FREMITUS

Mechanical Ventilation in SARS-COV-2

2020-04-06T18:55:00.000-04:00

Webinar from European Society of Intensive Care Medicine

Timestamps for easier viewing

Note- I also did this in the video comments, which hyperlinks to the portion of the video.

1:30 Start

2:55 Classification of Phenotypes

7:07 SARS-COV-2 vs. Classical Definition of ARDS

7:48 Stages of Therapy

8:57 Non-Invasive Assessment

14:24 Oxygenation

17:01 Work of Breathing

19:06 Disease Course

20:19 Invasive Management of Respiratory Failure

23:10 Considering ECMO

27: 39 Summary

29:53 Q&A

31:18 Intubation Criteria

32:17 HFO2 vs. NIV

35:17 Recruitment Maneuvers

37:00 Prone Positioning

38:24 Anti-coagulation Therapy

40:16 Inflammatory Response

43:02 Inhaled Nitric Oxide (INO)

44:09 Inhaled Prostacyclin

44:22 Angiotensin Converting Inhibitors

45:57 Ozone Therapy & Hypothermia

46:57 Criteria for INO or Inhaled Prostacyclin

47:53 Early vs. Late Intubation

50:07 Statins

50:57 CPR & Infection Risk

51:42 Weaning

53:43 Higher Tidal Volumes

54:56 IL-1 receptor antagonist & IL-6 inhibitors

55:51 Sevoflurane, Sedation, Fluid Balance

57:27 Ethics

59:39 Renal Replacement Therapy

1:00:42 Transfusion, ECMO

Build Your Own Ventilator "MIT E-VENT"

2020-03-29T20:58:00.007-04:00

MIT E-VENT- Image from https://e-vent.mit.edu

RESOURCES @ https://e-vent.mit.edu

Advance Breathing System (ABS)- Disassembly, Cleaning, & Reassembly

2020-03-29T20:28:00.000-04:00

Disassembly, Cleaning, & Reassembly for the Advance Breathing System on the Aespire, Avance, & Aisys anesthesia delivery systems.

LUNG PROTECTIVE TAPE

2019-03-13T21:09:00.001-04:00

I'm currently prototyping a new Idea. I'm designing a 76 inch (193 cm) measuring tape and adding 6 Lung protective tables to it.
Think of it as a "Broselow Tape" for adults in regards to lung protective ventilation which can be used with any mechanical ventilator.
Tables may assist in setting optimal set-points on the mechanical ventilator. tables include;

Predicted minute ventilation based on Ideal body weight.
Ideal body weight and tidal per ml.
Minimum inspiratory time setting.
Minimum expiratory time setting.
Pressure control setting for targeting tidal volume per Ideal body weight.
I-time related to set frequency & duty cycle.

For the more information on the "Lung Protective Tape" please sign up for my news letter

http://eepurl.com/bOs4IX

Limiting Driving Pressure

Minimizing the Risk of Volutrauma

Hypoxic & Hyperoxic Guard

Lung Protective Tabulations Multi-touch book

2018-07-10T11:49:00.000-04:00

Lung Protective Tabulations now availabe as a multi-touch books on iTunes (see link below).

LUNG PROTECTIVE TABULATIONS

Limiting Driving Pressure

2018-07-04T11:14:00.001-04:00

Pressure Control Setting For Targeting Tidal Volume per Ideal Body Weight [1].

Driving pressure has been shown to be a better determinant of ARDS outcomes than tidal volume, plateau pressure, or PEEP. "A driving pressure > 14 cmH2O was associated with increased 60 day mortality" [1].

Titrating tidal volume to maintain driving pressures < or = to 14 cmH2O with minimal costs in regards to CO2 clearance is a practical strategy to reduce the risk of volutrauma [1].

The practitioner can easily meet this target by utilizing Pressure-control ventilation and never setting the pressure > 14 cmH2O.

The above set of tables "Pressure Control Setting for Targeting Vt/Kg IDBW" displays the relationships between tidal volume, compliance, and pressure control setting (driving pressure). These tables can be used a few ways:
1. To determine the PC setting to target a specific VT for a measured compliance.
2. If using Volume-control (fully decelerating flow pattern only) or a Adaptive Pressure-control
(e.g. PRVC, Auto-Flow, APV, VC+) predicts what the driving pressure will be for your set VT based on measured compliance.
3. Titrating tidal volumes to maintain driving pressures < or = to 14 cmH2O.

