setting up and initializing a ventilator
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Setting up and Initializing a Ventilator. Ventilator Circuit. Before you can begin mechanical ventilation your ventilator must be correctly assembled - PowerPoint PPT PresentationTRANSCRIPT
Setting up and Initializing a
Ventilator
Before you can begin mechanical ventilation your ventilator must be correctly assembled◦ Step 1: Assemble expiratory and inspiratory
filters on the ventilator. (ventilators vary, so this process will also vary and be taught during lab)
◦ Step 2:Attach circuit to ventilator. Acute ventilator circuits will have an inspiratory limb and an expiratory limb so that the circuit is unbroken and the patients returned volumes are assessed on the vent.
(long term vents typically have a inspiratory limb only)
Ventilator Circuit
A expiratory filter with H2O trap for condensation- this is for the 840 ventilator. Attached to the ventilator, prevents H2O from entering the machine
A inspiratory filter, attached to the vent and inspiratory limb, prevents small particulates from the machine to the patient
Subacute/long term vent circuit, the patients exhalation does not go back into the ventilator. Uses a separate pressure line
Pt exhalation
Pressure line
To pt
WyeInspiratory limb
Expiratory limb
Extra tubing for heater
Heater probe inlet
Heater probe inlet
To Pt
Step 3: Once circuit is attached, close all open ports on the circuit. Circuits have ports for heated humidification temperature probes
If circuit is a heated circuit attach humidifier and probes
Most adult ventilators are setup with an HME initially. All neonatal and pediatric circuits are setup with heated humidifiers with heated circuits
If you setup a heater, but do not have a heated circuit, you must use water traps inline to catch the condensation that will develop
Ventilator Circuit
Non-heated circuit with water traps
Water trap
Concha Heater. Heats up a metal column water
Passover heatedHME, placed at Wye
Ventilator circuits are age specific. For an adult you must use an adult circuit, pediatric and neonates have specific circuits as well
Neonatal and Pediatric circuits are always heated circuits- meaning they have a coil inside to maintain temperature during humidification
Depending on the ventilator usedsome circuits will have a pressureline inlet attached to the machineand/or a flow sensor adapter
Ventilator Circuit
Ventilator circuits should not be changed routinely for infection control purposes, however you can change a circuit if soiled
Circuits are sterile, meaning you should not insert a younker inside the circuit to remove secretions.
Once the circuit is attached you can now plug in the electrical and air/O2 connections to your ventilator…
Ventilators are electrically powered and pneumatically driven
Ventilator Circuit
Ventilator SetupLong term vent
Transport vent with O2/Air cylinders
The use of closed suction catheters should be considered part of a VAP prevention strategy, and they do not need to be changed daily for infection control purposes. The maximum duration of time that closed suction catheters can be used safely is unknown
Inline Suction Ballards
Use only inline suction ballards on vents. They make ETT and Trach sizes
Once your circuit, filters and humidification is on and your vent is plugged in to electricity and Air and O2, you can now do the pre-use calibration
This varies greatly with all ventilators, but generally you start by turning on your vent (remember, most vents you will take off the stopper at the WYE when you first turn on the vent)
Once the vent is on you choose SST (short self test) option to run the calibration
Ventilator Calibration
The calibration will assess the circuits compliance/elastance, check for leaks and proper flow
http://www.youtube.com/watch?v=4p0SppVbGMs
Ventilator Calibration
Once it has been determined a patient requires a ventilator you must now attach them and apply the proper settings.
When you first turn on the ventilator you will press either “new patient” or “same patient”, verbiage will vary. Most new vents will save the previous settings in case you transfer a patient and reattach them
During the setup the patient is typically being bagged. The MD may or may not give you the settings.
Setting up your vent settings
Mode is AC, SIMV or CPAP◦ Assist control (no breathing, or inadequate
breathing, patient sedated…)◦ SIMV (same reasons as AC, but you expect
patient will breathe spontaneously soon, post ops)◦ Spontaneous/CPAP: Patient is breathing
spontaneously ◦ http://www.youtube.com/watch?v=IUZ3Plmz_YQ&f
eature=related
MODE
PCV: Used for patients where you want to control their pressure limit, set on AC or SIMV◦ Set inspiratory pressure limit, I-time, FIO2, PEEP, Rate
VC: Used in most patients, control minute volume, set on AC or SIMV◦ Set tidal volume, flow, FIO2, PEEP, rate
PRVC: Becoming a common mode for most patients, limits pressure and gives a minimum volume, set on AC or SIMV◦ Set minimum VT, pressure limit, FIO2, rate, peep, I-
time
Breath Type
Once you decide what mode and breath type, next you input the settings.
