MV: ventilator waveforms ppt (13/24)

different colored alarms

green = none

yellow = HAS happened but resolved

red = CURRENT issue

what do you set low Ve at?

75%

what alarms share the same sound?

increased RR + Ve

what does low PIP alarm mean?

leak or pt. actively sucking against vent

should you record numbers right after getting off standby?

NO! vent takes time to count and calculate breathes before giving accurate numbers which is why the alarms are naturally muted at first

importance of high PIP alarm? what happens when a patient is continuously capped?

CAPS PIP by limiting it to set alarm. default PIP is @40 as before it was extremely dangerous to go past 40 so be careful when placing a patient on the vent and not double checking.

if their PIP continues to hit the cap, this will cause their Ve and Vt to decrease as their breaths continue to get shorted to short the pressure

patient factors for patient-ventilator asynchrony

1. resp mechanics (e.g. resistance, elastane, compliance, hyperinflation, Ve demand)

2. muscle capacity

3. resp drive

ventilator factors for pt-vent asynchrony

1. trigger

2. breath delivery and termination

3. mode

4. applied PEEP

5. ETT size and circuit

what is the most important scalar?

PRESSURE! has the most moving contributionsP

peak pressure definition

pressure it takes to achieve breath including Raw + compliance, ETT resistance, speed/turbulence of flow, size of breath and set PEEP

On a waveform, where is the airway resistance represented? where is compliance represented?

Raw is the difference between the PIP and the pplat, compliance is the difference from 0 to pplat

definition of peak flow/Ti

speed at which breath is delivered by machine, w/ high flow giving more Te but more turbulence.

decal vs square in regards to Te

square has more Te due to its shark fin appearance

which scalar does air trapping show in? how is this different from a leak on a scalar?

FLOW scalar! It is a volume problem shown through flow. You may see volume plateau above 0 and then on exhalation drop to 0 to start a breath again; however, this would be a LEAK if the flow scalar remains normal. the breath HAS to start @0 so you don’t know where the rest of the volume when.

definition of asynchrony and its 3 types

when settings don’t match the patient’s lung dynamics

1. flow starvation

2. trigger

3. time

air hunger definition? what scalar does it show on? how is it fixed?

speed of breath not meeting pt demand so pt. sucks PRESSURE out of the system, being a FLOW issue showing on the PRESSURE SCALAR. this can be fixed in 5 ways:

1. decreased Ti or increase I:E (make breaths faster)

2. increase flow

3. square → decel

4. bronchodilator

5. decrease RR

need to see what the pt. WANTS to breathe, so set RR lower than what pt. breathes unless they cannot breathe independently. sicker the pt., the faster they breathe!

types of triggers

1. flow trigger: based on how much BIAS flow is drawn down by pt., being MC + most natural

2. pressure trigger: how much pressure pt. sucks back on system, being less sensitive but preventative for double-stacking or auto-triggering

3. none (be very careful!)

missed/ineffective trigger on scalars. would changing trig setting help?

a tiny bump on the pressure scalar and a negative dip in the flow scalar in replace of a full breath because the patient is TOO FULL to take a complete breath in, possibly being caused by air trapping.

changing trigger setting would not do anything.

breath stacking/double cycling definition

BAD!!!! LOTS of increased job to double stack as pt. is getting DOUBLE the volume, increasing the pressure in order to do so. this causes the pt. to be delivered more volume on the 2nd breath as the vent’s volume scalar will go in to the negatives on the 1st breath and then compensate for that on the 2nd breath.

how to fix breath stacking? what should you not do?

Fix it by INCREASING THE RR!!!!! as well as sedating or PS if pt. is capable

NEVER CHANGE TRIGGER!!!! this will cause more pressure and will now allow pt to get the breath they want.

auto cycling

delivering breaths NOT triggered by pt or timed by vent as a leak is so big it auto triggers. this is shown on the scalars as like a Vtach but for scalars (very rapid + incomplete breaths).

what is auto cycling caused by? what fixes it?

caused by leaks, obstructions in circuit, negative sxn through chest tube, nebulizer treatments, cardiac oscillations

fixed by fixing said issues above, increasing trig sensitivity or changing from flow to pressure triggering.

double triggering vs reverse cycling

double triggering is caused by UNDER sedation and small volumes, being PATIENT TRIGGERED

reverse cycling is caused by OVER sedation and large volumes (over distention), being VENT TRIGGERED and extremely dangerous

problem with aPEEP? what fixes it?

pt. has to FURTHER PULL to trigger breath as it needs to reach the set PEEP AND set trigger! fix this by stopping air trapping and/or match total PEEP!

ex. set PEEP +5, set trigger -2 = need to be @3cmH2O to trigger the vent. If aPEEP is at 10, pt. needs to pull -7cmH2O to trigger it!