bronchopneumonia symptoms may occur: in patients with prolonged high PO2, causing patchy infiltrates on chest x-ray, prominent in lower lung fields

16. bronchopulmonary dysplasia (BPD): hyperinflation of the lungs, chronic respiratory disorder, scarring of lung tissue thickened pulmonary arterial walls, mismatched b/t lung ventilation & perfusion, often seen in infants that have had long term pulmonary ventilation

17. Carbon Dioxide-Oxygen therapy: rarely used, treatment for hiccups, carbon monoxide poisoning, prevent complete CO2 washout

18. Clinical objectives for O2 therapy: correct documented or suspected acute arterial hypoxemia, decrease symptoms associated with chronic hypoxemia, decrease workload hypoxemia imposes on the cardiopulmonary system

19. COPD and chronic hypercapnia pt: tend to ventilate less

20. COPD hyperventilate when given O2 is likely because: of suppression of hypoxic drive

21. croup: infectious disorder of the upper airway occurring chiefly in infants/children that normally results in subglottic swelling & obstruction

22. Documented hypoxemia as evidenced by: PaO2 less than 60mmHg, and SaO2 less than 90% breathing room air

23. Enclosures: oldest O2 therapy approach, Oxygen Tents, Hoods, Incubators

24. Estimating FiO2 with low flow system: 1L/min of nasal O2 increases FiO2 by 4%. 1L/min starts at 24%FiO2

25. Examples of Reservoir system: Reservoir cannula, Reservoir mask, non-rebreathing reservoir circuit



26. exudative: relating to the oozing of fluid and other materials from cells and tissues, usually a result or inflammation or injury

27. Flow of less than 5L/min in a reservoir mask: acts as dead space and causes CO2 rebreathing

28. heliox therapy: used to reduce the work of breathing, in pt with severe acute asthma or upper airway obstruction,until the primary problem can be resolved

29. Heliox therapy use and inducations: COPD, 80%O2 and 20% helium most common, nonrebreathing mask, poor aerosol transport

30. High Flow devices: provide 60 L/min total flow, supply a given O2 concentration, flow meets or exceeds the pt peak inspiratory flow, mix air and O2 to achieve given FiO2

31. high flow nasal cannula: nonheated and humidified O2 up to 15L/min, hard to determine the amount of positive pressure delivered

32. high-flow system: O2 therapy equipment that supplies inspired gases at a consistent preset O2 concentration

33. How does O2 therapy correct hypoxemia?: by increasing alveolar and blood levels of O2

34. hyperbaric oxygen therapy (HBO): therapeutic application of O2 at pressures greater than one atm

35. hypoxemia causes: pulmonary vasoconstriction and pulmonary hypertension

36. hypoxemia causes other manifestations: tachypnea, tachycardia, cynosis, distressed appearance

37. Incubators or Isolette: combine servo-control convection heating with supplemental O2

38. low-flow system: variable performance O2 therapy device that delivers O2 at a flow that provides only a portion of the pt inspired gas needs

39. Low Flow systems: supplemental O2 directly to airway, 1/4 to 6L/min of less, nasal cannula, nasal catheter, transtracheal catheter

40. Magic Box: Air to O2 ratio, used to estimate high flow FiO2, 20 top left, 100 bottom left, desired O2 in center, subtract diagonally number in upper right is amount of air, number in lower right is O2

41. Most common air entrainment devices: air entrainment mask (venturi mask), air entrainment nebulizer

42. The most common mode of respiratory therapy: gas therapy

43. neovascularization: formation of new capillary beds

44. neutral thermal environment (NTE): ambient environment that prevents or minimizes the loss of body heat

45. Nitric oxide: pulmonary vasodilation, used in airway obstruction, colorless, odorless, diffusible, lipid soluble, relaxes capillary smooth muscle, improves blood flow to ventilated alveoli, used in neonates, ARDS, adults, with pulmonary hypertension, dose in ppm

46. nitric oxide (NO): an inhaled gas used as inhaled therapy to reduce pulmonary artery pressure and improve arterial oxygenation

