The goal of this clinical trial is to test the feasibility of pacing the phrenic nerve to stimulate the diaphragm in order to improve the lung function in brain dead organ donors. The main questions it aims to answer are:

• Proof of concept and feasibility
• Can lung function be improved in lungs that have been disqualified for donation

Participants will have an AeroPace catheter inserted and will be paced on every breath up to the time of organ donation.

Single-center, single-arm, proof-of-concept trial. Up to twenty (20) subjects on mechanical ventilation who are determined to be brain dead and whose lungs are declined for donation based on a PaO2/FiO2 ratio < 300 mmHg will be enrolled. Subjects may also be enrolled in the study at the request of the donation team if the lungs are accepted for donation but of marginal quality. Consent from the temporary substitute decision maker (TSDM) will be obtained for (i) organ donation and (ii) for study participation.

All subjects will receive Lungpacer AeroPace Protect System catheter-based transvenous phrenic nerve stimulation (LAPS-PNS) with lung-protective mechanical ventilation and standard of care for transplant donors. Insertion of the AeroPace Catheter will be conducted as soon as possible after the determination of lung transplant ineligibility. LAPS-PNS will be titrated with the ventilator to provide a contribution to the work of breathing sufficient to retain diaphragm activation.

Measurements to determine the effects of LAPS-PNS on donor lung function and physiology will be conducted until the time of organ donation. An esophageal-gastric manometer and electrical impedance tomography (EIT) unit will be utilized, respectively, to assess transdiaphragmatic pressure and lung volume distribution. Data collected for brain dead donors admitted to the same ICU over the 2 years preceding the study start who did not qualify for lung donation will serve as an unmatched comparator group.

Inclusion Criteria:

• Designated as brain dead according to BC provincial guidelines, and
• Are 19 years or older, and
• Are mechanically ventilated, and
• TSDM consented for organ donation, and
• TSDM consented to study participation, and
• Accepted by BC transplant team to donate at least 1 organ system, and
• Declined by BC transplant team for lung donation based on hypoxia with the PaO2/FiO2ratio < 300 mmHg or other criterion that precludes lung donation as requested by the organ donation team.

Exclusion Criteria:

• Greater than 8 hours from time declined for lung donation and initiation of LAPS-PNS,
• Inability to place a central venous catheter in the left internal jugular or left subclavian vein,
• Neuromuscular disease (e.g., Amyotrophic Lateral Sclerosis, Guillain-Barre),
• Previous phrenic nerve injury,
• Spinal cord injury above the 6th cervical spine level,
• Implanted electronic cardiac or neurostimulation device in situ
• 2nd or 3rd degree heart block on at least 2 EKGs conducted during routine care,
• Treating physician deems enrollment not clinically appropriate for other reason

IPD is unable other be shared due to data sharing agreements with study sponsor and research ethics approvals pertaining to brain dead patients