The FlightBridgeED Podcast

PART 2 of 2

In this episode, Dr. Michael Lauria is joined by several EM/Critical Care and Transport/Retrieval physicians as we discuss the management of acute respiratory distress syndrome (ARDS) in the critical care transport setting. We cover the pathophysiology of ARDS, the criteria for diagnosis, and the basics of lung protective ventilation. We also explore the concept of driving pressure and its role in determining optimal ventilation settings. The conversation highlights the importance of individualizing treatment based on patient characteristics and monitoring parameters such as plateau pressure, driving pressure, and compliance. 

Our team provides practical tips for adjusting ventilation settings and emphasizes the need for ongoing assessment and optimization. In the previous episode, we started out with some fundamental concepts of mechanical ventilation: the approach to low tidal volumes in ARDS patients and the use of point-of-care blood gases. We also explored the use of steroids in ARDS, the target oxygen saturation levels, and the use of paralysis in unstable patients. In addition, we touched on controversial topics such as inhaled pulmonary vasodilators in ARDS as well as the application of evidenced-based therapies such as proning in the transport environment (in this episode, part 2). Also, in this part of the conversation, we review the use of alternative ventilator modes, such as APRV, and the indications for ECMO in refractory ARDS. We emphasize the importance of optimizing conventional, evidence-based therapies before considering ECMO and highlight the need for clear guidelines and training when using these advanced interventions. We also discuss the challenges and potential complications associated with ECMO. 

Takeaways

  • ARDS is a syndrome characterized by acute onset, bilateral infiltrates on imaging, and hypoxemia.
  • The diagnosis of ARDS is based on criteria such as acute onset, infectious or inflammatory etiology, bilateral opacities on imaging, and impaired oxygenation.
  • Lung protective ventilation aims to minimize lung injury by using low tidal volumes (6-8 ml/kg), maintaining plateau pressures below 30 cmH2O, and keeping FiO2 below 60%.
  • Driving pressure, the difference between plateau pressure and PEEP, is a marker of lung compliance and can be used to guide ventilation adjustments.
  • Individualized management is crucial, considering factors such as patient characteristics, response to therapy, and monitoring parameters.
  • Regular assessment and optimization of ventilation settings are necessary to ensure effective and safe management of ARDS. 
  • Low tidal volumes should be based on the patient's pH and PCO2, with a focus on maintaining a safe pH level.  If crews are unable to measure these parameters not decreasing tidal volumes lower than 4 cc/kg is reasonable.
  • Point-of-care blood gases are essential for monitoring patients on low tidal volumes and making adjustments as needed.
  • Oxygen saturation targets should be individualized based on the patient's condition and physiology, with a range above 88-92% often considered reasonable. However, this issue is controversial, and occasionally, lower saturations are considered acceptable.
  • Steroids may be beneficial in ARDS patients, especially those with severe pneumonia, but the timing and dosing should be determined based on the patient's specific situation.
  • Paralysis can be considered in unstable ARDS patients who cannot tolerate low tidal volumes, but it should be used selectively and in conjunction with deep sedation.
  • The use of inhaled pulmonary vasodilators in ARDS is controversial, and no significant mortality benefit has been demonstrated. However, they may be considered a salvage therapy in patients on their way to an ECMO center or when other interventions have been exhausted. Inhaled pulmonary vasodilators, such as epoprostenol, can improve oxygenation and pulmonary arterial pressure in patients with ARDS and RV failure.
  • The use of inhaled pulmonary vasodilators should be based on individual patient characteristics and the availability of resources.
  • Proning in transport has been shown to be safe and effective.  It should be considered for select cases, such as patients with high pulmonary arterial pressure or basilar atelectasis.
  • Transport teams should be prepared to continue inhaled pulmonary vasodilator therapy if the patient is already receiving it.
  • ECMO should be considered when conventional therapies have failed, and the patient's condition is reversible and not contraindicated.
  • ECMO transport requires specialized training, clear guidelines, and ongoing communication with the receiving center.
  • Alternative ventilator modes, such as APRV, have not shown significant benefit in large trials.  Their use is controversial but not unreasonable in certain circumstances.  Implementing these settings requires training, education, and clear protocols.  Generally speaking, they should be used judiciously and in consultation with the receiving physician.
  • Optimizing conventional therapies and providing high-quality care can often obviate the need for ECMO.
  • Transport teams should be proactive in discussing potential ECMO candidates with the receiving physician and considering the appropriateness of ECMO for each patient.

