Spring/Summer 2021 Adult Acute Care Bulletin

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Notes from the Chair

Maria Madden, MS, RRT, RRT-ACCS

Welcome to the Spring-Summer edition of the Adult Acute Care Section Bulletin. I am very excited to continue Carl Hinkson’s great work as chair of the Adult Acute Care Section. My goal is to continue the insightful discussions on the section discussion list on AARConnect, invite new members into our discussions, and promote continuing education for our section. I have been highlighting the AARC JournalCasts and webcasts that would benefit our team.

I will also be posting a section meeting that will include Mindy Conklin and fellow graduates from the new Advanced Practice Respiratory Therapist (APRT) program at Ohio State. It would be great to hear about their training and future careers.

In this Bulletin, Sarah Bazelak, BS, RRT, RRT-ACCS, AE-C, discusses the role RTs played in the COVID-19 pandemic. MaryAnn Couture, MSc, RRT-ACC, covers some of the tools we have in our bedside toolbox. Thanks to both of them for taking the time to write an article.

If you’d like to contribute to the Bulletin, please email our Bulletin editor, Karsten Roberts, MS, RRT, RRT-ACCS, RRT-NPS.

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Respiratory Therapists Instrumental in Navigating the COVID-19 Pandemic

Sarah Bazelak, BS, RRT, RRT-ACCS, AE-C, Education and Quality Coordinator for Respiratory Care, Froedtert Hospital, Milwaukee, WI

In March 2020, the United States felt the sudden daunting impact of the unknown brought on by SARS-CoV-2. While health care professionals feared the unimaginable, the overwhelming burden that this disease would place on our health care system became clear to the public eye.¹ Health care systems prepared to take on the uphill battle, and one thing became apparent: to endure the tumultuous days ahead, all disciplines and teams needed to work together and streamline processes.

Interprofessional collaboration (IPC) has been an increasing focus within health care systems over the past decade, as it can improve practice and lead to favorable outcomes.² IPC was heavily utilized throughout many organizations to adapt to the needs of the pandemic.

Respiratory therapist extenders and more

According to the U.S. Bureau of Labor Statistics, there were 135,800 respiratory therapist jobs in 2019, with an anticipated growth of 19% over the next ten years.³ With an already much greater demand for services than trained professionals available, respiratory therapists were certainly one of the teams heavily impacted by the pandemic’s increased demand for specialized care.⁴

This extreme need for expertise led to the implementation of respiratory therapist extenders (RTE). Organizations that implemented RTEs reallocated certified registered nurse anesthetists, paramedics, medical students, or registered nurses to support mechanical ventilation in tandem with respiratory therapists.^5,6

In order to support the RTE, programs were established that included RT-led training sessions on navigating ventilator interfaces and understanding varying modes of mechanical ventilation.6 In addition to mechanical ventilation assistance, some RTE programs also included other respiratory therapy interventions, such as inhalers and noninvasive ventilation, as well as other tasks like oxygen rounds and equipment stocking^.5

Respiratory therapy teams, in partnership with critical care providers, developed just-in-time education for the RTEs that provided a foundation for application and care in mechanical ventilation. To further support this, the AARC and Society of Critical Care Medicine developed training resources for the novice clinician.^7,8

Respiratory therapist collaboration was also evident in the development and application of guidelines on aerosol generating procedures (AGP) and triaging systems.^9,10 Since respiratory therapy is deeply embedded in many AGPs, RT expertise was necessary to adapt interventions to provide safe and/or alternative care solutions. If the demand far exceeded available skilled

personnel, effective triaging and prioritization algorithms were needed to guide staff to maximize care.¹⁰

RTs were also involved in collaborative efforts to develop proning teams and protocols to establish early application of heated high flow oxygen in settings outside the ICU.¹¹

Time to keep the momentum going

Respiratory therapists have exemplified incredible leadership, collaboration, and adaptability throughout the pandemic. RTs rose to the challenge and were instrumental in the ability of the health care system to navigate its way through COVID-19. They demonstrated the profession’s ability to collaborate, lead, and set the standard for lean processes.^5,6,8,10,11

The work is not done, even with the light at the end of the pandemic tunnel beginning to present.1 RTs must take this opportunity to continue the forward momentum that will continue to push the profession forward.
References

