800 Series Ventilator System Operator’s Manual Addendum Rev B Ventilation Plus Option

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Volume Ventilation Plus option

Introduction The Volume Ventilation Plus™ option for 800 Series™ Ventilators allows the ventilator to deliver a pressure-based breath with a target tidal volume. Volume Ventilation Plus includes two breath types: •

VC+ (volume control plus), a mandatory, pressure-controlled breath type for A/C or SIMV mode, and

•

VS (volume support), a spontaneous, pressure-supported breath type for SPONT mode.

Conventional volume control restricts flow during inspiration and requires the clinician to attempt to set an inspiratory flow that matches patient demand. Conventional pressure control allows unrestricted inspiratory flow but does not change inspiratory pressure in response to changes in patient compliance. Volume Ventilation Plus does not restrict flow during the inspiratory phase, and automatically adjusts inspiratory pressure in response to changes in the patient’s condition. For example, if a patient’s lungs become more compliant due to treatment, Volume Ventilation Plus reduces the target pressure (lessening the forces on the alveoli) to achieve the target tidal volume.

Setting up Volume Ventilation Plus Follow these steps below to set up Volume Ventilation Plus (for more information see 840 Operator’s and Technical Reference Manual).

VC+ breath type (A/C or SIMV mode) 1. Touch the VENT SETUP button on the lower screen. 2. Touch the MODE button on the lower screen, then turn the knob to select the mode (the VC+ breath type is available in A/C and SIMV modes). 3. Touch the MANDATORY TYPE button, then turn the knob to select the VC+ breath type.

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Volume Ventilation Plus option 4. Touch the CONTINUE button. The applicable settings appear on the lower screen. 5. Touch the button for each setting you want to change, and then turn the knob to set its value. Proposed changes are highlighted. The settings applicable to the VC+ breath type include: •

VT (target volume)

•

TI (inspiratory time), or I:E or TE (expiratory time)

•

RISE TIME PERCENT

6. Press ACCEPT to apply the new settings, or the VENT SETUP button to cancel the changes.

VS breath type (SPONT mode) 1. Touch the VENT SETUP button on the lower screen. 2. Touch the MODE button on the lower screen, then turn the knob to select the mode (the VS breath type is available in SPONT mode). 3. Touch the SPONTANEOUS TYPE button, then turn the knob to select the VS breath type. 4. Touch the CONTINUE button. The applicable settings appear on the lower screen. 5. Touch the button for each setting you want to change, and then turn the knob to set its value. Proposed changes are highlighted. The settings applicable to the VS breath type include: • VT SUPP (target support volume). • ESENS (expiratory sensitivity). • RISE TIME PERCENT. 6. Press ACCEPT to apply the new settings, or the VENT SETUP button to cancel the changes.

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Volume Ventilation Plus option

Volume Ventilation Plus settings This section summarizes settings associated with Volume Ventilation Plus: Table 1 summarizes settings applicable to VC+ breaths, and Table 2 summarizes settings applicable to VS breaths.

NOTE: The NeoMode™ option is required for the neonatal ranges listed in Table 1 and Table 2.

Table 1: VC+ breath type (A/C or SIMV mode) settings Setting

Function

Range, resolution, accuracy

Expiratory time (TE)

Sets the expiratory time for mandatory VC+ breaths.

Range: ≥ 0.2 second. New patient: Based on TI and f settings. Resolution: 0.01 second. Accuracy: 0.01 second.

I:E ratio (I:E)

Sets the ratio of inspiratory time to expiratory time for mandatory VC+ breaths.

Range: 1:299 ≤ I:E ≤ 4.00:1. New patient: Based on TI and f settings. Resolution: 1 for 1:299 to 1:100 0.1 for 1:99.0 to 1:10.0 0.01 for 1:9.99 to 4.00:1 Accuracy: ± 0.01 second of the inspiratory time determined by I:E ratio and respiratory rate settings.

Inspiratory time (TI)

Sets the inspiratory time for mandatory VC+ breaths.

Range: 0.20 to 8.00 seconds. New patient: Based on VT and VMAX. M Resolution: 0.01 second. Accuracy: ± 0.01 second.

