A randomized clinical trial to investigate the use of the temporary Diaphragm Pacing Therapy System (DPTS) to rehabilitate the diaphragm in mechanically ventilated patients who have failed at least two weaning attempts. The goal is to strengthen and rehabilitate the diaphragm to liberate the patient more quickly from mechanical ventilation.

Mechanical ventilation (MV) is a life saving technology but can also cause damage to the lungs and diaphragm such as ventricular induced diaphragmatic dysfunction (VIDD). Research has shown that after being on mandatory MV and sedated the diaphragm begins to atrophy within as short as 18 hours. The Lungpacer Diaphragm Pacing Therapy System (DPTS) is a temporary therapy that consists of the Lungpacer IntraVenous Electrode Catheter (LIVE Catheter) and the Lungpacer Control Unit system. The LIVE Catheter is a proprietary central venous catheter that incorporates pacing electrodes in strategic areas that align with the left and right phrenic nerves. The LIVE Catheter can also be used for fluid delivery like any other central venous catheter. The randomized clinical trial will investigate the safety, effectiveness and performance of the Lungpacer DPTS. By stimulating the diaphragm through daily therapy sessions, with the intention of exercising and rehabilitating the diaphragm muscle so the patient may be able to be more quickly liberated from MV. The patient population includes those who have been mechanically ventilated for greater than or equal to 96 hours (4days), have failed two or more spontaneous breathing trials (SBT), and were not hypervolemic during the latest spontaneous breathing trial. Patients must have resolution of the initial indication for placement on mechanical ventilation before entering the trial.

Inclusion Criteria:

• 18 years of age or older
• have been mechanically ventilated for > or = to 96 hours (4 days), and
• have satisfied the Readiness-to-Wean criteria and
• have failed at least two VLTs, one of which is the study specific VLT.

Exclusion Criteria:

• currently on extracorporeal membrane oxygenation (ECMO);
• weaning failure due to hypervolemia;
• medical history or known anatomy that prevents insertion of the LIVE Catheter into the left subclavian vein;
• currently being treated with neuromuscular blockade;
• clinically overt congestive heart failure that is preventing weaning;
• pre-existing neuromuscular diseases that could affect the respiratory muscles;
• pre-existing severe chronic pulmonary fibrosis;
• pleural effusions occupying greater than one third of the pleural space on either side;
• BMI > or = 40;
• known or suspected phrenic nerve paralysis;
• any electrical device (implanted or external) that may be prone to interaction with or interference from the Lungpacer DPTS including neurological pacing/stimulator devices, cardiac pacemakers and defibrillators;
• prior bacteremia reported within the last 48 hours;
• current hemodynamic instability, sepsis or septic shock;
• terminally ill with 6 months or less life expectancy or not committed to full care;
• known or suspected to be pregnant or lactating; and
• currently being treated in another clinical trial studying an experimental treatment that could affect the study primary outcome.

Only investigators participating in this clinical trial will be able to see final de-identified participant data at the completion of the study and it will be available through the clinical research organization (CRO).

The ultrasound core lab reviewers will be blinded to study allocation groups