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Overview: Pulmonary Diagnostic Laboratory (PDL) Resource Center

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Greetings and thanks so much for stopping by.

I know I shouldn’t start off with a negative, but I simply want to set expectations.

While this site is labeled as a Resource Center, it is not a repository for Pulmonary Diagnostic positions or recommendations as published by the ERS, ATS, etc.. Instead it contains information that could potentially augment the quality of the services that Pulmonary Diagnostic Technologists (PDTs) provide to their customers (internal and external).

Assuring the quality of instrumentation accuracy, test result derivation and reporting is paramount to ensuring the most appropriate patient management. But while those aspects are extremely important, they’re not the totality in what makes an outstanding Pulmonary Diagnostic Laboratory. It’s the other “stuff”, that isn’t contained in professional organization guidelines/recommendations, that will be the focus of this PDL Resource Center.

The primary focus, of the Pulmonary Diagnostic Laboratory Resource Center, is on process improvement with an emphasis on service delivery. Over the years, pulmonary diagnostic technology and professional recommendations have evolved. So too have process improvement methodologies and strategies. That is why a Focus Area addresses some Implementation Science concepts that may be applicable to not only the pulmonary diagnostic laboratory setting, but to the respiratory care arena as well.

Additionally, the PDL Resource Center may not provide the absolute answers a particular laboratory setting may need. However, it’s my hope that it will provide some pearls, a platform, a beginning, from which the Pulmonary Diagnostician can then use his/her critical thinking skills to develop the solution(s) to what is being sought for their specific laboratory.

  • While it’s good laboratory practice to incorporate (and hopefully exceed) professional society recommendations, it’s also important to recognize and appreciate that each laboratory setting is unique and, as such, has different needs.
  • Therefore, in my opinion, each laboratory should investigate/research and develop solutions that meet the needs of that specific environment.
  • Of course a particular laboratory can use ideas from their counterparts. But the PDT should not necessarily rely entirely upon what other laboratories have developed, and implemented, and try and make those solutions fit into their practice.
  • This is a especially important concept if supporting information (e.g., evidence-based data) is not provided, from the other laboratory, detailing how decisions were made and validated

My intention is for this site to be organic, so that as additional areas need to be addressed, they can easily be added.

As of this writing (beginning in April 2021), there are five essential Focus Areas addressed in the PDL Resource Center:

1. Indications for Pulmonary Diagnostic Testing / Summary of Services

2. Technologist Driven Protocols

3. Bronchial Provocation Method Selection: An Evidence-Based Approach (UNDER CONSTRUCTION)

4. Airway Mechanics

5. Implementation Science

So why start with these 5 areas?

1.         Indications for Pulmonary Diagnostic Testing / Summary of Services:

Having a well-designed description of what services you offer should improve on the quality that you bring to your organization. I’m basing this statement on personal experience coming from a “Big 10” academic medical center where customers/subjects were referred, to the Pulmonary Diagnostic Services, from a variety of specialty services. Generally, outside of Pulmonary services, there was a high degree of variability in the understanding of Pulmonary Diagnostics (e.g., what each test was, along with how to apply the information into patient management). Most EHRs today should be able to accommodate a summary of services as a quick reference guide for internal customers.

Providing clear documentation, as to what services you provide, allows referring physicians (internal customers) to understand what test(s) might be most appropriate for their patients (external customers). Such understanding should help to reduce variability in requested tests (reduce inappropriate testing) and improve quality.

  • This concept is particularly important today since a primary focus on healthcare delivery remains on transitioning from quantity to quality.

Both the Indications and the Summary of Services content were developed prior to current professional society recommendations. Therefore, while the overall intent remains the same, some of the testing indications (and procedures) may be outdated, and are provided as informational only. The focus, however, should remain on the processes outlined in this section.

  • As you review this section, ask yourself these questions:
    • which professional society recommendation aspects have changed from what is described?
    • do I agree with the focus of the section? If yes, then Why? If no, then Why?
    • what information can be gleaned and applied in my laboratory setting? What would I do differently?
    • am I willing to provide a similar service to my internal customers? Which processes should I utilize to design, implement and evaluate the effectiveness of the service?

2.         Technologist Driven Protocols (TDPs):

Pulmonary Diagnostic TDPs are a method to standardize the approach to detecting and quantifying lung dysfunction. Ideally they are developed from a body of evidence-based scientific literature. In the absence of scientific data to support specific concepts, then expert opinion may be substituted with that limitation being recognized. Implementing well designed and validated Pulmonary Diagnostic TDPs should improve the efficiency, consistency and the quality of delivered services.

The TDPs subsequently listed were developed a number of years ago. They are largely based upon the best available scientific data (evidence) at the time (AARC Diagnostic Clinical Practice Guidelines [CPGs], ATS recommendations), as well as decades of clinical and laboratory experience.

Note: The information from Focus Area 1, “Indications for Pulmonary Diagnostic Testing / Summary of Services” was used to develop, and begin validation of, these Technologist Driven Protocols.

These TDPs are provided simply as a roadmap for the interested, since they were developed for a specific Pulmonary Diagnostic Laboratory system. Your work environment may be different, recommendations may have changed, and this information may not be directly transferable. However, there may be some “pearls” of information that might be gleaned from them as you develop, or update, your own TDPs.

  • For the interested I suggest you revisit the AARC Diagnostic Clinical Practice Guidelines (CPGs), if for no other reason, than to review the body of scientific literature that was used to support the published CPGs. Additionally, the more recent (retired) AARC Diagnostic CPGs included descriptors that addressed quality system essentials which are applicable to all the operations in workflow pathways. Please see the American Association for Respiratory Care (AARC) Clinical Practice Guidelines at . Also, the “ATS Pulmonary Function Laboratory Management and Procedure Manual 3rd Edition” contains referenced Indications and Contraindications for each of the procedures described. Purchasing information for this manual can be located at .

