S5 and AS3 ADU Carestation Ventilation supplement, Supplement to Users Reference Manual April 2005

S/5 and AS/3 ADU ventilation Supplement to User’s Reference Manual

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Conformity according to the Council Directive 93/42/EEC concerning Medical Devices

All specifications subject to change without notice. Document No. M1038740 Issue M1044700 April 8, 2005

Manufacturer: GE Healthcare Finland Oy Helsinki, Finland P.O. Box 900, FI-00031 GE Tel: +358 10 39411 Fax: +358 9 1463310 www.datex-ohmeda.com www.gehealthcare.com  2005 General Electric Company. All rights reserved

English About this Supplement Controlled mechanical ventilation (Auto)

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New way to change ventilation modes... 2

Pressure Support Ventilation, PSV (optional)

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Description... 4 Switch to PSV mode... 5 PSV controls... 6

Ventilator settings

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Pressure settings... 7 PEEP settings... 7 Trigger settings... 8 Backup time... 11 Presetting values... 11 Default settings... 12

Restart of the display

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Display description... 13 Recommended actions... 13

Technical specifications Appendix

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PSV pressure curve... 17

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English About this Supplement This supplement to the ADU User’s Reference Manual describes the Pressure Support Ventilation mode and some other new features on the ADU. The supplement applies to the Datex-Ohmeda S/5 Anesthesia Delivery Unit (ADU) and AS/3 ADU. In this supplement, both the S/5 ADU and the AS/3 ADU will be referred to as ADU. This supplement is not intended to give a complete and detailed description of all functions to the operator, such description will be found in the ADU User’s Reference Manual.

Controlled mechanical ventilation (Auto) This section replaces the corresponding section in chapter “5 Operating and adjusting the settings” of the ADU User’s Reference Manual. Before starting Controlled Mechanical Ventilation, check that the patient circuit pressure alarm limits have been adjusted to values appropriate for the patient. 1. Push Alarms Setup key to view alarm limits and adjust if necessary. 2. Turn the selector on the ventilator bellows unit from Man./Spont. to Auto position to start the controlled mechanical ventilation. The brackets around the ventilator settings disappear.

Figure 1 Turn the Auto/Manual selector to Auto

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The ventilator is electronically controlled and pneumatically driven. The mechanical ventilation modes are: • Volume Controlled Ventilation (VCV) • Synchronized Intermittent Mandatory Ventilation (SIMV) • Pressure Controlled Ventilation (PCV) • Pressure Support Ventilation (PSV)

Volume Control

SIMV

Pressure Control

Pressure Support

Figure 2 Appearance of ventilation modes in the ventilator settings field

New way to change ventilation modes The ADU has been enhanced with a new method to switch between ventilation modes. The new method is factory default, but the ADU can be configured to use the old method. Contact a service technician to reconfigure. 1. Push the Ventilator key. 2. Review the settings for the new mode. 3. Select Mode. 4. Select the desired mode. 5. The main parameter for the selected mode is highlighted and activated for adjustment for 10 s. The ventilator switches mode when the parameter has been confirmed. There are three alternatives to confirm: • Confirm the value with ComWheel. • Wait 10 s and let the system automatically confirm the setting. • Adjust the value and follow with either of the two actions above.

Ventilator Mode VCV Patient Weight

VCV

Tidal Volume

SIMV

Set Pressure [AUT

PCV

Resp. Rate

PSV

I:E Ratio Set PEEP OFF Sensitivity Options Normal Screen Volume-controlled ventilation selected.

NOTE: Some setting combinations may not allow switching from one mode to another. In such cases, advice on what to do is stated in the Help Field.

