How the Aurora Shootings Helped Boston Hospitals Prepare for the Marathon Bombing

Image from Prisonplanet.com

Audio Podcast available from NPR's "Here & Now".

Click Link:  Before Marathon Bombings, Aurora Helped Boston Prepare

Mid-Frequency Ventilation (MFV) During Cardiac Ablation Procedure

More information at GMEP Media Gallery (click link): https://gmep.org/media/14474

RELATED POST

The versatility of MFV

The utilization of MFV with a sophisticated transport ventilator

Application of MFV

Waveform of the Week

Waveform of the week 

I posted a patient ventilator asynchrony case on the GMEP Media Gallery.

Here is the link for viewing:

https://gmep.org/media/14733

PC-CMV Relationship of Delivered Minute Ventilation & Set Frequency

Mathematical Review of Pressure Preset Ventilation

Minute ventilation as a function of set frequency with no airflow obstruction. Minute ventilation rises toward a final plateau determined by I-time & resistance. However, compliance determines the rate of the rise of the curves.

RELATED POST

Minute Ventilation as a Function of Inspiratory Time

Mathematical Models of PC-CMV: Duty Cycle & Resistance

Mathematical Models of PC-CMV: The Relationship of PEEPi to set Frequency

Mathematical Models of PC-CMV: Max Tidal Volume

Relationship of Frequency to Tidal Volume During PC-CMV

REFERENCE 
J. Appl Physiology 67 (3) (1982), 1081-1092. 

Relationship of frequency to tidal volume during PC-CMV

Review of Mathematical Principles of Pressure Preset Mechanical Ventilation

This video demonstrates the relationship between set frequency to delivered tidal volume during Pressure control ventilation. Reductions in compliance or increases in frequency decrease delivered VT.

RELATED POST

Minute Ventilation as a Function of Inspiratory Time

Mathematical Models of PC-CMV: Duty Cycle & Resistance

Mathematical Models of PC-CMV: The Relationship of PEEPi to set Frequency

PC-CMV Relationship of Delivered VE & Set Frequency 

Limits of Pressure Control Ventilation: a introduction to the MFV simulator. 

Don't waste my time! Physician Rounds.

Image from: http://house.download-tvshows.com/files/Hugh%20Laurie_1.jpg

Physician rounds, ICU rounds, or multi-disciplinary rounds are very important in the care and treatment of mechanically ventilated patients. It is the only time (usually only once in a 24 hour period) that many specialties can share their concerns, ideas, and goals with the attending intensivist.  The attending physician is very busy, and  responsible for the over-site of many patients, so it is ideal to present your goals during rounds.

I have worked many places and still can't believe how RT's do not attend rounds or do not engage during rounds. These are usually the same RT's that complain that they do not have protocols or that ventilator management is by physician order only. 

"Its your own fault, your NOT allowed to manage the ventilator". 

Why is this patient on mechanical ventilation TODAY?

Photo from: http://theprogressivepatient.wordpress.com/2012/04/22/6/

It is very frustrating when I meet with the ICU staff Respiratory Therapist and ask why is this patient on the ventilator today and I get the following response “they had surgery”, “they coded”, “they had ventilatory failure”, “they have ARDS”, etc. Yet, these events happened hours, days, or even weeks ago, and they are not in the acute stages of their illness anymore.  There is a huge difference between initial indications for mechanical ventilation (MV) versus current goals for MV.

The Infectious Disease Post

Before getting into Respiratory Therapy I was thinking about majoring in microbiology, specifically infectious diseases, so I have taken quite a bit of classes on the subject.

These last few months I have took an interest again on the subject, and have spent my down time researching through books, movies, a mobile game, and even a scavenger hunt.

This post is a hybrid part video/ part text so I would recommend watching the video first.

The references from the video are below:

ZEEP Trial

Zero End-Expiratory Pressure "ZEEP" trial is an alternative to a standard SBT with minimal ventilator settings and/or trach collar or T-piece trials. See video for more information.

RELATED POST/ LINKS

Tobin: minimal PEEP & pressure support during SBT kills some patients

Myth Buster:ventilator weaning should be done on minimal settings (no T-Piece)

Is the T-piece trial futile?

Performing a T-piece trial through the ventilator.

The intrinsic diaphragmatic frequency. 

Mathematical Models of PC-CMV: Max Tidal Volume

RELATED POSTS

Minute Ventilation as a Function of Inspiratory Time

Mathematical Models of PC-CMV: Duty Cycle & Resistance

Mathematical Models of PC-CMV: The Relationship of PEEPi to set Frequency

Relationship of Frequency to Vt During PC-CMV

PC-CMV Relationship of Delivered VE & Set Frequency 

Limits  of Pressure-Control Ventilation: a Introduction to the MFV Simulator. 