1. WHO Director-General’s opening remarks at the media briefing on COVID-19. https://who.int/dg/speeches/detail/who-director-general-s-opening-remarks-at-the-media-briefing-on-covid-19%2D%2D-11-march-2020. Accessed 22 Apr 2020
2. Centers for Disease Control and Prevention. (2021). CDC COVID Data Tracker. https://covid.cdc.gov/covid-datatracker/#trends_dailytrendscases.
3. Reeves S, Pelone F, Harrison R, Goldman J, Zwarenstein M. Interprofessional collaboration to improve professional practice and healthcare outcomes. Cochrane Database Syst Rev 2017;Issue 6:Art. No.: CD000072.
4. U.S. Bureau of Labor Statistics. (2020). Occupational Outlook Handbook: Healthcare: Respiratory Therapists. https://bls.gov/ooh/healthcare/respiratory-therapists.htm.
5. Hanley ME, Bogdan GM. Mechanical ventilation in mass casualty scenarios. Augmenting staff: project XTREME. Respir Care 2008;53(2):176-189.
6. Hester TB, Cartwright JD, DiGiovine DG, Karlic KJ, Kercheval JB, DiGiovine B, et al. Training and deployment of medical students as respiratory therapist extenders during COVID-19. ATS Sch 2020;1(2):145-151.
7. Roberts KJ, Johnson B, Morgan HM, Vrontisis JM, Young KM, Czerpak, E, et al. Evaluation of respiratory therapist extender comfort with mechanical ventilation during COVID-19 pandemic. Respir Care 2021;66(2):199-204.
8. AARC. (2021). Strategic national stockpile ventilator training program. http://www.aarc.org/resources/clinical-resources/strategic-national-stockpile-ventilator-training-program/. 8. SCCM. (2021). COVID-19 resources for non-ICU clinicians. https://covid19.sccm.org/.
9. Li J. (2021). Updated guidance on aerosol-generating procedures. http://www.aarc.org/wp-content/uploads/2021/02/Updated_AGP-021021.pdf.
10. Rubinson L, Hick JL, Curtis JR, Branson RD, Burns S, Christian MD, et al. Definitive care for the critically ill during a disaster: medical resources for surge capacity: from a Task Force for Mass Critical Care Summit Meeting, Jan 26-27, 2007, Chicago, IL. Chest 2008;133(5Suppl):32S-50S.

11. 11. Jackson JA, Spilman SK, Kingery LK, Oetting TW, Taylor MJ, Pruett WM, et al. Implementation of high-flow nasal cannula therapy outside the intensive care setting. Respir Care 2021;66(3):357-365.

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What’s in Your Bedside Toolbox?

MaryAnn Couture, MSc, RRT, RRT-ACCS, Retired; Former associations with Hartford Hospital, Hartford, CT, and adjunct faculty with the University of Hartford, Hartford, CT, and Goodwin College, East Hartford, CT

Critical care clinicians can be challenged by patients with poor oxygenation. Ventilator settings may generate concern for alveolar stress and strain. Some clinicians may have a plethora of equipment to choose from. Others may have none at all, except for ventilator graphics and a calculator. Our ability to address concerns is dependent on tools we have at the bedside to measure various data, such as static compliance (Cstat), end inspiratory pressure (Pplat), and driving pressure (∆P), as well as our skill in applying these measurements in real time as a preemptive attempt to prevent further lung injury.¹

Many diagnostic data share similar values, while others, such as ∆P have a tighter range of perceived safety. This is an exercise to help determine best PEEP with or without diagnostic devices for a patient case (n=1) in ARDS. The clinician should be mindful of safe limits of ventilator settings to limit lung damage. An open lung strategy seeks to recruit but not over-distend lung tissue in order to reduce alveolar stress and strain.¹ It is up to the clinician to determine the end point when ranges are large. When diagnostic machinery such as capnography is available, some real time values can be added as a data surrogate.

A method for finding optimal PEEP

PEEP optimization trials can begin with a lung recruitment maneuver, followed by stepwise decreases in PEEP starting at a set high level (or open lung approach). It is suggested that PEEP adjustments be done by titrating 2 cmH2O at a time. If lung recruitment is not able to be used or if the patient is hemodynamically unstable, then maneuvering PEEP upwards or downwards by a few cm in total may be adequate for the exercise. The patient ideally should be sedated and paralyzed, however keeping the patient in a stable, quiet state still can be useful.

Consider collecting data for each PEEP level by starting with bedside calculations such as Cstat, Pplat, and ∆P, then add data from diagnostic equipment that is available, including pertinent vital signs. Keep in mind any data from monitors, such as a pulmonary artery catheter, can indicate cardiovascular instability when PEEP levels are increased.

After a change has been made, observe for decreases in mean arterial pressure, which can be related to compression of pulmonary vasculature and venous return to the heart. A team approach procedure is provided by Hubmayr and Kallet when the benefits of increasing PEEP necessitate supporting blood pressure.²

Capnography is a diagnostic device that provides more data than just end tidal CO2 (PETCO2). VCO2 from capnography may also be used as a surrogate to help clinicians in optimizing PEEP. VCO2 can be found in some ventilators that have integrated capnography.

While PETCO2 may be prominent on a ventilator screen, other capnography information can be found in hidden screens. The goal at the bedside is to achieve the highest VCO2 until it begins to decrease. When arterial blood gases are available after PEEP optimization, PaCO2 can be utilized in the formula to calculate VD/VT, a predictor of mortality.^3-7 Another novel way to predict mortality without the complex formula is the PETCO2/PaCO2 ratio. This may be another useful alternative.⁸

Some time for stabilization should be allowed between PEEP changes. Femgmai et al. allowed for 30 minute time intervals as part of their study.⁹ While impractical for a bedside exercise, their paper mentions PEEP optimization in the discussion. However, data can be obtained within a couple of minutes as the observed data stabilizes. It is advisable to stop titration when data changes in the wrong direction and return PEEP to the previous step.