Inputs- height (inches or centimeters), VT target (4, 5, 6, ml kg), compliance, gender.
Outputs- IDBW (KG), VT/Kg (ml), Driving pressure.

REFERENCE
Richey KS. Lung Protective Tabulations, 2018

MINIMIZING THE RISK OF VOLUTRAUMA

2018-07-03T22:17:00.000-04:00

Ideal Body Weight & Tidal Volume Tables[1].

The aim to minimize the risk of volutrauma is associated with the objective to optimize the pressure/volume curve. To accomplish this the clinician targets a minimal tidal volume and optimal PEEP which maximizes compliance and avoids volutrauma as well as atelectrauma.

One strategy to reduce the risk volutrauma is to target a tidal volume of 4 to 6 ml/kg/Ideal body weight per ARDS net guidelines
.
The pictured group of tables "IDEAL BODY WEIGHT & TIDAL VOLUME Per Ml for both genders" [1] provide tidal volume targets of 4,5,& 6 ml/kg/IDBW.

Inputs- Height (inches or centimeters) & Gender.Outputs- Ideal body weight (kg), target tidal volume (4, 5, 6 ml/kg).

Reference
1. Richey KS. Lung Protective Tabulations 2018

Hypoxic & Hyperoxic Guard

2018-06-17T18:37:00.001-04:00

Predicted PaO2 Table setup as a Hypoxic & Hyperoxic Guard.

Maximizing oxygenation to prevent hypoxia and hyperoxia can be accomplished by titrating FiO2 to target a optimal paO2 goal. Practitioners often consider a liberal oxygenation strategy of a target SPO2 > 95% & consider hyperoxemia acceptable. Conversely, "hyperoxia and hyperoxemia may promote lung injury during mechanical ventilation and lead to poor outcomes" [1].

The above table "Predicted PaO2" from my new reference [1] is color-coded and setup as a "Hypoxic & Hyperoxic Guard", the tables are based on a more conservative oxygen strategy of a PaO2 target of 60-100. Additionally, the tables
where created using a newer formula which allow for more accuracy in the presence of shunts.

Inputs- Old FiO2 (starting FiO2), Old PaO2Outputs- predicted PaO2 for new FiO2 settings 25-100%

1. Richey KS. Lung Protective Tabulations, 2018

FREE MECHANICAL VENTILATION COURSE

2018-04-25T13:37:00.000-04:00

FREE MECHANICAL VENTILATION COURSE

Courtesy of Robert Chatburn & the Cleveland Clinic

From Robert Chatburn:

My colleagues and I at Cleveland Clinic have been developing a standardized system to teach basic mechanical ventilation technology, over the last decade. We have now completed a 12 module, self-directed course (PowerPoint files) and a ventilator simulator (Excel file) that contains links to many additional resources.

We offer both freely (no strings attached) with the intent of improving the lives of patients through better understanding of those who serve them; clinicians, educators, researchers, and engineers

To access these tools, do the following:

The Basic Course in Mechanical Ventilation and SIVA ventilator simulator are now available on the MyLearning website at Cleveland Clinic.

This course is best viewed using Internet Explorer. If using Google Chrome, please make sure the Adobe Flash plugin is installed.

Please log into https://mylearning.ccf.org to access the course. The course can be found under the Find Learning tab by searching for the course title. The course is open for self-enrollment.

You can also access the course by clicking on the direct link https://mylearning.ccf.org/course/view.php?id=1320.

If you have not yet created a password to log into MyLearning, please follow the instructions shown below.

Feel free to contact elearning@ccf.org if you have any problems accessing the course.

MyLearning Password Instructions

1. Click the link https://mylearning.ccf.org/login/index.php

2. If you are NOT a Cleveland Clinic employee (do not have a CCF employee id#), Click Create New Account and follow instructions.

