Mean airway pressure and inspiratory time

In this episode of our series on respiratory critical care called Every Breath They Take, Dr. Lauria is joined by EM/Critical Care and Flight Physician Brittney Bernardoni as they discuss how to grapple with optimizing lung protective ventilation in ARDS.  

Lung protective ventilation at 6 cc/kg and maintaining plateau pressures of less than 30 cmH2O have been the cornerstones of invasive respiratory support since the findings of the ARMA trial in 2000.  In recent years, some interesting new developments have resulted in changes and improvements in lung protective ventilation strategies.  With a particular focus on ventilator "jiu-jitsu," this episode explores the intricate adjustments required to optimize patient care during ARDS management. From ventilator modes and plateau pressure to the impact of PEEP, FiO2, and mechanical power, this episode equips listeners with actionable knowledge for mastering the art of ventilation. Whether in the field or the ICU, the nuanced approaches discussed in this episode will enhance your understanding of optimizing respiratory support in critical patients. 

Listen to the episode wherever you get your podcasts or directly on our website at https://flightbridgeed.com/explore. While you're there, explore our award-winning courses that have helped thousands of providers clarify and understand the world of critical care transport and pre-hospital medicine.

Takeaways
• Early care in managing respiratory failure in the transport environment is crucial and can significantly impact patient outcomes.
• Lung protective ventilation with low tidal volumes is the foundation of ARDS management.
• The choice of ventilation mode (volume control or pressure control) depends on the clinician's comfort and ability to titrate the settings, but neither has proved superior.
• Permissive hypercapnia is generally well-tolerated in ARDS patients if the pH exceeds 7.15-7.20.
• The initial PEEP setting should be at least eight -  several strategies can be used to guide titration.
• High FiO2 levels can be detrimental to ischemic organs, alveolar patency, and the lung tissue itself.  Aiming for a FiO2 of less than or equal to 60% is important.
• Set, check, and change parameters to ensure optimal ventilation!
• Driving pressure may be an important factor in patient outcomes.
• Mean airway pressure and inspiratory time can improve oxygenation and minimize lung damage

