Mosbys Respiratory Care Equipment 9th Edition By J.M. Cairo – Test Bank

Mosbys Respiratory Care Equipment 9th Edition By J.M. Cairo – Test Bank

Chapter 08: Assessment of Pulmonary Function

MULTIPLE CHOICE

1. The accuracy of an instrument depends on which of the following?
2. The standard deviation of repeated measurements
3. The instrument’s linearity and frequency response
4. The instrument’s ability to reproduce a measurement
5. The instrument’s sensitivity to environmental conditions

a.

1 and 2

c.

2 and 3

b.

1 and 3

d.

2 and 4

ANS: D

Accuracy can be explained as how closely a measured value is related to the correct value of the quantity measured. The accuracy of any instrument depends on its linearity and frequency response, its sensitivity to environmental conditions, and how well it is calibrated.

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2. The precision of an instrument depends on:

a.

linearity.

c.

repeatability.

b.

calibration.

d.

frequency of response.

ANS: C

An instrument’s precision can be quantified by calculating the standard deviation of repeated measurements. Precision is the expression of an instrument’s ability to reproduce a measurement.

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3. Which of the following is a volume-collecting device?

a.

Turbine flowmeter

c.

Dry rolling seal spirometer

b.

Thermal anemometer

d.

Pressure pneumotachograph

ANS: C

A typical example of a volume-collecting device is a dry rolling seal spirometer. The other devices are flow-sensing devices.

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4. Airflow is measured by which of the following?

a.

“Hot-wire” anemometer

c.

Water-sealed spirometer

b.

Bellows spirometer

d.

Dry rolling seal spirometer

ANS: A

A typical example of a flow-sensing device is a hot-wire, or thermal, anemometer. The other devices are volume-collecting devices.

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5. The rotating motor-driven drum used to document the bell movement of a water-sealed spirometer is known as which of the following?

a.

Spirograph

c.

Anemometer

b.

Kymograph

d.

Pneumotachograph

ANS: B

This is the definition of a kymograph.

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6. “An aluminum bell suspended by a chain-and-pulley mechanism with a weight that counterbalances the weight of the bell” describes which of the following?

a.

Dry rolling spirometer

c.

Bellows spirometer

b.

Water-sealed spirometer

d.

Pneumotachograph

ANS: B

This is the description of a water-sealed spirometer.

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7. The visual picture of volume and flow measurements is known as which of the following?

a.

Spirogram

c.

Kymograph

b.

Spirometer

d.

Turbine flowmeter

ANS: A

As a patient exhales into a water-sealed spirometer, the bell moves upward and the attached pen moves proportionately downward on graph paper, creating a spirogram.

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8. When a patient inhales while connected to a water-sealed spirometer, the bell moves _____ and the pen moves _____.

a.

Up; up

c.

Down; up

b.

Up; down

d.

Down; down

ANS: C

Inhalation causes the bell to move downward and the pen to move upward.

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9. What speed should be used for the rotating drum of a water-sealed spirometer to measure volume changes during a forced vital capacity maneuver?

a.

16 mm/min

c.

160 mm/min

b.

32 mm/min

d.

1920 mm/min

ANS: D

The fastest speed (1920 mm/min) is used for recording volume changes during forced vital capacity maneuvers.

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10. Speed settings of 32 and 160 mm/min on a water-sealed spirometer can be used to measure which of the following?
11. Minute ventilation
12. Peak expiratory flows
13. Maximum voluntary ventilation
14. Forced vital capacity maneuvers

a.

1 and 2

c.

2 and 4

b.

1 and 3

d.

3 and 4

ANS: B

The slower speeds (32 and 160 mm/min) are used for measuring tidal volume, minute ventilation, and maximum voluntary ventilation.

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11. The bell factor for a 9-L water-sealed spirometer bell is _____ mL/mm.

a.

13.5

c.

20.93

b.

29.3

d.

41.73

ANS: C

The bell factor is the number of milliliters of gas that must be displaced to cause the kymographic pen to move 1 mm. The bell factor for a 9-L bell is 20.93 mL/mm.

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12. What is the tidal volume measurement when the pen of a 9-L water-sealed spirometer moves 25 mm?

a.

