Early Use of Airway Pressure Release Ventilation (APRV) in ARDS

Early Use of Airway Pressure Release Ventilation (APRV) in Patients With Acute Respiratory Distress Syndrome

Airway pressure release ventilation (APRV) is a time-cycled, pressure controlled, intermittent mandatory ventilation mode with extreme inverse I:E ratios. Currently it is considered as a non-conventional ventilatory mode. The investigators aim to compare APRV with conventional mechanical ventilation (MV) in patients with acute respiratory distress syndrome (ARDS).

Despite the advances in technology and ventilatory modes, mortality of ARDS is still around 40%. Besides prone positioning, the best approach of management is low tidal volume ventilation (LTV). This 'protective ventilation' strategy is not aways effective to improve oxygenation and is associated with an increased requirement of sedation and neuromuscular blocking agents, which increase length of stay and morbidity. APRV is a ventilatory mode based on relatively high and sustained continuous positive pressure, combined with a short phase of release to allow carbon dioxide removal. It also allows unrestricted spontaneous breathing throughout respiration, independent of the ventilator cycle. Providing sustained inflation while limiting duration and frequency of release phase permits limiting volume loss, resulting in progressive and improved alveolar recruitment, an increased alveolar surface area available for gas exchange and improved ventilation-perfusion matching. In this multi-center, prospective, randomized, controlled, open trial, the investigators aim to compare the effects and safety of the early application of time-controlled adaptive method of APRV and conventional ventilation with LTV strategy in patients with severe to moderate ARDS.

Protective lung conventional strategy with volume-controlled ventilation (VCV) or pressure-controlled ventilation (PCV) mode, with low tidal volume and adequate positive end expiratory pressure (PEEP) level.

Airway Pressure Release Ventilation with Time-controlled adaptive ventilation method. Allowing for spontaneous breathing.

APRV consist of an extended time at plateau pressure (a continuous positive airway pressure phase) comprising about 90% of the respiratory cycle, while providing very brief releases to enhance carbon dioxide removal. Time-controlled adaptive method requires interpretation of the expiratory flow curve to assess changes in lung elastance and, therefore, set the Time low to optimize carbon dioxide removal, but not at the expense of alveolar derecruitment and instability.

Lung protective ventilation consist of delivery of low tidal volumes (4-6 ml/kg PBW), high PEEP enough to avoid de-recruitment, titrated according to ARDSNet PEEP/fraction of inspired oxygen (FiO2) table, while avoiding excessive transpulmonary pressure.

Inclusion Criteria: Acute respiratory distress syndrome, according to the Berlin definition of ARDS, with adjusted pO2/FiO2 for altitude <300, and less than 48 h of endotracheal mechanical ventilation Exclusion Criteria: Pregnancy Less than 18 years-old Expected duration of mechanical ventilation less than 48 h Preexisting conditions with an expected 3-month mortality exceeding 50% Concurrent chemotherapy Confirmed intracranial hypertension Catastrophic cranial trauma or neuromuscular disorders that are known to prolong mechanical ventilation Pneumothorax at enrollment (resolved or not) Do-not-resuscitate order

Lopez Saubidet I, Maskin LP, Rodriguez PO, Bonelli I, Setten M, Valentini R. Mortality in patients with respiratory distress syndrome. Med Intensiva. 2016 Aug-Sep;40(6):356-63. doi: 10.1016/j.medin.2015.10.007. Epub 2015 Dec 31. English, Spanish.

Guerin 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. Epub 2013 May 20.

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.

Albert S, Kubiak BD, Vieau CJ, Roy SK, DiRocco J, Gatto LA, Young JL, Tripathi S, Trikha G, Lopez C, Nieman GF. Comparison of "open lung" modes with low tidal volumes in a porcine lung injury model. J Surg Res. 2011 Mar;166(1):e71-81. doi: 10.1016/j.jss.2010.10.022. Epub 2010 Nov 12.

Sydow M, Burchardi H, Ephraim E, Zielmann S, Crozier TA. Long-term effects of two different ventilatory modes on oxygenation in acute lung injury. Comparison of airway pressure release ventilation and volume-controlled inverse ratio ventilation. Am J Respir Crit Care Med. 1994 Jun;149(6):1550-6. doi: 10.1164/ajrccm.149.6.8004312.

Ibarra-Estrada MA, Garcia-Salas Y, Mireles-Cabodevila E, Lopez-Pulgarin JA, Chavez-Pena Q, Garcia-Salcido R, Mijangos-Mendez JC, Aguirre-Avalos G. Use of Airway Pressure Release Ventilation in Patients With Acute Respiratory Failure Due to COVID-19: Results of a Single-Center Randomized Controlled Trial. Crit Care Med. 2022 Apr 1;50(4):586-594. doi: 10.1097/CCM.0000000000005312.