Deck 16: Weaning From Mechanical Ventilation

Question 1

If pulse oximetry is used to monitor a patient's oxygenation status, the pulse oximetry O₂ saturation (SpO₂) should be kept in the mid-80s for allowance of machine inaccuracies.

Answer 1

False

Question 2

When the RSBI or f/V_T ratio becomes greater than 100 breaths/min/L, it correlates with weaning failure.

Answer 2

True

Question 3

Patients who fail the SBT often do so within the first 10 minutes of the trial.

Answer 3

False

Question 4

Respiratory work is a product of transpulmonary pressure and tidal volume.

Question 5

Normal subjects using an endotracheal (ET) tube have an increase of 54% to 240% in the work of breathing depending on the size of the ET tube and ventilator flow rate.

Question 6

____ is defined as an absence of ventilatory support 48 hours following an extubation.

A) Weaning success
B) Weaning in progress
C) Weaning failure
D) Spontaneous breathing trial

Question 7

Patients who fail an SBT often exhibit the following objective clinical signs: tachypnea, ____, hypertension, hypotension, hypoxemia or acidosis, arrhythmias.

A) bradycardia
B) tachycardia
C) atrial fibrillation
D) ventricular fibrillation

Question 8

Generally accepted ventilatory weaning criteria includes a ____.

A) vital capacity of greater than 5 mL/kg
B) minute ventilation of less than 15 L with satisfactory blood gases
C) spontaneous V_T of greater than 5 mL/kg
D) PaCO₂ of less than 65 mm Hg with normal pH

Question 9

The ____ is used to estimate how much pulmonary perfusion is wasted.

A) P/F index
B) Q_S/Q_T ratio
C) P(A-a)O₂ gradient
D) CaO₂ content

Question 10

For a successful weaning outcome, ____.

A) the PaO₂ should be > 75 mm Hg
B) the P(A-a)O₂ should be < 450 mm Hg while on 100% O₂.
C) the PaO₂/F_IO₂ should be 150 mm Hg
D) the Q_S/Q_T should be < 45%

Question 11

The ____ is measured by dividing the patient's tidal volume (measured at the airway opening) by the difference in the plateau pressure and the PEEP.

A) airway resistance
B) static lung compliance
C) deadspace to tidal volume ratio
D) vital capacity

Question 12

For a successful weaning outcome, the patient should have a ____.

A) static lung compliance <30 mL/cm H₂O
B) VC <10 mL/kg
C) V_D/V_T ratio should be >60%
D) MIP of at least -30 cm H₂O

Question 13

____ remains an effective tool in altering the degree of partial ventilatory support during continuous mechanical ventilation.

A) ATC
B) CPAP
C) PS
D) SIMV

Question 14

Sometimes SIMV and ____ are used together in patients who have failed the spontaneous breathing trial.

A) PSV
B) VS
C) VAPS
D) APRV

Question 15

In ____, the pressure support level is adjusted automatically to achieve the target tidal volume.

A) VS
B) VAPS
C) MMV
D) APRV

Question 16

Termination criteria for weaning from mechanical ventilation includes a ____.

A) SpO2 < 80%
B) heart rate >120/min
C) systolic pressure >180 mm Hg
D) systolic pressure < 75 mm Hg

Question 17

____ is an indicator of weaning failure.

A) Increasing PaO₂
B) Increasing PaCO₂
C) Increasing SpO₂
D) Increasing PaO₂/F_IO₂

Question 18

Which of the following is an indicator of weaning failure?

A) decreasing V_D/V_T
B) increasing MIP
C) increasing f/V_T
D) decreasing f

Question 19

____ is a clinical condition that decreases static compliance.

A) Kinking of ET tube
B) Bronchospasm
C) Airway obstruction
D) Tension pneumothorax

Question 20

____ = P_AO₂ - PaO₂

A) Q_S/Q_T
B) P(A-a)O₂
C) CaO₂
D) PaCO₂

Question 21

Use of _______________ allows early weaning attempts and minimizes complications associated with prolonged mechanical ventilation and artificial airway.

Question 22

The criteria for passing a SBT include normal respiratory pattern, adequate gas exchange, and _______________.

Question 23

Early signs of weaning failure include _______________, use of accessory muscles, and paradoxical abdominal movements.

Question 24

Weaning failure is generally related to (1) _______________, (2) decrease of compliance, or (3) respiratory muscle fatigue.

Question 25

Weaning with _______________ is done by starting the pressure support level at 5 to 15 cm H₂O and adjusting it gradually (up to 40 cm H₂O) until a desired spontaneous V_T (10 to 15 mL/kg) is obtained.

Question 26

What two questions pertaining to the patient's clinical condition should be considered before any weaning attempt?

Question 27

What are the procedures to obtain the f/V_T Ratio?

Question 28

Describe automatic tube compensation.

Question 29

What steps should be taken prior to withdrawal of mechanical ventilation?

Question 30

How do you minimize the effects of airflow resistance?