Os Gráficos do Ventilador

Os Gráficos do Ventilador

Identificando a Assincronia Paciente-Ventilador e Otimizando as Definições 

AMAZON KINDLE

http://www.amazon.com/Ventilador-Identificando-Assincronia-Paciente-Ventilador-ebook/dp/B00CPBHZUU/ref=sr_1_1?s=books&ie=UTF8&qid=1368070803&sr=1-1

Comparison of 3 Methods to Set T-Low on APRV: REVISTED

RELATED POST

Automatic Setting of T-Low during APRV: Is it beneficial? 

Setting T-Low During APRV to Achieve Lung Protective Goals.

4 Reasons not to use APRV.

Limits of Pressure-Control Ventilation: a Introduction to the Mid-Frequency Simulator

In respiratory therapy school I was never taught about the various mathematical models of pressure-control ventilation (PC-CMV) and we probably only had a hour lecture on respiratory time constants. In clinical rotations PC-CMV was seldom used and had a bad reputation only being used on the sickest patients. This was due to the practice of utilizing  inverse-ratio ventilation in treating patients with ARDS and  serve hypoxia, which led to the administration of neuro-muscular blocking agents and poor outcomes.

Even today many practitioners are unfamiliar with the most versatile mode of ventilation (PC-CMV) and do not know how to optimize the settings. If one wants to have a understanding of the advance modes of ventilation, PC-CMV is were to start.

Assessment of Collateral Circulation of the Hand via Pulse Oximetry

The assessment of collateral circulation of the hand is performed often by surgeons, anesthesiologists, and Respiratory Care Practitioners (Cook, L, 2001; Galvin and Jones, 1989; Gerhring et al, 2002; Raju, 1986; Van de Louw et al, 2001) and Wisely and Cook, 2001). 

Surgeons may use this evaluation before performing a radial artery harvest for coronary artery bypass surgery, Anesthesiologists assess collateral circulation of the hand before arterial cannulation and Respiratory Care Practitioners check the collateral circulation before performing radial artery sticks for blood gas analysis. Each health care professional assesses collateral circulation of the hand for a different reason; however, they all primarily use the same evaluation technique.

Using the Quasi-Static Pressure/Volume Curve to Identify Optimal PEEP & Recruitability

             

In previous post I mention evaluating the static P/V curve to set P-High when using Airway Pressure Release Ventilation (aka. APRV, BiLevel, BiVent) and to set optimal PEEP.

Another advantage of analyzing the static P/V curve is to identify if the patients lungs are recruitable. If they are not recruitable, then they will most likely not respond to higher levels of PEEP or placing them on APRV. 

The above video demonstrates the difference between recruitable & Non-recruitable lungs. 

RELATED POST
APRV: Setting P-High Based on the Static Pressure Volume Curve

Setting PEEP

The Constant Low Flow Method: Utilizing the PB840 part two

Identifying Optimal PEEP with the PB840 Ventilator: the Constant Low Flow Method

Obtaining Plateau Pressures Revisited

I receive many questions in regards to plateau pressure.

What is a plateau pressure?

What is the difference between Peak & plateau pressures?

How do I measure/obtain a plateau pressure measurement?

Are my peak & plateau pressures always equal when using pressure control ventilation?

How do I get a plateau pressure when using PRVC, AutoFlow, or VC+?

My new video (above) describes obtaining plateau pressure when using VC-CMV, PC-CMV, & APC (a.k.a. PRVC, AutoFlow, VC+). 

RELATED POST
A review of Plateau Pressure

A Problem with Plateau Pressure

Why is my Peak & Plateau Pressures the Same? 

3D Printing for Medicine

Floating Exhalation Valve

What is a floating exhalation valve?

What is the difference between a traditional exhalation valve and a floating one?

How do I know if my ventilator has a floating exhalation valve?

See my new video for answers. 

RELATED POST

All Exhalation Valves are not Created Equal

APRV Preview Videos

The above video is an example of the content that is in my new course APRV, BiLevel, BiVent the Utilization of Airway Pressure Release Ventilation.

I posted four additional videos from this course on my YouTube page for review. 

RELATED POST

APRV, BiLevel, BiVent FREE Course

APRV, BiLevel, BiVent FREE course

OFFER HAS EXPIRED

_______________________________________________________________________

My new course is available FREE for the first 10 participants. 

1. Go to the "COURSES" tab on top of this page.
2. Click on the link provided.
3. Use the following coupon code: xab5-1013-sal1-aprv

Dumbing Down Ventilator Taxonomy

In a recent letter to the editor “Ventilatory modes. What’s in a name?”[1] Authors provide a strong argument for the need to standardize terminology in regards to mechanical ventilation and propose an oversimplified classification system specifically for non-invasive ventilatory devices. I applaud the authors for their call to action; conversely their viewpoint is neither novel nor applicable to ventilator taxonomy.