47. O2 blenders: Air and O2 enter this device, pass through dual pressure regulators match pressures, needs to be calibrated often, with neonate analyzer kept inline all the time

48. O2 can reduce: high ventilatory demand and the work of breathing

49. O2 protocol: assessment, evaluated protocol criteria, treatment plan, stop treatment as needed

50. O2 therapy can do what to mental function in patients with chronic hypoxemia?: improve

51. Oxygen hoods: best method for control O2 for infants, allows access for infant care, heated air entrainment nebulizer or blending system with humidifier

52.Oxygen Tents: cooled, opening often makes it hard to keep the O2 concentration at needed level, used mostly for pediatric aerosols croup or CF

53. Patients with chronic hypoxemia, this increased workload over long-term can lead to: right ventricular failure which is called cor pulmonale

54. Reservoir mask: most common reservoir system, types include simple mask and partial re-breathing, nonrebreathing mask

55. reservoir system: O2 delivery system that provides a reservoir O2 volume that the pt taps, into when the pt inspiratoy flow exceeds the device flow

56. retinopathy of prematurity (ROP): abnormal ocular condition that occurs in some premature or low birth-weight infants who receive O2

57. selecting delivery: purpose-increase FiO2 correct arterial hypoxemia, patient-severity, age, alertness, airway, minute ventilation, mouth vs nose breathing, performance-the stability of FiO2

58. SpO2 threshold is what value that indicates the need for therapy: 92%

59. Two Types of Reservoir cannula: nasal reservoir and pendant reservoir

60. Vicious cycle: O2 toxicity-increased shunting-Low PaO2-increased FiO2

61. Bag-Mask Device (Ambu-Bag): Provide 100% (in theory) O2 often during emergencies

62. How is a transtracheal catheter placed?: Surgically placed in trachea through neck by physician

63. Hyperbaric O2 (HBO) Therapy is administered via?: Multiplace or monoplace chamber

64. What are 2 acute conditions for which HBO would be administered by the RT?: 1. Air embolism, 2. Carbon Monoxide Poisoning (>1-2%)

65. What are bedside findings that would lead to necessity of O2 therapy?: Tachypnea, tachycardia & confusion

66. What are determining factors for O2 toxicity?: PO2 & exposure time

67. What are drawbacks of HBO therapy?: Ear or sinus trauma (ie busted eardrum), Worsened Pneumothorax (Don’t use if diagnosed), Oxygen Toxicity, Fire (not spontaneous combustion)

68. What are drawbacks to Nitric Oxide Therapy?: Poor paradoxical response, rebound hypoxemia, pulmonary hypertension.

69. What are examples of high flow O2 delivery systems? (Provides 100% of patient’s O2 needs): High flow nasal canula, Cascade high flow, Passover high flow, Venturie Mask, regular high flow with Aerosol mask

70. What are examples of low flow O2 delivery systems? (part of patient’s O2 needs): Nasal canula, regular mask, partial rebreather mask, oxymizer, non rebreather mask

71. What are three designs for O2 delivery systems?: 1. low-flow systems, 2. Reservoir systems, 3. High-flow systems

72. What are three goals of O2 Therapy: 1. Correct documented or suspected acute Hypoxemia, 2. Decrease symptoms associated with chronic hypoxemia, 3. Decrease workload hypoxemia imposes on cardiopulmonary system

73. What are three types of O2 delivery masks: 1. Simple Mask, 2. Partial Rebreathing mask, 3. Non Rebreathing mask

74. What causes infiltrates in lung parenchyma?: Prolonged exposure to high FiO2

75. What do Demand & Pulse-dose systems do?: Conserve O2 by providing flow during inspiration only

76. What does High-Flow nasal cannulas provide?: High FiO2, High relative humidity and positive pressure

77. What does O2 toxicity primarily affect?: The lungs & CNS

78. What happens in retinopathy of prematurity?: Excessive blood O2 levels cause retinal vasoconstriction & necrosis

79. What is a downfall to an O2 Tent?: Regulating cooling and FiO2 can be difficult

80. What is an example of a clinical problem needing O2 therapy?: suspected Carbon Monoxide poisoning



81. What is an O2 hood (Oxyhood): Generally the best method for delivering controlled O2 to infants

82. What is Laboratory documentation for assessing the need for O2 Therapy?: PaO2, SaO2 & SpO2

83. What is the difference between multiplace and monoplace chambers: Multiplace chambers can, hold 12 or more people, Monoplace can only hold 1 person