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Volume Ventilation Plus option Table 1: VC+ breath type (A/C or SIMV mode) settings (continued) Setting Rise time percent

Function Sets how quickly pressure rises to reach the target. The higher the setting, the less time to reach inspiratory pressure.

Range, resolution, accuracy Range: 1 to 100%. New patient: 50%. Resolution: 1%. Accuracy: Not applicable.

Warning Under certain clinical circumstances (such as stiff lungs or high airway resistance), a rise time percent greater than 50% could cause a pressure overshoot and premature transition to exhalation. Carefully evaluate the patient’s condition before setting the rise time percent above the default setting of 50%.

Target volume (VT)

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Sets the target volume for a mandatory VC+ breath. Compensated for body temperature and pressure saturated (BTPS) and circuit compliance.

Range: Neonatal: 5 to 315 mL. Infant/pediatric/adult: 25 to 2500 mL. IBW-based range is 1.16 x IBW minimum; 45.7 x IBW maximum. (continued)

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Volume Ventilation Plus option Table 1: VC+ breath type (A/C or SIMV mode) settings (continued) Setting

Function

Target volume (VT) (continued)

Range, resolution, accuracy New patient: Neonatal: The greater of 5 mL or (7.25 x IBW). Infant/pediatric/adult: The greater of 25 mL or (7.25 x IBW). Resolution: 1 mL for 5 to 100 mL. 5 mL for 100 to 400 mL. 10 mL for 400 to 2500 mL. Accuracy: Compliance and BTPS compensated. Neonatal: ± (4 + 10% of setting) mL with a neonatal circuit. Infant/pediatric/adult: For TI < 600 ms, ± (10 + 10% x (600 ms/TI) of setting) mL. For TI > 600 ms, ± (10 + 10% of setting) mL.

Table 2: VS breath type (SPONT mode) settings Setting

Range, resolution, accuracy

Expiratory sensitivity (ESENS)

The percent of peak inspiratory flow at which the ventilator cycles from inspiration to exhalation.

Range: 1 to 80%. New patient: 25%. Resolution: 1%. Accuracy: Not applicable.

Rise time percent

Sets how quickly pressure rises to reach the target. The higher the setting, the less time to reach inspiratory pressure.

Range: 1 to 100%. New patient: 50%. Resolution: 1%. Accuracy: Not applicable.

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Function

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Volume Ventilation Plus option Table 2: VS breath type (SPONT mode) settings (continued) Setting

Function

Range, resolution, accuracy

Warning Under certain clinical circumstances (such as stiff lungs or high airway resistance), a rise time percent greater than 50% could cause a pressure overshoot and premature transition to exhalation. Carefully evaluate the patient’s condition before setting the rise time percent above the default setting of 50%.

Target support volume (VT SUPP)

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Sets the target volume for a spontaneous VS breath. Compensated for body temperature and pressure saturated (BTPS) and circuit compliance.

Range: Neonatal: 5 to 315 mL. Infant/pediatric/adult: 25 to 2500 mL. IBW-based range is 1.16 x IBW minimum; 45.7 x IBW maximum. New patient: Neonatal: The greater of 5 mL or (7.25 x IBW). Infant/pediatric/adult: The greater of 25 mL or (7.25 x IBW). Resolution: 1 mL for 5 to 100 mL. 5 mL for 100 to 400 mL. 10 mL for 400 to 2500 mL. Accuracy: Compliance and BTPS compensated. Neonatal: ± (4 + 10% of setting) mL with a neonatal circuit. Infant/pediatric/adult: For TI < 600 ms, ± (10 + 10% x (600 ms/TI) of setting) mL. For TI > 600 ms, ± (10 + 10% of setting) mL.

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Alarms Table 3 summarizes the alarms associated with Volume Ventilation Plus. Table 3: Volume Ventilation Plus alarms Base message

Urgency

Analysis message

Remedy message

Comments

VOLUME NOT DELIVERED

Low

Last 2 mand breaths, pressure > max allowable level.

Check patient and setting for 2PPEAK.

Medium

Last 10 or more mand breaths, pressure > max allowable level.

This alarm applies to VC+ and VS breaths. Target pressure = PPEAK - PEEP - 3 cmH2O. Ventilator cannot deliver target volume. Possible dependent alarms: For VC+ For VC+ breaths: 3VTE MAND 3VE TOT 1fTOT For VS breaths: 3VTE SPONT 3VE TOT 1fTOT Corrective action: Check patient and settings.