3. If you are a Cleveland Clinic employee OR non-employee that may already have an account from mCOMET, click the Existing Account button. Anyone with a CCF employee id# or a non-employee ID# (e.g., student, contractor, vendor) will automatically have an account. Enter one of the following depending on your employment status:

o Cleveland Clinic Employees: Enter your Cleveland Clinic employee ID in the Employee id field

o Non-Cleveland Clinic Employees: Enter your email address (used in mCOMET) in the Email address field

4. Click the Search button

5. A message displays, click the Continue button

6. Check your email for further instructions (This may be your ccf.org email or a personal email depending on which one is your contact email in your HR record. Please also check your Junk email)

7. In the email, click the link provided

8. The Set password screen displays, enter a new password following the instructions provided

9. If the password is accepted you will be automatically logged into the MyLearning site (Save the site to your Favorites/Bookmarks)

Ventilator Graphics Now a Multi Touch Book

2017-07-04T11:04:00.003-04:00

If you were contemplating getting a version of "Ventilator Graphics: Identifying Patient Ventilator Asynchrony & Optimizing Settings" electronic version from Amazon I would recommend getting instead the Multi touch version on iTunes store. It is the same price as the Kindle version however has videos.

Thank you for your support see below links.

https://itunes.apple.com/us/book/ventilator-graphics/id1254741949?ls=1&mt=11

Ventilator Graphics (Mandarin) FREE PDF download

2016-07-08T13:39:00.003-04:00

DOWN LOAD at

Mediafire

Ventilator Graphics (Japanese edition)

2016-06-16T17:45:00.002-04:00

人工呼吸器グラフィック患者の人工呼吸器外れを識別すると、設定を最適化します。

Whats your mode? Episode ii (VC-CMVd)

2016-02-20T12:31:00.002-05:00

Image 1. Pressure limitation associated with dual targeting may reduce the incidence of premature cycling.

Episode two of "Whats your mode" VC-CMV with dual targeting is now finished and available to my news letter subscribers. To receive access to this video please sign up for my news letter at this link: http://kscottrichey.blogspot.com/p/news-letter.html

You can also access the the news letter link from the tab on the top of the page labeled "News letter".

PRE-REQUISITE/RECOMMENDED VIDEOS

TARGETING SCHEMES

DUAL TARGETING

RELATED VIDEOS

EPISODE i

WHATS YOUR MODE

REFERENCE

A taxonomy for mechanical ventilation: 10 fundamental maxims.

A rational framework for selecting modes of ventilation.

Building a Ventilator Simulator with Power Point

2016-02-17T23:31:00.000-05:00

I worked on this project for a mobile app wire-frame three years ago and recorded the process (over 70 short videos) thinking someone else might want to use this technique. This technique is for anyone that has ever wanted to build a simulator however does not have a computer programming background. These videos demonstrate how to build a interactive operator interface for an mechanical ventilator using MS Power Point. These lessons can be applied to create simulators for education, presentations, mobile app prototyping, etc.

VIDEO PLAYLIST

VENTILATOR SIMULATOR w MS PPT

Whats Your Mode? Episode i

2016-02-11T17:22:00.000-05:00

Image 1. Settings within "Volume Control" a VC-CMVs modality on the FLOW-i anesthesia Delivery system. All highlighted settings may affect patient comfort.

My first episode of my new video series is now available to my news letter subscribers.
I posted a teaser video on YouTube (see below).

Note- if you signed up to receive my news letter and do not have it in your "in-box" please check your spam folder.

VIDEOS to COME
(a * next to the name indicates this video is only available to news letter subscribers)

VC-CMVd*

VC-IMVs,s
VC-IMVds*
VC-IMVda,s*
VC-IMVd,a*
VC-IMVa,s*

PC-CMVs
PC-CMVa*

PC-IMVs,s
PC-IMVa,s*
PC-IMVa,a*
PC-IMVo,o*

PC-CSVs
PC-CSVr (PAV+)*
PC-CSVr (NAVA)*
PC-CSVa
PC-CSVi (Smart Care)*

To receive these extra videos please sign up for my free news letter by following the link on the page "News Letter".

ATTRIBUTION
These videos have been conceived from the following two journal articles.

Respir Care. 2014 Nov;59(11):1747-63. doi: 10.4187/respcare.03057. A taxonomy for mechanical ventilation: 10 fundamental maxims. Chatburn RL, El-Khatib M, Mireles-Cabodevila E.