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When changing ventilation mode new ventilation settings will be activated. The settings are either suggested values based on the previous ventilation mode or defaults. Examples: • When changing from VCV to PCV the ADU suggests an inspiratory pressure: The suggested pressure is based on the pressure difference between Pplat and Peep in VCV when the set volume is delivered. • When changing from PCV to VCV the ADU suggests a volume: The suggested volume is the volume measured by the monitor during the pressure controlled mode. It is important that the operator reviews all the ventilation parameters when changing to another ventilation mode. The most important parameter in the new ventilation mode is highlighted with a flashing background and can easily be adjusted. The new ventilation mode will be activated when that parameter is manually confirmed or automatically confirmed after a 10 second delay. Switching to and from SIMV Note the following when switching to and from SIMV: When entering SIMV mode the current Insp (inspiration time) remains unchanged, but new values that are appropriate for SIMV are suggested for Resp. Rate, Minute Volume, exp (expiration time), I:E Ratio and Insp. time %. When leaving SIMV mode, the insp, Resp. Rate, Minute Volume, exp and I:E Ratio will resume the values they had before entering SIMV. Changes made to these parameters while in SIMV will no longer be in effect. Confirming settings The new method to switch between ventilation modes also changes the timeout of changed ventilator settings from cancel to confirm. This applies when the setting is changed via the quick keys. If the changed setting is not confirmed by the user within 20 s, it is automatically confirmed by the system. WARNING: Before activating Volume Controlled Mode, ensure that Tidal Volume, Resp. Rate and I:E Ratio are correctly adjusted. WARNING: When switching from PCV or PSV to Volume or SIMV, ensure that the set Tidal Volume is appropriate for the patient.

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WARNING: Most anesthetic agents may cause patients to have reduced ventilatory responses to CO2 and hypoxemia. As a result, triggered modes of ventilation may not produce adequate ventilation. WARNING: Neuromuscular blocking agents may interfere with triggering.

Pressure Support Ventilation, PSV (optional) Description PSV is a pressure supported ventilation mode with apnea backup. PSV supports the patient’s spontaneous breathing and is intended for patients with weak breathing effort - both low inspiratory flow and pressure drop - for example during the wake-up phase of anesthesia. The PSV mode will give best performance using low flow anesthesia. When the patient has triggered a breath, the ventilator builds up the patient circuit pressure to the set level and maintains the pressure until the expiration phase. The inspiratory flow is decelerating and optimized to provide the set pressure level as quickly as possible. There is no guarantee of the delivered volume in PSV - use of a volume monitor is therefore required. Inspiration The inspiration support starts when the patient triggers a breath within the set trigger sensitivity. If the patient does not trigger a breath, the ventilator will deliver a backup breath after the set backup time. Expiration The expiration phase starts when the inspiratory flow drops to 15% of the peak flow.

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Pressure

Set pressure level

Patient effort Time Trig sensitivity level

Insp. trig

Figure 3 PSV mode pressure curve

Switch to PSV mode 1. Review the settings for the PSV mode. 2. Push Ventilator key. 3. Select Mode. 4. Select PSV. 5. The pressure parameter is highlighted and activated for adjustment for 10 s. The ventilator switches mode when the parameter has been confirmed. There are three alternatives: • Confirm the value with ComWheel and the ventilator switches immediately to PSV mode. • Wait 10 s and let the system automatically confirm the value, then the ventilator switches to PSV mode. • Adjust the value and follow with either of the two actions above.

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PSV controls Controls Set Pressure Backup Time Set PEEP (Positive End Expiratory Pressure) Sensitivity Trigger window

The fields for Backup Time and Trigger are possible to configure on or off in the Screen Layout menu. The Trigger field is activated via the menu items Screen Layout-Extra I:E Times or Extra I:E Ratio and the Backup Time is activated via Inspiratory Pause.

Set Pressure

Backup Time sec

Trigger Sens Window

Pressure

Set PEEP

Support

Figure 4 PSV controls

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Ventilator settings The following sections replace the corresponding sections in chapter “5 Operating and adjusting the settings” in the ADU User’s Reference Manual.

Pressure settings Set Pressure Current

Volume/ Pressure

• Adjustable range: 5 to 40 cmH2O above Peep. • Default setting: 12 cmH2O above Peep. • Set in ventilation modes: PCV and PSV • The pressure is maintained during the inspiration phase. NOTE: The set pressure is always above Peep.

PEEP settings Volume Control

Set PEEP Current

OFF

PEEP

• Adjustable range: 5 to 20 cmH2O • Default setting: OFF • Set in ventilation modes: VCV, SIMV, PCV and PSV. NOTE: Because of the standing bellows and the overflow valve design, there is a minimum positive end-expiratory pressure between +2 and +4 cmH2O. • For Tidal Volumes below 100 ml, Set PEEP cannot be adjusted to values above 10 cmH2O. • The Set PEEP value also adjusts: Ppeak Low pressure alarm (Set PEEP+4 cmH2O)

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Datex-Ohmeda ADU ventilation Pressure

Pause

Time

Peep Inspiration

Figure 5 Example of Peep curve

Trigger settings Trigger sensitivity settings • Adjustable range: - 0.5 to -5 cmH2O • Default setting: -1.0 cmH2O • Set in ventilation modes: SIMV and PSV 1. Push Ventilator key to display menu. 2. Select Sensitivity. 3. Turn ComWheel to adjust Sensitivity. 4. Push ComWheel or Normal Screen. Ventilator Sensitivity Sensitivity Trigger window

Change the pressure decrease needed to detect an attempted inspiration.