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Volume Ventilation Plus option Table 3: Volume Ventilation Plus alarms (continued) Analysis message

Remedy message

Comments

Low

Last spont breath ≥ set limit.

Check patient and settings.

Medium

Last 3 spont breaths ≥ set limit.

High

Last 4 or more spont breaths ≥ set limit.

High inspired tidal volume. Delivered inspiratory volume ≥ inspiratory limit. Ventilator transitions to exhalation. Possible dependent alarms: 3VTE SPONT 3VE TOT 1fTOT

Base message

Urgency

1VTI SPONT

Corrective action: Check for leaks. Check the VTI or VTI SPONT setting

1VTI MAND

Low

Last mand breath ≥ set limit.

Medium

Last 3 mand breaths ≥ set limit.

High

Last 4 or more mand breaths ≥ set limit.

Check patient and settings.

High inspired tidal volume. Delivered inspiratory volume ≥ inspiratory limit. Ventilator transitions to exhalation. Possible dependent alarms: 3V TE MAND 3V E TOT 1f TOT Corrective action: Check for leaks. Check the VTI or VTI MAND setting

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Volume Ventilation Plus option Table 3: Volume Ventilation Plus alarms (continued) Analysis message

Remedy message

Comments

Low

Last 2 breaths, pressure < min allowable level.

Check patient and target volume.

Medium

Last 10 or more breaths, pressure < min allowable level.

This alarm applies to VC+ breaths only. Target pressure = the low limit: PEEP + 5 cmH2O for VC+ breaths Ventilator cannot deliver target volume. Possible dependent alarms: 1fTOT

Base message

Urgency

LOW INSP PRESSURE

Corrective action: Check patient and settings.

Ventilator settings/guidelines Monitored settings Table 4 lists the monitored settings associated with VV+. Table 4: Monitored settings Setting Spontaneous inspired tidal volume

Function

Range, resolution, accuracy

Displays the compliance and BTPS-compensated value for inspired tidal volume. Data updated at the beginning of the following expiratory phase.

Range: 0 ml to 6000 ml Resolution: 1 ml for 0 ml to 6000 ml Accuracy: For TI ≥ 200 ms and < 600 ms, ± (10 + 10%* 600 ms/ TI ms of reading) ml; otherwise, ± (10 + 10% of reading) ml

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Volume Ventilation Plus option

Technical description Volume Ventilation Plus includes these breath types: •

VC+ (volume control plus) for use in A/C and SIMV modes. The set target volume (VT) is the target volume for pressurecontrolled breaths.

•

VS (volume support) for use in SPONT mode. The target support volume (VT SUPP) is the target volume for pressuresupported breaths.

In the absence of leaks or changes in patient resistance or compliance, VC+ and VS breaths achieve and maintain a steady target volume within five breaths of VC+ initiation or startup. Volume Ventilation Plus notifies the clinician if the calculated inspiratory pressure would be too high or too low in VC+ only, to achieve the target volume.

Volume Ventilation Plus Startup During startup, the ventilator delivers a breath (test breath) to determine the pressure target needed to deliver the desired (set) volume. During the time the ventilator is delivering the test breath, the message “VC+ startup” or “VS startup” will be displayed in the “waveform” or “more patient data” screens.

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Volume Ventilation Plus option The test breaths are defined as follows: For VC+:VC mandatory breath (up to 3) or PC mandatory breath with PI = the lesser of 15 cmH2O and (PPEAK-PEEP-3) cmH2O For VS: PS spontaneous breath with Ps= the lesser of 15 cmH2O and (PPEAK-PEEP-3) cmH2O

Figure 1. VC+ Startup

Figure 2. VS Startup

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Volume Ventilation Plus option Startup will be initiated after any of the following conditions: •

Ventilator startup with VC+ or VS selected.

•

Change in breath type to VC+ or VS

•

After a disconnect if IBW ≤ 7 kg.

•

High circuit pressure alarm for four consecutive breaths.

•

Reduction in PEEP by more than 10 cmH2O.

•

Exhaled volume (VE) is less than 25% minus 15mL of delivered volume for 5 consecutive breaths.

