# Mechanical Ventilation LAB and in class work

```VVC Ventilator Lab: Ventilator Manipulation
Ventilation = PaCO2; improve by increasing or decreasing minute ventilation
On AC mode
Uncompensated Respiratory Acidosis: Increase VT first (unless pressure is high, or
patient is at the higher end of the VT range; either 5-7 or 8-12 ml/kg); then increase rate,
over patients total rate. Rate is increased in increments of 2-4
Uncompensated Respiratory Alkalosis: Decrease rate first; then VT
Example: Settings: AC 12, total rate 18, VT 500, patient’s IBW 60 kg
ABG: 7.28, PaCO2 58, HCO3 25: Increase VT in increments of 50-100 ml
Make one Ventilation change only (either VT or Rate); when increasing VT or Rate you
may have to increase flow or decrease I-time to maintain the same I:E ratio
If on Pressure control, you can increase pressure limit to increase VT
On SIMV mode
You may increase rate first, since on SIMV the patient’s spontaneous rate will not
necessarily generate the same VT as the set VT. On SIMV patients triggered breath are
also completed by the patient, so any increase in mechanical rate will increase
ventilation. You may also increase the patients PSV
Oxygenation = PaO2; improve by increasing FIO2 or PEEP
Initiate PEEP for refractory hypoxemia, assessed by looking at A-a gradient. The rule is
if patient is on 60% FIO2 and remains with refractory hypoxemia you may initiate PEEP
or increase PEEP, generally in increments of 1-2 cmH2O.
Station 1. Puritan Bennett 840
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Attach filters, HME and circuit to ventilator
Attach circuit to compressor and plug in
Turn on ventilator
Based on the below scenario input your initial settings (ONCE DONE INFORM
THE INSTRUCTOR TO CHECK OFF):
An 81 year old man, height 5’7, 200 pounds enters the ER in full arrest. The patient
regains a pulse but remains apneic. The patient is intubated. No prior history is known,
patient was found down alone in the hallway of his apartment complex
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Calculate the patients IBW_________________________________
Set the patient in Volume control on AC mode
Set Rate, flow, sensitivity, FIO2 and Alarms (settings), record settings below
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__________________________________________________________________
Place patient in Square waveform pattern, then on Ramp, note the change in PIP
and I:E ratio ______________________________________________________
One hour later an ABG is obtained with the following results:
pH
7.28
PaCO2
67
PaO2
167
HCO3
29
BE
2.8
Correct the above ABG by making the appropriate changes to the ventilator (ONCE
DONE INFORM THE INSTRUCTOR)
 After your changes Calculate the patients RAW __________________________
 Obtain a Static and Dynamic Compliance
Cs__________________________________________________________________
Cd_________________________________________________________________
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Perform a expiratory pressure hold ________________________
Change the patient to SIMV mode, set PSV (above calculated RAW), decrease
the rate
Monitor the following and record the results:
PIP __________________
MAP _________________
Ve ___________________
I:E ratio _______________
VTe__________________
Go to plot setup and select Flow/time and Pressure/time
Trigger a breath and note appearance of trigger on graphic
Change graphic to Pressure/volume and draw appearance in space below
Change patient to Spontaneous mode, initiate PEEP. (note in this mode you will
have to stimulate breaths)
Note changes to MAP when PEEP is added. Also note baseline pressure change in
the Pressure/time graphic
WHEN FINISHED, DIASSEMBLE VENTILATOR CIRCUIT AND FILTERS
FOR THE NEXT GROUP
Station 2: Gaileo ventilator
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Attach filters, HME and circuit to ventilator
Attach circuit to compressor and plug in
Turn on ventilator
Based on the below scenario input your initial settings (ONCE DONE INFORM
THE INSTRUCTOR TO CHECK OFF):
A 27 year old man, height 5’10, 187 pounds enters the ER in status asthmaticus. The
patient is in severe respiratory distress and is intubated.