Respir Care. 2013 Feb;58(2):348-66. doi: 10.4187/respcare.01839. A rational framework for selecting modes of ventilation. Mireles-Cabodevila E, Hatipoğlu U, Chatburn RL.

I recommend reading both articles to obtain a deeper knowledge and appreciation for the different modes of mechanical ventilation.

RECOMMENDED PREREQUISITE POSTS/VIDEOS

Targeting Scheme Intro

Targeting Scheme Post

Whats Your Mode?

What’s Your Mode?

2016-01-28T09:22:00.000-05:00

Happy 2016! This post is to inform readers on two topics related to this blog.

First

This year I will begin transitioning this blog and my YouTube page to a FREE email subscription based newsletter. Throughout the year I will continue to post content on the blog and brief videos on my YouTube page, however subscribers to my newsletter will receive additional content on the topics of mechanical ventilation and respiratory therapy (e.g. extended more detailed videos, PDF files, etc.).

After December 2016 no additional content will be posted here, however the blog & YouTube page will remain open as an archive.

Image 1. Ventilator Screen shot of Adaptive Support Ventilation, patient safety and comfort targets.

Second

I will be starting a new video series similar to ones I have already created (e.g. APRV, PC-CMV, Adaptive Pressure Control). The title of this series is “What’s your mode?”

This series will be comprised of approximately 18 videos providing operational transparency to the various modes of mechanical ventilation. I believe this is important because clinicians’ need to understand the boundaries of these modalities which is not always disclosed by the device manufacturer.

The video idea was conceived after reading I believe one of the most brilliant papers and theories on mechanical ventilation “A rational framework for selecting modes of mechanical ventilation” [1]. This paper questions why we use a specific ventilator mode and proposes selecting a mode based on the three central goals of mechanical ventilation; patient safety, patient comfort, and transitioning to liberation. The paper also introduces selecting a mode of mechanical ventilation based on mode capabilities and features to accomplish these goals.

Note- two evident things;

The mode has to be available on the ventilator in use.

The clinician has to be competent and know the capabilities and boundaries of a specific mode.

If interested in receiving additional content please sign up for the News Letter below or on the page labeled “News Letter”.

CLICK LINK to Sign up

http://eepurl.com/bOs4IX

REFERENCE

[1]. Mireles-Cabodevila, E. Hatipoglu, U. and Chatburn, R. (2013). A rational framework for selecting modes of ventilation. Respiratory Care. 58 (2): 348-364.

[2]. Respir Care. 2013 Feb;58(2):348-66. doi: 10.4187/respcare.01839. A rational framework for selecting modes of ventilation. Mireles-Cabodevila E, Hatipoğlu U, Chatburn RL.

Changing Flow Patterns vs. Changing Ventilator Modes

2015-11-30T12:16:00.004-05:00

Figure 1: Various flow patterns within VC-CMVs on the Hamilton G5 Ventilator.

When a device operator thinks about changing the inspiratory flow pattern while administering a Volume-Controlled breathing pattern they do not assume it will change the mode of ventilation.

However newer software in the Servo-i allows the operator to change the flow pattern

from the traditional constant flow pattern, to either a fully decelerating flow pattern (similar to PC-CMV) or to adaptive flow (Fig. 2). The Adaptive Flow pattern was the default in older software which makes Volume Control a Dual Control mode [1]. The operator now has a choice of using Volume Control as a traditional VC-CMV mode by selecting the square waveform or providing a Dual Control breathing pattern by selecting the Adaptive Flow icon.

Figure 2: Flow patterns available on the Servo-i, courtesy of Robert Chatburn.

For more information on flow patterns and Dual Control see the below links.

DUAL CONTROL

Dual Targeting Schemes

FLOW PATTERNS

Flow Patterns & Flow Rates

HYPERCAPNEA & ATELECTRAUMA: MIMICKING APRV

2015-11-23T16:18:00.001-05:00

In a previous post "APRV in the operating room is it practical?" I argue that bringing a ICU ventilator into the operating room to utilize APRV is not practical and may lead to hypoventilation and hypoxia due to administration of anesthetic agents [1].