References:

  1. Abou-Arab O, Huette P, Debouvries F, Dupont H, Jounieaux V, Mahjoub Y. Inhaled nitric oxide for critically ill Covid-19 patients: a prospective study. Crit Care. Nov 12 2020;24(1):645. doi:10.1186/s13054-020-03371-x
  2. Gattinoni L, Camporota L, Marini JJ. Prone Position and COVID-19: Mechanisms and Effects. Crit Care Med. May 1 2022;50(5):873-875. doi:10.1097/ccm.0000000000005486
  3. Grasselli G, Calfee CS, Camporota L, et al. ESICM guidelines on acute respiratory distress syndrome: definition, phenotyping and respiratory support strategies. Intensive Care Med. Jul 2023;49(7):727-759. doi:10.1007/s00134-023-07050-7
  4. Griffiths MJ, Evans TW. Inhaled nitric oxide therapy in adults. N Engl J Med. Dec 22 2005;353(25):2683-95. doi:10.1056/NEJMra051884
  5. Guérin C, Reignier J, Richard JC, et al. Prone positioning in severe acute respiratory distress syndrome. N Engl J Med. Jun 6 2013;368(23):2159-68. doi:10.1056/NEJMoa1214103
  6. 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
  7. Acute Respiratory Distress Syndrome Network; 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. 2000 May 4;342(18):1301-8. doi: 10.1056/NEJM200005043421801.
  8. Grasselli G, Calfee CS, Camporota L, et al; European Society of Intensive Care Medicine Taskforce on ARDS. ESICM guidelines on acute respiratory distress syndrome: definition, phenotyping and respiratory support strategies. Intensive Care Med. 2023 Jul;49(7):727-759. doi: 10.1007/s00134-023-07050-7.
  9. Qadir N, Sahetya S, Munshi L, Summers C, Abrams D, Beitler J, Bellani G, Brower RG, Burry L, Chen JT, Hodgson C, Hough CL, Lamontagne F, Law A, Papazian L, Pham T, Rubin E, Siuba M, Telias I, Patolia S, Chaudhuri D, Walkey A, Rochwerg B, Fan E. An Update on Management of Adult Patients with Acute Respiratory Distress Syndrome: An Official American Thoracic Society Clinical Practice Guideline. Am J Respir Crit Care Med. 2024 Jan 1;209(1):24-36. doi: 10.1164/rccm.202311-2011ST.
  10. Matthay MA, Arabi Y, Arroliga AC, Bernard G, Bersten AD, Brochard LJ, Calfee CS, Combes A, Daniel BM, Ferguson ND, Gong MN, Gotts JE, Herridge MS, Laffey JG, Liu KD, Machado FR, Martin TR, McAuley DF, Mercat A, Moss M, Mularski RA, Pesenti A, Qiu H, Ramakrishnan N, Ranieri VM, Riviello ED, Rubin E, Slutsky AS, Thompson BT, Twagirumugabe T, Ware LB, Wick KD. A New Global Definition of Acute Respiratory Distress Syndrome. Am J Respir Crit Care Med. 2024 Jan 1;209(1):37-47. doi: 10.1164/rccm.202303-0558WS.
  11. Juffermans NP, Rocco PRM, Laffey JG. Protective ventilation. Intensive Care Med. 2022 Nov;48(11):1629-1631. doi: 10.1007/s00134-022-06820-z. 
  12. Fuller BM, Ferguson I, Mohr NM, et al. Lung-protective ventilation initiated in the emergency department (LOV-ED): a study protocol for a quasi-experimental, before-after trial aimed at reducing pulmonary complications. BMJ Open.  2016;6:e010991. doi: 10.1136/bmjopen-2015-010991
