doctrine of medicine: types of ventilator

Draeger EVITA 4

Classification:

· microprocessor controlled electronic ventilator

· multiple weaning modes

· three power sources (Gas, electrical, internal and external battery source)

Modes available:

· SIMV +/- PSV

· PCV +/- PSV

· PSV

· CPAP

· BIPAP (MMV, APRV, PAV)

Default ventilator setting:

MMV TV 800 x 10 BPM x FIO 2 .5 x Peep 5cms x PPS 10 cms Rise time 0.2 sec

Insp time 1.8 sec

· connect the ventilator to mains supply

· push the mains switch

· press alarm silence and alarm reset

· select devise check

· select mode settings

· select basic settings and adjust parameters as desired (default settings available)

· select extra settings

· select flow trigger (default setting of 5.0)

· select tube compensation (select desired size 8/9 )

· select compensation (defaults to 80 %)

· select alarm limits (adjust default settings according to patient’s weight)

Confirm changes by pressing the rotary knob. The parameter will change to yellow, select degree of change and confirm by pressing the rotary knob, the parameter will return to blue.

MANDATORY MINUTE VOLUME VENTILATION:

· press mode setting

· select mode MMV on touch screen and confirm by pressing central rotary knob

· TV 800

· RR 10

· adjust inspiratory time so that 1.8 secs

· rise time 0.2 sec

· pressure support 10 cms H 2 O

· PEEP 5 cms H 2 O

· FiO2 .5

Select Extra Settings Mode:

· flow trigger (default setting) 5l/min

· tube compensation (appropriate ETT size and 80 % compensation)

Alarm /limits:

· minute volume +- 50 % of expected MV

· frequency spontaneous 32

· VT i 50% below expected

· Paw 35cm H 2 0

· T apnoea 20 sec

· et CO 2 30 - 45

PRESSURE CONTROL + PEEP ± PSV

Default prescription: Pinsp. = 30 ´ 12 + 5 PEEP, FiO2 .5, I: E 1:2.

Select Mode: PCV+

Select settings:

· select FiO2 .5

· select T insp 2 secs adjust inspiratory time so that I:E ratio is 1:2

· select desired rate 10

· select rise time 0.2 sec

· select total inspired level of pressure (Pinsp) which includes PEEP: default 10cm H 2 0

· select PEEP 5cm H 2 0

· select pressure support 10cm H 2 0

· alarm limits unchanged from default

· do not exceed total inspired pressure > 35cm H 2 0

· tidal volume is determined by the patient’s compliance

· ensure I: E ratio is 1:2: alteration of the I: E ratio is potentially hazardous and must be done in consultation with medical staff

Measurement of Autopeep:

Measurement of intrinsic PEEP at end of expiration + closed glottis (non spontaneous modes) If I: E ratio is altered: auto peep must be measured.

· press special procedure button

· select PEEPi, press start to begin automatic 7second manoeuvre

· read off auto peep and trapped volume (Vtrap)

· the value displayed is misleading and includes external PEEP, so that determining the actual value of Autopeep requires the external PEEP to be subtracted from the displayed (PEEPi) value

· adjust applied PEEP if Autopeep > 0-1 to obtain total applied PEEP

Measurement of occlusion pressure (P0.1)

Measurement (100msec) of mouth pressure at start of inspiration against closed glottis. Pressure is dependent on diaphragmatic effort and reflects neuro muscular drive. Normal value = 3 - 4 mbar, higher values (e.g.> 6nbar) reflect fatigue.

Press special procedure button

· select P0.1and press start to begin

· read off P0.1

PRESSURE SUPPORT + PEEP

Settings described for use with SIMV, PCV and CPAP

Stand alone settings:

· select mode Psupp