References
1. Ahn HJ, Park M, Kim JA, et al. Driving pressure guided ventilation. Korean J Anesthesiol. Jun 2020;73(3):194-204. doi:10.4097/kja.20041
2. Amato MB, Meade MO, Slutsky AS, et al. Driving pressure and survival in the acute respiratory distress syndrome. N Engl J Med. Feb 19 2015;372(8):747-55. doi:10.1056/NEJMsa1410639
3. Azizi BA, Munoz-Acuna R, Suleiman A, et al. Mechanical power and 30-day mortality in mechanically ventilated, critically ill patients with and without Coronavirus Disease-2019: a hospital registry study. J Intensive Care. Apr 6 2023;11(1):14. doi:10.1186/s40560-023-00662-7
4. Battaglini D, Fazzini B, Silva PL, et al. Challenges in ARDS Definition, Management, and Identification of Effective Personalized Therapies. J Clin Med. Feb 9 2023;12(4)doi:10.3390/jcm12041381
5. Battaglini D, Sottano M, Ball L, Robba C, Rocco PRM, Pelosi P. Ten golden rules for individualized mechanical ventilation in acute respiratory distress syndrome. J Intensive Med. Jul 2021;1(1):42-51. doi:10.1016/j.jointm.2021.01.003
6. Bellani G, Laffey JG, Pham T, et al. Noninvasive Ventilation of Patients with Acute Respiratory Distress Syndrome. Insights from the LUNG SAFE Study. Am J Respir Crit Care Med. Jan 1 2017;195(1):67-77. doi:10.1164/rccm.201606-1306OC
7. Briel M, Meade M, Mercat A, et al. Higher vs lower positive end-expiratory pressure in patients with acute lung injury and acute respiratory distress syndrome: systematic review and meta-analysis. Jama. Mar 3 2010;303(9):865-73. doi:10.1001/jama.2010.218
8. Brower RG, Matthay MA, Morris A, Schoenfeld D, Thompson BT, Wheeler A. Ventilation with lower tidal volumes as compared with traditional tidal volumes for acute lung injury and the acute respiratory distress syndrome. N Engl J Med. May 4 2000;342(18):1301-8. doi:10.1056/nejm200005043421801
9. Chacko B, Peter JV, Tharyan P, John G, Jeyaseelan L. Pressure-controlled versus volume-controlled ventilation for acute respiratory failure due to acute lung injury (ALI) or acute respiratory distress syndrome (ARDS). Cochrane Database Syst Rev. Jan 14 2015;1(1):Cd008807. doi:10.1002/14651858.CD008807.pub2
10. Chiumello D, Carlesso E, Cadringher P, et al. Lung stress and strain during mechanical ventilation for acute respiratory distress syndrome. Am J Respir Crit Care Med. Aug 15 2008;178(4):346-55. doi:10.1164/rccm.200710-1589OC
11. Fuller BM, Ferguson IT, Mohr NM, et al. Lung-Protective Ventilation Initiated in the Emergency Department (LOV-ED): A Quasi-Experimental, Before-After Trial. Ann Emerg Med. Sep 2017;70(3):406-418.e4. doi:10.1016/j.annemergmed.2017.01.013
12. Gattinoni L, Collino F, Camporota L. Mechanical power: meaning, uses and limitations. Intensive Care Med. Apr 2023;49(4):465-467. doi:10.1007/s00134-023-06991-3
13. Harvey CE, Haas NL, Chen CM, et al. Initiation of a Lung Protective Ventilation Strategy in the Emergency Department: Does an Emergency Department-Based ICU Make a Difference? Crit Care Explor. Feb 2022;4(2):e0632. doi:10.1097/cce.0000000000000632
14. Laffey JG, Bellani G, Pham T, et al. Potentially modifiable factors contributing to outcome from acute respiratory distress syndrome: the LUNG SAFE study. Intensive Care Med. Dec 2016;42(12):1865-1876. doi:10.1007/s00134-016-4571-5
15. Maddry JK, Mora AG, Perez CA, et al. Improved Adherence to Best Practice Ventilation Management After Implementation of Clinical Practice Guideline (CPG) for United States Military Critical Care Air Transport Teams (CCATTs). Mil Med. Jan 4 2023;188(1-2):e125-e132. doi:10.1093/milmed/usab474
16. Maddry JK, Mora AG, Savell SC, et al. Impact of Critical Care Air Transport Team (CCATT) ventilator management on combat mortality. J Trauma Acute Care Surg. Jan 2018;84(1):157-164. doi:10.1097/ta.0000000000001607
17. Ranieri VM, Rubenfeld GD, Thompson BT, et al. Acute respiratory distress syndrome: the Berlin Definition. Jama. Jun 20 2012;307(23):2526-33. doi:10.1001/jama.2012.5669
18. Roginski MA, Burney CP, Husson EG, Harper KR, Atchinson PRA, Munson JC. Influence of Critical Care Transport Ventilator Management on Intensive Care Unit Care. Air Med J. Jan-Feb 2022;41(1):96-102. doi:10.1016/j.amj.2021.10.005
19. Sahetya SK, Hager DN, Stephens RS, Needham DM, Brower RG. PEEP Titration to Minimize Driving Pressure in Subjects With ARDS: A Prospective Physiological Study. Respir Care. May 2020;65(5):583-589. doi:10.4187/respcare.07102
20. Yoshida T, Uchiyama A, Fujino Y. The role of spontaneous effort during mechanical ventilation: normal lung versus injured lung. J Intensive Care. 2015;3:18. doi:10.1186/s40560-015-0083-6
21. Zaidi SF, Shaikh A, Khan DA, Surani S, Ratnani I. Driving pressure in mechanical ventilation: A review. World J Crit Care Med. Mar 9 2024;13(1):88385. doi:10.5492/wjccm.v13.i1.88385