Mechanical Ventilation

Front 1

What is the recommended tidal volume for mechanical ventilation in acute respiratory failure?

Back 1

4 to 8 ml/kg

Front 2

What gastrointestinal conditions are commonly associated with long term positive pressure ventilation (PPV)

Back 2

Bleeding and Ulceration

Front 3

Physiological effects of adding a volume-limited inflation hold to mandatory breaths include what?

Back 3

Decreased PaCO2, Increased inspiratory time, decreased Vd/Vt

Front 4

What are some characteristics of CPAP?

Back 4

It maintains alveoli at greater inflation volumes. It holds airway pressure essentially constant, It has side effects similar to those of positive pressure ventilation.

Front 5

What is considered safe settings for a recruitment maneuver?

Back 5

Pressures up to 50 cm H2O, pressures applied for 1 to 3 minutes.

Front 6

Primary indications for using PEEP in conjunction with mechanical ventilation include:

Back 6

When dynamic hyperinflation occurs in COPD patients. When acute lung injury causes refractory hypoxemia.

Front 7

Beneficial physiological effects of PEEP include what?

Back 7

Increased PaO2 for given FIO2, Increased lung compliance (CL), Decreased shunt fraction, Increased functional residual capacity.

Front 8

What is considered a normal spontaneous tidal volume?

Back 8

5 to 7 ml/kg

Front 9

To prevent muscle fatigue or atrophy, the level of PSV should be adjusted to achieve what work load?

Back 9

0.6 to 0.8 J/L

Front 10

What is a consequence of decreased resistance and compliance?

Back 10

It takes less time to fill and empty the alveoli.

Front 11

What factors contribute to the development of auto positive end-expiratory pressure (PEEP)

Back 11

High expiratory Raw, Inadequate expiratory time

Front 12

Administration of PEEP or CPAP is associated with all the of the following benefits:

Back 12

Alveoli open, alveoli stable, fluid-filled alveoli open

Front 13

Pressure-controlled (PC) modes of ventilatory support include all the of the following:

Back 13

Pressure controlled continuous mandatory ventilation (PC-CMV), pressure controlled intermittent mandatory ventilation, volume-assured pressure-supported ventilation (VAPSV)

Front 14

What mode of pressure-controlled ventilation is designed to prevent alveoli with short time constants from collapsing, thereby improving oxygenation?

Back 14

Pressure-controlled inverse ratio ventilation

Front 15

Which of the following are potential effects of positive-pressure ventilation on the cardiovascular system?

Back 15

Decreased venous return, decreased ventricular stroke volume.

Front 16

What lung unit would be most prone to air trapping?

Back 16

One with high resistance and high compliance.

Front 17

What does pressure-supported ventilation consist of?

Back 17

Patient-triggered, pressure-limited, flow-cycled breaths

Front 18

A patient receiving long-term positive-pressure support exhibits a progressive weight gain and a reduction in hematocrit. What is most likely cause of this problem?

Back 18

Water retention

Front 19

What are some primary uses for pressure-supported ventilation (PSV)?

Back 19

Augmenting patient's spontaneous Vt. Overcoming the imposed work of breathing.

Front 20

What mode of support provides all of the patient's minute ventilation (VE) as mandatory volume-controlled (VC) breaths?

Back 20

VC continuous mandatory ventilation

Front 21

What term describes the lung injury associated with the release of prostanoids?

Back 21

Biotrauma

Front 22

In what type of ventilation is alveolar expansion during inspiration due to an increase in alveolar pressure

Back 22

Positive -pressure ventilation

Front 23

Positive-pressure ventilation (PPV) can reduce uninary output by how much?

Back 23

30% to 50%

Front 24

Compared with a square wave flow pattern, a decelerating flow waveform has what benefits?

Back 24

Reduced peak pressure. less inspiratory work, decreased volume of dead space-to-tidal volume ratio (Vd/Vt)

Front 25

What are characteristics of negative-pressure ventilation (NPV)?

Back 25

NPV is similar to spontaneous breathing. Airway (mouth) pressure during NPV is zero, Expiration during NPV is by passive recoil, NPV decreases pressure at the body surface.

Front 26

During volume-controlled continuouse mandatory ventilation, should either compliance decrease or airway resistance (Raw) increase, what will happen?

Back 26

The peak airway pressure will increase.