During surgical procedures the patient is maintained in stage 3 of anesthesia known as the "surgical stage". Stage 3 is broken down into four distinct planes, "from onset of automatic respiration to respiratory paralysis" [2]. The patient is usually maintained in Plane 3 (intercostal muscle paralysis) or Plane 4 (diaphragmatic paralysis) leading to the cessation of spontaneous breaths.

One key advantage of APRV is that the patient may breathe spontaneously contributing to the overall minute volume, with the termination of spontaneous efforts the patient will become severely hypercapnic.

Below is an image (fig 1) I captured from a "Pressure Control Ventilation Simulator" [3] demonstrating an ARDS patient on APRV.

Figure 1. Pressure Control Ventilation Simulator, notice patients PaCO2 at 100.7 mmHg.

Notice in figure 1 the outcome for a patient not contributing to the overall minute ventilation the PaCO2 would be 100.7 mmHg.

Another example of how APRV maybe harmful in the operating room is when trying to mimic APRV with a anesthesia delivery system.

I posted a video "Mimicking APRV with the FLOW-i anesthesia delivery system" revealing how one could use Pressure Control- Inverse Ratio with a floating exhalation valve on a anesthesia machine to mimic APRV [4]. This technique involves multiple steps and may lead to atelectrauma from the prolonged expiratory phase associated with PC-IRV.

Again using the Pressure Control Simulator [3] and ventilator screen shots I will explain how mimicking APRV puts a patient at a higher risk for atelectrauma.

First, lets evaluate the traditional settings of a adult patient on APRV specifically the T-Low which affects the expiratory phase.

Figure 2. APRV settings screen on Hamilton C-1 ventilator, T-Low set at 0.25 second.

In figure 2 the T-Low is set at 0.25 second or one expiratory time constant (RCexp) for this example. Setting the T-Low based on one RCexp will generate a "Peak Expiratory Flow Termination Point" (T-PEFR) of 50 to 75 percent [5] preventing total alveolar collapse.

Figure 3. Resulting affect of setting T-Low on RCexp arrow shows T-PEFR ~ 50%.

The above image shows a T-PEFR of ~ 50% based on the T-Low setting of 0.25 second.

Below (fig 4.) I selected inputs on the Pressure Control Ventilation Simulator to match the settings and patient characteristics of the Hamilton C1 ventilator simulator. Notice the duty cycle is 97% which equals a 30:1 I:E ratio.

Figure 4. Physiologic simulator with same settings and patient characteristics.

Second, lets demonstrate mimicking these settings with PC-IRV. Notice in the below image (Fig 5.) for a Inverse Ratio of 4:1 the maximum duty cycle in PC-CMV the T-Low phase would be 1.5 seconds.

Figure 5. Physiologic simulator ventilator settings inputs for PC-IRV 4:1 I:E ratio or 80% duty cycle.

A T-Low or expiratory phase of 1.5 seconds allows for a patient with a expiratory time constant of 0.25 for complete alveolar emptying/collapse increasing the risk of atelectrauma. Figure 6 is a screen shot of PC-IRV with a 4:1 I:E ratio notice complete exhalation during the expiratory phase which puts the patient at higher risk for alveolar collapse. Mathematically any patient that has a RCexp of less than ~ 0.4 (e.g. resistance of 10 & compliance of 40) there would be complete exhalation using PC-IRV.

Figure 6. PC-IRV with a 4:1 I:E ratio notice purple flow waveform complete exhalation during exhalation.

The operator may try to mitigate alveolar collapse by setting a P-Low or PEEP, however this does not prevent complete exhalation and decreases the delivered tidal volume (fig. 7). Additionally, it is not known on how much PEEP to apply to prevent alveolar de-recruitment.

Figure 7. Even with PEEP set at 15 cmH2O during PC-IRV exhalation is complete.

It is not hard to mimic APRV in the operating room, but with the increase risk for ventilator induced lung injury should we?

