Egans Ch 40/41 Storage and Delivery of Medical Gas

Which of the following are considered therapeutic gases?

1. Oxygen (O2)

2. O2-NO mixture

3. O2-He mixture

D) 1, 2, and 3 only

Which of the following statements regarding O2 are true?

1. It is only slightly soluble in water.

2. It is odorless and transparent.

3. It is flammable.

4. It is heavier than air.

B) 1, 2, and 4 only

What is the most common and least expensive method for commercial production of O2?

Fractional distillation of air

Which of the following statements about He is false?

A) It is an inert gas.

B) It is odorless.

C) It is nonflammable.

D) It is heavier than air.

D) It is heavier than air.

Compressed gas cylinders are manufactured from which of the following?

Seamless steel

According to the U.S. Department of Commerce, a gas cylinder that is color coded blue should contain which of the following?

N2O

What is the key difference between small compressed gas cylinders (sizes AA to E) and their larger counterparts (sizes F to K)?

Small gas cylinders use a yoke (not threaded) connector.

Cylinders of liquid gases are filled according to what specification?

Filling density

When using a Bourdon gauge against high outflow resistance, what will the flowmeter reading show?

Exceed actual flow

Which of the following components are common to a standard compressed gas cylinder manifold system?

1. Automatic switch-over control

2. Pressure-reducing valves

3. Primary and reserve bank

4. Alarm system

D) 1, 2, 3, and 4

The NFPA standard for bulk liquid O2 systems requires that the reserve supply be which of the following?

C) Equal to the average gas use of 1 day

Why are zone valves incorporated into a hospital's central gas piping systems?

1. To terminate O2 delivery to an area in case of fire

2. To allow selective maintenance without shutting the system down

3. To allow variable pressure reduction throughout the system

A) 1 and 2 only

You must connect a large-volume nebulizer to a bedside compressed-air outlet through a flowmeter. You have only standard O2 flowmeters available. Which of the following actions is appropriate?

B) Use an O2-to-air DISS adapter to join the flowmeter and outlet.

Helium must always be combined with at least how much O2?

20%

How can one determine whether a pressure-reducing valve uses multiple stages for pressure reduction?

By noting the number of pressure relief vents

When used to control the flow of medical gases to a patient, how is a flow restrictor classified?

Fixed-orifice, constant-pressure flowmeter device

You are preparing to conduct a complex transport of a patient receiving O2, and you expect to have to alter O2 flows during the transport. Which of the following devices would best meet your needs?

Bourdon gauge

You are called by a nursing home to help set up O2 for a patient, delivered through a jet nebulizer. Unfortunately, all that is available is an old uncompensated Thorpe tube flowmeter. When set to 8 L/min, the nebulizer creates an additional 30 psig of downstream pressure. Approximately what flow of O2 will the patient now receive?

12 L/min

Structural requirements for the central piping systems that are used in hospitals to distribute gases are established by whom?

National Fire Protection Association (NFPA)

Which of the following are true about a Bourdon gauge?

1. It is always used with an adjustable high-pressure reducing valve.

2. It actually senses pressure but is calibrated to display flow.

3. It reads a flow higher than actual if downstream pressure increases.

4. It will register zero flow when the outlet is completely blocked

B) 1, 2, and 3 only

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

Premature or low-birth-weight infants

What is the recommended maximum initial dose of inhaled NO in neonates with respiratory distress syndrome?

20 ppm

What is the only major factor limiting the use of pressure-compensated Thorpe tube flowmeters?

Effect of position (gravity)

Which of the following gases is used to treat conditions causing hypoxic respiratory failure?

Nitrous Oxide

What is the usual method of monitoring the remaining contents in a gas-filled cylinder?

Read the pressure gauge.

A physician orders a 70% He:30% O2 mixture to reduce the work of breathing in a patient having an acute asthmatic attack. Which of the following delivery systems would be appropriate in this case?

D) Nonrebreathing mask at 10 L/min

Which of the following mechanisms do all compressed gas cylinders use to avoid excessively high buildup of cylinder pressure?

Pressure-relief mechanism on the valve stem

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?

Increase the device's input flow to 10 L/min.

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?

Emergency inlet valve

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?

40%

Where do respiratory therapists typically find DISS connections?

1. At the outlets of pressure-reducing valves attached to cylinders

2. At the nurse station

3. At the station outlets of central piping systems

4. At the inlets of blenders, flowmeters, ventilators, and other pneumatic equipment’s

C) 1, 3, and 4 only

Criteria for initiating HBO therapy on an adult patient suspected of suffering from acute carbon monoxide poisoning include which of the following?

1. History of unconsciousness

2. Carboxyhemoglobin saturation less than 20%

3. Presence of neurologic abnormality

4. Presence of cardiac instability

B) 1, 3, and 4 only

Which of the following statements about CO2 are true?