Front 27

What are some physiological advantages of volume-assured pressure-supported ventilation?

Back 27

Improved patient-ventilator synchrony and decreased work of breathing.

Front 28

What groups of patients are primarily affected by ventilator-associated pneumonia?

Back 28

Infants, Adults older than 65 yrs, Immunosuppressed, Thoracoabdominal surgery, depressed sensorium

Front 29

What variable(s) determines the level of support achieved with adaptive support ventilation?

Back 29

Patient effort and time constant.

Front 30

What term describes the lung injury associated with the use of low tidal volumes?

Back 30

Atelectrauma

Front 31

Ventricular dysfunction occurs in patients receiveing positive-pressure ventilation for all of the following reasons:

Back 31

hypovolemia, excessive tidal volume, receiving more than optimal PEEP

Front 32

Assuming a constant rate of breathing, what I:E ratio would tend to most greatly impair a patient's systemic diastolic pressure?

Back 32

1:1

Front 33

Bilevel positive airway pressure (BiPAP) is used for what purposes?

Back 33

Nocturnal ventilatory support of chronic disease patients. Preventing intubation of patients wiht acute exacerbations of COPD, treatment of obstructive sleep apnea in the home. Would NOT be used for vent support in status asthmaticus

Front 34

The increased work of breathing associated with auto PEEP during mechanical ventilation is due to

Back 34

Hyperinflation or impaired contractility of the diaphragm, Large alveolar pressure drops required to trigger breaths

Front 35

What are characteristics of positive-pressure ventilation (PPV)?

Back 35

During inspiration, pressure in the alveoli increases, the pressure gradients of normal breathing are reversed, during inspiration, alveolar pressure exceeds pleural pressure.

Front 36

What actions can you use to decrease compressed volume loss during mechanical ventilation?

Back 36

Low-volume, Low-compliance tubing, Ventilator with minimal internal volume, Low-volume humidifier or heat-moisture exchanger.

Front 37

On what does volume delivered depend during pressure-targeted modes of ventilatory support?

Back 37

Set pressure limit. Patient effort

Front 38

For patients with respiratory insufficiency, pressure supported ventilation (PSV) has what advantages over spontaneous breathing?

Back 38

Decreased respiratory rate
Increased VT
Decreased O2 consumption

Front 39

What is the explanation for the increased V/Q ratio when excessive PEEP is used?

Back 39

Diversion of blood from ventilated alveoli to hypoventilated alveoli

Front 40

What mode(s) of ventilatory support is used to help decrease airway and alveolar pressure?

Back 40

Pressure-controlled continuous mandatory ventilation.

Front 41

The volume of gas actually delivered to a patient by most positive pressure ventilation is always less than that expelled from the machine. What factors help explain this?

Back 41

Gas compression under pressure.
Presence of built-in leaks
Expansion of the ventilator circuitry

Front 42

What variables determine the level of support achieved with adaptive support ventilation?

Back 42

Patient effort
Resistance of the endotracheal tube

Front 43

During volume assured pressure supported ventilation, the breath will be pressure limited under what conditions?

Back 43

The delivered tidal volume (Vt) is greater than the preset minimum Vt.

Front 44

When bedside work of breathing measures are unavailable, you should adjust the level of pressure-supported ventilation (PSV) to what breathing pattern?

Back 44

Spontaneous rate 15 to 25/min. Vt 5 to 8 ml/kg

Front 45

Ventilatory support strategies likely to result in auto PEEP include:

Back 45

Continuous mandatory ventilation (CMV) assist-control. Inverse ratio ventilation (IRV). Low Inspiratory flows. NOT low-rate intermittent mandatory ventilation.

Front 46

Volume-controlled (VC) modes
of mechanical ventilation include:

Back 46

VC continous mandatory ventilation. VC intermittent mandatory ventilation.

Front 47

What patients are at greatest risk for auto PEEP?

Back 47

Those with high airway resistance. Those with high expiratory flow resistance

Front 48

What conditions are associated with a lack of response to increased FIO2 in patients receiving positive-pressure ventilation?

Back 48

Shunt

Front 49

Factors that would tend to increase mean airway pressure

Back 49

Increased mandatory breaths. Increased levels of positive inspiratory pressure (PIP). Increased levels of positive end expiratory pressure (PEEP)

Front 50

What condition does not require high mechanical respiratory rates?