VT: set in VC mode, based on IBW, normal range 8-12 ml/kg, restrictive lungs 5-7 ml/kg
Flow: Set to give an appropriate I:E ratio, typically 40-60 LPM, set higher for COPD patients, watch for airtrapping
Pressure Limit: set to achieve an acceptable VT, typically set between 15-25 cmH2O
Settings
I-time: Decrease when rate is set high, otherwise start around 0.8-1 second
Rate: Initial rates are 8-12 per min. If you suspect or know patient has high PaCO2 you may start higher
FIO2: typically set at 100% if it’s a new patient and you do not know their PaO2, otherwise set per patients FIO2 before vent if it was acceptable
PEEP: typically started at 0, and added once FIO2 is at 60% and patient has refractory hypoxemia, then initiate at 5
Settings
Pressure Support: If you started in CPAP or SIMV mode, you will set a PSV. Typically around 10-12 cmH2O, but give to increase spontaneous Vte to acceptable ranges and give enough to over come RAW
Sensitivity: Set as either flow or pressure. In either one it is set between 0.5-3, the higher this number the harder it is for the patient to trigger the breath, the lower =auto trigger
Settings
Flow pattern: In VC mode you can choose how the set flow will be delivered to the patient. Either as a constant flow (Square) or as a decelerating pattern. In PC and PRVC the flow is not set, so the pattern in always decelerating. A constant flow will increase MAP, this will increase oxygenation but increase PIP
Settings
Pressure Control
Indications for Pressure Controlled Breaths Any time it is desired to limit inspiratory
pressure.
High PIPs
Low Pa02
Need high, variable flow rates
Goals in ARDS
ARDS goal - control/minimize lung damage
Literature suggests – low alveolar pressure / low Vt
strategy– recently more concerned with
lung damage caused by over distention
– preventing repeated collapse and reopening of alveoli
Treating ARDS
What are your goals for these patients?– O2 delivery– oxygenation is more affected by
MAP– PCV, BiLevel, or APRV may be a
better way to approach these patients peak airway pressure and MAP is
controlled oxygenation is favored ventilation is sacrificed if it conflicts
with controlling pressure
Pressure Control Pressure Control is time cycled.
Rapid rise to set pressure and pressure is maintained for the duration of the inspiratory time.
Inspiratory plateau promotes alveolar recruitment and oxygenation.
Pressure Time Curve
1 2 3 4 5 6
30
-10
PawcmH20
Sec
ACCESS FUNCTION 60 TO CHANGE OR EXIT WAVEFORMS
FEB 11 1996 WAVEFORM MONITORING PATIENT ID 98787987 13:50
Volume
Expiration
1 2 3 4 5 6
30
PawcmH20
Sec
Volume Pressure
Pressure Time Curve
V.
Inspiratory Time
Selecting Inspiratory Pressure Use the plateau
pressure obtained during volume ventilation as a starting point (if you started in VC first)
Adjust pressure to obtain desired Vt in the range of 5 – 8 cc/kg
Selecting Peep Level
0 20 40 60204060PawcmH
20
VTLITERS
“D” = Lower Inflection Point
A B
“A” represents PEEP“B” Represents Inspiratory Pressure
.6
.2
.4
“C” = Upper
Inflection point
Setting I-Time in PCV
Observing the Flow and Tidal Volume Time curve during PCV can help determine adequate inspiratory time.
Observing the Pressure Time curve will assist in determining if the I -Time is too long
1 2 3 4 5 6
SEC
1 2 3 4 5 6
VT
600 cc
-20
120
120
SEC
V.
LPM
0
450cc
1 2 3 4 5 6
SEC
1 2 3 4 5 6
VT
-20
120
120
SEC
V.
LPM
0
500cc450cc
Lost VT
600 cc
1 2 3 4 5 6
30
-10
PawcmH20
Sec
Assessing correct Inspiratory Time in PCV
Too Long
Optimal
Answer - Inspiratory time set too long
Patient is starting to exhale prematurely.
Setting Inspiratory Time Flow x Time = Volume Increasing the I time can increase the Vt.
Try this before increasing the inspiratory pressure.
Watch for I time too long, causing auto peep and dyschrony.
Keep I time constant to maintain more stable tidal volumes
The Pressure Control Mode
Pressure Control
Pressure Control– Set high pressure =
PI PI is PEEP compensated
and changes as PEEP level changes
– Set low pressure = PEEP
– Set breath timing parameters = TI, TE, I:E ratio
Rise TIme Commonly referred to as rise %, or
rise time
Available in all pressure breaths (PC, PS, and spontaneous)
Tailors inspiratory rise to match patient demand. Does not change I time.
Rise Time % Commonly referred to as rise %, or rise
time
Tailors inspiratory rise to match patient demand
Rise Time %
Pressure Relief
Transient Overshoot
FAP = 1 FAP = 50 FAP =
100
Expiratory Sensitivity (ESens)
V
T
Peak Inspiratory Flow
5%20%
40%