AB093. SOH23ABS_233. The management of respiratory failure with level 2 strategies including the airway pressure release ventilation-time controlled adaptive ventilation mode in a regional intensive care unit—a case series

Background: Airway pressure release ventilation-time controlled adaptive ventilation (APRV-TCAV) is a level 2 strategy for severe respiratory failure. Other strategies include nitric and proning. The evidence in favour of APRV-TCAV remains limited due to the lack of large scale randomised controlled trials. It is used with increasing frequency as a rescue mode of ventilation in severe acute respiratory distress syndrome (ARDS), particularly in centres without direct access to extracorporeal membrane oxygenation (ECMO) therapy. Concerns regarding barotrauma and pneumothorax remain.

Methods: We present a case series involving four patients with severe ARDS who were ventilated using APRV-mode ventilation in a regional adult intensive care unit (ICU). A few months prior to these cases [during the coronavirus disease 2019 (COVID-19) pandemic], a group of six healthcare professionals including ICU nurse educators, ICU clinical nurse managers and ICU physicians from our unit attended a 5-hour workshop on APRV-TCAV ventilation.

Results: Four patients were mechanically ventilated using the APRV-TCAV mode on our Draeger ventilators in the setting of refractory hypoxaemia and hypercarbia. All patients had worsening respiratory failure despite nitric therapy. Proning was contra-indicated in one patient. Proning failed or needed to be deferred in the other patients. Two of the patients were subsequently weaned from APRV-TCAV mode to traditional ventilation modes, and two patients were accepted for transfer to an ECMO centre. One patient did not receive ECMO due to a substantial improvement in his oxygenation 24 hours after the APRV-TCAV mode was commenced. One patient has been discharged home, two patients have progressed to ward-level care and continue to make clinical progress and one has recently been commenced on ECMO.

Conclusions: In conclusion, four heterogeneous patients with severe hypoxaemia and hypercapnia were successfully rescued/bridged to ECMO using APRV-TCAV ventilation in a regional ICU. In patients who do not respond to (or cannot have) other level 2 strategies, APRV-TCAV can be considered as a rescue strategy. It may be a bridge to recovery or facilitate lung recruitment prior to transfer to an ECMO centre. It is important that a team approach is taken when introducing this mode of ventilation as a treatment modality in an ICU setting.

Keywords: Acute respiratory distress syndrome (ARDS); airway pressure release ventilation (APRV); mechanical ventilation; critical care