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%