3. Bronchial Provocation Method Selection: An Evidence-Based Approach

Published professional recommendations (e.g., ERS/ATS) address select methods for Bronchial Provocation testing. Overall, these recommendations focus on the rationale, indications, and limitations/contraindications for each of the tests described. They are well defined, purposeful, and provide an abundance of supporting (evidence-based) published medical literature. However, what is lacking is a clear guidance regarding how to determine/select the appropriate method of bronchial provocation that is based upon the initial subject presentation.

For example, within your practice you use Methacholine Chloride as the primary source for bronchial provocation testing. However, if you have other options available (e.g., Mannitol, Exercise, etc.) why would you continue to do that? What evidence-based information do you have at your disposal to make a more informed decision? This is particularly important since not all individuals, with reactive airways disease, will have a positive response to Methacholine inhalation. Using the rationale that always starting with Methacholine is acceptable since “that’s the way we’ve always done it” is actually an unacceptable stance to take. That particular justification is based solely upon convenience and not evidence.

The purpose of this Focus Area is to hopefully provide some guidance on selecting appropriate Bronchial Provocation methods. This guidance is based upon published information that addresses the Indications, Contraindications (absolute and relative), and Limitations of the methods described**; Methacholine Chloride Inhalation, Mannitol Inhalation, Exercise-Induced (bicycle ergometer or treadmill), Frigid Air Inhalation, or Eucapnic Voluntary Hyperpnea.

This topic is controversial. I’ve provided you with published information that I believe supports my standpoint. However, as always, please let me know your thoughts regarding the validity and feasibility of this Focus Area.

**Histamine was not included as it used infrequently in the U.S., primarily due to the potential side-effects incurred with non-responsive individuals. Environmental challenge studies were not an option since there are very few sites capable of providing prolonged subject observation; a positive response may take hours, to days, to months to be elicited.

4.         Airway Mechanics:

This section is included as there is a paucity of information on this topic. Technical descriptors are published, but very little information is available on the applications of Airway Mechanics measurements.

Airway Mechanics (Airway Resistance [Raw], Airway Conductance [Gaw], Specific Airway Resistance [sRaw] and Specific Airway Conductance [sGaw]), are important pulmonary diagnostic tools. The derived data can be used in conjunction with other pulmonary diagnostic procedures, or as stand-alone information if the subject is unable to perform more traditional testing (e.g., Spirometry) in an acceptable and reproducible manner.

  • Actual examples are included which hopefully illustrate how Airway Mechanics can readily be included as part of the Pulmonary Diagnostic Services armamentarium. The procedure is easy to perform and readily accepted by most subjects. 
  • The key to success is for the PDT to be well informed on the nuances of the testing system, the procedure and assuring the derived data is consistent with the client’s clinical presentation.
  • It’s essential that the derived data (in particular the open-shutter tangent) be measured in the same manner as to how the reference authors determined theirs.
    • An example of an open-shutter loop measurement is provided, with Raw determined two ways, that should clarify this comment.

5.         Implementation Science:

Implementation Science (IS) is a new and evolving area that numerous professional healthcare organizations have recently embraced and encouraged their members to do as well. Some IS concepts have long been incorporated into Pulmonary Diagnostic practices, but have not been recognized/labeled as such.

This section is written with the Respiratory Care Practitioner in mind, as a primer addressing some key IS concepts and the importance of incorporating these principles into practice. The primary goal, of IS, is to improve the quality of service to the customer, which is consistent with the Affordable Care Act of 2010, as well as the Quadruple Aim.

As reviewed, there are numerous options that may be utilized. This section addresses select key IS concepts and provides some examples of applications of these concepts.

  • In general, the Respiratory Care profession is woefully behind other professional organizations in understanding, embracing and employing IS principles into practice. This lack of understanding and acceptance of IS concepts may negatively affect the quality of the patient experience.
    • For example, the SARS-CoV-2 pandemic shuttered most Pulmonary Diagnostic Laboratories during much of 2020 and 2021. Many PDTs, who are credentialed RCPs, were redeployed to direct patient care teams. By necessity, these teams incorporated IS concepts in-order-to maximize and optimize the quality of delivered patient care. Many RCPs/PDTs were unaware of the IS terminology being used by their nursing and physician team members. Time permitting, they had to catch-up to their healthcare colleagues understanding of IS concepts, to maximize their individual skill sets and remain a valued, contributing, team member as a physician-extension and not merely a task-completer.

So that’s it in a nutshell. Hopefully the following content will provide some useful information. Whether that information is new, or supports what you have already incorporated into your practice. Again, healthcare delivery focus is on quality and NOT quantity.

The Respiratory Care profession (PDTs included), like all other health care specialties, will continuously need to evolve, transform and demonstrate organization value. Simply providing a service, without evidence of value, is no longer a justifiable position to take.  It is imperative that all PDTs maximize their total understanding of Pulmonary Diagnostic practice to provide the best service and experience to their clients.

My intent is for the PDL Resource Center to be of value to you and to the profession. Please don’t hesitate to provide your constructive feedback on the content of this site….what didn’t make sense, what additional topics would be helpful, etc.. 



Robert A. Brown, BS, RRT, RPFT, FAARC

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NOTE:  The Focus Areas formatting is being worked on….. Things are aligning in the draft mode, but not necessarily so when displayed on the web page…..hang tight dear Technologist, I’m working on it.