Back 50

Metabolic alkalosis

Front 51

What ventilator is controlled by fluidic logic systems?

Back 51

Sechrist IV-100B

Front 52

What are major categories of ventilator function are useful in classifying ventilators?

Back 52

Control scheme, Power conversion, Ventilator output

Front 53

When setting the tidal volume on a patient being mechanically ventilated, what criteria should be kept in mind?

Back 53

It should never cause the plateau pressure to exceed 30 mm Hg.

Front 54

What would you assess immediately after a patient is placed on a ventilatory support device?

Back 54

ABG's, Patient airway, Patient's vital signs

Front 55

A patient receiving continuous mandatory ventilation in the assist-control mode develops auto-PEEP. What changes in ventilatory patterns would you consider to minimize the effects of auto-PEEP in this patient?

Back 55

Decreasing the rate or increasing the Vt. Using low-rate synchronized intermittent mandatory ventilation. Lowering the Vt and letting the PaCO2 rise

Front 56

To prevent atelectasis and improve gas exchange, most thorasic surgery patients placed on ventilatory support receive how much PEEP?

Back 56

5cm H2O PEEP

Front 57

On some ventilators, what can a trigger setting that is too sensitive cause?

Back 57

Auto-cycling

Front 58

In which of the following clinical situations is the incidence of auto-PEEP the greatest?

Back 58

Patients with high respiratory rates. Intubated patients with obstructive lung disease.

Front 59

What will most likely result if the patient ventilated in the assist-control mode develops a high ventilatory drive?

Back 59

Respiratory alkalosis

Front 60

What factors can have a major impact on adult patient-ventilator interation?

Back 60

Humidification system.
PEEP valve function
Trigger sensitivity
NOT tubing compliance

Front 61

Which of the inspiratory flow patterns would result in the lowest peak inspiratory pressure?

Back 61

Decelerating flow pattern

Front 62

What mode of ventilation will automatically vary the pressure support provided as patient effort changes to maintain a "normal" work of breathing?

Back 62

Proportional assist ventilation (PAV)

Front 63

On a ventilator that has separate rate and minute ventilation (VE) controls, the rate is set at 13/min. and the VE at 11L/min. About what Vt is the patient receiving?

Back 63

850 ml

Front 64

What goal(s) does the practitioner hope to achieve when selecting intial ventilatory support settings?

Back 64

Optimize oxygenation
Optimize ventilation
Maintain acid-base balance
Avoid harmful side effects

Front 65

Compared with a volume-cycled strategy, what are some potential advantages of pressure-targeted ventilatory support?

Back 65

Limit and control of peak airway pressures. Provision of a decelerating flow pattern.

Front 66

What is the primary advantage of negative-pressure ventilation?

Back 66

No need for artificial airway.

Front 67

What limits should be initially set for high and low Vt values and/or minute volume alarms on a ventilatory support device?

Back 67

+/- 10% to 15%

Front 68

What mode(s) of ventilatory support would you initially recommend for a patient whose compliance or resistance is likely to change rapidly?

Back 68

Volume-targeted CMV

Front 69

When titrating the FIO2 level downward from 100% to 40%, what is the maximum increment that should be applied between estimates of oxygenation?

Back 69

20%

Front 70

For adults with otherwise normal lungs who are receiving ventilatory support in the continuous mandatory ventilation control or assist control mode, inpiratory flow should be set to provide what I:E?

Back 70

1:2

Front 71

After placing a patient on ventilatory support, how long should you wait before drawing a sample for measurement of the ABG to ensure proper equilibration between alveolar and arterial gas tensions.

Back 71

30 minutes

Front 72

Immediately after cardiac arrest and resuscitation, a patient is placed on a ventilator in the continous mandatory ventilation assist-control mode. What initial FIO2 would you recommend?

Back 72

1.0

Front 73

When adjusting the FIO2 setting for a patient receiving mechanical ventilatory support, what should your goal be?

Back 73

Decrease the FIO2 to below 0.50 as soon as possible

Front 74

What is the recommended range for the tidal volume for the intial ventilator settings in the volume control mode?

Back 74

8 to 10 ml/kg

Front 75

Air-trapping is a major concern in patients with what diagnosis when using the assist control mode?