Figure 6 Sensitivity settings

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In the SIMV mode a negative pressure (in relation to actual Peep value) created by the patient, triggers the delivery of a mechanical breath. In PSV mode the negative pressure triggers the delivery of a pressure supported breath. The triggered breath is indicated by a color change of the pressure waveform. The delivery is very smooth as the breath is delivered as a natural progression of the negative pressure, which initiated the breath. A high sensitivity corresponds to a low threshold level for triggering and conversely, low sensitivity means a high threshold level. Trigger window • Adjustable range: 5 to 95 % • Default setting: 50 % • Set in ventilation modes: SIMV and PSV 1. Push Ventilator key to display menu. 2. Select Options and then Trigger window. 3. Turn ComWheel to adjust Trigger window. 4. Push ComWheel or Normal Screen.

Options Trigger window Trigger window Sensitivity

Set the window in which an attempted inspiration initiates a breath..

Figure 7 Trigger window setting In the SIMV mode, the patient may trigger a mechanical tidal volume breath within a Trigger window. The window is placed at the end of the expiration phase as defined by the respiratory rate (RR). In this way mandatory breaths are synchronized with spontaneous efforts. In the PSV mode, the patient may trigger a pressure-supported breath within a Trigger window. A wide window (95%) will allow a new pressure-supported breath immediately after the previous, whereas a narrow window (5%) will allow a new pressure-supported breath after a delay period.

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Datex-Ohmeda ADU ventilation Pressure Triggered mandatory breath

Mandatory breath Spontaneous breaths

+ 0

Time

- Trigg sens level cm H2O Patient triggering

Trigger window

Figure 8 Trigger window and sensitivity level for SIMV Pressure Spontaneous breaths Triggered breath

Backup breath Backup time

+ 0

-

Patient triggering

Trigg sens level cm H2O

Time

Trigger window

Figure 9 Trigger window and sensitivity level for PSV The trigger function is activated by a spontaneously created negative pressure (in relation to PEEP value) which exceeds the set Trigger Sensitivity level. SIMV: The frequency of the mandatory breaths can never be lower than the preset Respiration Rate (RR). On the other hand, the possibility for the patient to trigger mandatory breaths within the Trigger Window may lead to a situation where the actual mechanical breaths are more than the pre-set value for RR. This gives also rise to an increased Minute Volume. To avoid hyperventilation and still support spontaneous breaths - decrease pre-set RR on the ventilator and adjust the Trigger Window accordingly.

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PSV: The time between pressure supported breaths can never be longer than the pre-set Backup time. On the other hand, the possibility to trigger pressuresupported breaths within the Trigger Window may lead to an increased Minute Volume. To avoid hyperventilation and still support spontaneous breathsdecrease Set Pressure and/or adjust the Trigger window accordingly. Some setting combinations may not allow switching from one mode to another. In such cases, advice on what to do is stated in the Help Field.

Backup time • Adjustable range: 5 to 30 s • Default setting: 30 s • Set in ventilation modes: PSV 1. Push Ventilator key to display menu. 2. Select Options-Backup Time. 3. Turn ComWheel to adjust backup time. 4. Push ComWheel or Normal Screen.

Ventilator Options Trigger window Inspiratory Pause Inspiratory Rise [Mediu Sigh [OFF] Backup Time Previous Menu

Select timeout (s) for backup breaths.

Presetting values Some values in the Ventilator menu are automatically set when switching modes and are thus not possible to preset. In these cases the value is replaced with the text [AUTO].

Ventilator Mode VCV Patient Weight Tidal Volume Set Pressure [AUTO] Resp. Rate I:E Ratio Set PEEP OFF Sensitivity Options Normal Screen Select the mode of ventila- tion: volume-controlled, SIMV, or pressure-controlled.

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Default settings Changing default settings 1. Push Setup key. 2. Select Install. 3. Select Password digits 10. In Install menu, the user has the possibility to change the measurement units, interfacing, trend setup, save default setting for screen layout, trend layout, alarm setting and ventilation settings.