1. It does not support animal life.

2. It is a flammable gas.

3. It is odorless and colorless.

4. It is heavier than air.

D) 1, 3, and 4 only

What is/are the primary organ system(s) affected by O2 toxicity?

1. Central nervous system (CNS)

2. Lungs

3. Kidneys

B) 1 and 3 only

What cylinder factor is used to compute the duration of flow O2 or air E cylinder?

0.28

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

What is the U.S. Food and Drug Administration (FDA) purity standard for O2?

99%

Unlike CO2 or N2O, O2 cannot be stored as a liquid at room temperature but must be kept in special cryogenic containers. Why is this so?

O2 has a critical temperature well below room temperature.

What is the primary purpose of indexed connector systems?

To prevent inadvertent misconnections between equipment

Which of the following are advantages of using a flow restrictor to control the delivery of medical gases to a patient?

1. Preset metered flow

2. Low cost and simplicity

3. Gravity independence

4. Wide range of utility

A) 1, 2, and 3 only

The measured pressure in a liquid-filled cylinder is equivalent to which of the following?

The pressure of the surface vapor at any given temperature

Mixtures of carbon dioxide and oxygen in blends of 5%:95% or 7%:93%, which are occasionally used to prevent complete washout of carbon dioxide during cardiopulmonary bypass or treat hiccoughs is known as which of the following?

Carbogen

Which of the following is true about an uncompensated Thorpe tube?

Flow lower than actual if downstream pressure increases

Which device is used to reduce the pressure and control the flow of a compressed medical gas?

Regulator

Which of the following are components of a typical O2 blender?

1. Precision metering device or mixture control

2. Audible dual low-pressure alarm system

3. Pressure regulating and equalizing valves

4. Variable-size air-entrainment port

B) 1, 2, and 3 only

Under what conditions will the gauge pressure of a cylinder of N2O accurately represent its contents?

When the ambient temperature exceeds the critical temperature

Air for medical use in a hospital should be which of the following?

1. Particle-free

2. Oil-free

3. Dry

D) 1, 2, and 3

What is the most common complication of hyperbaric oxygen therapy?

Ear or sinus barotrauma

What factors affect the combustion-supporting properties of O2?

1. Concentration

2. Partial pressure

3. Humidity

C) 1 and 2 only

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

Patchy infiltrates

The measured pressure in a gas-filled cylinder is equivalent to which of the following?

The force required to compress its volume within the cylinder.

When used to control the flow of medical gases to a patient, how is a Bourdon gauge classified?

Fixed-orifice, variable-pressure flowmeter device

Which of the following is false about a compensated Thorpe tube?

B) Calibrated in liters per minute at atmospheric pressure

Which of the following is an indication for the use of helium-O2 mixtures?

Large-airway obstruction

To prevent this type of accident, all cylinders have high-23. In clinical practice, how is a positive identification made of the contents of a medical gas cylinder?

C) Reading the cylinder label

A very common application of the adjustable pressure-reducing valve is in combination with which of the following?

Bourdon gauge

Large hospital air compressor systems must be capable of maintaining 50 pounds per square inch gauge (psig) at what flows?

100 L/min

To confirm proper operation of an O2 blending system, what should you do?

1. Test low-pressure alarms and bypass systems.

2. Analyze FiO2 at 0.21, 1.00, and prescribed level.

3. Confirm air and O2 inlet pressures.

D) 1, 2, and 3

What does 1 atmospheric pressure absolute (ATA) equal?

1. 101 kPa

2. 50 psi

3. 760 mm Hg

C) 1 and 3 only

By what means is O2 for medical use in a hospital most commonly produced?

Fractional distillation

During inspection of the shoulder of a compressed gas cylinder, you note an asterisk (*) next to the test date. This indicates what about the cylinder?

It only requires a 10-year DOT testing.

A physician places a patient in respiratory failure on 100% O2. To avoid the hazards of O2 toxicity, you would recommend that every effort is made to reduce this FiO2 to less than 50% within what timeframe?

D) 5 days

The pressure of O2 or air in a bulk supply system is reduced to what standard working pressure?

50 psig

If you have to deliver O2 to a patient directly from a bedside outlet station, which of the following devices would you select?

Thorpe tube flowmeter

Some strategies for minimizing the risk of fire hazard with O2 therapy include which of the following?

1. Using the lowest effective FiO2

2. Properly educating patients and caregivers

3. Avoiding aluminum regulators and other high-risk devices

4. Mixing the oxygen with carbon dioxide.

B) 1, 2, and 3 only

Potential adverse effects associated with NO therapy include which of the following?