  13. Barrot L, Asfar P, Mauny F, Winiszewski H, Montini F, Badie J, Quenot JP, Pili-Floury S, Bouhemad B, Louis G, Souweine B, Collange O, Pottecher J, Levy B, Puyraveau M, Vettoretti L, Constantin JM, Capellier G; LOCO2 Investigators and REVA Research Network. Liberal or Conservative Oxygen Therapy for Acute Respiratory Distress Syndrome. N Engl J Med. 2020 Mar 12;382(11):999-1008. doi: 10.1056/NEJMoa1916431.
  14. Capellier G, Barrot L, Winizewski H. Oxygenation target in acute respiratory distress syndrome. J Intensive Med. 2023 May 13;3(3):220–7. doi: 10.1016/j.jointm.2023.03.002.
  15. Boyle AJ, Holmes DN, Hackett J, Gilliland S, McCloskey M, O'Kane CM, Young P, Di Gangi S, McAuley DF. Hyperoxaemia and hypoxaemia are associated with harm in patients with ARDS. BMC Pulm Med. 2021 Sep 8;21(1):285. doi: 10.1186/s12890-021-01648-7. 
  16. Ohshimo S. Oxygen administration for patients with ARDS. J Intensive Care. 2021 Feb 6;9(1):17. doi: 10.1186/s40560-021-00532-0. 
  17. Villar J, Ferrando C, Martínez D, Ambrós A, Muñoz T, Soler JA, Aguilar G, Alba F, González-Higueras E, Conesa LA, Martín-Rodríguez C, Díaz-Domínguez FJ, Serna-Grande P, Rivas R, Ferreres J, Belda J, Capilla L, Tallet A, Añón JM, Fernández RL, González-Martín JM; dexamethasone in ARDS network. Dexamethasone treatment for the acute respiratory distress syndrome: a multicentre, randomised controlled trial. Lancet Respir Med. 2020 Mar;8(3):267-276. doi: 10.1016/S2213-2600(19)30417-5.
  18. Feng LH, Li XD, Zhang XY, Cheng PJ, Feng ZY. Dexamethasone for the treatment of acute respiratory distress syndrome: A systematic review and meta-analysis. Medicine (Baltimore). 2022 Sep 30;101(39):e30195. doi: 10.1097/MD.0000000000030195.
  19. Metlay JP, Waterer GW, Long AC, Anzueto A, Brozek J, Crothers K, Cooley LA, Dean NC, Fine MJ, Flanders SA, Griffin MR, Metersky ML, Musher DM, Restrepo MI, Whitney CG. Diagnosis and Treatment of Adults with Community-acquired Pneumonia. An Official Clinical Practice Guideline of the American Thoracic Society and Infectious Diseases Society of America. Am J Respir Crit Care Med. 2019 Oct 1;200(7):e45-e67. doi: 10.1164/rccm.201908-1581ST. 
  20. Jayasimhan D, Matthay MA. Corticosteroids in adults with acute respiratory distress syndrome and severe pneumonia. BJA Educ. 2023 Dec;23(12):456-463. doi: 10.1016/j.bjae.2023.08.005.
  21. Nasrullah A, Virk S, Shah A, Jacobs M, Hamza A, Sheikh AB, Javed A, Butt MA, Sangli S. Acute Respiratory Distress Syndrome and the Use of Inhaled Pulmonary Vasodilators in the COVID-19 Era: A Narrative Review. Life (Basel). 2022 Nov 2;12(11):1766. doi: 10.3390/life12111766.
  22. Liu K, Wang H, Yu SJ, Tu GW, Luo Z. Inhaled pulmonary vasodilators: a narrative review. Ann Transl Med. 2021 Apr;9(7):597. doi: 10.21037/atm-20-4895. 
