Auto Flow 20Questions – 20Answers

1 auto Flow 20 Questions 20 AnswersJoseph FitzgeraldImportant Notice: Medical knowledge changesconstantly as a result of newresearch and clinical author of this introductoryguide has made every effort toensure that the information given is completely up to date,particularly as regards applicationsand mode of operation. However,responsibility for all clinicalmeasures must remain with by: Dr ger Medizintechnik GmbHJoseph FitzgeraldMoislinger Allee 53/5523542 L beckGermanyAll rights, in particular those ofduplication and distribution, are reserved by Dr gerMedizin-technikGmbH. No part of this work may be reproduced or storedin any form using mechanical,electronic or photographic means,without the written permission ofDr 3-926762-40-3 auto Flow 20 Questions 20 AnswersJoseph Fitzgerald20 Questions 20 Answers using AutoFlow 4 ContentsnWhat is AutoFlow ?

2 6nIs AutoFlow a new Ventilator Mode?7nWhen would you use AutoFlow ?8nHow does AutoFlow compare to BIPAP9nHow is AutoFlow combined with other modes such as IPPV?10nHow does AutoFlow work with SIMV?11nHow does AutoFlow work with MMV?12nHow does ventilation with AutoFlow compare with volume controlled ventilation?14nHow does ventilation with AutoFlow compare to pressure regulated modes?15nWhat type of lung diseases is AutoFlow suitable for?16nAre there situations where it is not indicated?17nWhat has to be considered when switching fromconventional modes to AutoFlow ?18nHow do you set up AutoFlow ?19nWhat monitoring parameters are important toobserve when using AutoFlow ?2020 Questions 20 Answers using AutoFlow 5nWhat are the advantages to observe when using AutoFlow ?

3 22nWhat would be the subsequent management of the patient?23nWhat are the safeguards againsthypo/hyperinflation?24nHow does AutoFlow interact with inverse ratioventilation?25nHow can mechanical ventilation and spontaneous breathing be mixed in one mode?26nWhat is the technology behind this latest advance in therapy?28 Explanatory note: In some regions of the world IPPV mode of ventilation is referred to as CMV andAssist/CMV. The mode BIPAP is referred to as PCV+ inthe USA and Canada. BIPAP* is trademark used underlicence. AutoFlow is registered as a trademark ofDr 20 Answers using AutoFlow 61. What is AutoFlow ?This is a new advance in volume controlled modes of mechanical ventilation where the ventilatorautomatically regulates inspiratory flow. This autoregulation is in accordance with the set VTandcurrent lung compliance.

4 The set VTis always given at minimum possiblepressure and spontaneous breathing is possible (openvalves) through the whole Inspiratory and Expiratoryphases of the mechanical ventilatory decelerating flow pattern reduces Peak pressuresand as lung compliance changes further they arerecognised and responded ControlledSwitch-on AutoFlow TVTA decelerating flow patternreduces Peak pressures20 Questions 20 Answers using AutoFlow 72. Is AutoFlow a new Ventilator Mode?It is a new addition to all volume controlled modes onthe Evita4 and Evita2 dura ventilator. It is not a modeindependently selected in itself. It could be comparedto the way one function enhances another such asflow trigger enhances pressure is intended to simplify strategies in mechanicalvolume controlled ventilation by offering more patientbenefits with a wider therapy range and with lessparameters to 20 Answers using AutoFlow 83.

5 When would you use AutoFlow ?There are very few exceptions to using AutoFlow inall volume oriented modes where it is available. Ingeneral we can divide its use into two areas, that ofthe type of ventilatory strategy we want to apply andthat of the type of patient that it is particularly suitedto. In the first case in volume strategy ventilationwhere we want to reduce high airway pressures andcapitalise on spontaneous breathing with reduced useof sedation and muscle relaxants. The deceleratingflow and the regulated inspiratory and expiratoryvalves provide a response to every inhalatory andexhalatory effort of the patient. This feels like breathingthrough an open other strategies we may want to use inverse ratiotimings. The occlusion of the expiratory valve for suchlengths of time can produce risk of barotrauma for apatient who becomes awake and starts an open breathing system this risk is terms of patient types, there are those with quitevariable compliance levels after surgery who requirecareful manipulation of inspiratory pressure andvolume to prevent barotrauma and continually adjusts the pressures ascompliance changes to ensure volume delivery at thelowest possible , as a smooth weaning strategy we want thefirst efforts by the patient to be responded to in allphases of the mandatory stroke unlike conventionalmodes of SIMV where there are closed phases in thecycle.