0.338 L

c.

0.843 L

b.

0.523 L

d.

1.043 L

ANS: B

The bell factor for a 9-L water-sealed spirometer is 20.93 mL/mm. Therefore, 20.93 mL/1 mm = X mL/25 mm; X = 523 mL, or 0.523 L.

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13. What is the volume displacement when the pen of a 13.5-L water-sealed spirometer moves 28 mm?

a.

0.378 L

c.

0.586 L

b.

0.563 L

d.

1.168 L

ANS: D

The bell factor for a 13.5-L water-sealed spirometer is 41.73 mL/mm. Therefore, 41.73 mL/1 mm = X mL/28 mm; X = 1168 mL, or 1.168 L.

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14. Which of the following is true concerning the Stead-Wells spirometer?

a.

Counterweights are necessary.

b.

The pen and bell move in opposite directions.

c.

The pen recorder is attached directly to the bell.

d.

On exhalation, the bell and pen move downward.

ANS: C

The pen recorder for the Stead-Wells spirometer is attached directly to the bell, so as the bell moves upward during exhalation, the pen also moves upward.

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15. ________ is used to measure lung-volume changes by collecting exhaled gas into an expandable wedge-shaped device.

a.

A bellows spirometer

c.

A vortex pneumotachometer

b.

A water-sealed spirometer

d.

A screen pneumotachometer

ANS: A

The expandable wedge-shaped device is a bellows, making this a bellows spirometer.

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16. Which statement is true concerning thermal flowmeters?

a.

Gas flow can be measured bidirectionally.

b.

Gas velocity affects the amount of cooling.

c.

Cooling increases the resistance of a heated wire.

d.

Cooling decreases the resistance of a thermistor bead.

ANS: B

Gas flow is calculated by the amount of power needed to maintain the temperature of the heating element. A high gas velocity will cool the heating element, requiring more power to maintain the temperature of the thermistor.

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17. Which of the following devices is bidirectional?

a.

Turbine flowmeter

c.

Vortex ultrasonic flowmeter

b.

Screen pneumotachograph

d.

Variable-orifice pneumotachograph

ANS: D

The variable-orifice pneumotachograph is a disposable, bidirectional, flow-measuring device that uses a flexible obstruction with a variable area for measuring flow as a function of the pressure differential generated by the obstruction. Turbine flowmeters, thermal anemometers, and vortex ultrasonic flowmeters are all unidirectional.

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18. Peak flowmeters are calibrated in which of the following units?

a.

liters/second

c.

milliliters/second

b.

liters/minute

d.

millimeters/minute

ANS: B

Peak flowmeters operate by measuring the gas flow against a rotating vane. Peak flowmeters are usually calibrated in liters per minute.

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19. The principle that gas flow is proportional to the pressure drop across a known resistance is used by which of the following devices?

a.

Turbine flowmeter

c.

Fleisch pneumotachograph

b.

Thermal flowmeter

d.

Ultrasonic pneumotachograph

ANS: C

All pneumotachographs, except the ultrasonic pneumotachograph, operate on the principle that gas flow through them is proportional to the pressure drop that occurs as the gas flows across a known resistance.

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20. Which type of flow-measuring device uses struts to create a partial obstruction to gas flow, causing whirlpools to be produced when gas flows through it?

a.

Monel pneumotachograph

c.

Vortex ultrasonic flowmeter

b.

Ceramic pneumotachograph

d.

Variable-orifice pneumotachograph

ANS: C

The vortex ultrasonic flowmeter uses struts to create a partial obstruction to gas flow. As gases flow past these struts, whirlpools (or vortices) are produced. The frequency at which these whirlpools are produced is related to gas flow through the struts.

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21. Which type of pneumotachograph uses the Doppler effect to measure airflow velocity?

a.

Fleisch

c.

Nonvortex

b.

Screen type

d.

Variable-orifice

ANS: C

The nonvortex ultrasonic pneumotachograph estimates airflow by projecting pulsed sound waves along the longitudinal axis of the flowmeter. The theory is that the speed of the ultrasonic wave transmission is influenced by the rate of gas flow through the device, which is the Doppler effect.