FiO2 Titration Augmented by Artificial Intelligence

I have been a Registered Respiratory Therapist for greater than twelve years and have never considered the titration of oxygen a big deal. Furthermore, practicing at > 10 different facilities in eight different States I have never needed to be prompted by a physician or surveillance system to titrate the FiO2 during mechanical. Fortunately, I have only worked at facilities with respiratory care practitioner driven protocols. So when two recent articles were published on the subject within the last month I took notice [1, 2].

Sterilizing Mosquitos

Simplifying Mechanical Ventilation

From Global Nerdy @ www.globalnerdy.com

In a recent letter to the editor “Ventilatory modes. What’s in a name?”[1] Authors provide a strong argument for the need to standardize terminology in regards to mechanical ventilation and propose an oversimplified classification system specifically for non-invasive ventilatory devices. I applaud the authors for their call to action; conversely their viewpoint is neither novel nor applicable to ventilator taxonomy.

A Review of Plateau Pressure

What is Plateau Pressure? 

Why is it important?

How can I measure plateau pressure?

In pressure control ventilation is the peak pressure and plateau pressure always equal?

Is plateau pressure always accurate? 

RELATED POST

Obtaining Plateau Pressures Revisited

Obtaining Pulmonary Mechanics with the PB840 Ventilator.

A Problem with Plateau Pressures.

Why is my Peak & Plateau Pressures the Same? 

TISSUE ENGINEERING to PERSONALIZE MEDICINE

Medical Fraud: Admitting Patients To Increase Revenue

CPAP as a LOW TIDAL VOLUME VENTILATION STRATEGY

Image 1: Ventilator Screen Shot of Continuous Positive Airway Pressure. 

In October’s issue of the Chest Journal, a few colleagues of mine authored the abstract “The Use of Invasive Continuous Airway Pressure for Low Tidal Volume Ventilation”.

 This abstract was very intriguing to me for various reasons, one this goes against many traditional methods of providing ventilatory support for the patient with Acute Lung Injury and/ or ARDS.

Zealots of Airway Pressure Release Ventilation would argue that using pure CPAP would lead to extreme work of breathing and not off load the respiratory muscles sufficiently.

I myself would be concerned about using CPAP only, especially in extra-pulmonary ARDS primarily sepsis and septic shock where patients metabolic demand is high, which leads to a vigorous inspiratory demand. Off-loading these patients is very difficult and even using APRV or traditional methods leads to severe hypercapnea.  

However, I was baffled so I questioned my friend Troy Whitacre, a coauthor of the abstract to find more details and to share his experience.

Video Games on the Brain

How Video Games may help us learn and focus.

New Project: Concepts of Mechanical Ventilation

I have started a new project called "Concepts of Mechanical Ventilation".

This will be a educational page reviewing basic to advance concepts of mechanical ventilation.

I will be adding short educational videos, which links can be accessed under the "Video Library" tab at the top of this Blogs  page.

The above video is an example, more to come.

The Versatility of Mid-Frequency Ventilation

MFV first proposed in the medical literature in 2008 as a “conceptual” [1] ventilator modality which maximizes alveolar ventilation and minimizes the delivered tidal volume. MFV provides an alternative to traditional Volume-Control (VC) ventilation for patients with ARDS. This is extremely beneficial because lung protective strategies using VC ventilation are limited by predestined hypercapnia and hypercapnic acidosis.

Rebuttal to APC a False Sense of Security

Image 1: Laparoscopic surgery.

In a previous post "Adaptive Pressure Control Ventilation during Anesthesia: a False Sense of Security", I argue that the anesthesia provider should use this mode with caution and described how the mode reacts during changes in pulmonary mechanics. 

After reading the post one could assume that I'm against using this mode of ventilation.

However, I believe this mode has many advantages. 

Flu season not for me!: Surveillance screening for scheduling.

I have always believed in the motto "work smarter, not harder". 

As a respiratory therapist one is paid hourly and it does not matter how much work you do in that hour. You will not receive a bonus if you administer 100 more breathing treatments then your coworker. 

So what are the optimal times to be at work versus being on vacation, in regards to working smarter?

Publication Bias: Evidence Based Medicine Dirty Secret

Dr. Ben Goldacre presents the topic of research misconduct in medicine and how unreported negative trials may mislead practitioners to the actual safety of a pharmaceutical agent. 

Goldacre, states that positive results are two times as likely to be published than the negative results and believes that all human trials should be published regardless of outcomes. 

Determinants and Limits of the Bellows: The Katz Study

Image 1: Draeger Narkomed 2c Anesthesia Delivery System.

In a previous post "Determinants and Limits or the Draeger Narkomed Anesthesia Machine in Regards to Ventilating the Morbidly Obese Patient", I tried to calculate the largest patient a bellows system could ventilate safely. 