6 The fixed set VTdelivery of SIMV is also addressedfor Bronchospasm patients with air hunger as alldemands for flow and volume are responded to by 20 Answers using AutoFlow 94. How does AutoFlow compare to BIPAP?BIPAP has been established for a number of years as a real advance in pressure controlled ventilationstrategies. Pressures are regulated at a specific valueand pressure peaks are eliminated and together withtime synchronisation the patient is able to breathespontaneously at any stage. Many of these features arenow transferred across into the volume controlledmodes as the benefits of this therapy have becomemore extensively accepted. The prime parametersetting in BIPAP is inspiratory pressure (Pinsp) andtidal volume (VT) is variable, the prime adjustment inAutoFlow is VTand the pressure is the variable,depending on the benefits of BIPAP are transferred into volumecontrolled modes withAutoFlow 20 Questions 20 Answers using AutoFlow 105.

7 How is AutoFlow combined with other modessuch as IPPV?The addition of AutoFlow to IPPV mode for example is achieved by the on-going measurement of pressure,flow, volume and lung compliance and a ventilatorresponse that regulates the flow to achieve the set VTin the inspiratory time available. When you switch onthere is a change from manual control to an automaticcontrol of the inspiratory flow. Other than the removalof the control knobs of pressure (Pmax) and flow fromthe touch screen panel all the core settings includingtrigger function and pressure support capability aretotally core settings includingtrigger function and pressuresupport are 20 Answers using AutoFlow 116. How does AutoFlow work with SIMV?Equally in SIMV any of the usual parameters such as PEEP are fully functional and superimposingAutoFlow brings auto -regulation to the flow associated potential advantages have a dominoeffect in that a lower peak pressure usually means alower mean airway pressure with a positive effect onhaemodynamics, the inspiratory flow varies accordingto individual patient needs and may alter on a breathto breath basis.

8 AutoFlow supports the preservation ofan intact respiratory drive as less sedation and musclerelaxants are used. The matching of flow and volumeto patient needs in synchrony with inspiratory time at minimum pressure promotes harmony betweenpatient and ventilator. This reduces considerably thephenomena known as fighting the ventilator whichis a misnomer in that the ventilator fights the patient with its imposed fixed supports thepreservation of an intactrespiratory drive as less sedation and musclerelaxants are 20 Answers using AutoFlow 127. How does AutoFlow work with MMV?The mode is similar to SIMV in many respects wherethe clinician sets a rate and VTfor the patient to satisfyadequate gaseous exchange. It differs from SIMV inthat as spontaneous breathing activity increases andthe patient achieves more than the set mandatoryminute volume then the mechanical strokes fade intothe background.

9 The patient, often with the aid ofpressure support takes over the full volume work ofminute ventilation. In MMV, AutoFlow influences themechanical strokes if present and reduces asynchronyby allowing spontaneous breathing activity andreducing pressures to a logical progression of this is that the patientcan be sedated and on full controlled ventilation, ashe wakes up he will still get mechanical strokes but he will be able to breathe through them and notexperience any discomfort with these breaths ,as hiscontribution increases the ventilator breaths fadeaway completely so the patient does not have to beswitched to a weaning addition to this if we now use the Ideal BodyWeight setting and programme the weight into theventilator before start of therapy then the right volumeand ventilator settings will be selected for that patientand appropriate alarm defaults also.

10 All this meansthat post operatively we can easily select what we wantfor the patient and in straight forward ventilationcases we can start with full ventilation therapy and goright through to full spontaneous breathing withouthaving to readjust the ventilator adjustmentrequired when going fromfully controlled ventilation tofull spontaneous 20 Answers using AutoFlow 13nSelect Ideal Body Weight (70kg).Key values and alarms set automaticallynSet ventilator to standby arriving patient. Start ventilationnRecord monitored parametersnMaintain observation of the patient as they wake AutoFlowControlledVentilationSpont. effortsandmandatory phasesTotal spontaneouseffortsCPAP withpressure supportIdeal body weight 70kg20 Questions 20 Answers using AutoFlow 148.