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22. A screen pneumotachograph is:

a.

built with metal struts.

c.

bidirectional and very accurate.

b.

expensive and non-disposable.

d.

heated to prevent condensation.

ANS: D

The screen pneumotachograph is similar to Fleisch-type devices in that a heating element is incorporated to prevent water condensation on the metal screens.

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23. The standard for repeatability for forced expiratory volume in 1 second (FEV₁) is ___ mL.

a.

100

c.

200

b.

150

d.

250

ANS: B

The repeatability standard for FEV₁ is 150 mL.

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24. The best method for accurately measuring the thoracic gas volume of a patient with emphysema is:

a.

helium dilution.

c.

pressure plethysmography.

b.

nitrogen washout.

d.

chemiluminescence monitoring.

ANS: C

Inert gas techniques, such as helium dilution and nitrogen washout, can measure gas volumes only in communicating airways. Body plethysmography measures all of the volume in the thorax. Therefore, inert gas measurements of functional residual capacity (FRC) for a patient with chronic obstructive pulmonary disease and severe air trapping will be lower than functional residual capacity measurements obtained during body plethysmography.

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25. Which of the following represents the relationship used by body plethysmography to calculate functional residual capacity?

a.

V_FRC = DV ÷ DP ´ (P_B – P_H2O)

c.

V_FRC = DV ÷ DT ´ (P_B – P_H2O)

b.

V_FRC = DP ÷ DV ´ (P_B – P_H2O)

d.

V_FRC = (P_B – P_H2O) ´ DV

ANS: A

V_FRC = DV ÷ DP ´ (P_B – P_H2O), where DV and DP are the box volume and alveolar pressure changes measured during the panting maneuver, P_B is the ambient barometric pressure, and P_H2O is the water vapor pressure (assume 47 mm Hg for 37° C).

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26. The end point of a helium dilution test occurs when:

a.

nitrogen is washed out.

b.

there is no more helium.

c.

the change in pressure remains steady.

d.

the helium percentage remains steady for 2 minutes.

ANS: D

The end point of the helium dilution test is reached when the helium percentage remains steady for 2 minutes, indicating that the helium is equilibrated between the spirometer and the patient’s lungs.

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27. One type of ventilatory pattern necessary for calculating functional residual capacity through the use of a body plethysmograph is:

a.

deep breathing with a breath hold.

c.

deep, rapid breathing.

b.

rapid, shallow breathing.

d.

slow, deep breathing.

ANS: B

Mouth pressure and box pressure changes are measured during tidal breathing and panting maneuvers.

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28. Which of the following equipment is necessary to perform a nitrogen washout test?

a.

Pneumotachometer

c.

Drying column

b.

Carbon dioxide (CO₂) absorber

d.

Pressure transducer

ANS: A

See Figure 8-10, which shows the breathing circuit for performing a nitrogen washout test.

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29. Body plethysmography is based on which of the following gas laws?

a.

Boyle’s

c.

Dalton’s

b.

Charles’

d.

Gay-Lussac’s

ANS: A

Body plethysmography measures mouth pressure and box pressure changes during tidal volume and panting. The microprocessor unit calculates the functional residual capacity from empirically derived pressure-volume relationships. It is Boyle’s law that explains the relationship between gas volume and pressure when temperature is held constant.

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30. A comparison of functional residual capacity measured by body plethysmography with that measured by nitrogen washout reveals that the measurement obtained during the nitrogen washout test is less than that during body plethysmography. This discrepancy is most likely caused by which of the following?

a.

Poor technique

c.

Restrictive lung disease

b.

Severe air-trapping

d.

Directional valve malfunction

ANS: B

Severe air-trapping will produce lower functional residual capacity results than body plethysmography because the nitrogen washout test measures gas volumes only in communicating airways.

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31. Aneroid manometers use ________ to measure pressure.

a.

a vacuum chamber with a flexible diaphragm

b.

capacitance and changes in output voltage

c.

changes in inductance of two coils

d.

a Wheatstone bridge circuit

ANS: A

An aneroid manometer consists of a vacuum chamber with a flexible cover or diaphragm that flexes when pressure is applied to it. Electromechanical transducers use variable capacitance; strain gauge pressure transducers use Wheatstone bridge circuits; and variable inductance transducers use the magnetic flux between two coils to measure pressure.