1. Poor or paradoxical response

2. Increased blood clotting

3. Increased left ventricular filling pressures

4. Rebound hypoxemia or pulmonary hypertension

B) 1, 3, and 4 only

To clean a cylinder valve outlet of foreign material, what should you do?

Quickly open and then close the valve.

During inspection of the shoulder of a compressed gas cylinder, you note a plus sign (+) next to the test date. This indicates what about the cylinder?

It can be filled to 10% above its service pressure.

To accurately determine the remaining contents of a liquid-filled CO2 cylinder, what would you do?

Weigh the contents of the cylinder.

Which of the following medical gases can be stored in cylinders as liquids at room temperature?

1. CO2

2. O2

3. N2O

C) 1 and 3 only

In which of the following procedures is air embolism a potential complication?

1. Central line placement

2. Lung biopsy

3. Hemodialysis

D) 1, 2, and 3

Which of the following are true about absorption atelectasis?

1. It can occur only when breathing supplemental O2.

2. Its risk is increased in patients breathing at low tidal volumes (VT values).

3. Its risk is decreased through the natural "sigh" mechanism.

4. It results in an increase in the physiologic shunt fraction.

D) 2, 3, and 4 only

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

Some of the major disadvantages of the transtracheal catheter are which of the following?

1. Infection

2. Mucus plugging

3. Excessive oxygen use

4. Lost tract or insertion opening

B) 1, 2, and 4 only

What is the maximum FiO2 expected to be delivered by most air-entrainment masks?

C) 50%

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

B) It can easily deliver high FiO2 values (>0.6 to 0.7).

When determining a need for O2 therapy, the respiratory therapist should assess which of the following?

1. Neurologic status

2. Pulmonary status

3. Cardiac status

D) 1, 2, and 3

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?

1. Decrease in the device's total output flow

2. Increase in the percent O2 delivered by the device

3. Change in the FiO2 received by the patient

A) 1 and 2 only

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 hr

At what level of carboxyhemoglobin saturation is hyperbaric oxygen (HBO) therapy indicated for an adult patient?

Greater than 25%

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?

Look for crimped or twisted delivery tubing.

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

Substernal chest pain

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

Production of harmful noise levels

You are giving a 80% He:20% O2 mixture to an asthmatic patient through a nonrebreathing mask with a compensated Thorpe tube O2 flowmeter set at 8 L/min. What is the actual flow being delivered to the patient?

C) 14 L/min

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?

O2 blending system

Which of the following methods of producing O2 is commonly used in the home care setting?

Physical separation

Which of the following medical gases support combustion?

1. O2

2. N2O

3. Compressed air

4. CO2

C) 1, 2, and 3 only

What do the components of a liquid O2 bulk storage tank include?

1. Inner and outer steel shells, separated by a vacuum

2. Safety system that vents O2 if warming occurs

3. Vaporizer system that converts liquid O2 to gas

4. Pressure-reducing valves to lower pressure to 50 psig

C) 1, 2, 3, and 4

What is the indexed safety system for threaded high-pressure connections between large, compressed gas cylinders and their attachments?

American Standard Safety System (ASSS)

Which of the following are true about NO2?

1. NO2 levels greater than 10 ppm can cause hemorrhage, pulmonary edema, and death.

2. NO2 is produced spontaneously whenever NO is exposed to O2.

3. The Occupational Safety and Health Administration (OSHA) safety limit for NO2 exposure is 5 ppm.

4. NO2 exposure should be kept below 5 ppm during NO administration.

B) 1, 2, and 3 only

Department of Transportation (DOT) regulations require compressed gas cylinders to be hydrostatically tested for leaks and expansion every how often?

5 to 10 years

When minimal fluctuations in pressure and flow are critical factors, which of the following pressure-reducing valves would be the best choice?

Multiple-stage pressure-reducing valve

When used to control the flow of medical gases to a patient, how is a Thorpe tube classified?

Variable-orifice, constant-pressure flowmeter device

Components of a large medical air compressor include which of the following?

1. Drying system

2. Diaphragm or turbine

3. Reservoir tank

4. Pressure-reducing valve

D) 1, 3, and 4 only

What key property of He makes it useful as a therapeutic gas?

Low density

A cylinder of N2O has a gauge pressure of 750 psig when full. What will be the pressure in this cylinder when it is half full?

B) 750 psig

What is the greatest potential problem with quick-connect DISS systems?

Incompatibility among different manufacturers

If you have to deliver medical gas to a patient from a compressed gas cylinder, which of the following devices would you select to control gas flow?

Flowmeter

What safety system is designed to prevent accidental interchanging among low-pressure (<200 psig) connectors such as those found on flowmeters and ventilators?

DISS

One cu/ft of liquid O2 is the equivalent to approximately how many cu/ft of gaseous O2?

860