RELATED POST

A Quick & Easy way to set T-Low

APRV, BiLEvel, BiVent

REFERENCE

1. http://kscottrichey.blogspot.com/2011/11/aprv-in-operating-room-is-it-practical.html

2. https://en.wikipedia.org/wiki/Guedel%27s_classification#Stages_of_Anesthesia

3. Chatburn, R. (2011). Pressure Control Ventilation Simulator V2.6 Mandu Press LTD.

4. Mimicking APRV

The Volume Control Ventilation Fallacy

2015-11-04T20:42:00.004-05:00

Volume Control- Continuous Mandatory Ventilation with a “Set-point” targeting scheme (VC-CMV(s)) is likely the most utilized mode of mechanical ventilation in adult patients in North America. This is due to a few a reasons:

1. VC-CMV is a standard mode on almost every intensive care ventilator and anesthesia delivery system.

2. VC-CMV is one of the first modes of mechanical ventilation.

3. VC-CMV is easy to understand in both theory and operation.

4. VC-CMV is the standard of care when ventilating patients with Acute Respiratory Distress Syndrome (ARDS) and Acute Lung Injury (ALI).

5. VC-CMV is the standard of care for adult patients intraoperatively.

The key advantage of VC-CMV(s) is the safety and simplicity of the set-point targeting scheme. The operator can manually set all parameters of the volume/flow waveform and adjust the minimum minute ventilation parameters (relating to frequency and tidal volume). “One can quickly trouble-shoot a patient’s situation, so during a change the operator can diagnose the problem and intervene rapidly”. [1]

When one sees a mode of ventilation labeled “Volume Control”, “VC”, “Volume A/C”, or “CMV” it affirms that the breathing pattern delivered to the patient will consist of a constant tidal volume and inspiratory flow waveform (fig. 1)

Figure 1. Volume Control Ventilation Breath Pattern.

Figure 2. Volume and Flow waveform remains constant even-though compliance decreased to 25, compared to Figure 1.

regardless of changes in a patient’s respiratory system mechanics and/or inspiratory drive (fig. 2) [2]. Conversely, due to no industry standard for ventilator mode taxonomy and medical device manufacturers marketing schemes the actual breath delivered to the patient does not resemble the predicted breath pattern and may result in a tidal volume much larger than the expected preset value.

How does this happen?

EXAMPLE 1: DECEPTION

The device operator selects a mode labeled “Volume Control” and the breath delivered actually resembles a Pressure Control or Pressure Support breath. This is due to the modes “targeting scheme”. A targeting scheme is the third building block for constructing a mode of mechanical ventilation the first is “Ventilator Control Variable” and second is the “Breath Sequence” [3]. The targeting scheme is usually a closed-looped feedback control system (similar to “If then statements” in conditional computer programming) which tries to achieve a specific ventilatory pattern. Thus making the targeting scheme the culprit for the change in breath pattern.

Volsko and colleagues [2] demonstrated this well when comparing differences in VC-CMV(s) and VC-CMV dual targeting (VC-CMV(d)). The researchers used an ASL 5000 lung model (Ingmar Medical) and simulated the pulmonary mechanics of an adult patient with ARDS during active and passive ventilation. During the simulated spontaneous breathing VC-CMV(s) delivered a consistent tidal volume similar to operator settings. However, VC-CMV(d) delivered a breathing pattern similar to pressure support resulting in higher flow rates and delivered tidal volume.

The deception is buried in the manufactures naming of the mode. In this study researchers used the “Volume Control” mode on the Servo-i ventilator for the dual targeting scheme arm of the study. The name “Volume Control” and the generic settings (fig. 3) associated with the mode on the Servo-i misleads the operator to believing that the mode is simply VC-CMV(s). The Dual Control targeting scheme happens behind scenes in which the device operator cannot control.

Figure 3. Settings for Volume Control on the Servo-i ventilator.

The mode mimics the standard set-point functionality associated with the traditional VC-CMV(s), until the patient makes an inspiratory effort that decreases the inspiratory pressure by 3 cmH2O. If this happens “the ventilator switches to pressure control and, if the effort last long enough, flow cycles the breath” similar to pressure support [4]. Thus delivering a higher inspiratory flow resulting in a larger tidal volume than predicted (fig. 4).

Figure 4. Screen shot demonstrating the dual control targeting scheme of Volume Control in the Servo-i, the inspiratory flow increases based on patient effort resulting in a higher tidal volume.