I concluded that if you wanted to deliver a minute ventilation greater than 9 liters per minute, using conventional ventilator settings (tidal volume of 10 ml/kg/IDBW) that the operator would run into issues. 

Designing Medical Equipment for the Real World

______________________________________________________

RELATED POST

Frustrated with Medical Therapy Options? Design Your Own.

The Universal Anesthesia Machine. 

Adaptive Support Ventilation in the Morbidly Obese

Mechanically ventilating the morbidly obese patient has many considerations

Dead Falls, Trip Wires, and Ventilator Settings

As many may not know I grew up in the Midwest and was raised on the principles of self-reliance and the respect for nature. I was taught how to hunt, fish, trap, forge, and grow one’s own vegetables. Our family even attempted to save enough food for a year, preparation for hard times or a catastrophic event (most likely a tornado).

Obtaining P0.1 on Various Ventilators

Airway Occlusion at 0.1 Second (P0.1)

In previous post I provide a brief description of the P0.1 and how one can apply this to adjusting  settings on the ventilator [1,2] and provide greater detail in my book [3].

However, how does one obtain this measurement?

Fortunately, modern mechanical ventilators have this as a software option.

Even though the procedure for obtaining a P0.1 is automated, it is a little different on each device.

Volume-Control to Pressure Control

Image 1: The Settings of VC-CMV. The settings highlighted in yellow are associated with patient-ventilator asynchrony. 

VC-CMV is likely the most utilized mode of mechanical ventilation. This is due to a few a reasons:

     1. VC-CMV is a standard mode on almost every intensive care ventilator (table 1).

     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).

Frustrated with Medical Therapy Options? Design Your Own.

Image 1: Modeled Aorta. 

Tal Goleworthy  frustrated with his options for conventional treatment of a dilated aorta decided to design his own therapy. 

Minimal Fresh Gas Flow: "A Reassuringly Safe Anesthetic Technique".

Image 1: Minimal FGF on the FLOW-i anesthesia delivery system

In this months Canadian Journal of Anesthesia authors of the article "Brief Review: Theory and Practice of Minimal Fresh Gas Flow Anesthesia", conclude that with newer anesthesia delivery systems that using minimal fresh gas flow and third generation of inhaled anesthetic agents is a safe technique with many benefits [1]. 

The authors review advantages, potential limitations, and safety considerations when utilizing minimal fresh gas flow technique (mFGF). 

Setting PEEP

There is many ways to set Positive End Expiratory Pressure (PEEP). Setting PEEP too low may result in under or tidal recruitment of the lung and PEEP that is too high results in over-distention, both contribute to Ventilator Induced Lung Injury (VILI).  This post provides a synopsis of the various techniques as well as potential pros & cons.

Vent Graphics Contest WINNERS

First, I would like to thank all my readers who entered the "Vent Graphics Contest" , I appreciate all of the efforts.

First Prize

John Priest

Equipment Used: Epiphan 

Image 1 & 2: Preventing auto-triggering.

NAVA vs. Pressure Support in Pediatric Patients

Pressure Support Ventilation can be  associated with 8 types of patient ventilator asynchronies. 

Overview

The researchers sought to determine if neurally adjusted ventilatory assist (NAVA) enhances asynchrony, ventilatory drive, breath-to-breath variability and COMFORT score when compared to pressure support (PS).  Twelve pediatric patients with asynchrony (auto-triggering, double triggering or non-triggered breaths) were enrolled in a non-randomized short-term cross-over trial.  Four sequential 10-min periods of data were recorded after 20 min of ventilatory stabilization (wash-out) at pre-determined settings.

Results

The median asynchrony index was notably lower during NAVA than during 2-PS(opt) and 4-PS(opt). In NAVA mode, the NAVA trigger accounted for approximately 66% of triggered breaths. The median trigger delay with respect to neural inspiratory time was considerably lower during NAVA than during 2-PS(opt) and 4-PS(opt). The median electrical activity of the diaphragm (EAdi) change during trigger delay normalized to maximum inspiratory. EAdi difference was notably lower during NAVA than during 2-PS(opt) and 4-PS(opt).  Additionally, NAVA produced a significantly higher coefficient of variation of tidal volume than 2-PS(opt) and 4-PS(opt). The median comfort score during NAVA was lower than that during 2-PS(opt) and 4-PS(opt).

Conclusion

This research shows that NAVA results in improved synchrony, reduced ventilatory drive, increased breath-to-breath mechanical variability and improved patient comfort compared to optimized PS.

Reference

De le Olivia, P., Schuffelmann, C., Gomez-Zamora, A., & Kacmarek, R. M., (2012). Asynchrony, neural drive, ventilatory variability and COMFORT: NAVA versus pressure support in pediatric patients. A non-randomized cross-over trial. Intensive Care Medicine, 38(5), 838-846.