84. What is the difference in O2 use between transtracheal catheter and nasal cannula?: TT Catheter uses 40-60% less O2 to achieve the same PaO2 as nasal canula

85. What is the FiO2 level delivered by a nasal catheter?: 0.22-0.45 (replaced by nasal cannula)

86. What is the FiO2 relationship between Nose and Mouth breathers: Nose Breathers= Increased FiO2; Mouth Breathers= Decreased FiO2

87. What is the main benefit Nitric Oxide Therapy?: Improves oxygenation without shunting

88. What is the relationship between O2 and FiO2?: Higher O2= Increased FiO2; Lower O2= Decreased FiO2

89. What should the FiO2 level be at when using the nasal canula (low flow): 0.24-0.40 dependent on how much room air patient inhales in addition to O2

90. What’s the difference between a Venturie mask and a Venti mask?: Not a damn thing Yo!

91. What was the reservoir cannula designed for?: To conserve oxygen and make you look like Iron Man

92. Where are O2 related fire hazards at high risk?: O2 enriched environments & surgical suites in presence of hyperbaric O2 therapy.

93. Which patients would benefit from Nitric Oxide Therapy?: 1. Patients with pulmonary hypertension; 2. ARDS & COPD patients

94. Who does depression of ventilation occur in?: COPD patients with chronic hypercapnia

95. Who is at risk of Absorption atelectasis?: Patients breathing small tidal volumes with FiO2 above 0.50 are at great risk

96. The overall goal of oxygen therapy: to maintain adequate tissue oxygenation while minimizing cardiopulmonary work

97. The three specific clinical objectives for oxygen therapy: 1) correct documented or suspected acute hypoxemia, 2) decrease the symptoms associated with chronic hypoxemia, 3) decrease the workload hypoxemia imposes on the cardiopulmonary system

98. Define cor pulmonale: enlargement of the right ventricle of the heart due to disease of the lungs or of the pulmonary blood vessels

99. The 4 major harmful effects of oxygen therapy: O2 toxicity, depression of ventilation, retinopathy of prematurity, absorption atelectasis

100. Basic characteristics of low-flow systems: supply O2 @ 8 L/ or less, don’t meet the patient’s inspiratory flow needs so pt draws room air resulting in low & variable FiO2 (amount depends on the patient’s inspiratory flow rate, tidal volume, and the O2 flow delivered)

101. At what point is humidification needed for nasal cannula?: over 4 L/min

102. What is the most common liter flow and resultant FiO2s for nasal cannula?: 1-5 L/min, there is a 4% increase in FiO2 for every 1 L/min so the pt’s FiO2 from room air is .21 and if @ 2 L/min, will be .21 + .08 = .29

103. Basic characteristics of a transtracheal catheter: deliver O2 directly into the trachea through a small bore catheter that is surgically inserted into the trachea; uses 40-60% less O2 flow than cannula so no humidification necessary; O2 builds up in trachea during expiration & is taken in during inhalation

104. What is the cause and procedure for when there is no gas flow felt coming from the cannula: cause = flow meter not on or system leak; procedure = adjust flow meter, check connections

105. What is the cause and procedure for when the humidifier pop-off is sounding: there is an obstruction distal to humidifier – find and correct obstruction; flow is set too high – use alternative device; obstructed naris – use alternative device

106. What is the cause and procedure for when patient reports soreness over lip or ears: irritation or inflammation caused by appliance straps – loosen straps or place cotton balls at pressure pints or use an alternative device

107. What is the cause and procedure for when the patient is mouth breathing: habitual mouth breathing or blocked nasal passages – switch to a simple or venturi mask

108. Define reservoir systems: Provides a mechanism to gather and store oxygen between patient breaths. Classified as a variable performance device, however can be a fixed performance device as long as the stored volume equals or exceeds the patient’s tidal volume and there are not any air leaks. Consist of the reservoir cannula and reservoir masks.

