Chapter 295 - Mechanical Ventilatory Support

Question 1

What is the primary indication for initiation of MV

Answer 1

Respiratory Failure

Question 2

Types of respiratory failure

Answer 2

hypoxemic

hypercarbic

Question 3

Hypoxemic respiratory failure occurs when arterial O2 saturation falls below which level despite an increased FiO2

Answer 3

<90%

Question 4

Hypoxemic respiratory failure results from which conditions?

Answer 4

VQ mismatch

Shunt

Question 5

Hypercarbic respiratory failure occurs if arterial CO2 values are greater than which level?

Answer 5

> 50 mmhg

Question 6

Hypercarbic respiratory failure results from which conditions?

Answer 6

decrease minute ventilation

increase physiologic dead space

Question 7

When respiratory failure is CHRONIC, patients are obligatorily treated with mechanical ventilation.

Answer 7

FALSE

only when acute is MV lifesaving

Question 8

Respiratory failure with hypoxemia is the most common reason for instituting MV. This accounts for how many percent of all ventilated cases?

Answer 8

65%

Question 9

Most common cause of hypercarbic respiratory failure?

Answer 9

Coma (15%)

COPD in exacerbation (13%)
Neuromuscular disease (13%)

Question 10

What are the primary objectives of MV?

Answer 10

1. decrease work of breathing

2. reverse life threatening hypoxemia and acidosis

Question 11

Complications of NIV?

Answer 11

pneumonia

tracheolaryngeal trauma

Question 12

2 most frequently implemented ways of NIV

Answer 12

1. bilevel positive airway pressure ventilation

2. pressure support ventilation

Question 13

Major limitation of NIV

Answer 13

patient intolerance

Question 14

Most important group of patients who benefit from a trial of NIV

Answer 14

COPD in exacerbation
Respiratory acidosis (pH <7.35)

Question 15

blood pH level associated with low failure rates (15-20%) and good outcomes with NIV

Answer 15

7.25 - 7.35

Question 16

In more severely ill patients, with blood pH <7.25, the rate of NIV failure is inversely related to the severity of the respiratory acidosis; the lower the pH the higher the rate of failure

Answer 16

TRUE

Question 17

Good clinical indicators of the therapeutic benefit of NIV

Answer 17

1. reduction in respiratory frequency

2. decrease in the use of accessory muscles

Question 18

What characterizes a conditioned gas?

Answer 18

warmed, oxygenated, humidified

Question 19

Good choices of sedatives during intubation but can have a deleterious effect on hemodynamics in patients with depressed cardiac function or low systemic vascular resistance

Answer 19

Opiates and benzodiazepines

Question 20

Drug used during intubation that can promote histamine release from tissue mast cells and may worsen bronchospasm

Answer 20

Morphine

Question 21

Drug that may increase systemic arterial pressure and has been associated with hallucinatory responses

Answer 21

Ketamine

Question 22

Contraindications for NIV

Answer 22

Cardiac/ respiratory arrest
Severe encephalopathy
Severe GI bleed
Hemodynamic instability
Unstable angina or MI
Facial surgery or trauma
Upper airway obstruction
High risk aspiration
inability to clear secretions

Question 23

Basic goals of MV

Answer 23

to optimize oxygenation while avoiding ventilator induced lung injury due to overstretch and collapse/re-recruitment

(protective ventilatory strategy)

Question 24

Refers to the manner in which ventilator breaths are triggered, cycled, and limited

Answer 24

Mode

Question 25

defines what the ventilator senses to initiate an assisted breath

Answer 25

Trigger

Question 26

refers to the factors that determine the end of inspiration

Answer 26

Cycle

Question 27

operator specified values that are monitored by transducer internal to the ventilator circuit throughout the respiratory cycle

Answer 27

Limiting factors

Question 28

most widely used mode of ventilation

Answer 28

ACMV

Question 29

patient or timer triggered | delivers an operator specified tidal volume

Answer 29

ACMV

Question 30

Ventilatory rate is determined either by the patient or by the operator specified back up rate, whichever is of higher frequency