Setup Reset Case Gas Usage Screen Layout Set Time and Date Install Normal Screen

Entry to Install menu requires password.

Saving changed default settings Install 1. Change all settings to the desired values. Save As Defaults NOTE: The Resp. Rate must be set for both VCV Save ALL Screen Layout and SIMV before saving as defaults. Trend Layout 2. Push Setup key. Alarm Settings Vent. Settings 3. Select Install. Previous Menu 4. Select Save As Defaults. 5. Select specific setting or Save ALL for saving all of the settings. Save current screen layout, trend, This menu allows the user to save permanent alarm and ventilator settings as user defaults. changes of the default settings. Screen and trend layout as well as operating parameters such as alarm limits and ventilator settings may be saved. The factory default settings may be retrieved for all changed settings. NOTE: It is not possible to save Ventilator mode, Set PEEP or Sigh default settings.

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Restart of the display Under rare interacting circumstances microprocessor-controlled systems may enter a state when the program resets to a defined default condition. Should the display function of the ADU enter a reset state, it will be automatically restarted. During the restart, the Ventilator and Fresh Gas Control units continue to deliver gas as set, but you will be unable to adjust the ventilator settings. Fresh gas flows and anesthetic agent settings can be adjusted, but the settings are not displayed on the screen. After the display has been restarted, parameter and alarm settings may be adjusted again.

Display description If a reset condition occurs, the ADU displays the following: 1. The screen blanks out. 2. After approximately 10 seconds, the screen displays the Datex-Ohmeda logotype. 3. After approximately 15 seconds, the startup screen is displayed. 4. Within 40 seconds the screen has been restarted and can be used again. 5. The alarm message ‘Display SW has been restarted‘ and the messages ‘Check ventilator settings‘ and ‘Check alarm limits‘ are shown in the alarm message field. Display SW has been restarted

Check ventilator settings

Check alarm limits

Recommended actions If a reset condition occurs, perform the following steps: 1. Observe the information on the Patient Monitor to follow the patient conditions. 2. If you need to adjust the ventilation during the restart of the display, switch to MAN mode and ventilate manually as needed until step 4. 3. Follow the inspired/expired concentrations of gases on the Patient Monitor and adjust concentration settings if needed.

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4. When the display has restarted, acknowledge the alarm ‘Display SW has been restarted‘ by pushing the Silence Alarms key. When the alarm is acknowledged, the alarm message is removed from the alarm message field and appears again as a message in the general message field. NOTE: The message ‘Display SW has been restarted‘ remains in the general message field until the ADU has been restarted using the ON/Stand-by switch. NOTE: Only parameter and alarm settings will be restored to the values before the reset. Changes to the screen layout not saved using the Install menu will be lost. Check ventilator settings

Check alarm limits

5. Check the ventilator settings. When checking the ventilator settings, this message is removed from the alarm message field.

Display SW has been restarted

Check alarm limits

Ventilator Mode VCV Patient Weight Tidal Volume Set Pressure Resp. Rate I:E Ratio Set PEEP OFF Sensitivity Options Normal Screen Select the mode of ventila- tion: volume-controlled, PSV, SIMV, or pressure-controlled.

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6. Check the alarm limits. When checking the alarm limits, this message is removed from the alarm message field.

Alarms Setup Adjust Limits Default Limits Cancel Changes

ALARM LIMITS AND 10 MIN TREND:

Exit

AUTO

Ppeak

Pmax Release

Alarm Volume

Ppeak High

Audio ON/OFF

Ppeak Low

Alarm History Normal Screen

Ppeak High

Push wheel to adjust alarm limits manually.

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Technical specifications The following specifications are either new or replace the corresponding specification in chapter “10 Technical specifications” of the ADU User’s Reference Manual. Controls Pressure support level Resolution

5 to 40 cmH2O above measured Peep 1 cmH2O

Trigger level for SIMV and PSV from baseline Resolution

-0.5 to -5 cmH2O (default -1.0) 0.1 cmH2O

Trigger window

5-95 %

Pressure support backup time trig

5-30 s (default 30)

Accuracy Pressure control and pressure support accuracy

±2 cmH2O

Circuit pressure monitoring Volume mode SIMV mode PCV mode PSV mode Man mode

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Ppeak, Pplat, Peep Ppeak, Pplat, Pmin Ppeak, Peep Pplat, Peep Ppeak, Pmin

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