Sunday, June 17, 2018

Hypoxic & Hyperoxic Guard

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

Wednesday, April 25, 2018



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 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
If you have not yet created a password to log into MyLearning, please follow the instructions shown below.
Feel free to contact if you have any problems accessing the course.
MyLearning Password Instructions
1.      Click the link
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 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)

Tuesday, July 4, 2017

Ventilator Graphics Now a Multi Touch Book

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.

Sunday, March 6, 2016


Pea Island Life Saving Station and Crew. Pea Island, NC Circa 1890

I have decided to stop posting public content and plan to keep this site up as an archives. However, new content available via subscription to the free newsletter. If interested sign up by selecting News letter tab or below. 

Saturday, February 20, 2016

Whats your mode? Episode ii (VC-CMVd)

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:

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

Wednesday, February 17, 2016

Building a Ventilator Simulator with Power Point

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.

Thursday, February 11, 2016

Whats Your Mode? Episode i

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.

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





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". 

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

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


Targeting Scheme Intro

Targeting Scheme Post

Whats Your Mode?

Thursday, January 28, 2016

What’s Your Mode?

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


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. 


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




Monday, November 30, 2015

Changing Flow Patterns vs. Changing Ventilator Modes

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.




Monday, November 23, 2015


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.

Wednesday, November 4, 2015

The Volume Control Ventilation Fallacy

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?

Sunday, September 20, 2015

Ventilator Mode Map App

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.


Ventilator Mode Map

Friday, September 18, 2015

Free Virtual Mechanical Ventilator

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. 



Thursday, November 6, 2014

Intelligent Targeting Schemes

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.


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

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

Monday, November 3, 2014

Optimal Targeting Schemes

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. 



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

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

Friday, October 31, 2014

Adaptive Targeting Schemes

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. 

Adaptive Pressure Control Playlist


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

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

Tuesday, October 28, 2014

Servo Targeting Schemes

Ventilator modes that use Servo targeting schemes are very responsive and provide the most comfort and synchrony in the spontaneous breathing patient. Servo targeting is "a control system for which the output of the ventilator automatically follows a varying input. This means that the inspiratory pressure is proportional to inspiratory effort" (Chatburn, R.). 

The below videos give a brief description of Servo targeting schemes and ventilator modes that use Servo targeting schemes. 

Thursday, September 25, 2014

Automatic Tube Compensation

Automatic Tube Compensation is "a feature that allows the operator to enter the size of the patient's endotracheal tube & have the ventilator calculate the tubes resistance & then generate just enough pressure to compensate for the added resistive load" (Chatburn, R. 2012).

Free Mechanical Ventilation Handouts

Servo Targeting 


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

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

Tuesday, September 23, 2014

Saturday, September 20, 2014

Correcting flow mismatch by increasing ventilator flow rate

Flow mismatch is a common patient ventilatory asynchrony associated with volume ventilation, which may lead to cardiovascular instability, increased oxygen consumption, increased carbon dioxide production, increased patient discomfort and prolonged mechanical ventilation[iv]. Fortunately, flow mismatch can be simply identified with the proper assessment of the pressure waveform.

To correct flow mismatch titrate the flow rate to match the patient’s inspiratory demands. Another corrective action is switching from a constant flow pattern to a decelerating flow pattern this provides a high initial peak flow. One must consider that changes in ventilatory demand may result in unnecessary higher than average assist resulting in ventilator induced diaphragm dysfunction[ii], a lower PaCO2 set-point, and delay in liberation.


Creating Flow Mismatch with a Simulator

Oxylog 3000 Simulator

Why I do not use Draeger ventilator simulators

Flow mismatch: patient ventilator asynchrony associated with volume ventilation

Waveform of the week: Flow Mis-match

Decreasing Dyspnea During Mechanical Ventilation