Deck 20: Weaning and Discontinuation from Mechanical Ventilation

Question 1

Which mode of ventilation delivers the exact amount of pressure required to overcome the resistive load imposed by the ET tube for the flow measured at the time?

A) Automode
B) Volume-targeted PSV
C) Pressure support ventilation
D) Automatic tube compensation

Answer 1

D
ATC reduces the work of breathing associated with increased ET tube resistance.ATC is designed to deliver exactly the amount of pressure required to overcome the resistive load imposed by the ET tube for the flow measured at the time.In a sense,this is providing variable PSV with variable inspiratory flow compensation.Volume-targeted PSV maintains a target volume by varying the pressure support level.PSV provides an operator-selected set pressure for every spontaneous breath.The automode can switch between time-triggered mandatory breaths and patient-triggered,volume-targeted,pressure-limited breaths as long as the patient is breathing spontaneously.

Question 2

Assess the following data obtained from the spontaneous breathing trials of four patients.Which patient is most likely to be weaned successfully at this time?

A) Spontaneous rate = 32 breaths/min, Vᴛ = 375 mL, PₐO₂ = 98 mm Hg, FɪO₂ = 0.4
B) Spontaneous rate = 15 breaths/min, Vᴛ = 450 mL, PₐO₂ = 87 mm Hg, FɪO₂ = 0.6
C) Spontaneous rate = 15 breaths/min, Vᴛ = 650 mL, PₐO₂ = 91 mm Hg, FɪO₂ = 0.28
D) Spontaneous rate = 12 breaths/min, Vᴛ = 680 mL, PₐO₂ = 79 mm Hg, FɪO₂ = 0.5

Answer 2

C
Calculate the f/Vᴛ and PₐO₂/FɪO₂ for each patient.The patient with acceptable criteria has an f/Vᴛ of 23 and a PₐO₂/FɪO₂ of 325.

Question 3

What ends inspiration in pressure support ventilation?

A) Time
B) Flow
C) Volume
D) Pressure

Answer 3

B
Each pressure support breath is flow cycled.

Question 4

A female intubated patient has been weaned from full ventilatory support to PSV 5 cm H₂O,CPAP 5 cm H₂O,and an FɪO₂ of 0.3.The patient is alert and oriented and doing well.The respiratory therapist performs a cuff leak test.The average peritubular leak is 70 mL.The respiratory therapist should recommend which of the following?

A) Maintain the patient on the current settings and redo the cuff leak test in 24 hours.
B) Increase the PSV to 10 cm H₂O and maintain the CPAP and FɪO₂.
C) Extubate the patient and place her on a heated aerosol generator with an FɪO₂ of 0.4.
D) Pretreat the patient with steroids and/or racemic epinephrine before extubation.

Question 5

A 46-year-old male patient (IBW = 85 kg)who was injured in a motor vehicle crash has been receiving invasive mechanical ventilation for 24 hours.The patient is awake,alert,and looks comfortable on the following settings: VC-IMV with pressure support of 5 cm H₂O; set rate = 8 breaths/min; set Vᴛ = 500 mL; FɪO₂ = 0.4; PEEP = 5 cm H₂O.A 10-minute spontaneous breathing trial (SBT)yields this information: f = 30 breaths/min,RSBI = 145,P₀.₁ = 10 cm H₂O.What should the respiratory therapist suggest to the physician during patient rounds?

A) Sedate the patient and place him on VC-CMV.
B) Continue with the current ventilator settings.
C) Switch to PC-CMV with a rate of 14 breaths/min.
D) Decrease the mandatory SIMV rate to 4 breaths/min.

Question 6

The mode of ventilation that maintains a minimum Vᴇ by increasing or decreasing the amount of support (Vᴛ or respiratory rate)given to the patient is ___________________.

A) volume support
B) automatic tube compensation
C) mandatory minute ventilation
D) adaptive support ventilation

Question 7

A recently extubated patient develops a partial upper airway obstruction,which causes stridor.What action can the respiratory therapist take to improve the patient's condition?

A) Aerosolize 11.25 mg (2.25% solution) of racemic epinephrine.
B) Put a nonrebreather mask on the patient.
C) Place the patient on NPPV.
D) Suggest the use of lorazepam (Ativan).

Question 8

A postoperative patient,still under anesthesia,is being ventilated with VC-CMV with automode.After 2 hours,the patient is waking up and beginning to breathe spontaneously.The ventilator will respond by _____________________.

A) switching to the pressure support mode
B) switching to the volume support mode
C) delivering time-triggered, pressure-limited breaths
D) ensuring minimum mandatory minute ventilation

Question 9

Which of the following is considered a closed loop mode used for weaning from mechanical ventilation?

A) Pressure support ventilation
B) Adaptive support ventilation
C) Continuous positive airway pressure
D) Intermittent mandatory ventilation

Question 10

All of the following patients are intubated and receiving mechanical ventilation.Which of them is most likely to require slow liberation from mechanical ventilation?

A) A patient who overdosed on diazepam
B) A postoperative patient who had knee surgery
C) A patient with a severe exacerbation of asthma
D) A patient with chest contusions from a motor vehicle crash

Question 11

A patient is being weaned from invasive mechanical ventilation using VC-IMV.The respiratory therapist reviews the following data from the past few hours.

What should the respiratory therapist recommend for this patient?

A) Switch the mode to VC-CMV.
B) Add and titrate pressure support.
C) Extubate and place the patient on NPPV.
D) Increase the set rate to 8 breaths/min.

Question 12

At what pressure is pressure support not high enough to contribute significantly to ventilatory support but is sufficient to overcome the work imposed by the ventilator system?