Back 75

Chronic obstructive pulmonary disease (COPD)

Front 76

What percentage of mechanical ventilated patients has a tracheostomy tube placed at some point?

Back 76

25%

Front 77

For adolenscents in the 8 to 16 year old range, what ranges of ventilator settings would you initially recommend?

Back 77

Rate 20 to 30/min. Vt 8 to 10 ml/kg

Front 78

Causes of hypoxemia:

Back 78

Ventilation/perfusion (V/Q) mismatch. Shunt. Alveolar hypoventilation. Diffusion/perfusion impairment. Decreased inspired O2. Venous admixture

Front 79

Clinical signs suggesting a more severe hypoxemia?

Back 79

CNS dysfunction ranging from irritability to confusion to coma. A "white" chest xray is evident when alveoli are partially occluded.

Front 80

Clinical signs associated with hypoxemia due to shunt:

Back 80

a "white" chest radiograph. Lack of increase in PO2 as FIO2 is increased

Front 81

Clinical signs of interstial lung disease with hypoxemia due to diffusion defect:

Back 81

Dyspneic patient with a dry cough and fine basilar crackles. Clubbing of the nail beds. Pulmonary hypertension may be present. Signs of edema, jugular vein distension.

Front 82

V/Q mismatch and shunt:

Back 82

Both result in elevated P(A-a)O2 levels indicating that the hypoxemia is due to an abnormality of lung tissue.

Front 83

Normal values for P(A-a)O2 range:

Back 83

10mmHg in the young and to 25mmHg in the elderly while breathing room air

Front 84

What are the three basic methods for discontinuing ventilatory support?

Back 84

Spontaneous breathing trials (SBTs). Synchronized intermittent mandatory ventilation (SIMV). Pressure support ventilation (PSV)

Front 85

Hypoxemia commonly presents with?

Back 85

Dyspnea, tachycardia, and tachypnea. The use of accessory muscles. Leaning forward on his/her arms. Nasal flaring.

Front 86

Disease associated with perusion/diffusion impairment?

Back 86

Liver disease

Front 87

Common cause of low mixed venous oxygen?

Back 87

Congestive heart failure with low cardiac output.

Front 88

Treatment of intrapulmonary shunt:

Back 88

Directed toward opening collapsed alveoli or clearing fluid or exudative material before O2 can be beneficial at below toxic levels.

Front 89

Causes of hypercapnic respiratory failure (ventilatory failure)

Back 89

Decreased ventilatory drive. Neurologic diseases. Increased work of breathing.

Front 90

Guillain-Barre syndrome:

Back 90

lower extremity weakness progressing to the respiratory muscles in 1/3 of patients. Weak cough and gag can be seen.

Front 91

Myathenia gravis:

Back 91

Ocular muscle weakness - can exhibit bulbar weakness on its path to respiratory muscle failure.

Front 92

Distinguish chronic hypercapnic respiratory failure from acute hypercapnic respiratory failure?

Back 92

Chronic - elevated PaCO2 and elevated HCO3, normal pH.
Acute - will have an elevated PaCO2 but normal HCO3 and pH will be low.

Front 93

What is the cardinal sign of increased work of breathing?

Back 93

Tachypnea is the cardinal sign of WOB.

Front 94

Vital capacity (VC ml/kg):

Back 94

Normal = 65 to 75 Support is needed when <10

Front 95

Normal work of breathing:

Back 95

0.3 to 0.6 J/L

Front 96

In intubated patients what are sources of imposed work of breathing?

Back 96

endotracheal tube, ventilator circuit and auto-PEEP due to hyperinflation with airflow obstruction.

Front 97

Normal Minute Ventilation

Back 97

5 to 6 L/min. A VE above 10L/min is cause for concern.

Front 98

Normal respiratory rate (adults)

Back 98

12-20 breaths/minute
Rates exceeding 35 breaths/min. for extended periods are a signal of inadequate alveolar ventilation or hypoxemia. This eventually will lead to respiratory muscle fatigue.

Front 99

Standard criteria for instituting mechanical ventilation:

Back 99

Apnea or absence of breathing.
Acute respiratory failure.
Impending respiratory failure. Refractory hypoxic respiratory failure with increased WOB or an effective breathing pattern.

Front 100

Normal VD/Vt range is:

Back 100

0.3 to 0.4 at normal tidal volumes.

