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Flashcards in ch 3 how a breath is delivered Deck (70):
1

During mechanical ventilation what are the two forces (pressures) that act on the respiratory system to produce transrespiratory pressure?

-muscle pressure
-ventilator pressure

2

what are the 4 control variables?

-pressure
-volume
-flow
-time

3

the amount of volume delivered will depend on compliance and resistance to what?

gas flow

4

what is the Rhorer equation of motion?

Pmus + Ptr = V/C + (Raw x flow)

5

there are only 2 pressures that can ventilate a patient what are they?

-patients muscles
-ventilator

6

The delivery of__________ is a ventilators single most important function?

inspiration

7

this is the primary variable that the ventilator manipulates to cause inspiration?

control variable

8

the volume and flow waveforms are constant pressure varies with changes in compliance and resistance?

volume control

9

what are 3 names used for volume ventilation?

-volume targeted
-volume controlled
-volume limited

10

what control is used in A/C and SIMV?

volume ventilation

11

pressure delivered constant, volume and flow vary with changes in compliance and resistance?

pressure control

12

what are 3 names used for pressure ventilation?

-pressure targeted
-pressure controlled
-pressure limited

13

pressure waveform will be unaffected by changes in compliance and resistance. The flow and volume waveforms change with comp/resist?

pressure controlled breath

14

what control are we in if flow usually starts out high and then tapers off?

pressure ventilation

15

high gas flows produce uneven distribution of gases. "slow spaces" are underventiated. at end inspiration what flows tend to ventilate better? what should the flow patter look like?

-reduced flows
-decelerating

16

what is the flow control formula?

flow= volume / time
or
volume= flow x time

17

if changes in comp/resist do not affect volume waveform they will not effect______ waveform?

flow

18

when both pressure and volume waveforms are affected by changes in lung characteristics the ventilator is _______controlled?

time

19

many high frequency jet and oscillators are ____controlled?

time

20

what are the 4 basic shaped for waveforms?

-rectangular (square or constant)
-exponential (increasing ((rising)) or decreasing((decaying))
-sinusoidal (sine)
-Ramp (ascending, descending) ((decelerating))

21

start of breath, initiation

trigger

22

what is controlled during breathing. Inspiration itself. one of the 4 phases of CMV

limit variable

23

what terminates breath, end of breath?

cycle

24

expiratory phase goes to what?

baseline

25

what begins or triggers inspiration?

-patient
-machine (time)

26

ventilator begins itself, machine is insensitive to patients efforts, rate of breathing controlled by the machine?

"machine" time triggered

27

if a rate was set at 12 breaths per minute how many seconds in between breaths?

5 sec
60/12

28

determines the amount of effort when a patient triggers?

sensitivity

29

how fast the machine responds. usually at 0.08 seconds. cannot be adjusted?

response time

30

machine begins inspiration when patient starts to inspire and removes a small amount of volume from the circuit which creates negative pressure?
there will be a drop below baseline

-pressure triggered (assist)

31

breaths may not occur at equal, timed intervals

(assist) pressure control

32

a patient has a baseline of 10cmH20 the sensitivity is set at -2cmH20 at what pressure will the ventilator sense a patient effort and start inspiration?

8 from base line

33

a continuous supply of low level flow is delivered past the patient during expiration is known as what trigger?

flow trigger (flow-by)

34

flow measuring devices are positioned at inlet and outlet side of circuit to compare flow. ________ triggering occurs when the net difference reaches a pre-selected level.

flow

35

patient has access to continuous flow during "response time" which lowers work of breathing what trigger is this?

flow triggered

36

for flow trigger the base flow must be at least twice the _____ flow

trigger

37

flow triggering can cause _______breaths due to leaks or movement caused by turbulent gas flow through circuit

spurious (auto trigger)

38

what does bias flow mean?

constant flow through machine

39

don't forget to look over important slide on page

11 of power point slide

40

the machine cycles when a preset volume has been removed from the circuit. what are 2 machines that have this cycle capability? (volume cylcle)

-dragger babylog
-cardiopulmonary ventrui

41

a ______ button on the machine, when pushed, will initiate a positive pressure breath?

manual

42

one of the four physical parameters that can be reached but not exceed during a breath?

limits of ventilation

43

reaching a limit does not _____ the breath?

end

44

the volume is held in the airway until a pre-set time, then time will end the breath

volume limited

45

the machine signal the i -time display and will not permit patient to trigger a breath till a set time

time limited

46

what is a example of a ventilator that is time limited?

bear cub

47

during PSV and PCV the pressure is increased to pre-set level at the beginning of inspiration and is held at the airway until the breath ends is known as ?

pressure limit

48

can be used as a pressure pop-off to limit the amount of pressure in the airway but if reached will not terminate the breath is know as what?

pressure limit

49

what is a example of a pressure limit ventilator ?

NC humidifier

50

what is more comfortable of a patient pressure control or volume control?

pressure control because patient gets to pick there breath

51

vents begin inspiration( pressure limit) and achieve the set pressure as quickly as possible, this can cause discomfort in patients. what is the setting in ventilators that allow a more gradual rise?

rise time (PRAMP)

52

if you lengthen the rise time (Pramp) what will go away if pressure is to fast?

spike

53

if your rise time (Pramp) is too high what could happen?

patient will not receive a full lung volume before E time kicks in.

54

what is statics asthmatics

have trouble exhaling

55

decrease flow by decreasing the _____ _______?

pressure gradient

56

if flow reaches a constant value before the end of inspiration then the ventilator is considered what?

flow limited

57

prevent excessive pressure from going to the patient. If this control also ends inspiration the ventilator is considered to be _____ _______

pressure cycled

58

if the ventilator limits the amount of pressure that can be delivered to the patient but does not end the breath only limits more pressure from being applied is considered what?

pressure limited

59

what I:E ratios are best to set a patient on?

1:2 or 1:3

60

what is the pause, plateau or inflation hold used?

-therapeutically
-diagnostically

61

what parameter is responsible for terminating the breath for a single breath?

cycle parameter

62

volume delivered from machine is not all entering patients lungs. Positive pressure expands circuit and some of the gas is used up is known as ?

tubing compressibility

63

most circuits have how many mL/cmH20 lost to tubing compressibility?

3-4 mL/cmH20 more volume will be lost at higher pressures

64

if a vent is volume cycled it will continue to cycle even though it may be disconnected from the ventilator is known as a ________?

system leak

65

exception: if vents driving pressure is _____then it may lose volume at high pressure

low

66

what cycle would a patient be in if there end inspiration reaches 25% of peak flow?

flow cycle

67

if in this mode careful monitoring of waveforms is required?

flow cycled

68

machine starts breath, and machine controls and ends the breath. vent does all the work?

mandatory breaths

69

patient starts the breath, and machine controls and ends the breath?

assisted breath

70

patient starts the breath, patient controls and ends the breath. Machine augments breath?

spontaneous breath