109. Characteristics of a simple mask: cover mouth and nose with the body of the mask gathering & storing O2 between pt breaths; exhaled air escapes through holes in its body. If O2 input is interrupted, air is drawn through these holes and around the mask edge. Flows of 5-12 L/min, minimum of 5 L/min to prevent rebreathing of CO2, FiO2 35-50%, chosen when moderate FiO2 are needed for a short time.

110. Characteristics of partial rebreather mask: Has a 1 liter reservoir bag which increases the reservoir volume therefore increases the FiO2 over a simple mask. The bag is open to the flow of exhalation gases and does allow the first portion of the exhaled gases to enter the reservoir, thus the rebreathing of air. At flows between 6 – 10 L/min FiO2’s are between 35 – 60 %

111. Characteristics of a nonrebreather mask: Like the partial rebreathing mask it has a 1 liter reservoir bag, however it also has a series of one-way valves. A one way valve between the bag and mask prevents exhaled gas from returning into the bag. One way valves placed on the exhalation ports will prevent entrainment of room air. In concept a leak-free mask with competent valves and adequate flow should deliver 100% source gas. A truly fixed performance situation is difficult to achieve, however the nonrebreather mask will provide the highest FiO2 of the reservoir mask, with FiO2 around 70+%.

112. Approximate FiO2 achieved with simple mask: 35-50% @ 5-12 L/min

113. Approximate FiO2 achieved with partial rebreathing mask: 35-60% @ 6-10 L/min

114. Approximate FiO2 achieved with nonrebreathing mask: 70+%

115. If the patient is constantly removing the mask: the causes can be claustrophobia (use alternative device) or confusion (use restraints)

116. If no gas flow can be detected with the reservoir mask: either the flowmeter is not on (so turn it on) or there is a system leak (check connections)

117. If the humidifier pop-off is sounding: either there is an obstruction distal to the humidifier ( find and correct the obstruction), the input flow is too high ( omit humidifier if treatment is short term), or there is a jammed inspiratory valve ( fix or replace valve)

118. If the reservoir bag collapses when the patient inhales: the flow is inadequate so increase the flow

119. If the reservoir bag remains inflated throughout inhalation: there is either a large mask leak (correct leak) or the inspiratory valve is jammed or reversed (repair or replace the mask)

120. If erythema develops over face or ears: irritation or inflammation due to appliance or straps (provide skin carem use an alternative device, or place cotton balls on affected areas to act as a buffer between the skin and equipment)

121. Describe high flow systems: Also known as fixed performance devices. High flow systems supply a given oxygen concentration at a flow that equals or exceeds the patients inspiratory flow, thus ensuring a stable FiO2. In order to meet variations in patient’s inspiratory demands, a high flow device should provide at least 60 L/min total flow.

122. There are two major categories of high flow devices: Air Entrainment Systems, Blending Systems

123. What is the minimum flowrate that high flow systems should be capable of delivering?: 60 L/min

124. How do air entrainment systems operate: Directs a high-pressure oxygen source through a small nozzle or jet surrounded by air entrainment ports

125. As the oxygen flows through the restricted orifice the velocity increases. The increased velocity pulls in or entrains room air through the air entrainment port

126. What 2 factors affect the amount of air entrained?: jet size or orifice and the air entrainment port size

127. What effect does the jet size have on the way the air entrainment system operates?: the smaller the jet the higher the velocity, the high the velocity the more air entrained so the lower the FiO2 and the greater the total output flow

128. What effect does the air entrainment port size have on the system?: the larger the air entrainment port the more air entrained so the lower the FiO2 and the greater the total output flow

129. What formula is used to calculate the air to oxygen ratio?: Liters of air divided by the liters of O2 = (100-%O2) / (%O2-21). %O2 = [(Air flow x 21) + (O2 flow x 100)] / total flow

130. What is the air to oxygen ratio for 40% oxygen?: 3:1

131. What is the air to oxygen ratio of 60% oxygen?: 1:1

132. What is the effect of down stream flow resistance on air entrainment devices?: Any resistance to flow distal to the jet will result in less air entrained, therefore the delivered oxygen concentration will be increased. However total flow will also be decreased, therefore if the total flow does not meet the patients needs the patient will inhale room air and the delivered oxygen concentration may actually be lower than what is being delivered.