Front 101

Normal PaO2

Back 101

80 to 100 mmHg on room air. A PaO2 <70 mmHg (or SpO2 <90%) on an O2 mask (FIO2 > 0.6) indicates inadequate oxygenation or lung failure.

Front 102

What is the definition of "mandatory breaths" with regard to mechanical ventilation?

Back 102

Mandatory breaths are breaths for which the ventilator controls the timing or tidal volume (or both). A patient-triggered, volume targeted, volume cycled breath is a mandatory breath. The machine controls tidal volume.

Front 103

What is the definition of "spontaneous breaths" with regard to mechanical ventilation?

Back 103

The patient controls the timing and the tidal volume. The volume or pressure (or both) delivered is based on patient demand and the patient's lung characteristics, not on a set value.

Front 104

Assisted breaths:

Back 104

Characteristics of both mandatory and spontaneous breaths. All or part of the breath is generated by the ventilator, which does part of the work of breathing.

Front 105

In patients suffering from acute respiratory acidosis, below what pH level are intubation and ventilatory support generally considered?

Back 105

7.2

Front 106

What indicators are useful in assessing respiratory muscle strenth?

Back 106

Maximum voluntary ventilation. (MVV)
Forced Vital Capacity (FVC)
Maximum inspiratory pressure (MIP)

Front 107

In intubated patients what sources of increased imposed work of breathing include?

Back 107

Endotracheal tube
Ventilator circuit
Auto-PEEP

Front 108

What diseases are associated with hypercapnic failure due to work of breathing?

Back 108

Asthma
Obesity
Kyphoscoliosis

Front 109

A patient develops acute respiratory failure due to muscle fatique. What modes of ventilatory support would be recommended?

Back 109

Assist control ventilation with adequate back up
Synchronized intermittent mandatory ventilation with adequate back-up rate
Bilevel pressure support by mask

Front 110

Hypoxemia can be caused by:

Back 110

Diffusion impairment
Alveolar hypoventilation
V/Q mismatch
Intrapulmonary shunting

Front 111

what vent mode would you suggest for a severly hypoxemic patient with acute lung injury or ARDS?

Back 111

Pressure-controlled ventilation

Front 112

What are some causes of dynamic hyperinflation?

Back 112

Increased airway resistance
Decreased expiratory flow rate

Front 113

What best helps to distinguish chronic hypercapnic respiratory failure from acute hypercapnic respiratory failure?

Back 113

Kidneys retaining bicarbonate to elevate the blood pH

Front 114

Ventilatory support may be indicated when the VC falls below what level?

Back 114

10ml/kg

Front 115

A patient can generate an MIP of -18cmH2O. Based on this information, what might you conclude?

Back 115

The patient has inadequate respiratory muscle strenth

Front 116

What is the most common cause of low mixed venous O2?

Back 116

Cardiac disease

Front 117

What clinical sign suggests more severe hypoxemia?

Back 117

central nervous system dysfunction

Front 118

When is respiratory muscle fatigue likely to occur?

Back 118

When VE exceeds 60% of MVV

Front 119

What is a feature of Guillain Barre?

Back 119

Ascending muscle weakness

Front 120

A patient with interstial lung disease who presents with hypoxemia due to diffusion defect would have what clinical signs?

Back 120

Fine bibasilar crackles
Clubbing of the finger nail beds
Jugular venous distention
Increased P2

Front 121

Hypercapnic (typeII) respiratory failure is a synonym for what term?

Back 121

Ventilatory Failure

Front 122

What is the optimal treatment of intrapulmonary shunt?

Back 122

Alveolar recruitment

Front 123

What measures should be used in assessing the adequacy of a patients alveolar ventilation?

Back 123

Arterial pH
PaCO2

Front 124

What are some characteristics regarding "acute-on-chronic" form of respiratory failure?

Back 124

It is most common with patients with COPD
Bacterial or viral infections are common precipitating factors
Mortality is associated with severity of acidosis

Front 125

What is the normal rate for PaO2/FIO2?

Back 125

350-450

Front 126

What is the normal range of Maximum inspiratory pressure (MIP) generated by adults?

Back 126

-80 to -100 cmH2O

Front 127

What best describes the difference between V/Q mismatch and shunt when supplemental O2 is administered?

Back 127

V/Q mismatch will respond well but shunt will not