  23. Al Sulaiman K, Korayem GB, Altebainawi AF, Al Harbi S, Alissa A, Alharthi A, Kensara R, Alfahed A, Vishwakarma R, Al Haji H, Almohaimid N, Al Zumai O, Alrubayan F, Asiri A, Alkahtani N, Alolayan A, Alsohimi S, Melibari N, Almagthali A, Aljahdali S, Alenazi AA, Alsaeedi AS, Al Ghamdi G, Al Faris O, Alqahtani J, Al Qahtani J, Alshammari KA, Alshammari KI, Aljuhani O. Evaluation of inhaled nitric oxide (iNO) treatment for moderate-to-severe ARDS in critically ill patients with COVID-19: a multicenter cohort study. Crit Care. 2022 Oct 3;26(1):304. doi: 10.1186/s13054-022-04158-y.
  24. Fuller BM, Mohr NM, Skrupky L, Fowler S, Kollef MH, Carpenter CR. The use of inhaled prostaglandins in patients with ARDS: a systematic review and meta-analysis. Chest. 2015 Jun;147(6):1510-1522. doi: 10.1378/chest.14-3161.
  25. Piecek J, Valentino T, Aust R, Harris L, Hancock J, Hardman C, van Poppel SF. The Use of Nitric Oxide as a Rescue Modality for Severe Adult Acute Respiratory Distress Syndrome Patients, Including COVID-19, in Critical Care Rotor Transport: A Retrospective Community Outcome Study. Air Med J. 2022 Sep-Oct;41(5):427-431. doi: 10.1016/j.amj.2022.06.002.
  26. Brown CJ, Rubel N, Lai J, Ward C, McLean J, Wheelock M, Steuerwald M, Cathers A. Initiation of Inhaled Nitric Oxide by an Air Transport Team in Adult Coronavirus Disease 2019 Respiratory Failure. Air Med J. 2022 Jul-Aug;41(4):406-410. doi: 10.1016/j.amj.2022.03.001.
  27. Buskop C, Bredmose PP, Sandberg M. A 10-year retrospective study of interhospital patient transport using inhaled nitric oxide in Norway. Acta Anaesthesiol Scand. 2015 May;59(5):648-53. doi: 10.1111/aas.12505.
  28. Guérin C, Reignier J, Richard JC, Beuret P, Gacouin A, Boulain T, Mercier E, Badet M, Mercat A, Baudin O, Clavel M, Chatellier D, Jaber S, Rosselli S, Mancebo J, Sirodot M, Hilbert G, Bengler C, Richecoeur J, Gainnier M, Bayle F, Bourdin G, Leray V, Girard R, Baboi L, Ayzac L; PROSEVA Study Group. Prone positioning in severe acute respiratory distress syndrome. N Engl J Med. 2013 Jun 6;368(23):2159-68. doi: 10.1056/NEJMoa1214103.
  29. Guérin C, Albert RK, Beitler J, Gattinoni L, Jaber S, Marini JJ, Munshi L, Papazian L, Pesenti A, Vieillard-Baron A, Mancebo J. Prone position in ARDS patients: why, when, how and for whom. Intensive Care Med. 2020 Dec;46(12):2385-2396. doi: 10.1007/s00134-020-06306-w.
  30. Pelosi P, Tubiolo D, Mascheroni D, Vicardi P, Crotti S, Valenza F, Gattinoni L. Effects of the prone position on respiratory mechanics and gas exchange during acute lung injury. Am J Respir Crit Care Med. 1998 Feb;157(2):387-93. doi: 10.1164/ajrccm.157.2.97-04023.
  31. Kallet RH. A Comprehensive Review of Prone Position in ARDS. Respir Care. 2015 Nov;60(11):1660-87. doi: 10.4187/respcare.04271.
  32. Priya V, Sen J, Ninave S. A Comprehensive Review of Prone Ventilation in the Intensive Care Unit: Challenges and Solutions. Cureus. 2024 Mar 30;16(3):e57247.
