Sunday, January 6, 2013

Simplifying Mechanical Ventilation

From Global Nerdy @

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.

For greater than two decades, +Robert Chatburn has invested tremendously in the creation, refinement, education, promotion, and defense of a standardized taxonomy for mechanical ventilation [2-9].  Chatburn’s current classification system [1, 10] addresses the concerns that Dr. Rabec and colleagues present, which can be easily applied to non-invasive ventilation (NIV). Establishing a new oversimplified classification system specifically for NIV, I believe would further exacerbate the confusion.

As an alternative to creating a whole new classification system for mechanical ventilation, I propose three actions that can be executed at the local level (eg, ICU, facility, organization) that would make management of mechanical ventilation easier.

First, standardize equipment.

A report identifying the primary causes of ventilator related deaths from 1995-to-2003, revealed that greater than 90% of the fatalities were related to human error primarily lack of orientation/training [11]. Too many devices can cause confusion and turns a low use device into a high risk machine. Practitioners do not like to be and should not be “baptized by fire”; operating a device they are not familiar with. As a respiratory care manager or educator one should observe how their staff practices. If staff members continually switch out ventilators some examples;

-Replacing the transport ventilator in the ER with the ICU ventilator.
-Transporting on the ICU ventilator instead of the transport ventilator.
-Switching out a newly purchased ventilator with the older model.

These are all ciphers that staff members are uncomfortable with the different ventilators.

Administrators and mangers of teaching facilities may argue that standardizing equipment does not provide a sufficient learning environment for physicians in training. I would argue that these institutions provide the basic concepts and taxonomy of mechanical ventilation; with a comprehensive understanding of these principles one can apply this knowledge across many ventilator platforms. Additionally, it is still foremost the respiratory care practitioner who operates the mechanical ventilator, implementing the physician orders.

Second, start with one mode of ventilation and become an expert.

Bruce Lee once stated I fear not the man who has practiced 10,000 kicks once, but I fear the man who has practiced one kick 10,000 times” [1]. As for me I fear the operator of a ventilator who has used many modes however, is not an expert at any.

Modern day mechanical ventilators have over-abundance in regards to modes of ventilation, conversely few are ever used and some are associated with poor patient outcomes. An example of this is the mode Intermittent Mandatory Ventilation (IMV) aka. SIMV. IMV has been associated with increased duration of mechanical ventilation and results in the most patient-ventilator related asynchronies. So why does this mode come standard in all newer devices?

I would recommend becoming an expert first with Pressure Control Continuous Mandatory Ventilation (PC-CMV). This is a versatile mode which can be applied in all patient categories, and during all stages of patient care.  Additionally, once one is proficient utilizing this mode the operator can apply this knowledge to more advance pressure based modes of ventilation (eg, adaptive pressure control, Adaptive Support Ventilation) and predict ventilator interactions to changes in pulmonary mechanics and/or changes in patient inspiratory demand.

Third, establish and standardize protocols for mechanical ventilation

There are many published examples of how standardizing mechanical ventilation practice improves patient outcomes. Two examples are weaning protocols and the ARDS Net recommendations of ventilating patients with lower tidal volumes during acute lung injury or acute respiratory distress syndrome. Protocols keep practitioners accountable, and allow for easier monitoring of patient outcomes.

Yes, mechanical ventilation can be simplified however changing or adding new taxonomy is not the solution. I would recommend starting at the local level by standardizing equipment, becoming an expert with basic modes, and standardizing mechanical ventilation practices.

1.      Rabec C, Langevin B, Rodenstein D, Perrin C, Leger P, Pepin JL, Janssens JP, Gonzalez-Bermejo J. Ventilatory modes. What’s in a name? Respir Care 2012; 57 (12): 2138-2150.
2.      Chatburn RL. A new system for understanding mechanical ventilators. Respir Care 1991; 36 (10): 1123-1155.
3.      Chatburn RL. Classification of mechanical ventilators. Respir Care 1992; 37 (9): 1009-1025.
4.      Branson RD, Chatburn RL. Technical description and classification of modes of ventilator operation. Respir Care 1992; 37 (9): 1026-1044.
5.      Chatburn RL, Primiano FP Jr. A new system for understanding modes of mechanical ventilation. Respir Care 2001; 46 (6): 604-621.
6.      Chatburn RL. Computer control of mechanical ventilation. Respir Care 2004; 49 (5): 507-517.
7.      Chatburn RL. Classification of ventilator modes: Update and Proposal for Implementation. Respir Care 2007; 52 (3): 301-323.
8.      Chatburn RL, Mireles-Cabodevila E. Closed-loop control of mechanical Ventilation:description and classification of targeting schemes. Respir Care 2011; 56 (1): 85-102.
9.      Chatburn RL, Volsko TA, Hazy J, Harris LN, Sanders S. Determining the basis for ataxonomy of mechanical ventilation. Respir Care 2012; 57 (4): 514-524.
10.  Chatburn RL. Classification of mechanical ventilators and modes of ventilation. In: Tobin MJ, ed. Principlesand practice of mechanical ventilation, 3rd edition. New York:  McGraw-Hill, 2012.
11.  Nilsestuen JO, Hargett KD. Using Ventilator Graphics to Identify Patient-Ventilator Asynchrony. Respir Care 2005; 50 (2): 202.
12.  Bruce Lee, Martial Arts Renaissance Man.

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