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Calculate the patients IBW_________________________________
Set the patient in Pressure Control on AC mode
Set Rate, I-time, sensitivity, FIO2 and Alarms (settings), record settings set below
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Set I time to achieve a I:E of 1:4, set I-time ______________________________
One hour later an ABG is obtained with the following results:
pH
7.68
PaCO2
27
PaO2
56
HCO3
22
BE
-2.8
Correct the above ABG by making the appropriate changes to the ventilator (ONCE
DONE INFORM THE INSTRUCTOR)
 After your changes Calculate the patients RAW __________________________
 Obtain a Static and Dynamic Compliance
Cs__________________________________________________________________
Cd_________________________________________________________________
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Perform a expiratory pressure hold ________________________
Change the patient to SIMV mode, set PSV (above calculated RAW), decrease
the rate
Monitor the following and record the results:
PIP __________________
MAP _________________
Ve ___________________
I:E ratio _______________
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VTe__________________
Note the pattern on the Flow/time and Pressure/time graphic
Trigger a breath and note appearance of trigger on graphic
Change graphic to Flow/volume and draw appearance
WHEN FINISHED, DIASSEMBLE VENTILATOR CIRCUIT AND FILTERS
FOR THE NEXT GROUP
Station 3: Espirit Ventilator
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Attach filters, HME and circuit to ventilator
Attach circuit to compressor and plug in
Turn on ventilator
Based on the below scenario input your initial settings (ONCE DONE INFORM
THE INSTRUCTOR TO CHECK OFF):
A 42 year old, 185 pound man, 5’8 tall, with advanced Myasthnia Gravis is admitted for
progressing weakness. A MIP is performed and indicates a value of -18. The patient is
therefore intubated with a size 6.0 ETT after difficulty by the RT to intubate.
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Calculate the patients IBW_________________________________
Set the patient in Pressure Control on SIMV mode
Set Rate, I-time, sensitivity, FIO2, PSV and Alarms (settings), record settings set
below
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Set I time to achieve a I:E of 1:3, set I-time ______________________________
Which parameter would you want to assess with a patient with a size 6.0 ETT?
__________________________________
One hour later an ABG is obtained with the following results:
pH
7.28
PaCO2
58
PaO2
120
HCO3
26
BE
1.2
Correct the above ABG by making the appropriate changes to the ventilator (ONCE
DONE INFORM THE INSTRUCTOR)
 After your changes Calculate the patients RAW __________________________
 Obtain a Static and Dynamic Compliance
Cs__________________________________________________________________
Cd_________________________________________________________________
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Perform a expiratory pressure hold ________________________
Change the patient to AC mode
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Monitor the following and record the results:
PIP __________________
MAP _________________
Ve ___________________
I:E ratio _______________
VTe__________________
Note the pattern on the Flow/time and Pressure/time graphic
Trigger a breath and note appearance of trigger on graphic
Change graphic to pressure/volume and draw appearance
WHEN FINISHED, DIASSEMBLE VENTILATOR CIRCUIT AND FILTERS
FOR THE NEXT GROUP
Station 4: In class work
1. Explain the procedure for a minimal leak technique
2. Explain what a MAP is and the factors that can increase it
3. Draw a flow/time graph with Auto-PEEP, label inspiration, expiration and the
point of air trapping
4. How can you decrease auto-peep in VC and PC?
5. Draw a pressure/volume loop for a patient on Volume control with over distention
6. What are the indications of PEEP? What are the side effects
7. What will occur if sensitivity level is set to high? Too low?
8. When is PEEP initiated?
9. What is the normal range for VC, MIP, MEP, RAW, Cs and Cd
For the following scenario, place the patient on initial ventilator settings
10. 89 year old, 5’8, with known respiratory acidosis, currently apenic, no other lung
disease.
11. Patient with pulmonary fibrosis, and a PaO2 40 on room air.
12. When would you place a patient on non-invasive ventilation as opposed to
invasive?
13. During mechanical ventilation what parameter would you adjust first in order to
correct a respiratory acidosis?
14. Describe what happens to Inspiratory time when flow is increase
15. What is the benefit of a constant flow pattern over a decelerating ramp?
16. What are some ways we could prevent or ease “bucking” or asynchrony with
mechanical ventilation?
Calculate the following formulas based on the scenario below
A 180 pound, 5’9, 56 year old man is intubated with a size 8.0 ETT. He is placed on
AC mode with a rate of 12, VT 550, 40% FIO2 and PEEP 5
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ABG: pH 7.30, PaCO2 52, PaO2 80, HCO3 20, BE -2
VBG: pH 7.26, PvCO2 60, PvO2 32, HCO3 22, BE -1.6
Na+ 150
K+ 5.5
Cl- 90
HCO3 26
Hb 10
Cardiac Output 4L
Inspiratory time 1.25 seconds, Expiratory time 3.25 seconds
PIP 36
Plateau pressure 32
17. CaO2
18. CvO2
19. VO2
21. Flow
22. VA
23. TCT
24. I:E ratio
25. Suction catheter size
26. Anion Gap
27. Desired PaCO2 of 40; calculate
New rate:
New VT:
28. Desired PaO2 of 90; calculate
New FIO2:
29. RAW
30. CD
31. CS
32. a/A ratio
33. MAP
A patient on SIMV mode with a set rate of 8 and total rate of 12, VT 500, PSV 10,
and FIO2 50%. Minute volume is 8 L
34. Calculate patients Spontaneous Ve
35. Calculate patients Spontaneous VT
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