  33. Seethala RR, Frakes MA, Cocchi MN, Cohen JE, Dargin J, Friedman F, Grant C Jr, Kaye A, Wilcox SR. Feasibility and Safety of Prone Position Transport for Severe Hypoxemic Respiratory Failure Due to Coronavirus Disease 2019. Crit Care Explor. 2020 Dec 3;2(12):e0293. doi: 10.1097/CCE.0000000000000293.
  34. Zhang T, Nikouline A, Riggs J, Nolan B, Pan A, Peddle M, Fan E, Del Sorbo L, Granton J. Outcomes of Patients Transported in the Prone Position to a Regional Extracorporeal Membrane Oxygenation Center: A Retrospective Cohort Study. Crit Care Explor. 2023 Jul 21;5(7):e0948. doi: 10.1097/CCE.0000000000000948.
  35. Flabouris A, Schoettker P, Garner A. ARDS with severe hypoxia--aeromedical transportation during prone ventilation. Anaesth Intensive Care. 2003 Dec;31(6):675-8. doi: 10.1177/0310057X0303100613.
  36. DellaVolpe JD, Lovett J, Martin-Gill C, Guyette FX. Transport of Mechanically Ventilated Patients in the Prone Position. Prehosp Emerg Care. 2016 Sep-Oct;20(5):643-7. doi: 10.3109/10903127.2016.1162888.
  37. Pan A, Peddle M, Auger P, Parfeniuk D, MacDonald RD. Interfacility Transport of Mechanically Ventilated Patients with Suspected COVID-19 in the Prone Position. Prehosp Emerg Care. 2023;27(3):287-292. doi: 10.1080/10903127.2022.2036882.
  38. Wieruszewski PM, Ortoleva JP, Cormican DS, Seelhammer TG. Extracorporeal Membrane Oxygenation in Acute Respiratory Failure. Pulm Ther. 2023 Mar;9(1):109-126. doi: 10.1007/s41030-023-00214-2.
  39. Combes A, Hajage D, Capellier G, Demoule A, Lavoué S, Guervilly C, Da Silva D, Zafrani L, Tirot P, Veber B, Maury E, Levy B, Cohen Y, Richard C, Kalfon P, Bouadma L, Mehdaoui H, Beduneau G, Lebreton G, Brochard L, Ferguson ND, Fan E, Slutsky AS, Brodie D, Mercat A; EOLIA Trial Group, REVA, and ECMONet. Extracorporeal Membrane Oxygenation for Severe Acute Respiratory Distress Syndrome. N Engl J Med. 2018 May 24;378(21):1965-1975. doi: 10.1056/NEJMoa1800385.
  40. Lewandowski K. Extracorporeal membrane oxygenation for severe acute respiratory failure. Crit Care. 2000;4(3):156-68. doi: 10.1186/cc689. 
  41. Schmidt M, Hajage D, Lebreton G, Monsel A, Voiriot G, Levy D, Baron E, Beurton A, Chommeloux J, Meng P, Nemlaghi S, Bay P, Leprince P, Demoule A, Guidet B, Constantin JM, Fartoukh M, Dres M, Combes A; Groupe de Recherche Clinique en REanimation et Soins intensifs du Patient en Insuffisance Respiratoire aiguE (GRC-RESPIRE) Sorbonne Université; Paris-Sorbonne ECMO-COVID investigators. Extracorporeal membrane oxygenation for severe acute respiratory distress syndrome associated with COVID-19: a retrospective cohort study. Lancet Respir Med. 2020 Nov;8(11):1121-1131. doi: 10.1016/S2213-2600(20)30328-3.
  42. Peek GJ, Mugford M, Tiruvoipati R, Wilson A, Allen E, Thalanany MM, Hibbert CL, Truesdale A, Clemens F, Cooper N, Firmin RK, Elbourne D; CESAR trial collaboration. Efficacy and economic assessment of conventional ventilatory support versus extracorporeal membrane oxygenation for severe adult respiratory failure (CESAR): a multicentre randomised controlled trial. Lancet. 2009 Oct 17;374(9698):1351-63. doi: 10.1016/S0140-6736(09)61069-2. 
