Project 4A: Inspiratory Muscle Training and Diaphragm Strength

Inclusion Criteria: * presence in the surgical or trauma ICU * age of ≥18 years * received mechanical ventilation (MV) for 3 days and expected to survive ICU stay * ability to obtain informed consent from patient or proxy Exclusion Criteria: * Inability to speak and understand English * Uncontrollable source of sepsis with imminent death (e.g., irreversible disease state, unresectable dead bowel) * Receiving "comfort care only" or have advanced care directives limiting resuscitative efforts * Known HIV infection with CD4 count \< 200 cells/mm * Organ transplant recipients on immunosuppressive agent(s), * Known pregnancy * Unable to follow simple, one-step commands, such as "breathe in as hard as you can!" * Prior arrangements to be transferred to other facilities before 28 days of treatment * Contraindications to being disconnected from MV for sham or inspiratory muscle strength training treatment * Unstable or "difficult airway" at 3 days of ICU care defined by ICU protocol, predicted to last for more than 72 hours * Ongoing use of vasopressor or vasodilatatory agents for unstable blood pressure. (beyond minimal intermittent amount or "renal perfusion dose," * Severe cardiac dysrhythmias * Esophageal varices or recent esophageal or gastric surgery, * Upper-airway issues that would be aggravated by inserting esophageal pressure transducers * Unstable neck/cervical anatomy that might be adversely impacted by bilateral magnetic stimulation of phrenic nerves at the neck * Acute coronary syndrome * Pulmonary contraindications (pneumon/hemothorax not drained, flail chest) * Cardiac pacemakers and/or implanted defibrillator or other implanted electronic devices interfering with magnetic stimulation * Implanted metal in the chest, neck or head, making magnetic stimulation contraindicated (dental fillings are permitted) * Postoperative severe surgical problems interfering with the respiratory training (serious postoperative bleeding, wound dehiscence, etc.) - when and if these problems resolve and the patient meets other entry criteria, they will be eligible to be recruited for participation * Active neuromuscular diseases that would prevent or interfere with responding to strength training (e.g. amyotrophic lateral sclerosis, multiple sclerosis, myasthenia gravis, polymyositis, muscular dystrophy or other dystrophies and myopathies) * Any other factor that in the investigators' opinions would prevent response to training or create an unsafe condition for the patient.