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32. Which type of pressure-measurement device is best suited to measure arterial blood pressure through an arterial catheter?

a.

Bourdon gauge

c.

Variable inductance

b.

Aneroid manometer

d.

Variable capacitance

ANS: C

Variable inductance and strain gauge pressure transducers are commonly used for measuring respiratory and cardiovascular pressures because they respond quickly to pressure changes.

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33. Which type of pressure-measurement device is used to measure a patient’s maximum inspiratory pressure?

a.

Variable inductance

c.

Plethysmograph

b.

Aneroid manometer

d.

Strain gauge

ANS: B

Aneroid manometers are used as independent units for instantaneous pressure measurements, such as maximum inspiratory and expiratory pressures.

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34. Which of the following is true concerning the triple-lumen esophageal catheter used with the BICORE CP-100 Pulmonary Monitoring System?

a.

It can measure intrapleural pressure indirectly.

b.

Its ideal position is the upper third of the esophagus.

c.

When the catheter enters the stomach, a negative pressure is recorded.

d.

The catheter can be positioned by observing the markings on its side.

ANS: A

Esophageal pressure is used clinically to estimate intrapleural pressure.

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35. The bedside respiratory mechanics of mechanically ventilated patients can be measured with which of the following?
36. VenTrak system
37. Tissot spirometer
38. BICORE CP-100 system
39. Stead-Wells spirometer

a.

1 and 2

c.

2 and 3

b.

1 and 3

d.

2 and 4

ANS: B

Stand-alone devices for the measurement of bedside respiratory mechanics include the BICORE CP-100 and the VenTrak system.

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36. “Opposition to the flow of an alternating current” is the definition of:

a.

electrical resistance.

c.

electrical impedance.

b.

variable capacitance.

d.

variable inductance.

ANS: C

Electrical impedance, which is opposition to the flow of an alternating current, is determined by the resistance and capacitance of the circuit through which the current must pass.

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37. Impedance plethysmographs operate by using _____-frequency, _____-amplitude electrical current.

a.

Low; low

c.

Low; high

b.

High; low

d.

High; high

ANS: B

A constant high-frequency, low-amplitude electrical current is passed between the two electrodes, and the return voltage is used to calculate the impedance.

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38. Which of the following might cause an apnea monitor to fail to alert the clinician to the presence of apnea?

a.

Tachycardia

c.

Upper airway obstruction

b.

Changes in blood volume

d.

Inadequate Sensitivity settings

ANS: C

Recent evidence suggests that bradycardia and upper airway obstruction might cause apnea monitors to fail to signal apnea.

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39. The parents of a newborn sent home with an apnea monitor call the respiratory therapist to report several periods of apnea as noted by the monitor’s alarm system. The respiratory therapist should check which of the following to ensure that the baby’s movement was not the cause of these alarms?

a.

Sensitivity of the monitor

c.

Amount of electrical current

b.

Placement of the electrodes

d.

Frequency of the vibrations

ANS: A

The sensitivity of the impedance pneumograph can be adjusted by the operator to prevent false alarms because of changes in impedance caused by movement instead of by changes in respiration.

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40. Which of the following are factors that influence the partial pressure of alveolar carbon dioxide (PACO₂)?
41. Diffusion
42. Ventilation
43. CO₂ production
44. Perfusion of the lungs

a.

1 and 2

c.

1, 3, and 4

b.

2 and 3

d.

1, 2, 3, and 4

ANS: D

Four major factors influence the PACO₂—CO₂ production, perfusion of the lungs, diffusion, and ventilation. The balance of these four components represents the total transport and elimination of CO₂.

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41. While working in the neonatal intensive care unit, a respiratory therapist notices that a baby with an apnea monitor is not breathing, but the apnea alarm is not ringing. Which of the following might cause this failure?
42. Tachypnea
43. Bradycardia
44. Excessive movement
45. Upper airway obstruction

a.

1 and 2

c.

1 and 3

b.

2 and 4

d.