  43. Yu X, Gu S, Li M, Zhan Q. Awake Extracorporeal Membrane Oxygenation for Acute Respiratory Distress Syndrome: Which Clinical Issues Should Be Taken Into Consideration. Front Med (Lausanne). 2021 Jul 1;8:682526. doi: 10.3389/fmed.2021.682526.
  44. Rypulak E, Szczukocka M, Zyzak K, Piwowarczyk P, Borys M, Czuczwar M. Transportation of patients with severe respiratory failure on ECMO support. Four-year experience of a single ECMO center. Anaesthesiol Intensive Ther. 2020;52(2):91-96. doi: 10.5114/ait.2020.94501.
  45. Mendes PV, de Albuquerque Gallo C, Besen BAMP, Hirota AS, de Oliveira Nardi R, Dos Santos EV, Li HY, Joelsons D, Costa ELV, Foronda FK, Azevedo LCP, Park M. Transportation of patients on extracorporeal membrane oxygenation: a tertiary medical center experience and systematic review of the literature. Ann Intensive Care. 2017 Dec;7(1):14. doi: 10.1186/s13613-016-0232-7.
  46. Vieira J, Frakes M, Cohen J, Wilcox S. Extracorporeal Membrane Oxygenation in Transport Part 1: Extracorporeal Membrane Oxygenation Configurations and Physiology. Air Med J. 2020 Jan-Feb;39(1):56-63. doi: 10.1016/j.amj.2019.09.008.
  47. Vieira J, Frakes M, Cohen J, Wilcox S. Extracorporeal Membrane Oxygenation in Transport Part 2: Complications and Troubleshooting. Air Med J. 2020 Mar-Apr;39(2):124-132. doi: 10.1016/j.amj.2019.09.009.
  48. Puslecki M, Baumgart K, Ligowski M, Dabrowski M, Stefaniak S, Ladzinska M, Goszczynska E, Marcinkowski P, Olasinska-Wisniewska A, Klosiewicz T, Pawlak A, Zielinski M, Puslecki L, Podlewski R, Szarpak L, Jemielity M, Perek B. Patient Safety during ECMO Transportation: Single Center Experience and Literature Review. Emerg Med Int. 2021 Feb 22;2021:6633208. doi: 10.1155/2021/6633208. 
  49. Sams VG, Anderson J, Hunninghake J, Gonzales M. Adult ECMO in the En Route Care Environment: Overview and Practical Considerations of Managing ECMO Patients During Transport. Curr Trauma Rep. 2022;8(4):246-258. doi: 10.1007/s40719-022-00245-1.


The FlightBridgeED Winter Sale is here! Save 20% on Online Review Courses, trusted by tens of thousands for over 12 years to help you pass your advanced certification exams.
Need to recertify? Our Advanced Refresher Course is built on research and evidence-based practice—not trends—and accepted in all 50 states.
Hurry—sale ends December 26th! Visit FlightBridgeED.com to save now.

Creators & Guests

Host
Dr. Michael Lauria
FlightBridgeED Chief Medical Director | Content Creator/Host

What is The FlightBridgeED Podcast?

The FlightBridgeED Podcast provides convenient, easy-to-understand critical care medical education and current topics related to the air medical industry. Each topic builds on another and weaves together a solid foundation of emergency, critical care, and prehospital medicine.