pilbeams ch 6

Question 1

The primary goal of volume controlled CMV

Answer 1

is to achieve a Ve that matches the patient’s metabolic needs

Question 2

Metabolic rate is directly related to

Answer 2

body mass and surface area in humans

Question 3

Male Ve=

Answer 3

4 x BSA

Question 4

Female Ve=

Answer 4

3.5 x BSA

Question 5

Ve must be adjusted for abnormal conditions such as

Answer 5

hypo/hyperthermia, hyper-metabolism, and metabolic acidosis.

Question 6

Lung disorders that increase physiological dead space

Answer 6

will also require an increase in Ve.

Question 7

Normal spontaneous Vt for a healthy adult is about

Answer 7

5 to 7ml/kg with a spontaneous rate of 12-20 bpm

Question 8

Vt for ventilated patients ADULTS

Answer 8

6-8ml/kg IBW

Question 9

Vt for ventilated patients CHILDREN

Answer 9

4-8 ml/kg IBW

Question 10

Lower Vt’s such as 4ml/kg IBW

Answer 10

have been successfully used with ARDS (minimize damage)

Question 11

RR=

Answer 11

Ve/Vt

Question 12

RT’s set the following in VC

Answer 12

Vt, RR, FiO2, PEEP, flow

Question 13

RT’s set the following in PC

Answer 13

IP(PiP), RR, FiO2, PEEP, Ti(inspiratory time)

Question 14

Ve=

Answer 14

(f)XVt

Question 15

TCT

Answer 15

total cycled time

Question 16

Ti

Answer 16

inspiratory time

Question 17

Te

Answer 17

expiratory time

Question 18

TCT=

Answer 18

Ti+Te

Question 19

Te=

Answer 19

TCT-Ti

Question 20

Ti=

Answer 20

Vt/flow/60sec

Question 21

I/E=

Answer 21

Te/Ti 1:? 1 is contant

Question 22

Vt=

Answer 22

IBW(10)

Question 23

To estimate metabolic rate

Answer 23

we use an individual’s gender, height and weight, body surface area(BSA).

Question 24

Ve (minute ventilation) can be estimated using

Answer 24

a patient’s BSA. Box 6-1

Question 25

Vt’s vary based on lung pathology

Normal lungs

Answer 25

6-8ml/kg, RR 10-20bpm

Question 26

Vt’s vary based on lung pathology

COPD/Asthma

Answer 26

6-8ml/kg, RR 8-12bpm

Question 27

Vt’s vary based on lung pathology

Restrictive disease

Answer 27

4-6ml/kg, RR15-25bpm

Question 28

Vt should be adjusted to maintain

Answer 28

Pplat less than 30cmh20 and rates adjusted to minimize auto-peep

Question 29

When setting Vt and rate, the goal is not to focus so much on the exact Vt and rate, but to focus on using settings that do not harm the patient

Answer 29

Maintaining plateau pressure lower than 30cmh20 is VERY important.

Question 30

In some cases it may even be necessary to let

Answer 30

PaC02 rise and pH fall outside the patient’s normal values to avoid lung injury.

Question 31

Tubing Compliance

Answer 31

As pressure builds in the ventilator circuit during inspiration, circuit expands along with the patients lungs, therefore the total volume that goes to the circuit never reaches the patient.-COMPRESSIBLE VOLUME
Current ICU ventilators measure and correct this
Can be calculated, Box 6-4

Question 32

Inspiratory Flowand Flow Patterns VC-CMV

Answer 32

Goal is to set the shortest possible Ti
I:E of 1:2 or less, usually 1:4
Initial peak flow rate of 60L/min
Range 40-60L/min

Question 33

Flow Patterns

Answer 33

Constant flow-most common *square
Ascending ramp
Sine flow *libra sign
Descending ramp-most common

Question 34

Constant flow-

Answer 34

most familiar to clinicians or only one on the ventilator in use. Provides the shortest Ti available flow pattern with an equivilent peak flow rate setting.

Question 35

Descending-

Answer 35

Descending-The amount of gas flow at the beginning of inspiration is always the highest. Descending pattern flow is greatest at the beginning. This occurs naturally with pressure ventilation.

Question 36

Ascending ramp-

Answer 36

not used. Progressive increase in flow.

Question 37

Sine-

Answer 37

Produces tapered flow at the end of inspiratory phase. Suggested that it can provide a more even distribution; it is not used.

Question 38

Inspiratory Pauseduring Volume Ventilation

Answer 38

Is used to:
Obtain measurements of Pplateau
Improve distribution of air throughout the lungs
Use with care or not at all in COPD and flow limitation
Not commonly used in clinic

Question 39

Setting baseline pressure—PEEP

Answer 39

Determining VT in pressure ventilation
Measure Pplateau and baseline pressure after initial volume-targeted breath.
Check VT and adjust after initiating pressure ventilation at low pressure(10-15cmh20)

Question 40

PEEP increases

Answer 40

FRC, FRC decreases when the pt. is intubated or placed in the supine position. Minimum levels of 3-5cm.h20.

Question 41

Raw =

Answer 41

(PIP – Pplateau)/flow

Question 42

PSV =

Answer 42

(PIP – Pplateau)

Question 43

Goals of adjusting PSV are

Answer 43

To help increase VT (4-8 mL/kg)
To decrease respiratory rate (to <30 breaths/min)
To decrease work of breathing (WOB) associated with breathing through an artificial airway

Question 44

PC-CMV

Answer 44

can improve oxygenation and gas exchange, increase Paw and facilitate lung healing.Initial values of 10-15cmH20 with volume measurement
the Ti required for the ventilator to reach the set pressure at the beginning of inspiration(PSV)

Question 45

PRVC

Answer 45

Closed loop pressure breaths and targets the pressure to achieve the set Vt.
Pressure limited, time cycled, Vt is feedback control
Important to set the upper pressure limit
Adaptive pressure support, PRVC,Vc+, Autoflow
Ti instead of flow

Question 46

Volume Support

Answer 46

Spontaneous mode
Operator sets sensitivy, Vt, and upper pressure limit
Advantage is that spontaneously breathing pt.’s can establish their own RR and Vt
The set Vt is the minimum
VS,SPN-CPAP/VS,VS