LUNG PROTECTIVE TAPE

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

RELATED POSTS

Lung Protective Tabulations Multi-touch book

Limiting Driving Pressure

Minimizing the Risk of Volutrauma

Hypoxic & Hyperoxic Guard

Lung Protective Tabulations Multi-touch book

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

LUNG PROTECTIVE TABULATIONS

Limiting Driving Pressure

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

A Synopsis of Strategies in Difficult Intra-Operative Ventilation

Image from: http://www.esicm.org

“Strategies in Difficult Intra-Operative Ventilation” was a continuing education course originally presented at the 2012 American Academy of Anesthesiologist convention. 

Now the course is available online through the ASA website for continuing education units. I would not recommend this course for the ICU practitioner because it overviews strategies that we practice daily or weekly, however for the anesthesia provider that is not familiar with lung protective strategies the course may be beneficial. 

Below is a synopsis of the course and a hyperlink to the website. 

Adaptive Pressure Control Ventilation Interactions with Improving Pulmonary Mechanics

RELATED POSTS

APC: Variances in Delivered Tidal Volume

Adaptive Pressure Control Ventilation: vigorous Inspiratory Drive

Adaptive Pressure Control Ventilation Video Series

APC Variable Patient Flow Rate

Minute Ventilation as a Function of Inspiratory Time

References

Rob Chatburn's MFV simulator

Journal of Applied Physiology 67 (3) (1982), 1081-1092

RELATED POST

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

PC-CMV Relationship of Delivered VE & Set Frequency 

Relationship of Frequency to Vt During PC-CMV

Mathematical Models of PC-CMV: Max Vt

The Relationship of I-Time & Mean Airway Pressure

References

Rob Chatburn's MFV simulator

Journal of Applied Physiology 67 (3) (1982), 1081-1092

RELATED POST

Minute Ventilation as a Function of Inspiratory Time 

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

PC-CMV Relationship of Delivered VE & Set Frequency 

Relationship of Frequency to Vt During PC-CMV

Mathematical Models of PC-CMV: Max Vt

Mathematical Models of PC-CMV: Duty Cycle & Resistance

References

Rob Chatburn's MFV simulator

Journal of Applied Physiology 67 (3) (1982), 1081-1092

RELATED POST

Minute Ventilation as a Function of Inspiratory Time

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

PC-CMV Relationship of Delivered VE & Set Frequency 

Relationship of Frequency to Vt During PC-CMV

Mathematical Models of PC-CMV: Max Vt

Mathematical Models of Pressure Control Ventilation: The Relationship of PEEPi to set Frequency

References

Rob Chatburn's MFV simulator

Journal of Applied Physiology 67 (3) (1982), 1081-1092

RELATED POST

Minute Ventilation as a Function of Inspiratory Time

Mathematical Models of PC-CMV: Duty Cycle & Resistance

PC-CMV Relationship of Delivered VE & Set Frequency 

Relationship of Frequency to Vt During PC-CMV

Mathematical Models of PC-CMV: Max Vt

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. 

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. 

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? 

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? 

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.

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.

The Minimal SSI Strategy

 

Stress Index (Si) Displayed on the SERVO-i Ventilator. 

In 2009 Brunner & Wysocki proposed that there is an optimal breathing pattern to minimize stress & strain during mechanical ventilation [1]. Stress and strain are primary causes of ventilator induced lung injury (VILI), so it would be imperative to provide a breathing pattern which decreases the chances of VILI. 

A Unique Way to Obtain the NIF



Using the trigger setting to quantify extubation readiness. Notice the measured PEEP value & set PEEP value, the patient is able to generate a NIF < -18 cmH2O.

There are multiple ways to obtain the Negative Inspiratory Force (NIF) NIP (negative inspiratory pressure), or MIP (maximal inspiratory pressure) measurement. The NIF “corresponds to the negative pressure generated by the inspiratory muscles during a maximal inspiratory effort, performed during temporary occlusion of the airway opening” [1]. This parameter is used to quantify that the respiratory drive is sufficient (paralytics, narcotics, sedation is worn off after general anesthesia) or that there is no respiratory muscle fatigue or exhaustion.

Obtaining Pulmonary mechanics with the PB840 Ventilator

In my opinion I believe the PB840 ventilator is an outdated platform. One thing that frustrates me is that additional functions/features cost the purchaser extra, where on most ventilators these functions are standard.

Examples:

-Trending

-P0.1

-No low flow lung mechanics tool.

The only thing I believe is useful is Proportional Assist Plus, however this is still a software upgrade charge.

Another frustration when using the PB840 is obtaining pulmonary mechanics measurements correctly.

When properly obtaining these measurements one has to place the patient in VC-CMV (volume controlled ventilation) and perform an additional three steps.

Here are the steps:

1. Place the patient in VC mode (if the patient is in another mode)

2. Change the flow waveform setting to a Square (constant) flow waveform pattern.

3. Change the flow setting value to obtain a I-time which matches the previous set I-time.

4. Perform an inspiratory pause, by pressing the inspiratory pause button (insp pause)