•

Estimated patient compliance is less than (0.1 x IBW) mL/cmH2O for five consecutive breaths.

•

There is a sudden increase in delivered volume of 100% or greater, for the same pressure target.

•

High VTI alarm for four consecutive breaths.

NOTE: To allow for optimal function of startup and operation of VV+ in the 840 ventilator it is important not to block the tubing while the patient is undergoing aspiration or other treatment that requires disconnection from the ventilator. The ventilator has a disconnect detection algorithm that suspends ventilation while the patient is disconnected.

Pressure adjustments After VV+ Startup, the ventilator will make adjustments to the target pressure in order to deliver the set volume (VT or VT SUPP). In order to reach the desired volume promptly, the maximum allowed pressure adjustments for an adult or pediatric patient will be greatest during the first five breaths following Startup or a change in VT or VT SUPP. The value of the maximum pressure adjustments for each patient type are summarized in Table 5.

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Table 5: Maximum Pressure Adjustments Maximum change in Target Pressure Conditions IBW ≥ 25 kg

15 ≤ IBW < 25 kg

IBW < 15 kg

Less than 5 breaths after: Startup (VC+ or VS), or Change in VT or VT SUPP

± 10.0 cmH2O

± 6.0 cmH2O

± 3.0 cmH2O

5 breaths or more after Startup (VC+ or VS)

± 3.0 cmH2O

± 3.0 cmH2O

± 3.0 cmH2O

Volume Ventilation Plus alarms Volume Ventilation Plus includes two non-adjustable and two adjustable alarms: •

VOLUME NOT DELIVERED: This alarm applies to VC+ and VS breaths. The calculated inspiratory pressure required to achieve the target volume would be too high (greater than PPEAK - PEEP - 3 cmH2O). Volume is delivered at a pressure no greater than the PPEAK - PEEP - 3 cmH2O limit, and would likely be less than the target volume.

•

LOW INSP PRESSURE: This alarm only applies to VC+ breaths. The calculated inspiratory pressure required to achieve the target volume would be too low (less than PEEP + 5 cmH2O) to achieve the target volume. The delivered volume would likely be greater than the target volume.

•

1VTI SPONT: A spontaneous breath (VS) has been truncated because the volume being delivered to the patient has met or exceeded the VTI SPONT or VTI limit set in the Alarm Setup screen.

•

1VTI MAND: A mandatory breath (VC+) has been truncated because the volume being delivered to the patient has met or exceeded the VTI MAND or VTI limit set in the Alarm Setup screen.

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Compliance compensation for volume-based breaths When the ventilator delivers a volume of gas into the patient circuit, not all of the gas actually enters the patient's respiratory system. Part of the delivered volume, called the compliance volume (VC), remains in the patient circuit. VC = C pt ckt (PIEND - PEEP) where: Cpt ckt

is the compliance of the patient circuit

PIEND

is the pressure at the patient wye at the end of the current inspiration

PEEP

is the pressure at the patient wye at the end of the current exhalation

For volume ventilation, practitioners often compute VC to estimate the loss of volume in the patient circuit, then increase the VT setting by that amount. Increasing the tidal volume by a single increment to compensate for compliance volume provides only partial compensation, and requires extra effort and understanding on the part of the practitioner. In addition, Pend insp and Pend exh can change with time. In the 840 Ventilator, an iterative algorithm automatically computes the compliance volume. There is a maximum tubingto-patient compliance ratio to reduce the potential for overinflation due to an erroneous patient compliance estimation. The maximum ratio is determined by the selected patient circuit type and ideal body weight (IBW) and is summarized by this equation: Factor =

Cpt ckt _______ Cpt

where: Cpt

is the compliance of the patient.

Factor

is the linear interpolation of the values in Table 6.

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Table 6: Compliance volume factors Adult patient circuit type

Pediatric patient circuit type

Neonatal patient circuit type*

IBW (kg)

Factor

IBW (kg)

Factor

IBW

Factor

≤ 10

5

≤ 10

5

0.5

10

15

4.6

11

3.5

1.5

5.4

30

3.4

12.5

2.9

2.5

3.7

60

2.75

15

2.7

3.5

2.9

≥ 150

2.5

≥ 30

2.5

≥4.5

2.5

* Approximate values

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