Patient synchrony and Unique Considerations

Common patient/asynchromies

• missied inspiratory effort

• patient trigger delay

• auto-triggering

• end of breath delay

patient/ventilator async con’t

• impedes gas exchange

• increase O2 comsumption and metabolic demands

• increases intrathoracic pressures

• agitates patients

asunchrony solutions

1. paralysis

2. sedation

paralysis

• no commonly done

• consider

  • drug toxicity

  • increase O2 requirements (especially small infants)

  • failure of skeltal muscle growth

  • delay in weaning

sedation

disadvantanges: Hypotension, may modify EEG activity

both paralysis and sedation would suppress ___

ventilatory

best way to reduce asynchrony

• ensure ventolator can reconginze your patient

• proximal flow sensing

• Edi signal and NAVA

proximal flow sensing

most common way to synchronize ventilation in our NICU today

ventilator like ____ and ____ very good internal flow sensors- still currently used for larger infants/peds

servo-u and PB980

pneumotachometer

• device that measures gas flow then integrates the signal to give a volume measurement

• “proximal” measuremnts is considered more accurate than a distal measurement

Mostly common pneumotachometer

• heated aneumometer

• variable orfice

flow sensor measurement principle - no gas flow

two tiny platinum wires are heated to 40^o

flow sensor measurement principle - no gas flow - with gas flow

• gas flow cools the wire down

• from the amount of cooling the amount of gas flowing can be calculated

Drager flow sensor

• flow sensor housing two different types

• difference deadspace volumes

• flow sensor cables

ISO deadspace drager flow sensor

0.9 mL

deadspace in this drager flowsensor

1.7 mL

variabke orifice pneuomotach

• uses resustance to create a pressure drop that is proportional to the flow

• bidirectional and disposable

• design relies on variable orficed to generation the flow-pressure signal

hamilton G5,C1, T1

<1.3 ml

problem with penumotachs

• moisture

• secretion

• ambient temperature

• humidity

• altitude

• placement of the sensor

• compressible volume loss

accuracy ± 10-15%

most neonatal ETT are

uncuffed

do we want small amount of leak around the ETT

yes

adapting to leaks (Trigger and cycle) - Hamilton G5

intelliTrig automatically adjusts inspiratory and expiratory trigger sensitivity to airway leaks

PB980 ventilator

leak sync tech

Servo-I, Servo-U and Servo-n

leak compensation tech and of course NAVA which was developed to improve patient/vent synchrony

Flow trigger are highly recommened, what is the rule of thumb for sensitivity

start as sensitive as possibel and decrease sensitivity if autotrigging occurs

Drager VN500 V500

0.3 lpm

Fabian HFO

0.12 lpm

G5, Servo u

flow trigger, (pressure trigger)

leak compensation during breath delivery

many ventilator have ability to compensated for volume loss due to leak.

leak compensation turned OFF

Vtmand = 200ml (target)

Vtimand =200ml

Vtemand = 119

(40% leak)

Leak Compesation turn ON

Vtmand = 200ml (target)

Vtimand =279ml

Vtemand = 169ml

(40% leak)