A) 2 cm H₂O
B) 5 cm H₂O
C) 8 cm H₂O
D) 10 cm H₂O

Question 13

If a patient who has failed an SBT still meets the criteria for discontinuation of ventilation,an SBT should be performed every _______ hours to determine weanability.

A) 6
B) 12
C) 24
D) 36

Question 14

An SBT should not continue for longer than _____ minutes.

A) 30
B) 60
C) 120
D) 180

Question 15

In which patient would continued use of an artificial airway be necessary?

A) A patient with upper airway burns and no peritubular leak
B) A patient who tests positive for a peritubular leak
C) A patient with bronchospasm and supplemental oxygen requirements
D) A patient with a strong cough who expectorates moderate amounts of sputum

Question 16

Sixty minutes after a patient is extubated,an arterial blood gas sample is drawn; the results are: pH = 7.20,PₐCO₂ = 60 mm Hg,PₐO₂ = 55 mm Hg,SₐO₂ = 80%,HCO₃⁻ = 23 mEq/L with a 2 L/min nasal cannula.The patient is SOB and complaining of chest pain.His blood pressure is 92/50 mm Hg.The most likely cause of this weaning failure is which of the following?

A) Chronic obstructive pulmonary disease
B) Acute left ventricular failure
C) Ventilatory muscle weakness
D) Hypophosphatemia

Question 17

A patient is extubated and placed on a cool,bland aerosol with 30% oxygen.Twenty minutes post extubation,the respiratory therapist is called to assess the patient,who has shortness of breath.The respiratory therapist observes intercostal retractions,accessory muscle use,and a respiratory rate of 38 breaths/min.Stridor can be heard without a stethoscope,and the SₚO₂ has dropped from 97% to 85%.The patient is given an aerosolized racemic epinephrine treatment and reassessed.Accessory muscle use continues,intercostal retractions decrease slightly,and stridor is heard on auscultation.The patient's respiratory rate is 30 breaths/min and the SₚO₂ is 88%.What should the respiratory therapist recommend?

A) Reintubation and mechanical ventilation
B) Heliox therapy and steroid administration
C) Increase the FɪO₂ on the cool bland aerosol to 40%
D) Use a nonrebreather mask with 15 L/min oxygen.

Question 18

Which parameter is used as the primary index of the drive to breathe?

A) Airway occlusion pressure
B) CROP index
C) Maximum inspiratory pressure
D) Rapid shallow breathing index

Question 19

The ACCP/SCCM/AARC task force recommends that a search for all possible causes that may be contributing to ventilator dependence be undertaken in patients who require mechanical ventilation for longer than ______ hours.

A) 12
B) 24
C) 48
D) 72

Question 20

Calculate and determine the weanability of patients with this data: Cᴅ= 25 mL/cm H₂O,PImₐₓ = -28 cm H₂O,PₐO₂ = 93 mm Hg,PᴀO₂ = 158 mm Hg,and f = 22 breaths/min.

A) 2-not weanable
B) 19-weanable
C) 32-not weanable
D) 54-weanable

Question 21

A patient being actively weaned from mechanical ventilation currently is receiving the following ventilatory support: pressure support = 15 cm H₂O,spontaneous Vᴛ = 575 mL,spontaneous rate = 14 breaths/min,spontaneous Vᴛ = 500 mL,FɪO₂ = 35%,PEEP = 5 cm H₂O.The arterial blood gas results are: pH = 7.42,PₐCO₂ = 38 mm Hg,PₐO₂ = 94 mm Hg,SₐO₂ = 98%,HCO₃- = 24 mEq/L.What should the respiratory therapist do next?

A) Reduce PEEP to zero.
B) Reduce the FɪO₂ to 30%.
C) Reduce the PS to 10 cm H₂O.
D) Extubate the patient.

Question 22

How long does a tracheostomy site typically take to mature?

A) 2-4 days
B) 4-6 days
C) 7-12 days
D) 10-15 days

Question 23

When weaning is unsuccessful for a patient who successfully performs an SBT,which of the following factors should be assessed?
1)Cardiac factors
2)Nutritional status and respiratory muscle strength
3)Acid-base status
4)Psychological factors

A) 1 and 3 only
B) 2 and 4 only
C) 2, 3, and 4 only
D) 1, 2, 3, and 4

Question 24

A patient who requires prolonged ventilatory support should not be considered permanently ventilator dependent until ________ month(s)has/have passed and all weaning attempts during that time have failed.

A) 1
B) 3
C) 6
D) 9

Question 25

Which of the following would suggest that a patient is ready to be weaned from a ventilator?

A) Vital capacity (VC) of 8 mL/kg ideal body weight (IBW)
B) PₐCO₂ or 65 mm Hg on and FɪO₂ of 0.6
C) Dead space-to-tidal volume ratio (Vᴅ/Vᴛ) of 0.75
D) Rapid shallow breathing index of 75 breaths/min/L

Question 26

A patient in the ICU who has successfully completed a 120-minute SBT requires extubation.Which of the following tests or values would indicate the potential for airway edema after extubation?

A) PImax
B) VC
C) Cuff leak test
D) Oxygen saturation measured by pulse oximeter (SₚO₂)

Question 27

A patient with amyotrophic lateral sclerosis has a tracheostomy tube in place.He has been unable to perform an SBT successfully and has been receiving mechanical ventilation for 4 months.An appropriate recommendation for this patient might be which of the following?
1)Transfer to a long-term care facility
2)Evaluation for the use of noninvasive ventilation (NIV)
3)Termination of ventilation
4)Waiting until the primary cause of respiratory failure has been resolved

A) 1 and 2 only
B) 2 and 3 only
C) 1, 2, and 3 only
D) 1, 2, and 4 only