Mechanical Ventilators

Question 1

Purpose of Ventilator

Answer 1

• decrease WOB
• provide ventilation (not respiration)
• maintain positive pressure

Question 2

Mechanical Ventilator

Answer 2

• process by which ventilation is maintained by an artificial or extrinsic means
• machine used to force gas into lungs

Question 3

Indications of ventilator use

Answer 3

• inability to spontaneously ventilate

- disorder of gas exchange (unable to get O2 in or CO2 out)

Question 4

Negative Pressure Ventilator

Answer 4

• Iron Lung

- change in pressure in caase around chest to increase/decrease intrathoracic pressure to ventilate patient

Question 5

Pressure Support Ventilation

Answer 5

• pt must have adequate spontaneous effort

- provide preset amount of pressure during spontaneous effort to support pt efforts

Question 6

Acute/impending respiratory failure

Answer 6

-pH 50mmHg

Question 7

Types of Ventilators

Answer 7

• negative pressure (iron lung)

- positive pressure

Question 8

Positive Pressure Ventilator

Answer 8

• blows air into lungs

- affected by compliance and resistance

Question 9

Volume-Cycled ventilation

Answer 9

ends inspiration after a preset tidal volume has been delivered

Question 10

3 types of positive pressure ventilation

Answer 10

• volume-cycled
• time-cycled
• flow-cycled

Question 11

Time-cycled ventilation

Answer 11

-ends inspiration after preset time has elapsed

Question 12

Flow-Cycled

Answer 12

-ends inspiration when a preset flow rate is obtained

Question 13

CPAP

Answer 13

• applies continuous positive pressure during inspiration and expiration to a spontaneously breathing person
• pressure prevents alveolar collapse, increased fuctional/residual capacity and oxygenation

Question 14

Indications for CPAP

Answer 14

• atelectasis

- sleep apnea

Question 15

Advantages vs Disadvantages of CPAP

Answer 15

ADV-maintain respiratory strenth, used to wean from partial vent support

DIS-possible compromise to CO

Question 16

Advantages vs Disadvantages of SIMV

Answer 16

ADV: to wan pts from vent, less likely to hypervent, CO less compromised

DIS: utilize demand valve that opens and allows airflow in response to certain neg pressures

Question 17

Assist Control Ventilation

Answer 17

• preset rate and tidal volume programmed, which are delivered in absence of spontaneous effort
• in response to effort, will assist pt’s efforts by delivering the tidal volume

Question 18

Indications of Assist Control Ventilation

Answer 18

pt with respiratory Mm fatigue, pulm edema or pneumonia

Question 19

Advantages vs Disadvantages of Assist Control Vent

Answer 19

ADV: pt may participate in vent

DIS: possibly hyperventilate

Question 20

Advantages vs Disadvantages of Pressure Support Ventilation

Answer 20

ADV: incr tidal volume to decr WOB & aids in weaning

DIS: difficult to ensure alveolar vent; no air given in absence of voluntary effort; increase tidal volume & decr RR

Question 21

BiPAP

Answer 21

• similar to CPAP but gives different levels of pressure during inhale and exhale
• help deliver more air to lungs
• used for same problems as CPAP

Question 22

Ventilator Parameters

Answer 22

• tidal volume
• RR
• FiO2
• PEEP
• PIP

Question 23

PIP

Answer 23

• peak inspiratory pressure
• how much force is needed to get air into lungs
• if have restrictive or intubated=need greater amount
• trauma risk: barotrauma

Question 24

High Pressure Alarm

Answer 24

• alarms when PIP exceeds preset limit
• indicates obstruction in tracheal tube or pt coughing/being agitated
• may indicate worsening condition

Question 25

Low PEEP/CPAP alarm

Answer 25

-when preset PEEP or CPAP not maintained

Question 26

Low exhaled volume alarm

Answer 26

- when exhale volume is < tidal volume | - indicates pt disconnected from tracheal tube or leak in cuff around tube

Question 27

6 Alarms

Answer 27

- high/low pressure alarms - low PEEP/CPAP alarm - High/low exhaled volume alarm - apnea alarm

Question 28

Low pressure alarm

Answer 28

- when tidal volume uses pressure below average PIP | - indicates leak in system

Question 29

High Exhaled Volume Alarm

Answer 29

- pt getting more than preset minute ventilation | - if pt incr RR or agitated

Question 30

Apnea Alarm

Answer 30

- when no air movement detected for period of time - indicates system failure or nonexistent O2 supply - initiate emergency procedures ASAP

Question 31

factors affecting weaning

Answer 31

- ABGs - PFTs - Presence of Contraindications

Question 32

Weaning Complications

Answer 32

- Atelectasis - Aspiration - Hypoxemia

Question 33

Signs of respiratory distress during mechanical vent

Answer 33

- increased SCM contraction - recession of suprasternal and supraclavicular spaces and intercostal spaces - paradoxical motion of abdomen - diaphoresis - nasal flaring - tachycardia - tachypnea - cyanosis

Question 34

Contraindications to weaning

Answer 34

- Required PEEP >5cm H20 - if FIO2 >0.4 - Unable to generate negative inspiratory pressure >/= 20 mmHg

Question 35

5 modes of ventilation

Answer 35

- assist-control ventilation - synchronized intermittent mandatory vent (SIMV) - Pressure support vent - CPAP - BiPAP

Question 36

SIMV

Answer 36

- programmed to deliver preset tidal volume and frequency - if pt fails to initiate, will deliver tidal volume and rate - if pt initiates, tidal volume depends on muscular effort by pt

Question 37

PEEP

Answer 37

- positive end expiratory pressure - used to maintain open airways - increased PEEP=worse the pt is

Question 38

monitoring needs | for weaning

Answer 38

- ABGs - Vitals - S/Sx respiratory distress