133. How can extra humidification be added to the venturi mask?: The best way to add humidification to a venturi mask is to use an air entrainment nebulizer connected to the mask with the nebulizer connected to an air flowmeter

134. Air entrainment mask vs air entrainment nebulizer: AEMs: indicated for patients with high or changing ventilatory demands needing a stable low – moderate FiO2. The most common problems with AEM’s are: Providing sufficient total output flow to ensure a stable FiO2 and providing extra humidification. AENs: Pneumatically powered nebulizer. Provides additional humidification and heat control. The oxygen jet serves two purposes, entrainment of air and also to entrain water into the jet stream producing an aerosol. Heat can also be added.

135. Device of choice for delivery of oxygen to patients with artificial tracheal airways by either a T-piece (Briggs Adaptor) or trachcollar. Due to increase resistance to flow the maximum oxygen input flow is between 12-15 L/min.

136. What are the two ways to assess adequacy of flow by an air entrainment nebulizer?: A visual inspection to see if mist escapes from the T tube (in which case the pt’s inspiratory flow needs are being met) and also to compare it to the pt’s peak inspiratory flow (during tidal breathing is ~3x minute volume) and as long as it exceeds this amount, the inspiratory flow needs are being met.

137. What are the 5 ways to achieve higher output flow for AENs: 1) add open reservoir to expiratory side of T tube. 2) provide inspiratory reservoir with one-way expiratory valve. 3) connect 2+ nebulizers together in parallel. 4) set nebulizer to low concentration; bleed-in oxygen; analyze, and adjust. 5) use a commercial dual-flow system

138. When is it approriate to use a blender system?: when air-entrainment devices cannot provide a high enough O2 concentraion or flow and if the power goes out and the treatment cannot be administered without the power being on

139. What are the 3 types of oxygen enclosure devices?: hood, tent, incubator

140. What are the key features of an oxygen hood?: best method for controlled oxygen therapy to infants, covers only the head so the rest of the body is free to be cared for, Oxygen is delivered to the hood via either a heated air entrainment nebulizer of a blending system with a heated humidifier, and a minimum flow of 7 L/min should be set in order to prevent accumulation of carbon dioxide.

141. What are the key features of an oxygen tent?: Air conditioned or cooled by ice to provide a comfortable temperature within a plastic sheet canopy, Major problem is that frequent opening and closing of the canopy causes wide swings in oxygen concentration, and because of variability of FiO2 and inability to produce high FiO2’s tents are used primarily to provide pediatric aerosol therapy to children with croup or cystic fibrosis

142. What are the key features of an incubator?: high infection risk, completely enclose the pt, wide swings in O2 concentration due to the opening and closing of the unit to care for the pt.

143. Nitric oxide therapeutic benefit: potent pulmonary vasodilator, by causing smooth muscle relaxation in the pulmonary capillary system. This improves blood flow to ventilated alveoli which helps reduce pulmonary vascular resistance

144. Helium’s value as a therapeutic gas and the purpose?: based on the low density and is used to decrease the WoB in pts with large airway obstruction by decreasing the turbulence of flow in the airways which int urn requires a reduction in the driving pressure needed to move air flow past the obstruction

145. What concentration should He/O2 be?: 80/20 or 70/30

146. How should heliox be delivered?: non-rebreather or simple mask

147. Since an O2 flowmeter will be inaccurate when regulationg He flow, what conversion factor must be used to determine flowrate?: 80/20 = 1.8; 70/30 = 1.6

148. What are the common problems with Helium therapy?: ineffective for aerosol delivery, coughing less effectived b/c of reduced turbulent air flow, distorted speaking, and hypoxemia because of adding high levels of O2 decreased the effectiveness of the He.