Another very simple measurement is achieved by calculating ∆P. The formula uses the patient’s exhaled VT/Cstat. Safe thresholds were initially considered at < 15 cm H2O.10-13 Yet, there may be some variation with spontaneous breathing that allows for >15 cm H2O.¹⁴

Creating an n-1 table

With each PEEP titration, list data in each column, then determine and circle the best data based on what is known of the patient’s condition and in consideration of predictors of mortality and ventilator induced lung injury. When we use calculations or diagnostic equipment and place data side-by-side for each change in PEEP, the clinician may notice those very close relationships. Some data will show very clear singular choices while others may show acceptable ranges of tolerance based on facility procedures and protocols. There should be a somewhat clear picture on where your recommendation should be. The goal is to be able to find optimal PEEP so you can confidently make recommendations to the provider.

While individual patient conditions may lead to a step higher or lower than what is shown, you should be able to closely triangulate and see how data share close relationships. Bedside clinicians should become familiarized with as many diagnostic devices as possible, but the calculator is still a useful guide.

Finally, this exercise should be used in consideration of local protocols and guidelines when recommending your findings of optimal PEEP. The purpose of this exercise is to show that there are some variations in defining optimal PEEP when different methods are used.

Recommendations are not yet absolute, but the range could be narrowed with more research utilizing combined methods. 
References

1. Nieman GF, Satalin J, Kollisch-Singule M, Andrews P, Aiash H, Habashi NM, Gatto LA. Physiology in medicine: understanding dynamic alveolar physiology to minimize ventilator-induced lung injury. (Includes supplemental animations). J Appl Physiol 2017;122(4):1516-1522. https://doi.org/10.1152/japplphysiol.00123.2017.
2. Hubmayr RD, Kallet RH. Understanding pulmonary stress-strain relationships in severe ARDS and its implications for designing a safer approach to setting the ventilator. Respir Care 2018;63(2):219-226.
3. McSwain SD, Hamel DS, Smith PB, Gentile MA, Srinivasan S, et al. End-tidal and arterial carbon dioxide measurements correlate across all levels of physiologic dead space. Respir Care 2010;55(3):288-293.
4. Raurich JM, Vilar M, Colomar A, Ibáñez J, Ayestáran I, Pérez-Bárcena J, Llompart-Pou JA. Prognostic value of the pulmonary dead-space fraction during early and intermediate phases of acute respiratory distress syndrome. Respir Care 2010;55(3):282-287.
5. Nuckton TJ, Alonso JA, Kallet RH, Daniel BM, Pittet JF, Eisner MD, Matthay MA . Pulmonary dead-space fraction as a risk factor for death in the acute respiratory distress syndrome. N Engl J Med 2002;346(17):1281-1286.
6. Kallet RH, Zhuo H, Ho K, Lipnick MS, Gomez A, Matthay MA, Lung injury etiology and other factors influencing the relationship between dead-space fraction and mortality in ARDS. Respir Care 2017;(62)10:1241-1248.
7. Siobal MS, Monitoring exhaled carbon dioxide. Respir Care 2016;61(10):1397-1416.
8. Kallet RH, Lipnick MS. End-tidal-to-arterial PCO2 ratio as signifier for physiologic dead-space ratio and oxygenation dysfunction in acute respiratory distress syndrome. Respir Care 2021;66(2):263-268.
9. Fengmei G, Jin C, Songqiao L, Congshan Y, Yi Y. Dead space fraction changes during PEEP titration following lung recruitment in patient with ARDS. Respir Care 2012;57 (10):1578-1585.
10. Amato MBP, Meade MO, Slutsky AS, Brochard L, Costa ELV, Schoenfeld DA, et al. Driving pressure and survival in the acute respiratory distress syndrome. N Engl J Med 2015;372(2):747-755.
11. Guérin C, Papazian L, Reignier J, Ayzac L, Loundou A, Forel JM. Effect of driving pressure on mortality in ARDS patients during lung protective mechanical ventilation in two randomized controlled trials. Crit Care 2016;20:384-393.
12. Bugedo G, Retamal J, Bruhn A. Driving pressure: a marker of severity, a safety limit, or a goal for mechanical ventilation? Crit Care 2017;21:199-206.
13. Ahn HJ, Park M, Kim JA, Yang M, Yoon S, Kim BR, Bahk JH, Oh YJ, Lee EH. Driving pressure guided ventilation. Korean J Anesthesiol 2020;73(3):194-204. https://doi.org/10.4097/kja.20041
14. Baldomero AK, Skarda PK, Marini JJ. Driving pressure: defining the range. Respir Care 2019;64(8):883-889.

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Section Connection

Section discussion list: Go to the Adult Acute Care Section on AARConnect to network with your fellow section members.

Next Bulletin: Fall/Winter Issue. Please email Karsten Roberts if you would like to contribute an article. He will be happy to help guide you through the process if you’re a new contributor!