Answer 30

ACMV

Question 31

allows synchronization of the ventilator cycle with the patient's inspiratory effort

Answer 31

ACMV

Question 32

Increased intrathoracic pressures resulting from dynamic hyperinflation occurring if there is inadequate time available for complete exhalation between inspiratory cycles

Answer 32

Auto-PEEP

Question 33

Variable set by ACMV

Answer 33

``` TV BUR PEEP FiO2 Pressure limit ```

Question 34

Patient triggered, flow cycled, pressure limited

Answer 34

Pressure support ventilation

Question 35

Operator sets the pressure level to augment every spontaneous respiratory effort

Answer 35

PSV

Question 36

Patients receive ventilator assistance only when the ventilator detects an inspiratory effort

Answer 36

PSV

Question 37

operator sets the number of mandatory breaths of fixed volume to be delivered by the ventilator; between those breaths, the patient can breathe spontaneously

Answer 37

Intermittent Mandatory ventilation

Question 38

If the patient fails to initiate a breath, the ventilator delivers a fixed TV breath and resets the internal timer of the next inspiratory cycle

Answer 38

SIMV

Question 39

time triggered, time cycled, pressure limited

Answer 39

Pressure control ventilation

Question 40

tidal volume and inspiratory flow rate are dependent and are not operator specified

Answer 40

PCV

Question 41

preferred mode of ventilation in whom it is desirable to regulate peak airway pressures, such as those with preexisting barotrauma, and for post-thoracic surgery patients in whom the shear forces across a fresh suture line should be limited.

Answer 41

PCV

Question 42

variant of PCV that incorporates the use of prolonged inspiratory time with the appropriate shortening of the expiratory time

Answer 42

Inverse ratio ventilation

Question 43

used in patients with severe hypoxemic respiratory failure. increases mean distending pressures without increasing peak airway pressures.

Answer 43

Inverse ratio ventilation

Question 44

provides fresh gas to the breathing circuit with each inspiration and sets to a constant operator specified pressure

Answer 44

Continuous positive airway pressure

Question 45

static pressure in the airway at the end of inspiration

Answer 45

Plateau pressure

Question 46

Preventive ventilatory strategy has decreased the mortality rate of patients with acute hypoxemic respiratory failure to how many percent?

Answer 46

30%

Question 47

Daily interruption of sedation in patients with improved ventilatory status results in a shorter time on the ventilator and a shorter ICU stay

Answer 47

True

Question 48

3 most common organisms causing VAP

Answer 48

pseudomonas aeruginosa enteric gram neg rods s aureus

Question 49

Hypotension resulting from elevated intrathoracic pressures with decreased venous return is almost always responsive to which management?

Answer 49

Intravascular volume repletion

Question 50

4 Conditions indicating amenability to weaning by the ventilatory weaning task force WEAN SCREEN

Answer 50

(1) Resolving disease (2) adequate gas exchange with low PEEP (<8 cmH2O) and Fio2 (<0.5) (3) stable hemodynamics (4) spontaneous breathing ability

Question 51

How is SBT implemented?

Answer 51

T-piece using 1–5 cmH2O CPAP with 5–7 cmH2O PSV

Question 52

How many percent of patients require reintubation despite all precautions instituted

Answer 52

10-15%

Question 53

3 complex complications of long term tracheostomy

Answer 53

tracheal stenosis granulation erosion of the innominate artery

Question 54

Tracheostomy is planned if a patient needs MV for how many days?

Answer 54

>10-14 days

Question 55

How many percent of ventilated patients ultimately become dependent on vent support?

Answer 55

2%

Question 56

When is SBT declared a failure?

Answer 56

- RR >35 for 5 min - O2 sat <90% - HR >140 or 20% inc or dec from baseline - SBP <90 or >180 - inc anxiety/ diaphoresis

Question 57

Mainstay for therapy for analgesia in MV patients

Answer 57

Opiates

Question 58

Use of neuromuscular blocking agents may result in prolonged weakness terms as

Answer 58

Post paralytic syndrome