3 and 4

ANS: B

Bradycardia and upper airway obstruction can cause apnea monitors to fail to signal apnea, because with bradycardia, cardiac oscillations and intrathoracic blood-volume changes cause an increase in impedance, which is sensed as part of the respiratory cycle. Continued respiratory efforts in the presence of upper airway obstruction are sensed as normal respiratory efforts.

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42. What type of device is used in an ICU to detect respiratory muscle fatigue?

a.

Aneroid manometer

c.

Inductive plethysmograph

b.

Pressure plethysmograph

d.

Electromechanical transducer

ANS: C

Respiratory inductive plethysmography has been used clinically as a means of monitoring the breathing patterns of patients in ICUs. In the ICU, it has been used primarily to identify uncoordinated thoracoabdominal movements that are associated with respiratory muscle fatigue or failure.

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43. The principle that the respiratory system moves with 2 degrees of freedom describes the basis for which of the following?

a.

Inductive plethysmography

c.

Strain gauge transducer

b.

Volume plethysmography

d.

Nitrogen washout

ANS: A

Inductive plethysmography is based on the principle that the respiratory system moves with 2 degrees of freedom. That is, it consists of two moving parts: the rib cage and the abdomen. During inspiration, the rib cage moves outward as the lungs expand in the thorax. Simultaneously, the abdomen is displaced outward by the downward movement of the diaphragm.

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44. As measured by inductive plethysmography, rib cage movement plus abdominal movement equals:

a.

tidal volume.

c.

expiratory reserve volume.

b.

inspiratory capacity.

d.

functional residual capacity.

ANS: A

Because the two moving parts in the respiratory system, the rib cage and the abdomen, are arranged in a series, the sum of the two displacements can be used to calculate the air volume inspired.

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45. Which device would be appropriate for monitoring respiratory rate and tidal volume during a sleep study?

a.

Capnograph

c.

Pneumotachograph

b.

Mass spectrometer

d.

Inductive plethysmograph

ANS: D

Respiratory inductive plethysmography has been used extensively in research on respiratory muscle function. It has been used as a means of monitoring breathing patterns of patients in sleep laboratories.

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46. Which of the following values is not measured directly?

a.

FEV₁

c.

Peak expiratory flows

b.

Airway resistance (Raw)

d.

Maximum inspiratory pressure

ANS: B

FEV₁ and peak expiratory flows are routine measurements during spirometry. Maximum inspiratory pressure is a common airway pressure measurement made on spontaneously breathing patients. Raw is calculated by subtracting plateau pressure (P_plateau) from peak inspiratory pressure and dividing the resultant pressure by the airflow.

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47. Which of the following variables can be measured directly?

a.

Lung compliance

c.

Raw

b.

Work of breathing

d.

P_plateau

ANS: D

P_plateau is measured during mechanical ventilation and represents the amount of pressure needed to maintain the tidal volume within the patient’s lungs during a period of no gas flow.

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48. To set up a pulmonary function laboratory that can measure all standard and dynamic lung volumes, which of the following equipment is necessary?

a.

Screen pneumotachograph and inductive plethysmograph

b.

Fleisch pneumotachograph and peak flowmeter

c.

Vortex ultrasonic flowmeter and inductive plethysmograph

d.

Stead-Wells spirometer and constant-volume plethysmograph

ANS: D

The Stead-Wells spirometer measures volumes and flows, whereas the constant-volume plethysmograph (the most common plethysmograph used) measures functional residual capacity. These two devices are able to measure all the volumes and flows necessary for full pulmonary function studies. The screen, Fleisch, and vortex ultrasonic pneumotachographs are unidirectional and are not able to measure inspiratory and expiratory flow simultaneously. Inductive plethysmography will provide respiratory rate and volume only, and is used in sleep laboratories.

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49. The most appropriate lung volume to measure for a mechanically ventilated patient is _____ volume.

a.

minute

c.

expiratory reserve

b.

residual

d.

inspiratory reserve

ANS: A

At the bedside, the most commonly measured lung volume is the expired minute volume.

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50. Newer ventilators can make tidal volume and minute volume measurements by incorporating which of the following?

a.

Capnograph

c.

Flow transducer

b.

Anemometer

d.

Pressure transducer

ANS: C

In most new ventilators, a flow transducer is incorporated into the system design to give continual updates on the tidal volume and minute volume.

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