EXAMPLE 2: ADJUNCTS

As mentioned in previous posts Adaptive Pressure Control Ventilation (APC) may not provide consistent tidal volumes during rapid changes in pulmonary mechanics and vigorous inspiratory efforts [5,6]. In 2007 Jaecklin demonstrated that APC in a variety of ventilators regularly delivered excessive tidal volume in response to sudden increases in patient compliance or decreases in resistance potentially putting neonates at risk for lung injury [7].

Why do I mention APC? Isn’t it obvious that APC is an entirely different mode then VC-CMV(s)?

APC actually classified as Pressure Control-Continuous Mandatory Ventilation with an “Adaptive” targeting scheme or PC-CMV(a) for short is much different than VC-CMV(s). The control variable, breath sequence, and targeting scheme are unrelated, furthermore the names for some of these modes “Pressure Regulated Volume Control (PRVC)” and “Adaptive Pressure Ventilation (APV)” make it difficult for the operator to believe that one of these modes is actually VC-CMV(s).

Unfortunately, the naming of a mode or modality adjunct can confuse the operator making them believe the mode is actually a volume controlled mode. I presented earlier how one may confuse “Volume Control” on the Servo-i with VC-CMV(s) based on the name and how the breath is delivered in a passive patient. Another example of this is in the PB840 ventilator with a mode called “Volume Control Plus (VC+)” this mode in fact is PC-CMV(a).

The mode adjunct “AutoFlow” on Draeger Series ventilators may deceive likewise.

Some consider AutoFlow an individual mode of ventilation, but I view it as an adjunct because it resides as an option among the additional settings in volume targeted modes.

Figure five shows the traditional settings for volume control ventilation on a Draeger V500 ventilator and figure six displays the additional settings rooted in the VC-CMV(s).

Figure 5. VC-CMV settings on the Draeger V500.

Figure 6. AutoFlow highlighted under additional settings of VC-CMV.

From this page the operator can turn on AutoFlow which switches VC-CMV(s) to PC-CMV(a). After selecting AutoFlow the displayed mode name does not change the word AutoFlow is added to it (e.g. VC-CMV, AutoFlow) (fig. 7).

Figure 7. Mode still labeled VC-CMV after AutoFlow activated.

If the operator does not know that AutoFlow actually changes the mode to PC-CMV(a) then they may assume that they are still in a volume control mode and that a constant volume breath pattern will be delivered.

Volume Control-Continuous Mandatory Ventilation with set-point targeting is a safe and simplistic mode of ventilation that allows the operator to manually preset a minimum minute ventilation and quickly trouble shoot during adverse events. Unfortunately, due to no industry standards for ventilator mode taxonomy one can be misled using a mode labeled “Volume control”, “Volume Control Plus”, or selecting a mode adjunct expecting a volume control breath.

RELATED POST

Adaptive Targeting Schemes

Dual Targeting Schemes

Targeting Schemes

Dumbing Down Ventilator Taxonomy

Reference

1. Williams, K. et. al. (2011). Control of Breathing During Mechanical Ventilation: Who is the Boss? Respiratory Care. 56 (2): 127-138.

2. Volsko, T. et. al. (2012). The Effect of Targeting Scheme on Tidal Volume Delivery During Volume Control Mechanical Ventilation. Respiratory Care. 57 (8): 1297-1304.

3. Chatburn, R. et. al. (2014). A Taxonomy for Mechanical Ventilation: 10 Fundamental Maxims. Respiratory Care. 59 (11)

4. Chatburn, R. (2012). Standardized Vocabulary for Mechanical Ventilation. Mandu Press Ltd.

5. APC: Variances in Delivered Tidal Volume.

6. Adaptive Pressure Control Ventilation: Vigorous Inspiratory Drive.

7. Jaecklin, T. et. al. (2007). Pressure Control Volume Targeted Modes of Modern Neonatal Ventilators: How Stable is the Delivered Tidal Volume? Intensive Care Medicine. 33 (2): 326-335.

Ventilator Mode Map App

2015-09-20T09:57:00.000-04:00

Ventilator Mode Map Mobile App

Due to no industry standard for ventilator mode taxonomy and over 170 unique names for modes of ventilation. Learning and understanding ventilator mode classification can be problematic. Ventilator Mode Map provides a easy to use handheld solution. With this app one can choose from 12 different vendors, 37 different models (with pictures) and provides hundreds of definitions. One would have to review various text books and journal articles to compile this knowledge base.

This app is for android devices, I have a copy on my Samsung Galaxy tablet & Motorola phone, works fine on both devices. Available on Google Play see link below.

GOOGLE PLAY

Ventilator Mode Map

Free Virtual Mechanical Ventilator

2015-09-18T09:54:00.001-04:00

OPENPediatrics website provides a free virtual mechanical ventilator that allows users to review mechanical ventilator knowledge, play scenarios, and test their skills with case simulations.

One just needs to register for free on their "Clinician Community Site" to utilize the simulator.

LINKS

OPENPediatrics

OPENPediatrics simulator

OPENPediatrics Clinician Community Site

RELATED POST

Creating Flow Mismatch with a Simulator

Intelligent Targeting Schemes

2014-11-06T09:43:00.001-05:00

A Intelligent targeting scheme is "a ventilator control system that uses artificial intelligence programs such as fuzzy logic, rule based expert systems, & artificial neural networks" (Chatburn, 2012). Examples of modalities that use Intelligent targeting are Smartcare & IntelliVent-ASV.

Please view the above video for more information on Intelligent targeting schemes.

RELATED POSTS

SmartCare Posts

Free Mechanical Ventilation Handouts

Reference

Chatburn, R. (2012). Standardized Vocabulary for Mechanical Ventilation. Mandu Press.

*Note- this reference is available under the link free mechanical ventilation handouts.

Optimal Targeting Schemes

2014-11-03T14:44:00.002-05:00

A Optimal targeting scheme is a "ventilator control system that automatically adjusts the targets of the ventilatory pattern to either minimize or maximize some overall performance characteristic" (Chatburn, 2002).

Please view the above video for more information on Optimal targeting.

RELATED VIDEOS

ASV Playlist

RELATED POSTS

Adaptive Support Ventilation Posts

Free Mechanical Ventilation Handouts

Reference

Chatburn, R. (2012). Standardized Vocabulary for Mechanical Ventilation. Mandu Press.

*Note- this reference is available under the link free mechanical ventilation handouts.

Adaptive Targeting Schemes

2014-10-31T09:02:00.001-04:00

Adaptive targeting schemes use "a control system that allows the ventilator to automatically set some (or all) of the targets between breaths to achieve other preset targets" (Chatburn, 2012). Adaptive Pressure Control is most likely the most recognized and most used modality that uses a adaptive targeting scheme.

Please review the above video for a more detailed description.

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Adaptive Pressure Control Playlist

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Adaptive Pressure Control List

Free Mechanical Ventilation Handouts

Reference

Chatburn, R. (2012). Standardized Vocabulary for Mechanical Ventilation. Mandu Press.

*Note- this reference is available under the link free mechanical ventilation handouts.

FREMITUS

Mechanical Ventilation in SARS-COV-2

Build Your Own Ventilator "MIT E-VENT"

Advance Breathing System (ABS)- Disassembly, Cleaning, & Reassembly

LUNG PROTECTIVE TAPE

Lung Protective Tabulations Multi-touch book

Limiting Driving Pressure

MINIMIZING THE RISK OF VOLUTRAUMA

Hypoxic & Hyperoxic Guard

FREE MECHANICAL VENTILATION COURSE

Ventilator Graphics Now a Multi Touch Book

Ventilator Graphics (Mandarin) FREE PDF download

Ventilator Graphics (Japanese edition)

ARCHIVES

Whats your mode? Episode ii (VC-CMVd)

A rational framework for selecting modes of ventilation.

Building a Ventilator Simulator with Power Point

Whats Your Mode? Episode i

What’s Your Mode?

Changing Flow Patterns vs. Changing Ventilator Modes

HYPERCAPNEA & ATELECTRAUMA: MIMICKING APRV

The Volume Control Ventilation Fallacy

Ventilator Mode Map App

Free Virtual Mechanical Ventilator

Intelligent Targeting Schemes

Optimal Targeting Schemes

Adaptive Targeting Schemes